Surveillance of Invasive Bacterial Disease in Alaska – 2000 

Arctic Investigations Program 

National Center for Infectious Diseases 

Centers for Disease Control 

4055 Tudor Centre Dr. 

Anchorage, AK 99508 

(907) 729-3400 

ncidaip@cdc.gov

Surveillance of Invasive Bacterial Disease in Alaska, 2000 2

Alaska Statewide Invasive Bacterial Disease 

Table of Contents 

 Page 

Summary 3 

Introduction 4 

Streptococcus Pneumoniae 4 

Haemophilus influenzae 15 

 

Neisseria meningitidis 21 

Group A Streptococcus 24 

Group B Streptococcus 28 

Appendix 33 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 3

Summary 

The Centers for Disease Control and Prevention's Arctic Investigations Program (AIP) in Anchorage, Alaska, 

maintains a statewide surveillance system for invasive diseases caused by Streptococcus pneumoniae, 

Haemophilus influenzae, Neisseria meningitidis, and Groups A and B Streptococci. Laboratories throughout 

the state are requested to send to AIP any isolates of these organisms recovered from a blood culture, CSF, or 

other normally sterile site. Isolate identification is confirmed and, when appropriate, serotyped and tested for 

antimicrobial susceptibility. The objectives of this system are to provide information on disease rates within 

the state, monitor the emergence of antimicrobial resistance, and to monitor the effectiveness of implemented 

vaccine programs, such as the 23-valent pneumococcal polysaccharide vaccine, the 7-valent pneumococcal

conjugate vaccine and Haemophilus influenzae type b vaccines. 

Invasive Bacterial Disease Surveillance Regions – Alaska, 2000 

In 2000, the total number of cases of invasive disease caused by these organisms reported to AIP were 125 S. 

pneumoniae, 16 H. influenzae, 9 N. meningitidis, 18 Group A Strep and 18 Group B Strep. Alaska Native 

populations had higher rates of disease than non-Native populations in all invasive disease except those 

caused by Group B Strep. Rates of invasive pneumococcal disease were highest in the YK Delta and 

Kotzebue regions; H. influenzae rates were highest in Bristol Bay and Norton Sound. Rates for each 

organism by region are presented in the following table. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 4

Surveillance Organisms Reported by Region – Alaska, 2000 

Region 

S. pneumoniae 

n (rate*) 

H. influenzae 

n (rate*) 

N. meningitidis 

n (rate*) 

Group A Strep 

n (rate*) 

Group B Strep 

n (rate*) 

Anchorage 69 (17.1) 9 (2.2) 7 (1.7) 12 (3.0) 15 (3.7) 

Arctic Slope 1 (15.8) 0 (0) 0 (0) 1 (15.8) 0 (0) 

Bristol Bay 1 (13.4) 2 (26.8) 1 (13.4) 0 (0) 0 (0) 

Interior 14 (14.5) 2 (2.1) 1 (1.0) 2 (2.1) 3 (3.1) 

Kotzebue 6 (75.3) 0 (0) 0 (0) 0 (0) 0 (0) 

Norton Sound 2 (21.7) 2 (21.7) 0 (0) 0 (0) 0 (0) 

Southeast 8 (11.0) 0 (0) 0 (0) 1 (1.4) 0 (0) 

YK Delta 24 (102.5) 1 (4.3) 0 (0) 2 (8.5) 0 (0) 

Total 125 (19.9) 16 (2.6) 9 (1.4) 18 (2.9) 18 (2.9)

*Cases per 100,000 

Introduction 

AIP conducts statewide surveillance of invasive Streptococcus pneumoniae, Haemophilus influenzae, 

Neisseria meningitidis, and Groups A and B Streptococcus. This program is part of a passive, laboratorybased surveillance system in which laboratories from all hospitals throughout the state are encouraged to 

participate. The population included in the AIP surveillance is the State of Alaska, a total of 626,932 persons 

(Census 2000). Case detection occurs year-round as participating laboratories send isolates recovered from 

sterile sites to the AIP lab in Anchorage, accompanied by basic demographic and clinical information on the 

cases. Materials and forms for isolate shipment and data collection are provided to each lab by AIP. At yearend, AIP asks that each laboratory review their records and provide information on any cases that may have 

been overlooked. In 2000, 21 of the 25 labs in Alaska participated in the invasive disease surveillance 

system, either by sending isolates to the AIP lab throughout the year, conducting year-end record reviews, or 

both. 

AIP defines a case of invasive Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, or 

Groups A and B Streptococcus as an isolate of the bacteria from a normally sterile site, including blood, 

cerebrospinal fluid, pleural fluid, peritoneal fluid or joint fluid that has been taken from a resident of Alaska. 

In addition, for Group A Streptococcus, isolates are requested from deep tissue infections such as might be 

collected from surgical debridement of cases of necrotizing fascitis.

Invasive Pneumococcal Disease 

Overall Incidence 

Between January 1 and December 31, 2000, AIP received a total of 110 pneumococcal isolates. An 

additional 15 cases were detected through year-end follow up with participating labs throughout the state, for 

a total of 125 cases of invasive pneumococcal disease. The result is an overall invasive pneumococcal case 

rate of 19.9/100,000 persons per year for the state of Alaska in the year 2000. The Alaska rate is similar to 

the Active Bacterial Core Surveillance (ABCs) 2000 national projected rate of 20.7/100,000 (Active Bacterial 

Core Surveillance (ABCs) Report Emerging Infections Program Network Streptococcus pneumoniae, 2000). 

ABCs is a surveillance system operated in 9 states and covers a population of over 30 million persons.

Seasonality 

Invasive Streptococcus pneumoniae cases were identified in every month of 2000. Nineteen cases occurred 

in the month of September, the highest number of cases occurring in any 1-month period in 2000. The 

September cases occurred in 9 different communities and included 10 different serotypes. Infected 

individuals ranged in age from infancy to 65 years. Of note, 13 of the 19 cases occurred in the time period 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 5

September 20 – 29. Four of the infections identified during this month resulted in death, producing a casefatality rate of 21% for September. Thirty-one percent of all cases of pneumococcal-related mortality in 2000 

were identified in September.

Invasive Pneumococcal Disease - Alaska, 2000

10

14 13 14

4

7

4

10

19

13

11

6

0

2

4

6

8

10

12

14

16

18

20

January

February

March

April

May

June

July

August

September

October

November

December

Month of Culture

Number of Cases

Race 

Although the Alaska Native population comprises only 17% of the state population (Census 2000: Alaska 

Natives 108,187, non-Natives 518,745), 47% of all reported S. pneumoniae cases occurred among this group 

in 2000. A total of 59 cases occurred among Alaska Natives, resulting in an age-adjusted rate for Alaska 

Natives of 55.3/100,000 persons per year. In contrast, 53% of cases occurred among the non-Native 

population, for a non-Native age-adjusted rate of 5.9/100,000 persons per year (66 cases). The age-adjusted 

rate ratio of disease for the Alaska Native population compared with the non-Native population is 9.4. 

Invasive Streptococcus Pneumoniae Cases, by Race - Alaska, 2000 

Race* Cases 

No. (%) 

Age Adjusted 

Rate 

% Male Deaths 

No. (%) 

Alaska Native 59 (47%) 55.3 56% 1 (8%) 

Non-Native 66 (53%) 5.9 53% 12 (92%) 

Total 125 (100%) 19.9 54% 13 (100%) 

*Race was unknown for 11 cases, they were included in the non-Native group. 

Region 

Most cases of invasive pneumococcal disease (69) were reported in the Anchorage area, however, rates of 

disease are highest in the YK Delta and Kotzebue, 102.5/100,000 persons per year and 75.3/100,000 persons 

per year respectively.
Surveillance of Invasive Bacterial Disease in Alaska, 2000 6

Rates of Invasive Pneumococcal Disease, 

by Region - Alaska, 2000

17.1 15.8

102.5

13.4

75.3

11 14.5 21.7

0

20

40

60

80

100

120

Anchorage

Arctic Slope

YK Delta

Bristol Bay

Kotzebue

Southeast

Interior

Norton Sound

Rate per 100,000

Invasive Pneumococcal Cases, by Region - 

Alaska, 2000

69

1

24

1

6 8

14

2

0

10

20

30

40

50

60

70

80

Anchorage

Arctic Slope

YK Delta

Bristol Bay

Kotzebue

Southeast

Interior

Norton Sound

Number of Cases

Age 

Invasive Pneumococcal Disease, by Age Group - 

Alaska, 2000

193.2

34.5

9.3 8.2 13.7 24.6

56

0

50

100

150

200

250

<2 2 - 4 5 - 18 19 - 44 45 - 54 55 - 64 65+

Age Group (years)

Rate per 100,000
Surveillance of Invasive Bacterial Disease in Alaska, 2000 7

Cases occurred in all age groups and ranged from 25 days to 98 years of age. Almost half of all invasive 

pneumococcal disease in Alaska occurred among the high-risk age groups, those under the age of 2 and those 

greater than 65 years. Overall, 29% of cases occurred among children <2 years. 

Invasive Pneumococcal Disease, by Age Group and Race

0

5

10

15

20

25

<2 2 - 4 5 - 18 19 - 44 45 - 54 55 - 64 65+

Age Group (years)

Number of Cases

Alaska Native

Non-Native

Unknown

Invasive Pneumococcal Disease, by Age Group and Race

435

38

121 97

8

46

0

50

100

150

200

250

300

350

400

450

500

<2 2 - 64 65+

Age Group (years)

Rate per 100,000

Alaska Native Non-Native

Sex 

The rate of invasive pneumococcal disease for males was 21.0/100,000 persons per year (68 cases). For

females, the rate of invasive pneumococcal disease was slightly lower at 18.8/100,000 persons per year (57 

cases). 

Census 2000 data: Male population 324,112, Female population 302,820 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 8

Clinical Presentation

Primary Clinical Presentations of Invasive 

Pneumococcal Disease - Alaska, 2000

11

4 3 1 1 1

67

2

9

26

0

10

20

30

40

50

60

70

80

Meningitis

Empyema

Septic Shock

Epiglottitis

Cellulitis

Pericarditis

Pneumonia

Septic Arthritis

Bacteremia

Septicemia*

Number of Cases

 *Septicemia of unknown focus 

The primary clinical presentation was determined by a review of the discharge diagnoses indicated in each 

patient’s chart. In cases with multiple discharge diagnoses, the most serious diagnosis related to the 

pneumococcal infection was recorded as the primary clinical. In 13 cases, a secondary pneumococcal-related 

presentation was noted: 12 patients experienced pneumonia and 1 patient experienced septic arthritis in 

addition to the primary presentation. 

Primary Clinical Presentations of Invasive Pneumococcal Disease in Alaska, 2000 

The most frequent source of a positive culture was blood, which was used to identify 92% of the 125 cases. 

CSF was the positive site for 5.6% of cases and 1 case each was identified through a positive culture of 

pleural fluid and joint fluid. One additional case was identified from an unspecified sterile site. 

Presentation No. Cases (%) % Male No. Deaths 

Meningitis 11 (9%) 55% 1 

Empyema 4 (3%) 50% 1 

Septic Shock 3 (2.4%) 0% 1 

Pericarditis 1 (0.8%) 100% - 

Epiglottitis 1 (0.8%) 0% - 

Cellulitis 1 (0.8%) 0% - 

Pneumonia 67 (54%) 54% 5 

Septic Arthritis 2 (1.6%) 50% - 

Bacteremia 9 (7%) 58% 1 

Septicemia 

(unknown focus) 

26 (20%) 58% 4 

Total 125 54% 13 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 9

Mortality 

Invasive Pneumococcal Mortality, by Age Group - 

Alaska, 2000

0 0 0 0.66 2.1

4.5

22.4

0

5

10

15

20

25

<2 2-4 5-18 19-44 45-54 55-64 65+

Rate per 100,000

In 2000, the overall case-fatality rate for S. pneumoniae in the state of Alaska was 10.4% (13 deaths out of

125 cases). The non-Native case-fatality rate was 18% (12 deaths), compared with the case-fatality rate for 

Alaska Natives of 1.7% (1 death). The case-fatality rate for adult non-Native cases was 29%, or 12 of 41 

cases. The relative risk of dying while infected with invasive Streptococcus pneumoniae for non-Native 

adults, compared with Alaska Native adults was 2.8 after adjusting for age. 

The highest mortality occurred in the 65+ year old age group, in which 61.5% of all pneumococcal deaths 

occurred. Together, 92% of the mortality occurred among those over the age of 45. No deaths were reported 

in those under the age of 18 years. 

Serotype 

Serotyping of invasive pneumococcal isolates is performed at AIP using internationally standardized 

methods. Serotype identification is based on the organism's polysaccharide capsule which is a principle 

virulence factor for pneumococci. This information provides a way to subtype organisms and to determine if 

the infection was due to a type that could be prevented by use of one of the two available pneumococcal 

vaccines. Serotyping was performed on 110 of the 125 pneumcoccal cases detected in Alaska in 2000. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 10

Invasive Pneumococcal Serotype Distribution, by Race and Age Group – Alaska, 2000 

 Alaska Native Non-Native*

Serotype Total 

N (%) 

<2 2-18 >18 All Ages <2 2-18 >18 All Ages 

14 19 (17.3) 9 1 - 10 3 1 5 9 

04 13 (11.8) 2 5 3 10 - - 3 3 

07F 10 (9.1) - - 2 2 - 3 5 8 

09V 9 (8.2) 2 1 1 4 1 1 3 5 

19F 7 (6.4) - 2 - 2 3 - 2 5 

03 6 (5.5) - - 3 3 - - 3 3 

01 5 (4.5) - 1 1 2 - 2 1 3 

22A 1 (0.9) 1 - - 1 - - - 0 

22F 5 (4.5) - - 1 1 1 - 3 4 

06A 4 (3.6) 1 - - 1 1 - 2 3 

18C 4 (3.6) - 1 - 1 - 2 1 3 

06B 4 (3.6) - - - 0 4 - - 4 

23F 3 (2.7) - 1 - 1 - - 2 2 

11A 2 (1.8) - - 1 1 - - 1 1 

16F 2 (1.8) - - 1 1 - - 1 1 

19A 2 (1.8) 1 - - 1 1 - - 1 

09N 1 (0.9) - - - 0 - - 1 1 

10A 1 (0.9) - - - 0 - - 1 1 

13 1 (0.9) - - - 0 - - 1 1 

15A 1 (0.9) 1 - - 1 - - - 0 

17F 1 (0.9) - - 1 1 - - - 0 

20 1 (0.9) - - 1 1 - - - 0 

33F 1 (0.9) - - 1 1 - - - 0 

35B 1 (0.9) - - - 0 - - 1 1 

35F 1 (0.9) - 1 - 1 - - - 0 

38 1 (0.9) - - - 0 - - 1 1 

NT* 4 (3.6) 2 - 2 4 - - - 0 

Total 110 19 13 18 50 14 9 37 60 

*Includes 11 cases for which race is unknown 

**Non-typeable isolates 

Vaccine Serotypes 

Two vaccines are licensed for prevention of pneumococcal disease. The 23-valent polysaccaride vaccine is 

recommended in Alaska for all persons 55 years and older, and for persons over age 2 who are at higher risk 

for pneumococcal disease. Revaccination is recommended after 6 years. In 2001, the pneumococcal 

conjugate vaccine was included in the Alaska childhood vaccination schedule. This vaccine provides 

protection against the 7 most common pneumococcal serotypes causing invasive disease among children 

(types 4, 6B, 9V, 14, 18C, 19F, 23F). The tables below show the proportion of invasive infections from 2000 

that were due to serotypes found in these vaccines.

Proportion of Invasive Isolates Contained in the PCV7 Vaccine, by Age Group and Race – Alaska, 2000

Age (yrs) Alaska Native (%)* Non-Native (%)* Total (%)** 

<2 13 (76%) of 17 11(79%) of 14 24 (77%) of 31 

2-4 5 (83%) of 6 2 (67%) of 3 7 (78%) of 9 

5+ 10 (43%) of 23 18 (43%) of 43 28 (43%) of 66 

Total 28 (61%) of 46 31 (52%) of 60 59 (56%) of 106 

*The percentage of isolates with a serotype in the PCV7 vaccine, out of all isolates for that age and racial group. 

**The percentage of isolates with a serotype in the PCV7 vaccine, out of the total number of isolates for that age group (total n=106). 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 11

Potentially Vaccine Preventable Invasive Illness

 < 2 years 2 – 4 5 - 54 55 - 64 65+ Total 

PCV7 24 (77%) 7 (78%) 17 (45%) 5 (56%) 6 (32%) 59 (56%) 

Ps23V 27 (87%) 9 (100%) 36 (95%) 8 (89%) 14 (74%) 94 (89%) 

Total 31 9 38 9 19 106 

Note: The number in parentheses is the percentage of cases with a serotype in the indicated vaccine, 

out of all isolates successfully serotyped in that age group. 

Vaccination Status

Pneumococcal vaccine status was known for 58 of the 125 cases; 13 cases (10%) did receive a pneumococcal 

vaccine prior to illness and 45 cases (36%) had no record of a pneumococcal vaccine. Vaccine status is not 

known for 67 cases (54%). 

Of the 13 confirmed to have received a pneumococcal vaccine, 11 were Alaska Native and 2 non-Native. 

Seven vaccine recipients were from the Anchorage area, 4 were from the YK Delta, 1 from Bristol Bay and 1 

from the Interior. Ages of vaccine recipients ranged from 4 months to 94 years, however 11 of the 13 vaccine 

recipients were over the age of 35. It is unknown if these individuals received the 7-valent or 23-valent 

vaccine. 

Three (23%) of the 13 deaths due to S. pneumoniae were due to serotypes found in the PCV7 vaccine. 

However, none of these occurred in persons in the age group for which vaccine is recommended. Eight 

(61%) of the fatal cases were due to serotypes contained within the 23 valent polysaccharide vaccine; 5 of 

these occurred in persons in the age group eligible for this vaccine. Vaccination status was known for only 1 

of the 13 deaths. 

Invasive Streptococcus pneumoniae Serotypes of Fatal Cases – Alaska, 2000 

Serotype Deaths (%) Frequency of Serotype 

03 3 (50%) 6 

04 1 (8%) 13 

06A 2 (50%) 4 

09V 1 (11%) 9 

11A 1 (50%) 2 

13 1 (100%) 1 

19F 1 (14%) 7 

20 1 (100%) 1 

35B 1 (100%) 1 

38 1 (100%) 1 

Total 13 (12%) 109 

Overall, 62% of all pneumococcal-related mortality was potentially vaccine preventable with the use of the 

23-valent polysaccharide vaccine in persons over 2 years old. 

Potentially Vaccine Preventable Deaths

 < 2 years 2 – 4 5 - 54 55 - 64 65+ Total 

PCV7 - - - 1 (50%) 2 (25%) 3 (23%) 

Ps23V - - 3 (100%) 1 (50%) 4 (50%) 8 (62%) 

Note: The number in parentheses is the percentage of cases with a serotype in the indicated vaccine, 

out of the number of deaths that occurred in that age group. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 12

Serotype by Region 

Serotype Anchorage YK Delta Bristol Bay Kotzebue Southeast Interior Norton Sound 

01 3 1 1 

03 4 2 

04 4 2 6 1 

06A 1 1 2 

06B 3 1 

07F 4 6 

09N 1 

09V 5 3 1 

10A 1 

11A 1 1 

13 1 

14 7 7 4 1 

15A 1 

16F 2 

17F 1 

18C 3 1 

19A 2 

19F 6 1 

20 1 

22A 1 

22F 4 1 

23F 1 2 

33F 1 

35B 1 

35F 1 

38 1 

Non-typeable 3 1 

Total 56 23 1 6 8 14 2 

Serotype 14 

 

Serotype 14 was the most frequently occurring serotype in the YK Delta, Southeast and Anchorage regions. 

In the Southeast region, it was responsible for 50% of all reported cases. In the YK Delta and Anchorage 

regions, 30% and 13%, respectively, of invasive pneumococcal isolates received by AIP were determined to 

be serotype 14. 

Additionally, serotype 14 was the most common type found among young children. Children under 2 years

of age infected with invasive Streptococcus pneumoniae had a relative risk of 3.7 of being infected with 

serotype 14 compared with cases 2 years and older. Sixty-three percent of serotype 14 isolates were found in 

this age group. 

Serotype 14 by Age Group 

 Proportion infected 

with Serotype 14 

Percentage with 

Serotype 14 

Under 2 years 12/33 36% 

2 years and older 7/72 10% 

Kotzebue: 

All 6 isolates received from the Kotzebue region were of serotype 04. Four of the cases occurred between 

September 6 and October 16, 2000 (one case occurred in March, the other in late July). 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 13

Interior 

Forty-three percent (6 of 14 cases) of reported invasive pneumococcal cases from the Interior region were of 

serotype 07F. Two isolates were determined to be serotype 23F and the remaining 12 were all of different 

serotypes. 

Associated Medical Conditions 

The presence of one or more associated medical conditions was reported in 58% of invasive pneumococcal

cases in 2000. Data on associated medical conditions was unavailable for 8% (10 cases). Excessive alcohol 

use was indicated for 31% of adult cases (19 years and older), and smoking and excessive alcohol use were 

reported together for 18% of adult patients (11 cases). Injection drug use was reported in 3 cases (5% of 

adult cases). Chronic lung disease was reported as a risk factor for 21 cases, or 17%. 

Associated Medical Conditions Identified in Invasive Pneumococcal Cases in Alaska, 2000* 

Associated Medical Condition No. Cases (%), N=125 No. Adult Cases (%), N=65 

Diabetes 13 (10%) 13 (20%) 

Cigarette smoking 25 (20%) 25 (38%) 

Chronic lung disease 21 (17%) 14 (22%) 

Alcohol abuse 20 (16%) 20 (31%) 

Immunosuppressive treatment 6 (5%) 5 (8%) 

Injection drug use 3 (2%) 3 (5%) 

Cigarette smoking only 8 (6%) 8 (12%) 

*More than one risk factor was identified in several cases.

Twenty-five (38%) of the 65 adult cases were known cigarette smokers. According to the 2000 BRFSS 

survey, the rate of smoking in the state of Alaska for persons aged 18 and older in 2000 was 25% (MMWR, 

December 14, 2001, Vol.50, No. 49). 

Invasive Pneumococcal Cases with Known Cigarette 

Smoking Status, by Age and Race

*Percent of cases in age/racial group

Antibiotic Resistance

Susceptibility testing was performed on 106 isolates. Of these, 23% showed decreased susceptibility to 

penicillin. Decreased susceptibility to trimethoprim/sulfamethoxazole (TMP-sulfa) was found in 32% of the 

106 isolates and 21% demonstrated a decreased susceptibility to erythromycin. Little or no resistance was 

discovered to ofloxacin, chloramphenicol, vancomycin, clindamycin, or rifampin. 

Cut points from the Minimum Inhibitory Concentration (MIC) Interpretive Standards were used to determine 

if an isolate was ‘susceptible’, ‘intermediate’, or ‘resistant’ to the antibiotic being tested (National Committee 

for Clinical Laboratory Standards (NCCLS) MIC Testing, Supplemental Tables, M100-S10 (M7), January 

2000). The MIC Interpretive Standards definitions of ‘susceptible’, ‘intermediate’, and ‘resistant’ can be

found in the appendix. 

Age (yrs) Alaska Native Non-Native 

 Smokers (%)* Smokers (%)* 

19-44 6 (60%) 4 (40%) 

45-54 0 (0%) 5 (56%) 

55-64 4 (100%) 3 (100%) 

65+ 0 (0%) 3 (30%) 

Total 10(43%) 15 (39%) 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 14

Antibiotic Resistance in Invasive Streptococcus pneumoniae Isolates – Alaska, 2000

Antibiotic Susceptible Intermediate Resistant I + R Total Tested 

Penicillin 81 (76.4%) 11 (10.3%) 14 (13.2%) 25 (23.6%) 106 

TMP-sulfa 72 (67.9%) 4 (3.8%) 30 (28.3%) 34 (32.1%) 106 

Erythromycin 84 (79.2%) 0 22 (20.8%) 22 (20.8%) 106

Ofloxacin 106 (100%) 0 0 106 

Chloramphenicol 104 (98%) 0 2 (2%) 2 (2%) 106 

Vancomycin 106 (100%) 0 0 106 

Clindamycin 35 (97%) 0 1 (3%) 1 (3%) 36 

Rifampin 103 (100%) 0 0 103 

Serotypes found in the PCV7 vaccine are more likely to be nonsusceptible to penicillin and erythromycin than 

non-vaccine serotypes. One potential benefit of the vaccine is an anticipated decline in antibiotic resistance 

among circulating pneumococci. 

PCV7 Serotypes and Resistance to Selected Antibiotics - Alaska, 2000

Serotype Penicillin Erythromycin 

 Resistant 

# (%) 

Intermediate 

+Resistant # (%) 

Total Resistant # (%) Total 

04 0 (0%) 0 (0%) 13 0 (0%) 13 

6B 1 (33%) 2 (66%) 3 2 (66%) 3 

9V 4 (44%) 7 (78%) 9 3 (33%) 9 

14 7 (37%) 9 (47%) 19 13 (72%) 19 

18C 0 (0%) 0 (0%) 4 0 (0%) 4 

19F 2 (29%) 2 (29%) 7 2 (29%) 7 

23F 0 (0%) 1 (33%) 3 2 (67%) 3 

Total 14 (24%) 21 (36%) 58 22 (38%) 58 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 15

Invasive Haemophilus influenzae

Overall Incidence 

A total of 16 cases of invasive Haemophilus influenzae were reported to AIP in 2000, resulting in an overall 

rate for the state of Alaska in 2000 of 2.6/100,000 persons per year. The 2000 Alaska rate is more than twice 

the ABCs national projected rate of 1.2/100,000 (Active Bacterial Core Surveillance (ABCs) Report 

Emerging Infections Program Network Haemophilus influenzae, 2000). However, in a relatively small 

population, one year trends are subject to wide variability. A fair comparison with national rates should be 

made using multiple years of data. There were 4 invasive Haemophilus influenzae-related deaths in Alaska in 

2000, resulting in a case-fatality rate of 25%, and an overall Haemophilus influenzae mortality rate of 

0.6/100,000 persons per year for Alaska. In contrast, the 2000 ABCs national projected mortality rate for 

invasive Haemophilus influenzae is 0.2/100,000 persons per year. 

Seasonality 

Invasive Haemophilus influenzae, by Month of 

Occurrence - Alaska, 2000

0

1

2

3

4

5

January

February

March

April

May

June

July

August

September

October

November

December

Number of Cases

Race 

Invasive Haemophilus influenzae Cases, by Race 

Racial Group Cases 

No. (%) 

Rate* % Male Deaths 

Alaska Native 10 (63%) 9.2 50% 2 

Non-Native** 6 (38%) 1.2 0% 2 

Total 16 (100%) 2.6 31% 4 

*Rate per 100,000 population: population figures calculated from Census 2000 data: 

 Alaska Native: 108,187, Non-Natives: 518,745 

**Unknown race (n=1) included in Non-Native group 

Sixty-three percent of invasive Haemophilus influenzae cases occurred among the Alaska Native population. 

The rate ratio of disease for the Alaska Native population, compared with the non-Native population, is 7.6, 

95% CI (2.68, 24.65). 

Region 

Residents of Anchorage accounted for 38% (6 cases) of invasive Haemophilus influenzae in 2000. One case 

each occurred in the following communities located throughout the state of Alaska: Fairbanks, Soldotna, 

Kwetheluk, Seward, Homer, Dillingham, New Stuyahok, Tok, Brevig, and Little Diomede. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 16

Age

Invasive Haemophilus influenzae, by Race and Age Group -

 Alaska, 2000, N=16

0

1

2

3

4

5

6

7

<2 2-4 5-19 20-44 45-54 55-64 65+

Age Group (years)

Number of Cases

Alaska Native

Non-Native

Invasive Haemophilus influenzae cases ranged in age from infancy to 80 years. Dramatically more disease 

occurred among Alaska Native children under 2 years of age. The Alaska Native rate for children <2 was 

124.4/100,000, compared with a rate of 6.5/100,000 for non-Native children of the same age. 

Invasive Haemophilus influenzae, by Race and Age Group - 

Alaska, 2000, N=16

124.4

4.1 0

6.5 0.63 7.1

0

20

40

60

80

100

120

140

<2 2-64 65+

Age Group (years)

Rate per 100,000

Alaska Native

Non-Native

Sex 

In 2000, the rate of invasive Haemophilus influenzae in females in Alaska was more than twice that of males, 

3.63/100,000 compared with 1.54/100,000 for Alaska males (11 female cases, 5 male cases).

Clinical Presentation 

The primary clinical presentation was determined by a review of the discharge diagnoses indicated in each 

patient’s chart. In cases with multiple discharge diagnoses, the most serious Haemophilus influenzae-related 

diagnosis was recorded as the primary clinical presentation.

Pneumonia was the most common primary clinical presentation, occurring in 9 (56%) of the invasive 

Haemophilus influenzae cases in 2000. Meningitis and septicemia of unknown focus were each diagnosed in 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 17

3, or 19%, of cases. One patient presented with septic arthritis. This patient also presented with osteomyelitis. 

No other cases were diagnosed with a secondary invasive Haemophilus influenzae-related syndrome. 

Primary Clinical Presentations of Invasive Haemophilus 

 influenzae – Alaska, 2000

Primary Presentation Cases 

No. (%) 

Deaths 

Meningitis 3 (19%) - 

Pneumonia 9 (56%) 2 

Septic Arthritis 1 (6%) - 

Septicemia 3 (19%) 2 

Total 16 (100%) 4 

Haemophilus influenzae was isolated from blood samples in 14 of 16 cases (88%). Two cases were 

identified through the isolation of Haemophilus influenzae from cerebrospinal fluid. 

Mortality 

Four patients died due to infection with invasive Haemophilus influenzae, resulting in a case-fatality rate for 

the state of Alaska in 2000 of 25% (4 deaths out of 16 cases). The overall invasive Haemophilus influenzaerelated mortality rate for Alaska is 0.6/100,000 persons per year – three times the national projected mortality 

rate of 0.2/100,000 (Active Bacterial Core Surveillance (ABCs) Report Emerging Infections Program 

Network Haemophilus influenzae, 2000 (preliminary)). 

Those who died ranged from newborn to 69 years old. Two cases resulting in death (50%) were residents of 

Anchorage, one case was from rural South Central and the other from the rural Bristol Bay area. Two cases 

were non-Native and two were Alaska Native. One associated medical condition was identified for each of 3 

cases: alcoholism, diabetes, and chronic lung disease. The only male case, a newborn Alaska Native, had no 

known associated medical conditions. Antibiotic susceptibility testing was performed on 3 of the isolates; no 

antibiotic resistance was detected. Serotyping was also performed on the 3 isolates: 1 was serotype B, the 

other 2 were non-typeable. 

Serotype 

Serotyping is performed on all isolates sent to AIP. The bacterial capsule forms the basis for typing

and is the major virulence factor. Type B is historically more prevalent and invasive, but due to 

routine childhood vaccination has decline by more than 90% since the 1980’s. Continued 

surveillance is important to evaluate vaccine effectiveness and to monitor for the emergence of nonvaccine types. 

Serotypes of Invasive Haemophilus influenzae Cases, by Race 

 - Alaska, 2000 

Serotype Alaska Native Non-Native Unknown Total (%)

B 6 3 - 9 (56%) 

E - 1 - 1 (6%) 

F 1 - 1 2 (13%) 

NT* 3 1 - 4 (19%) 

Total 10 5 1 16 (100%) 

*Non-typeable isolates
Surveillance of Invasive Bacterial Disease in Alaska, 2000 18

Serotypes of Invasive Haemophilus influenzae Cases, by Age Group - Alaska, 2000 

*Rate per 100,000 population 

**Non-typeable isolates 

Antibiotic Resistance 

Antibiotic susceptibility testing for chloramphenicol, ceftriaxone, and trimethoprim/sulfamethoxazole was 

performed on 15 isolates (94% of cases) at the AIP laboratory in Anchorage, Alaska. No resistance was

detected to chloramphenicol and ceftriaxone. One isolate (7%) demonstrated resistance to 

trimethoprim/sulfamethoxazole. 

Antibiotic Resistance of Invasive Haemophilus influenzae 

Isolates - Alaska, 2000

Antibiotic Susceptible Intermediate Resistant 

Chloramphenicol 15 (100%) - - 

Ceftriaxone 15 (100%) - - 

TMP/sulfa 14 (93%) - 1 (7%) 

 

Age Group B (rate)* Non-B (rate) Non-Type** (rate) Unknown Total (rate) 

<2 5 (24.7) - 2 (9.9) - 7 (34.6) 

2-64 3 (0.5) 2 (0.4) 1 (0.2) 1 (0.2) 7 (1.2) 

65+ 1 (2.9) 1 (2.9) - - 2 (5.9) 

Total 9 (1.4) 3 (0.5) 3 (0.5) 1 (0.2) 16 (2.55) 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 

Summary of Invasive Haemophilus influenzae Case Characteristics, Alaska 2000 

Gender Age 

(years) 

Race Anchorage 

/Other 

Site of Isolation 

Primary Clinical Presentation 

Other Hi Presentations 

Serotype Associated Medical C

Male 1 day AK Native Other Blood Septicemia - NT - Female 0.3 AK Native Other CSF Meningitis - B - Female 0.3 AK Native Other CSF Meningitis - B - Male 0.4 AK Native Other Blood Pneumonia - B Chronic lung disease Male 0.6 AK Native Anchorage Blood Septicemia - B -Male 0.8 AK Native Other Blood Meningitis - NT* - Female 1 Non-Native Other Blood Septic Arthritis Osteomyelitis B - Female 4 AK Native Other Blood Pneumonia - B Imm tx** Male 13 AK Native Anchorage Blood Pneumonia - B - Female 53 AK Native Anchorage Blood Pneumonia - F Cigarette smoking + c

disease + alcohol 

Female 54 AK Native Anchorage Blood Septicemia - Alcohol Female 55 Non-Native Other Blood Pneumonia - NT Chronic lung disease Female 57 Unknown Other Blood Pneumonia - F Smoking + Chronic luFemale 62 Non-Native Anchorage Blood Pneumonia - B Cigarette smoking Female 69 Non-Native Anchorage Blood Pneumonia - B Diabetes Female 80 Non-Native Other Blood Pneumonia - E Cigarette smoking + C

disease 

*Non-typeable isolates **Immunosuppressive treatment
Surveillance of Invasive Bacterial Disease in Alaska, 2000 20

Haemophilus influenzae Type B (Hib) 

The most common serotype of invasive Haemophilus influenzae in 2000 was serotype B, accounting for 56% 

of all reported cases. The rate of Haemophilus influenzae type B (Hib) in Alaska was 1.4/100,000 persons 

per year, significantly higher than the ABCs national projected rate of 0.1/100,000 persons per year (Active 

Bacterial Core Surveillance (ABCs) Report Emerging Infections Program Network Haemophilus influenzae, 

2000). However, in a relatively small population, one year trends are subject to wide variability. A fair 

comparison with national rates should be made using multiple years of data. Among children under 2 years 

of age diagnosed with invasive Haemophilus influenzae, 71% were infected with serotype B. 

Invasive Hib Cases, by Age Group - Alaska, 2000, N=9

0

1

2

3

4

<6

months

6-23

months

2-4 5-19 20-44 45-54 55-64 65+

Age Group

Number of Cases

Non-Native

Alaska Native

One-third of reported Hib cases in Alaska in the year 2000 occurred among the non-Native 

population, for an overall Hib rate for non-Natives of 1.2/100,000 persons per year. In contrast, the

rate of invasive Hib disease among the Alaska Native population in 2000 was 2.8/100,000 persons 

per year. The rate ratio of disease for the Alaska Native population compared with the non-Native 

population is 2.3.
Surveillance of Invasive Bacterial Disease in Alaska, 2000 21

Invasive Neisseria meningitidis

Overall Incidence 

A total of 9 cases of invasive Neisseria meningitidis were reported to AIP in Anchorage, Alaska in 2000,

resulting in an overall rate for the state of Alaska in 2000 of 1.4/100,000 persons per year. The Alaska rate is 

almost twice the ABCs 2000 national projected rate of 0.8/100,000 (Active Bacterial Core Surveillance 

(ABCs) Report Emerging Infections Program Network Neisseria meningitidis, 2000). There were no invasive 

Neisseria meningitidis-related deaths in Alaska in 2000. The ABCs National projected Neisseria 

meningitidis-related mortality rate is 0.1/100,000 persons per year for 2000. However, in a relatively small 

population, one year trends are subject to wide variability. A fair comparison with national rates should be 

made using multiple years of data. 

Seasonality 

Invasive Neisseria meningitidis, by Month of 

Illness, Alaska 2000

0

1

2

3

January

February

March

April

May

June

July

August

September

October

November

December

Number of Cases

 

Race 

Invasive Neisseria meningitidis, by Race 

Racial Group Cases 

No. (%) 

Rate* % Male 

Alaska Native 3 (33%) 2.8 67% 

Non-Native** 6 (67%) 1.2 83% 

Total 9 (100%) 1.4 78% 

*Rate per 100,000 population: population figures calculated from 

 Census 2000 data: Alaska Native: 108,187, non-Native: 518,745 

**Unknown race (n=1) included in non-Native group 

The relative risk of disease for Alaska Native population compared with the non-Native population is 2.4, 

95% CI (0.60, 9.59). 

Region 

Residents of Anchorage accounted for 56% (5 cases) of invasive Neisseria meningitidis in 2000. The 

remaining 4 cases occurred in 4 separate communities. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 22

Age 

Invasive Neisseria meningitidis, by Age 

Group - Alaska, 2000, N=9

0

1

2

3

4

<2 2-4 5-19 20-44 45-54 55-64 65+

Age Group (years)

Number of Cases

Invasive Neisseria meningitidis cases ranged in age from 1 year to 64 years old. Fifty-six percent of cases (5 

of 9 cases) occurred among children under 14 years of age. No cases were reported among Alaskans over 65. 

 

Rate of Invasive Neisseria meningitidis, 

by Age Group - Alaska, 2000, N=9

20.7

2

0 0

1.3 0

0

5

10

15

20

25

<2 2-64 65+

Age Group (years)

Rate per 100,000

Alaska Native

Non-Native

 

Sex 

In 2000, the rate of invasive Neisseria meningitidis in males in Alaska was 4 times that of females, 

2.66/100,000 compared with 0.66/100,000 for Alaska females (7 male cases, 2 female cases).

Mortality 

There were no Neisseria meningitidis-related deaths reported in Alaska in 2000. 

Clinical Presentation 

The primary clinical presentation was determined by a review of the discharge diagnoses indicated in each 

patient’s chart. In cases with multiple discharge diagnoses, the most serious diagnosis related to the Neisseria 

meningitidis infection was recorded as the primary clinical presentation. In cases with multiple discharge 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 23

diagnoses, the most serious Neisseria meningitidis-related diagnosis was recorded as the primary clinical 

presentation.

Meningitis was the most common primary clinical presentation, occurring in 5, or 56%, of the invasive 

Neisseria meningitidis cases in 2000. Septicemia of unknown focus was diagnosed in 2, or 22%, of cases. 

One patient each was diagnosed with septic shock and bacteremia. One patient that presented with 

meningitis was also diagnosed with pneumonia. No other cases were diagnosed with a secondary invasive

Neisseria meningitidis-related syndrome. 

Primary Clinical Presentations of Invasive 

Neisseria meningitidis – Alaska, 2000 

Primary Presentation Cases 

No. (%) 

Meningitis 5 (56%) 

Septic Shock 1 (11%) 

Bacteremia 1 (11%) 

Septicemia 2 (22%) 

Total 9 (100%) 

Neisseria meningitidis was isolated from blood samples in 6 of 9 cases (67%). Three cases were identified 

through the isolation of Neisseria meningitidis from cerebrospinal fluid. 

Summary of Invasive Neisseria meningitidis Case Characteristics – Alaska, 2000 

Gender Age Race Anchorage 

/Other 

Site of 

Isolation 

Primary Clinical 

Presentation 

Other NM 

Presentations 

Associated Medical 

Conditions 

Female 1 AK Native Other Blood Septicemia - - 

Male 2 Non-Native Other CSF Meningitis - - 

Male 7 Non-Native Anchorage Blood Sepsis/Septic Shock - - 

Male 12 AK Native Anchorage Blood Meningitis Pneumonia - 

Male 13 AK Native Other CSF Meningitis - - 

Male 22 Non-Native Other Blood Meningitis - Alcohol + cigarette 

smoking 

Female 23 Non-Native Anchorage CSF Meningitis - - 

Male 55 Non-Native Anchorage Blood Septicemia - Diabetes 

Male 64 Non-Native Anchorage Blood Bacteremia - Cigarette smoking 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 24

Invasive Group A Streptococcus

Overall Incidence 

In the year 2000, a total of 18 cases of invasive Group A Streptococcus (GAS) were reported to AIP resulting 

in an overall rate of invasive GAS for the State of Alaska in 2000 of 2.9/100,000 persons per year. This is 

slightly lower than the ABCs 2000 national projected rate of 3.2/100,000 persons per year (Active Bacterial 

Core Surveillance (ABCs) Report Emerging Infections Program Network group A streptococcus, 2000). 

However, in a relatively small population, one year trends are subject to wide variability. A fair comparison 

with national rates should be made using multiple years of data. There was 1 invasive GAS-related death in 

Alaska in 2000, resulting in a case-fatality rate of 5.5%, and an overall GAS mortality rate of 0.16/100,000 

persons per year for Alaska. 

Seasonality 

Ninety-four percent of invasive GAS cases were identified in the first 8 months of 2000; 17 cases occurred 

between January and August 2000. 

Invasive Group A Streptococcus - Alaska, 2000

0

1

2

3

4

5

January

February

March

April

May

June

July

August

September

October

November

December

Month of Isolation

Number of Cases

Race 

A total of 10 cases of invasive GAS were reported in the Alaska Native population in 2000, resulting in a case 

rate of 9.2/100,000 for this population. In contrast, the rate of invasive GAS among non-Natives for the same 

time period is 1.6/100,000 (8 cases). 

Invasive GAS Cases, by Race - Alaska, 2000 

Racial Group Cases 

No. (%) 

Rate* % Male Deaths 

Alaska Native 10 (56%) 9.24 50% - 

Non-Native 8 (44%) 1.54 63% 1 

Total 18 (100%) 2.9 63% 1 

*Rate per 100,000 population: population figures calculated from Census 2000 

data: Alaska Native: 108,187, non -Native: 518,745 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 25

Region 

Anchorage carried the bulk of the invasive GAS burden in Alaska in 2000, 61% of cases (11) occurred among 

residents of that city. The remaining 7 cases occurred in 7 other Alaska cities and villages. 

Sex 

In 2000, the rate of invasive GAS among males was 3.3/100,000 (10 cases). For females, the rate of invasive 

GAS was slightly lower at 2.5/100,000 (8 cases). 

Age 

Cases ranged in age from 6 months to 77 years, with 50% occurring between the ages of 19 – 44. Seventeen 

percent of cases occurred among individuals in the 45 – 54 year old age group. No cases were reported in 

children 5 – 18 years old. 

The highest rates of disease occurred among AK Natives under the age of 2 years and those over the age of 

65 years. 

Clinical Presentation 

The primary clinical presentation was determined by a review of the discharge diagnoses indicated in each 

patient’s chart. In cases with multiple discharge diagnoses, the most serious GAS-related diagnosis was 

recorded as the primary clinical presentation.

Of the 18 cases identified in 2000, 5 experienced multiple GAS-related presentations. In addition to the 

primary presentation, 2 cases were diagnosed with cellulitis, 1 with pneumonia and 1 additional diagnosis 

was unspecified. The patient who died was diagnosed with secondary endocarditis and septic arthritis, as 

well as the primary diagnosis of sepsis/septic shock. 

Rate of Invasive Group A Streptococcus , by Race and Age 

Group - Alaska, 2000, N=18

20.7

13.9

34.6

6.5

1.7 3.6

0

5

10

15

20

25

30

35

40

<2 2-64 65+

Age Group (years)

Rate per 100,000

Alaska Native

Non-Native
Surveillance of Invasive Bacterial Disease in Alaska, 2000 26

Primary Clinical Presentations 

of Invasive GAS – Alaska, 2000 

Primary 

Presentation 

Cases 

No. (%) 

Empyema 1 (5.5%) 

Septic Shock 1 (5.5%) 

Cellulitis 4 (22.5%) 

Peritonitis 1 (5.5%) 

Osteomyelitis 1 (5.5%) 

Pneumonia 2 (11%) 

Septic Arthritis 2 (11%) 

Bacteremia 1 (5.5%) 

Septicemia 4 (22.5%) 

Other 1 (5.5%) 

Total 18 

GAS was identified in blood samples of 78% of cases (14). The remaining cases were identified through

pleural fluid (1), joint fluid (2), and one unspecified sterile site. 

Associated Medical Conditions 

The most common associated medical conditions identified among the 18 Alaska GAS cases in 2000 were 

reported alcohol abuse (4 cases, 22%) and immunosuppressive treatment (4 cases, 22%). No associated 

medical conditions were indicated for 50% of cases (9). 

Associated Medical Conditions Identified in Invasive 

GAS Cases in Alaska, 2000 

Associated medical condition No. Cases* 

Diabetes 1 

Cigarette smoking 3 

Chronic lung disease 1 

Alcohol abuse 4 

Immunosuppressive treatment 4 

Injection drug use 1 

No associated medical conditions noted 9 

*More than 1 associated medical condition was identified in 5 cases 

Mortality 

In 2000, the overall case fatality rate for invasive GAS in the state of Alaska was 5.5%, or one death out of a 

total of 18 cases. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 

Summary of Invasive Group A Streptococcus Case Characteristics – Alaska, 2000 Gender Age Race Anchorage 

/Other 

Site of Isolation Primary Clinical 

Presentation 

Other GAS Presentations 

Associated MedicaConditions 

Female 6 months AK Native Anchorage Blood Septicemia - - Male 2 Non-Native Anchorage Blood Bacteremia - - Male 2 Non-Native Anchorage Pleural fluid Other - - Female 20 AK Native Other Blood Septicemia - Cigarette Smoking Female 22 AK Native Anchorage Blood Pneumonia Cellulitis Alcohol + Inj Drug Male 23 AK Native Other Joint fluid Osteomyelitis Other Cigarette Smoking Female 26 AK Native Anchorage Blood Cellulitis - Imm Tx Female 27 Non-Native Other Blood Peritonitis - - Male 30 AK Native Anchorage Joint fluid Cellulitis - - Female 32 Non-Native Anchorage Blood Septic Shock Endocarditis, Septic 

Arthritis 

Imm Tx* 

Male 39 AK Native Anchorage Blood Septic Arthritis - Cigarette Smoking Female 44 Non-Native Other Blood Cellulitis - Imm Tx Male 47 Non-Native Anchorage Blood Septicemia - - Male 51 Non-Native Anchorage Blood Septicemia - Alcohol Male 52 AK Native Other Blood Septic arthritis Cellulitis - Female 57 AK Native Anchorage Blood Cellulitis - - Male 74 Non-Native Other Blood Pneumonia - Chronic Lung Dx + Male 77 AK Native Other Unspecified 

sterile site 

Empyema Pneumonia - 

*Immunosuppressive treatment
Surveillance of Invasive Bacterial Disease in Alaska, 2000 28

Invasive Group B Streptococcus

Overall Incidence 

A total of 18 cases of invasive Group B Streptococcus (GBS) were reported to AIP in 2000, resulting in an 

overall rate for the state of Alaska in 2000 of 2.9/100,000 persons per year. This is lower than the rate of 

6.9/100,000 found in the CDC ABCs areas in 2000 and the national projected rate of 6.8/100,000 (Active 

Bacterial Core Surveillance (ABCs) Report Emerging Infections Program Network group B streptococcus, 

2000). However, in a relatively small population, one year trends are subject to wide variability. A fair 

comparison with national rates should be made using multiple years of data. There were 2 invasive GBSrelated deaths in Alaska in 2000, resulting in a case-fatality rate of 11%, and an overall GBS mortality rate of 

0.3/100,000 persons per year for Alaska. 

Seasonality 

Invasive Group B Streptococcus, by Month of Illness - 

Alaska, 2000

0

1

2

3

4

January

February

March

April

May

June

July

August

September

October

November

December

Number of Cases

Fifty-percent of all reported invasive GBS cases occurred in the summer months of June, July, and August. 

Race 

GBS Cases by Race – Alaska, 2000 

Racial Group Cases 

No. (%) 

Rate* % Male No. Deaths 

Alaska Native 3 (17%) 2.8 66% - 

Non-Native 15 (83%) 2.9 9% 2 

Total 18 2.9 17% 2 

*Rate per 100,000 population: population figures calculated from Census 2000 data: Alaska 

 Native: 108,187, non-Native: 518,745 

**Unknown race (n=2) included in non-Native group 

Region 

Invasive GBS cases were identified in 8 Alaska communities. Half of all reported cases occurred in residents 

of Anchorage. Two cases each were reported in Wasilla and Fairbanks. The remaining 5 cases occurred in 5 

separate communities. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 29

Age 

Invasive Group B Streptococcus, by Age 

Group - Alaska, 2000, N=18

0

2

4

6

8

<2 2-4 5-19 20-44 45-54 55-64 65+

Age Group (years)

Number of Cases

Non-Native children under 2 years of age carried the bulk of the invasive GBS burden in Alaska in 2000. 

One-third of all reported cases occurred in this age and racial group, resulting in a rate of 39/100,000 for nonNative children less than 2 years of age. There were no cases reported in Alaska Native children less than 2 

years of age, and no cases in any children from 2 – 20 years of age. The rate of invasive GBS for both the 

Alaska Native and non-Native populations between 2- 65 years is less than 2/100,000 in 2000. 

Rate of Invasive GBS, by Race and Age, Alaska 2000 

<2 years 

Rate* (no.) 

2 – 64 years 

Rate (no.) 

65+ years 

Rate (no.) 

Alaska Native 0 1.85 (2) 17.3 (1) 

Non-Native 39.0 (6) 1.26 (6) 10.7 (3) 

*Rate per 100,000 population: population figures calculated from Census 2000 data: 

 Alaska Native: 108,187, non-Native: 518,745 

**Unknown race (n=2) included in non-Native group 

Rate of Invasive GBS, by Race & Age - Alaska, 2000, N=18

0

1.85

17.3

39

1.26

10.7

0

10

20

30

40

50

<2 2-64 65+

Age Group

Rate per 100,000

Alaska Native

Non-Native

 *Number indicated above the bar is the rate of invasive GBS for each age and racial group per 100,000 population. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 30

Invasive GBS Cases Among Children Under 2 Years of 

Age - Alaska, 2000, N=6

4

1 1

0 0

0

1

2

3

4

5

<1 month 1-3 months 4-6 months 7-12 months 13-24 months

Number of Cases

Sex 

The rate of invasive GBS for Alaska females in 2000 was 1.98/100,000 (6 cases). The rate of invasive GBS 

for males was 3.7/100,000 (12 cases). 

Clinical Presentation 

The primary clinical presentation was determined by a review of the discharge diagnoses indicated in each 

patient’s chart. In cases with multiple discharge diagnoses, the most serious diagnosis related to the GBS 

infection was recorded as the primary clinical presentation. Septicemia of unknown focus was the most

common primary clinical presentation, occurring in 8, or 44%, of the invasive GBS cases in 2000. Cellulitis 

occurred in 4, or 22%, of cases. The remaining patients presented with pneumonia, peritonitis, meningitis, 

and bacteremia. 

Primary Clinical Presentations of Invasive GBS – Alaska, 2000 

Primary 

Presentation 

Cases 

No. (%) 

Deaths 

Bacteremia 1 (6%) - 

Meningitis 1 (6%) - 

Peritonitis 2 (11%) 1 

Cellulitis 4 (22%) - 

Pneumonia 2 (11%) - 

Septicemia 8 (44%) 1 

Total 18 (100%) 2 

Two cases were diagnosed with an additional GBS-related presentation. One patient with cellulitis also 

presented with osteomyelitis and one patient with a primary diagnosis of pneumonia also presented with

cellulitis. 

Group B Streptococcus was isolated from blood samples in 15 of 18 cases (83%). One case each was 

identified through the isolation of the GBS bacteria from cerebrospinal fluid, peritoneal fluid, and tissue. 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 31

Mortality 

Two of 18 cases died due to infection with invasive GBS, for an overall case fatality rate of 11%. The overall 

GBS-related mortality rate for Alaska is 0.3/100,000, less than half that projected as the national mortality 

rate of 0.7/100,000 (Active Bacterial Core Surveillance (ABCs) Report Emerging Infections Program 

Network group B streptococcus, 2000). However, year to year rates in a small population are likely to vary 

widely and multiple years would be needed to make a fair comparison. 

Associated Medical Conditions 

The presence of one or more associated medical conditions was noted in 33% of reported invasive GBS cases 

in 2000. One associated medical condition was identified in 5 of 6 cases and 3 (diabetes, alcohol use, and 

cigarette smoking) were reported for 1 case. Data were unavailable for 1 case.
Surveillance of Invasive Bacterial Disease in Alaska, 2000 

Summary of Invasive Group B Streptococcus Case Characteristics – Alaska, 2000 

Gender Age 

(Years) 

Race Anchorage 

/Other 

Site of Isolation Primary Clinical 

Presentation 

Other GBS Presentations 

Associated Medical Conditions 

Female 1 day Non-Native Anchorage Blood Septicemia - - Male 1 day Non-Native Anchorage Blood Septicemia - - Male 1 day Non-Native Other Blood Pneumonia - - Female 10 days Non-Native Anchorage CSF Meningitis - - Male 0.1 Non-Native Other Blood Septicemia - - Female 0.5 Non-Native Other Blood Septicemia - - Male 43 Non-Native Other Peritoneal fluid Peritonitis - Alcohol Male 46 Non-Native Anchorage Blood Septicemia - - Female 49 Non-Native Anchorage Blood Cellulitis - - Male 49 AK Native Other Joint Fluid Cellulitis Osteomyelitis - Male 50 Non-Native Other Blood Septicemia - Alcohol Male 55 AK Native Anchorage Blood Peritonitis - Diabetes + alcohol + Male 59 Non-Native Other Blood Cellulitis - Diabetes Male 62 Non-Native Anchorage Blood Septicemia - Chronic lung disease Male 66 Non-Native Other Blood Cellulitis - Diabetes Female 76 AK Native Anchorage Blood Septicemia - - Female 78 Non-Native Other Blood Bacteremia - Unknown Male 86 Non-Native Anchorage Blood Pneumonia Cellulitis - 
Surveillance of Invasive Bacterial Disease in Alaska, 2000 33

Appendix 

MIC Interpretive Standards Definitions: 

 NCCLS provides recommended interpretive categories for various Minimum Inhibitory Concentration values 

(cut points) for each organism which are defined as follows:* 

1. Susceptible (S): 

The “susceptible” category implies that an infection due to the strain may be appropriately treated 

with the dosage of antimicrobial agent recommended for that type of infection and infecting species, 

unless otherwise contraindicated. 

2. Intermediate (I): 

The “intermediate” category includes isolates with antimicrobial agent MICs that approach usually 

attainable blood and tissue levels and for which response rates may be lower than for susceptible 

isolates. The “intermediate” category implies clinical applicability in body sites where the drugs are 

physiologically concentrated (e.g., quinolones and β-lactams in urine) or when a high dosage of a 

drug can be used (e.g., β-lactams). The “intermediate” category also includes a buffer zone which 

should prevent small, uncontrolled technical factors from causing major discrepancies in 

interpretations, especially for drugs with a narrow pharmacotoxicity margins. 

3. Resistant (R): 

Resistant strains are not inhibited by the usually achievable systemic concentrations of the agent with 

normal dosage schedules and/or fall in the range where specific microbial resistance mechanisms are 

likely (e.g., β-lactamases) and clinical efficacy has not been reliable in treatment studies. 

* NCCLS, MIC Testing, Supplemental Tables, M100-S10 (M&), January 2000, p.9.