bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal fluctuation of antibody levels to Plasmodium falciparum parasitized red blood cell-associated antigens in two Senegalese villages with different transmission conditions.
Authors: Perraut R , Mercereau-Puijalon O , Diouf B , Tall A , Guillotte M , Le Scanf C , Trape J F , Spiegel A , Garraud O
Published: May 2017

The recombinant R23, PfEB200, and GST-5 antigens derive from conserved antigens associated with the Plasmodium falciparum-infected erythrocyte membrane. They were identified as targets of protective antibodies in the Saimiri sciureus model. We have assessed here the humoral response to these antigens in humans. Cross-sectional surveys were conducted in two Senegalese villages with different levels of endemicity. The prevalence of specific IgG and IgM was similar and influenced by age in both localities. The anti-R23 antibodies decreased after the rainy season, particularly in the children less than ten years old. The anti-PfEB200 response did not show significant seasonal variation. The anti-GST-5 response increased in both the less-than 10-year-old and the greater-than 10-year-old groups after the rainy season in Dielmo, but only in the Ndiop villagers who were more than 10-years-old. Thus, antigen-specific seasonal variations of antibody levels were influenced differently by age in both villages. The isotype distribution was antigen-specific and differed for both seasons.
SALP16, a gene induced in Ixodes scapularis salivary glands during tick feeding.
Authors: Das S , Marcantonio N , Deponte K , Telford S R , Anderson J F , Kantor F S , Fikrig E
Published: May 2017

Guinea pigs infested with Ixodes scapularis acquire antibody-mediated resistance to tick bites, a phenomenon known as tick-immunity. An I. scapularis salivary gland cDNA expression library was therefore probed with sera from tick-immune guinea pigs to identify antigens that elicit humoral responses in the host. Sera from sensitized guinea pigs strongly recognized 3 of 4,500 library clones in an initial screening. The open reading frames of all 3 clones encoded a putative 16.4-kD acidic protein, designated Salp16, with an N-terminal signal sequence and signal peptidase cleavage sites specific for secretory proteins. The salp16 mRNA and Salp16 protein were detected in the salivary glands of engorged, but not unfed, nymphal and adult ticks, and Salp16 was also found in the saliva of engorged ticks. Immunization with recombinant Salp16 induced high antibody titers in guinea pigs, but did not elicit tick-immunity. Salp16 is the first feeding inducible gene that has been cloned from L. scapularis. Molecular characterization of I. scapularis salivary antigens that are induced upon tick feeding should help to facilitate our understanding of tick-host interactions.
Mortality, morbidity, and microbiology of endemic cholera among hospitalized patients in Dhaka, Bangladesh.
Authors: Ryan E T , Dhar U , Khan W A , Salam M A , Faruque A S , Fuchs G J , Calderwood S B , Bennish M L
Published: May 2017

Mortality and morbidity associated with cholera acquired in a modern endemic setting have not been well defined. In Dhaka, Bangladesh from 1986 to 1996, we found that causative agents of cholera shifted over time, varying by serogroup, biotype, and serotype. At the International Centre for Diarrhoeal Disease Research (ICDDR,B: Centre for Health and Population Research) in 1996, 19,100 cholera patients were treated, 887 (4.6%) were admitted, and 33 died (mortality rate = 3.7% of cholera inpatients, 0.14% of all cholera patients). When cholera inpatients who were discharged improved were compared with those who died, bacteremia (odds ratio [OR] = 10.5, 95% confidence interval [CI] = 2.9-37.9), radiographic evidence of pneumonia (OR = 3.1, 95% CI = 1.2-7.7), and acidosis as estimated by the serum bicarbonate value (OR = 0.893, 95% CI = 0.825-0.963) were independently associated with death by multivariate analysis. Pneumonia was the leading cause of death and accounted for two-thirds of all deaths among individuals with cholera in this study. Death in hospitalized patients with cholera acquired in a modern endemic setting is, therefore, extremely rare, and most frequently due to concomitant infection, especially pneumonia.
Comparison of the polymerase chain reaction and serologic tests for diagnosis of septicemic melioidosis.
Authors: Sermswan R W , Wongratanacheewin S , Anuntagool N , Sirisinha S
Published: May 2017

For diagnosis of melioidosis, we compared polymerase chain reaction (PCR)-based DNA detection and three serologic methods with the culture method currently used as gold standard. The diagnostic values of the serologic methods were evaluated in 130 patients. All these patients resided in an endemic area. An enzyme-linked immunosorbent assay (ELISA) gave slightly higher specificity (86.2%) than a dot immunoassay (DOT) (85.3%), but was superior to an indirect hemagglutination assay (IHA) (79.8%). The sensitivities of the DOT (85.7%) and ELISA (71.4%) were considerably higher than that of IHA (61.9%). However, the PCR was the most sensitive (95.2%) and specific (91.7%). Nevertheless, DOT and ELISA are more practical for local hospitals. With the high negative predictive value of both the ELISA (94.0%) and DOT (96.9%) in a high prevalence area, clearly these methods can rule out most of the non-melioidosis patients.
The contrasting epidemiology of Cyclospora and Cryptosporidium among outpatients in Guatemala.
Authors: Bern C , Hernandez B , Lopez M B , Arrowood M J , De Merida A M , Klein R E
Published: May 2017

We compared epidemiologic characteristics of Cryptosporidium and Cyclospora in surveillance data from outpatient departments in Guatemala. Routinely-submitted stool specimens were screened by microscopy. Age, sex, and symptom data were collected. Cyclospora was detected in 117 (2.1%) and Cryptosporidium in 67 (1.2%) of 5,520 specimens. The prevalence of Cyclospora peaked in the warmer months, while Cryptosporidium was most common in the rainy season. Both affected children more than adults, but Cryptosporidium affected children at a younger age than Cyclospora (median age 2 years versus 5 years; P < 0.001). Cyclospora showed a stronger association with diarrhea than Cryptosporidium, even when data were stratified by age. These contrasts may reflect differences in the relative importance of transmission modes, the frequency of exposure, and the development of immunity.
Antimicrobial agent resistance in bacterial isolates from patients with diarrhea and urinary tract infection in the Sudan.
Authors: Ahmed A A , Osman H , Mansour A M , Musa H A , Ahmed A B , Karrar Z , Hassan H S
Published: May 2017

Antimicrobial sensitivity tests were performed on four-hundred and ninety-seven bacterial isolates from Sudanese patients with diarrhea or urinary tract infections. Shigella dysenteriae type I and enteropathogenic Escherichia coli showed high resistance rates (percentage of isolates showing antibiotic resistance) against the commonly-used antimicrobial agents: ampicillin, amoxicillin, chloramphenicol, tetracycline, cotrimoxazole, nalidixic acid, sulfonamide, and neomycin, and were completely sensitive to ciprofloxacin. Eighteen resistance patterns against nine antimicrobial agents tested were observed in enteric pathogens. Resistance to ampicillin, amoxicillin, tetracycline, cotrimoxazole, and sulfonamide was the most frequent pattern. The common urinary pathogens, E. coli, Klebsiella pneumoniae, and Proteus mirabilis showed high rates of resistance to ampicillin, amoxicillin, cotrimoxazole, tetracycline, sulfonamide, trimethoprim, streptomycin, and carbenicillin. We recommend that physicians seek updated knowledge of the common antibiotic-sensitivity patterns when starting empirical antibiotic therapy in Sudanese patients with diarrhea or urinary tract infection.
Rapid, simple, and culture-independent detection of rpsL codon 43 mutations that are highly predictive of streptomycin resistance in Mycobacterium tuberculosis.
Authors: Mieskes K T , RÃ¼sch-Gerdes S , Truffot-Pernot C , Feldmann K , Tortoli E , Casal M , LÃ¶scher T , Rinder H
Published: May 2017

The substitution of codon 43 in the gene rpsL is the single most common mutation found in streptomycin-resistant Mycobacterium tuberculosis. The characterization of this mutation has been hampered by the need for prior cultivation of the mycobacteria, the need for DNA sequencing, or both. In this report we describe a simple and culture-independent technique to detect this mutation directly from sputum samples, requiring little more than a polymerase chain reaction (PCR) machine and a simple agarose minigel. There is no need for labeled probes or DNA sequencing. In a preliminary test of feasibility, interpretable results were obtained from all of 16 smear-positive and 1 of 4 smear-negative, culture-positive samples. Two of two samples containing M. tuberculosis with rpsL codon 43 mutations were correctly identified.
Flaviviruses isolated from mosquitoes collected during the first recorded outbreak of Japanese encephalitis virus on Cape York Peninsula, Australia.
Authors: Van Den Hurk A F , Johansen C A , Zborowski P , Phillips D A , Pyke A T , Mackenzie J S , Ritchie S A
Published: May 2017

In response to an outbreak of Japanese encephalitis (JE) virus on Cape York Peninsula, Australia, in 1998, mosquitoes were collected using CO2 and octenol-baited Centers for Disease Control and Prevention light traps. A total of 35,235 adult mosquitoes, comprising 31 species, were processed for virus isolation. No isolates of JE virus were recovered from these mosquitoes. However, 18 isolates of Kokobera virus, another flavivirus were obtained from Culex annulirostris. Twelve isolates were from western Cape York (minimum infection rate (MIR) of 0.61: 1,000 mosquitoes) and 6 were from the Northern Peninsula Area (MIR of 1.0:1,000). Potential explanations for the failure to detect JE virus in mosquitoes collected from Cape York Peninsula include the timing of collections, the presence of alternative bloodmeal hosts, differences in pig husbandry, asynchronous porcine seroconversion, and the presence of other flaviviruses.
Treatment failure in children in a randomized clinical trial with 10 and 20 days of meglumine antimonate for cutaneous leishmaniasis due to Leishmania viannia species.
Authors: Palacios R , Osorio L E , Grajalew L F , Ochoa M T
Published: May 2017

Clinical response to supervised treatment of Colombian patients with cutaneous leishmaniasis was evaluated in a randomized controlled trial comparing 10 days versus 20 days of treatment with meglumine antimonate (20 mg Sb/kg/day). Masked examiners evaluated clinical response defined as 100% re-epithelialization of all lesions at 13 weeks and no relapses during 52 weeks of follow-up. The efficacy of meglumine antimonate for 10 days' treatment was 61% (28 of 46) compared to 67% (24 of 36) for 20 days. There was a significantly lower clinical response for children < 5 years in both 10-day (11%) and 20-day (25%) groups compared to patients aged 5-14 years (67% and 75%, respectively) and 15 years or more (81% and 83%, respectively). Overall efficacy of treatment schedules was comparable, but lower than expected, mainly because of low efficacy in children. Pathogenicity of infection and pharmacokinetics may affect the treatment response in children. New therapeutic alternatives should be evaluated in trials that include children and women.
A protocol for geographically randomized snail surveys in schistosomiasis fieldwork using the global positioning system.
Authors: Seto E , Liang S , Qiu D , Gu X , Spear R C
Published: May 2017

A protocol was created for performing geographically randomized snail surveys for schistosomiasis research using the global positioning system (GPS). This protocol differs from traditional surveys in its ability to accurately map and measure the spatial distribution of snail habitat. The protocol was used to map irrigation ditches, the primary habitat for Oncomelania hupensis, in two residence areas in Sichuan Province, China. From the 7,450 meters of mapped ditches, snail surveys were performed at 203 random sites along the ditch network. Of these, 116 (57.1%) sites had snails. The total number of living snails captured was 2,014, resulting in an average snail density of 0.27 snails per linear meter of potential habitat.
Toxins and colonization factor antigens of enterotoxigenic Escherichia coli among residents of Jakarta, Indonesia.
Authors: Oyofo B A , Subekti D S , Svennerholm A M , Machpud N N , Tjaniadi P , Komalarini T S , Setiawan B , Campbell J R , Corwin A L , Lesmana M
Published: May 2017

Infection caused by enterotoxigenic Escherichia coli (ETEC) poses a serious health problem among children and adults in developing countries. Colonization of the small intestinal mucosa by ETEC strains is mediated by antigenically specific fimbriae, also known as colonization factor antigens (CFA). The significance of this study arises from reports that active and passive immunization with ETEC strains harboring CFAs has previously been shown to induce protective immunity against diarrhea in animal models. The aim of this study was to determine toxin-associated CFAs of ETEC isolated from a diarrheal disease case-control study in Jakarta, Indonesia. Thirteen hundred and twenty-three diarrheic and control patients with lactose-fermenting colonies were screened by ganglioside GM1-enzyme-linked immunosorbent assay (GM1-ELISA) for heat-labile (LT) and heat-stable (ST) toxins. Two hundred and forty-six (19%) ETEC isolates identified by GM1-ELISA for the LT/ST toxins were screened for CFAs by Dot blot assay using monoclonal antibodies against CFA/I, II, and IV and against the putative colonization antigens (PCF) PCFO159, PCFO166, CS7, and CS17. Of the 246 ETEC isolates, 177 (72%) elaborated ST, 56 (23%) produced LT, while 13 (5%) elicited both the ST and LT toxins. CFA testing of the 246 ETEC isolates showed that 21 (8%) expressed CFA/I, 3 (1%) exhibited CFA/II, 14 (6%) elaborated CFA/IV, while 7 (3%) expressed PCFO159 and PCFO159 plus CS5. No CFAs or PCFs could be associated with 201 (82%) of the ETEC strains. This report documents the types of CFAs associated with ETEC strains in Jakarta, Indonesia. These data may help current research efforts on the development of CFA-based vaccines for humans against ETEC and provide additional information for future ETEC vaccine trials in Southeast Asia.
Probability of Trypanosoma cruzi transmission by Triatoma infestans (Hemiptera: Reduviidae) to the opossum Didelphis albiventris (Marsupialia: Didelphidae).
Authors: Rabinovich J , Schweigmann N , Yohai V , Wisnivesky-Colli C
Published: May 2017

The probability of Trypanosoma cruzi transmission to opossums by independent events of predation and fecal contamination during feeding ("biting") with positive Triatoma infestans was estimated. Negative female opossums were challenged for 23 hr with 10 infected third and fourth instars of T. infestans, and tests for positivity for T. cruzi by xenodiagnosis were performed at 30, 60, and 90 days. From these data, seven probability parameters were estimated by maximum likelihood, and likelihood ratio statistics confidence intervals were calculated. Simultaneous estimation of p1 (probability that a "bite" will infect an opossum), p3 (probability that a bug that has been eaten by an opossum will infect it), and p6 (probability that the opossum will become infected if faced with an infected triatomine), resulted in p1 = 0.06, p3 = 0.075, and p6 = 0.059. On average, each opossum should be exposed to an average of 700 encounters with bugs during its life, resulting in about eight potentially infective contacts, to produce the 35% opossum prevalence found in the field.
Short report: Hookworm infection is associated with decreased body temperature during mild Plasmodium falciparum malaria.
Authors: Nacher M , Singhasivanon P , Traore B , Dejvorakul S , Phumratanaprapin W , Looareesuwan S , Gay F
Published: May 2017

Malaria's pyrogenic threshold seems to depend on factors such as age and transmission patterns. We studied the temperature at admission of 200 patients with mild malaria and observed that after adjusting for body mass index, the presence of other helminths, and other confounders, only hookworm-infected patients had lower fever at admission that those without hookworm infection (37.5 +/- 0.9 and 38 +/- 0.8, respectively; P < 0.001). Thus, we suggest the age dependence of the pyrogenic threshold could have been confounded by the epidemiology of iron deficiency.
Effect of malaria on soluble transferrin receptor levels in Tanzanian infants.
Authors: Menendez C , Quinto L L , Kahigwa E , Alvarez L , Fernandez R , Gimenez N , Schellenberg D , Aponte J J , Tanner M , Alonso P L
Published: May 2017

The diagnosis of iron deficiency anemia in malaria endemic areas is complicated by the influence of the infection on the laboratory tests conventionally used to assess iron status. Determination of soluble transferrin receptor (sTfR) levels has been shown to be a sensitive indicator of iron deficiency in adults and is not affected by a range of infectious and inflammatory conditions. The utility of sTfR levels in the diagnosis of iron deficiency in malaria endemic areas remains unresolved. Three hundred and fourteen infants in a rural area of southern Tanzania living under conditions of intense and perennial malaria transmission were studied to determine the utility of sTfR plasma levels in the assessment of iron deficiency anemia. Independent of the presence of anemia, malaria parasitemia was associated with a significant increase in sTfR plasma levels that were even higher than those found in iron deficiency anemia. We conclude that the measurement of sTfR levels does not have a role in the diagnosis of iron deficiency anemia in young children exposed to malaria infection.
Mouse model for Chagas disease: immunohistochemical distribution of different stages of Trypanosoma cruzi in tissues throughout infection.
Authors: Guarner J , Bartlett J , Zaki S R , Colley D G , Grijalva M J , Powell M R
Published: May 2017

Different stages of Trypanosoma cruzi are seen during mammalian infection. Histologic sections of infected hearts have shown amastigotes and, when using immunohistochemistry (IHC), parasite antigens; however, demonstration of trypomastigotes in these tissues has proven elusive. Using a mouse strain that develops chagasic cardiomyopathy (histologically similar to human infection) 70 days after injecting T. cruzi-Brazil strain, we studied the distribution of parasite stages and the extent of inflammation. All organs had varying amounts of mononuclear inflammation by day 10, which peaked between day 20 and day 30, and decreased by day 50. Amastigotes were detected in myocytes, histiocytes, acinar pancreatic cells, astrocytes and ependymal cells by day 10, and the number of amastigotes peaked on day 30. Immunohistochemistry demonstrated trypomastigotes in sinusoids, vessels and interstitial tissues of several organs between day 15 and 50. Abundant parasite antigens (granular staining) were detected in connective tissues throughout the infection. The burden of amastigotes and trypomastigotes during the acute phase seems to correlate with the degree of inflammation and granular staining in the chronic stage.
Detection of eastern equine encephalitis virus in infected mosquitoes using a monoclonal antibody-based antigen-capture enzyme-linked immunosorbent assay.
Authors: Brown T M , Mitchell C J , Nasci R S , Smith G C , Roehrig J T
Published: May 2017

Surveillance of mosquito populations for virus activity is not often performed by small, vector-control districts because they do not have the financial resources to use virus isolation, or newer methods such as the polymerase chain reaction. Consequently, development and refinements of rapid, sensitive, and simple enzyme-linked immunosorbent assays (ELISAs) applicable to a wide variety of public health settings are justified. We have developed an antigen-capture ELISA for the detection of eastern equine encephalitis (EEE) virus in mosquitoes that uses both monoclonal capture and detector antibodies. The sensitivity of this assay is 4.0-5.0 log10 plaque-forming units/ml, which is comparable to previously published EEE antigen-capture assays developed with polyclonal antibody reagents. This test identifies only North American strains of EEE virus and does not react with either western equine encephalitis or Highlands J viruses. Test sensitivity was enhanced by sonicating mosquito pools, treating them with Triton X-100, and increasing the time and temperature of antigen incubation. The conversion of this ELISA to a monoclonal antibody-based format should result in a readily standardizable and transferable assay that will permit laboratories lacking virus isolation facilities to conduct EEE virus surveillance.
Impact of breast-feeding on Giardia lamblia infections in Bilbeis, Egypt.
Authors: Mahmud M A , Chappell C L , Hossain M M , Huang D B , Habib M , DuPont H L
Published: May 2017

A total of 152 infants were followed from birth to 1 year of age in a rural community of Egypt to document Giardia lamblia infection and to determine the effect of breast-feeding on enteric infections by this protozoan. Asymptomatic Giardia infections persisted as long as 4 months, with a mean duration of excretion of 7.18 weeks. The incidence of asymptomatic infection was 4.5 episodes per child-year. Exclusively breast-fed infants had lower risk for asymptomatic (odds ratio [OR] = 0.66, 95% confidence interval [CI] = 0.45-0.96, P < 0.05) and symptomatic infections (relative risk [RR] = 0.50, 95% CI = 0.27-0.90, P < 0.05). Furthermore, breast-fed infants had fewer clinical manifestations, including mucus in stool (23.8% versus 76.2%, P = 0.08), loss of appetite (17.6% versus 82.3%, P < 0.05), and abdominal tenderness (17% versus 82.9%, P < 0.05) compared with infants who were not exclusively breast-fed. Breast-feeding should be considered as an effective means to prevent Giardia infections and should be encouraged in regions where G. lambia is highly endemic.
A baseline study on the importance of bovines for human Schistosoma japonicum infection around Poyang Lake, China.
Authors: Guo J G , Ross A G , Lin D D , Williams G M , Chen H G , Li Y , Davis G M , Feng Z , McManus D P , Sleigh A C
Published: May 2017

We hypothesize that bovine infections are responsible for the persistence of human schistosomiasis transmission in the Yangtze marshlands of China. To test this hypothesis, we are carrying out a comparative intervention among four administrative villages in the Poyang Lake region, Jiangxi Province, two of which are experimental and two are control. The primary design involves treating, at the onset of the study, all the inhabitants in all four villages with praziquantel and all the bovines in two villages (the experimental or intervention villages). Following treatment, rates of reinfection in people of all villages, and in bovines in the experimental villages, will be assessed as will the ongoing prevalence of infection in bovines in the control villages. Before treatment, the prevalence and intensity of infection among humans and bovines was ascertained in the four villages. Our study design and baseline information are presented here, along with a description of the ecology of the study villages.
Cost-effectiveness and sustainability of lambdacyhalothrin-treated mosquito nets in comparison to DDT spraying for malaria control in western Thailand.
Authors: Kamolratanakul P , Butraporn P , Prasittisuk M , Prasittisuk C , Indaratna K
Published: May 2017

The cost-effectiveness of lambdacyhalothrin-treated nets in comparison with conventional DDT spraying for malaria control among migrant populations was evaluated in a malaria hyperendemic area along the Thai-Myanmar border. Ten hamlets of 243 houses with 948 inhabitants were given only treated nets. Twelve hamlets of 294 houses and 1,315 population were in the DDT area, and another 6 hamlets with 171 houses and 695 inhabitants were in the non-DDT-treated area. The impregnated net program was most cost-effective (US$1.54 per 1 case of prevented malaria). Spraying with DDT was more cost-effective than malaria surveillance alone ($1.87 versus $2.50 per 1 case of prevented malaria). These data suggest that personal protection measures with insecticide-impregnated mosquito net are justified in their use to control malaria in highly malaria-endemic areas in western Thailand.
Short report: transient antibody response in Taenia solium infection in field conditions-a major contributor to high seroprevalence.
Authors: Garcia H H , Gonzalez A E , Gilman R H , Palacios L G , Jimenez I , Rodriguez S , Verastegui M , Wilkins P , Tsang V C , _ _
Published: May 2017

The discordance between extremely high seroprevalence of Taenia solium antibodies in disease-endemic populations, relatively few symptomatic cases of neurocysticercosis, and high background levels of putatively inactive brain lesions (mainly calcifications) in seronegative controls have confused researchers, clinicians, and epidemiologists in the last decade. We reviewed longitudinal serologic data from general population serosurveys in 3 different disease-endemic areas of Peru and Colombia and found that approximately 40% of seropositive people were seronegative when resampled after 1 year (3 surveys) or after 3 years (1 survey). Transient antibodies may have significant implications for the epidemiology of and immunity to this disease.
Spotted fever in Brazil: a seroepidemiological study and description of clinical cases in an endemic area in the state of SÃ£o Paulo.
Authors: de Lemos E R , Alvarenga F B , Cintra M L , Ramos M C , Paddock C D , Ferebee T L , Zaki S R , Ferreira F C , Ravagnani R C , Machado R D , GuimarÃ£es M A , Coura J R
Published: May 2017

During 1985-1995, illnesses clinically and epidemiologically compatible with Brazilian spotted fever were identified in 17 patients in the county of Pedreira, in the state of SÃ£o Paulo, Brazil. Spotted-fever group rickettsial infection was confirmed by serology and/or immunostaining of tissues in 10 of these patients. Immunostaining confirmed infection in a 37-year-old pregnant patient, although rickettsial antigens were not demonstrable in the tissues of the fetus. A serosurvey was conducted in four localities in the county to determine the prevalence of subclinical or asymptomatic infections with spotted fever group rickettsiae. Five hundred and twenty-five blood samples were tested by an indirect immunofluorescence assay for antibodies reactive with Rickettsia rickettsii. Twenty-two (4.2%) of these samples demonstrated titers > or = 1:64. The results indicate that Brazilian spotted fever is endemic within this region of Brazil.
Association of helminth infection with decreased reticulocyte counts and hemoglobin concentration in Thai falciparum malaria.
Authors: Nacher M , Singhasivanon P , Gay F , Phumratanaprapin W , Silachamroon U , Looareesuwan S
Published: May 2017

Following a study showing an association between Ascaris and protection from cerebral malaria, we conducted a cross-sectional study comparing admission hemoglobin concentrations in relation to exposure to helminth infection in 2 separate groups of patients: 111 cerebral malaria cases and 180 mild Plasmodium falciparum malaria cases. Hookworm infections were excluded. Mean hemoglobin concentrations were significantly lower in helminth-infected patients compared to those without helminths, both in the cerebral malaria group (10.1+/-3 [n = 47] versus 11.2+/-2.4 g/dl [n = 64], P = 0.04) and the mild malaria group (11+/-2.5 [n = 89] vs 12.2+/-2.7 g/dl [n = 91], P = 0.004). Median reticulocyte counts, only available in the cerebral malaria group, were lower in helminth-infected patients compared to those without helminths (15,340/23,760 per microl, P = 0.03). Adjustments for confounders such as body mass index did not alter these associations. These data are consistent with a mechanism causing anemia linked to differences in the immune response of helminth-infected patients during malaria.
Ribodemes of Blastocystis hominis isolated in Japan.
Authors: Kaneda Y , Horiki N , Cheng X J , Fujita Y , Maruyama M , Tachibana H
Published: May 2017

To determine if genetic diversity of Blastocystis hominis exists in Japan, we monitored 64 B. hominis-infected people: 39 asymptomatic people whose infections were detected during routine medical check-ups (32 Japanese and 7 non-Japanese) and 25 patients with gastrointestinal symptoms who visited the outpatient clinics of St. Luke's International Hospital (19 Japanese and 6 non-Japanese). We detected 6 known and 2 new riboprint patterns in isolates from the infected people. There were no differences in the distribution of ribodemes between isolates from Japanese and non-Japanese people, similar to that in other countries. However, we noted a possible relationship between ribodeme type and pathogenicity. The results suggest that ribodemes I, III, and VI may be responsible for gastrointestinal symptoms.
Speciation of human microsporidia by polymerase chain reaction single-strand conformation polymorphism.
Authors: Fedorko D P , Nelson N A , Didier E S , Bertucci D , Delgado R M , Hruszkewycz A M
Published: May 2017

We describe the application of single-strand conformation polymorphism (SSCP) analysis to the speciation of human microsporidia after polymerase chain reaction (PCR) amplification with the panmicrosporidian primers PMP1 and PMP2. We compared the DNA extracted and amplified from different genotypes or isolates of Enterocytozoon bieneusi, Encephalitozoon cuniculi, E. hellem, and E. intestinalis plus an isolate of Vittaforma corneae. The PCR-SSCP, when performed at 20 degrees C, generated 2 bands in distinctive, reproducible patterns in polyacrylamide gels for each species of microsporidia tested, regardless of genotype or isolate. We found PCR-SSCP to be an easy and reproducible method for speciation of human microsporidia when the primer pair PMP1 and PMP2 is used.
Relationship between Trypanosoma cruzi and human chagasic megaesophagus: blood and tissue parasitism.
Authors: Lages-Silva E , Crema E , Ramirez L E , Macedo A M , Pena S D , Chiari E
Published: May 2017

The persistence of Trypanosoma cruzi in tissue and blood of 52 patients in the digestive form of chronic Chagas disease was studied. These patients had chagasic megaesophagus and underwent corrective surgery. Parasitologic (xenodiagnosis, hemoculture, or both), histopathologic (hematoxylin and eosin, and peroxidase-anti-peroxidase staining), and molecular (polymerase chain reaction [PCR] followed by slot-blot hybridization) tests were used in the analysis. The presence of T. cruzi, its genomic fragments, or its antigens could be detected in 98% (51 of 52) of the patients. The parasite was randomly identified in 76.9% of esophageal tissues and in 90.4% by PCR and in 73.1% by parasitologic methods from the blood. Fifty percent (26 of 52) of tissue samples had inflammation, 80.8% of which was associated with the parasite. Trypanosoma cruzi was also identified unassociated with inflammatory alterations. Higher tissue parasitism and intense inflammatory processes were observed in esophageal tissue from patients with Grade IV megaesophagus. These data demonstrate that in the digestive form of Chagas' disease, particularly in cases of megaesophagus, T. cruzi is frequently found, both in blood and tissues and may contribute to the pathogenic mechanisms involved.
Elimination of lymphocytes, but not eosinophils, by Fas-mediated apoptosis in murine schistosomiasis.
Authors: Rumbley C A , Sugaya H , Zekavat S A , Perrin P J , Phillips S M
Published: May 2017

Infection with the helminth parasite Schistosoma mansoni is associated with a pathogenic granulomatous response to parasite eggs. Multiple cell types constitute the granuloma with eosinophils achieving numerical dominance. We hypothesize that eosinophil dominance is achieved by selective apoptosis in lymphocytes. We report here that lymphocytes from both the spleens and granulomas of S. mansoni-infected mice undergo apoptosis. We also show that granuloma lymphocytes are more susceptible to Fas-FasL-mediated apoptosis than spleen lymphocytes and this apoptosis may be related to antigen concentration. Conversely, eosinophils from the granuloma and spleens of S. mansoni-infected mice are resistant to apoptosis in vivo and are protected in vitro from Fas-FasL-mediated apoptosis by the absence of FasL expression in the presence of Fas expression. Finally, the apoptotic regulatory molecules Bcl-2, Bcl-xL, and Bax, do not appear to play a significant role in the regulation of eosinophil apoptosis in the schistosome granuloma.
Population genetic structure and competence as a vector for dengue type 2 virus of Aedes aegypti and Aedes albopictus from Madagascar.
Authors: Vazeille M , Mousson L , Rakatoarivony I , Villeret R , Rodhain F , Duchemin J B , Failloux A B
Published: May 2017

Starch gel electrophoresis was used to assess the polymorphism of 7 isoenzymes in single mosquitoes (field-collected F0 or F1 generation) for Aedes albopictus (8 strains) from northern Madagascar. Mosquitoes of the F2 generation (3 strains of Aedes aegypti and 10 strains of Ae. albopictus) were tested for oral susceptibility to dengue type 2 virus. Aedes aegypti was less susceptible to viral infection than Ae. albopictus. The genetic differentiation was less high between Ae. albopictus populations collected in agglomerations connected by highly frequented roads, indicating that human ground transportation favors mosquito dispersal. These results have implications for the ecology, pattern of migration, and relative importance in epidemic transmission of dengue viruses between the 2 Aedes species.
High prevalence and seasonality of cryptosporidiosis in a small rural village occupied predominantly by aged people in the Republic of Korea.
Authors: Chai J Y , Kim N Y , Guk S M , Park Y K , Seo M , Han E T , Lee S H
Published: May 2017

The prevalence of Cryptosporidium parvum infection and its seasonality were studied in a small rural village occupied predominantly by aged people in Hwasun-gun, Chollanam-do, Republic of Korea. Fecal samples were collected monthly from November 1996 to October 1997 and examined for enteric parasites. To detect oocysts of C. parvum, the modified acid-fast stain was applied. To determine effects of climatic factors, local weather reports were collected. The overall oocyst prevalence during 1 year was 57.0% (77 of 135), and was significantly higher (P < 0.0001) in aged people--those aged 50-59 years (80.0%) and those aged 60-69 years (69.0%)--than in younger groups. No significant difference (P > 0.05) was noted between men and boys (53.6%) and women and girls (59.5%), but significant (P < 0.05) household clustering was recognized. People aged > 50 years tended to be more repeatedly positive than people in the younger group. The rate varied monthly from 7.8 to 20.0% (average, 12.6%), with significantly higher (P < 0.05) rates in spring than in summer and winter months. This seasonality had little relation with temperature (r = 0.04), but a weak correlation was found with rainfall (r = 0.4). It is of special interest that cryptosporidiosis is highly endemic among the aged population.
Risk factors for gametocyte carriage in Gambian children.
Authors: von Seidlein L , Drakeley C , Greenwood B , Walraven G , Targett G
Published: May 2017

A widespread reduction in Plasmodium falciparum gametocyte prevalence could reduce malaria transmission. After infection with P. falciparum, a variable proportion of people are found to be gametocytemic. We analyzed risk factors associated with gametocytemia at presentation and 7 days later. We enrolled 1,198 children in 2 antimalarial drug trials between September and December 1998. The children were assigned to 1 of 4 treatment groups: chloroquine only; pyrimethamine-sulfadoxine (PSD) only; PSD combined with 1 dose of artesunate; and PSD combined with 3 doses of artesunate. By the time of enrollment, 200 (17%) of 1,198 children were gametocyte carriers. Three independent risk factors were associated with gametocytemia at enrollment. Children with anemia were more likely to carry gametocytes, whereas children with fever (> 37.4 degrees C) or high parasite densities (> 100,000 parasites/microL) were less frequently gametocyte carriers. Children with at least 2 of the risk factors were 4 times more likely to be gametocytemic than children with < 2 risk factors (odds ratio [OR], 4.4; 95% confidence interval [CI], 2.7-7.1). Seven days after the start of treatment, 355 (37%) of 466 assessable children were found to be gametocyte carriers. Children treated with PSD alone had a significantly higher risk of being gametocytemic by Day 7 compared with children in the other 3 treatment groups. In the subgroup of children who had no detectable gametocytes on enrollment, the effect of treatment with PSD + 3 doses of artesunate was most marked. Nineteen (10%) of 198 children treated with PSD + 3 doses of artesunate became gametocytemic, in contrast to 184 (57%) of 321 children treated with PSD alone (OR, 12.7; 95% CI, 7.3-22.1). Early treatment with highly effective antimalarial therapy has the greatest chance of preventing gametocytemia. The choice of a first-line antimalarial drug for uncomplicated malaria should not only take into consideration the ablation asexual parasitemia but also the suppression of gametocytemia.
Canine surveillance system for Lyme borreliosis in Wisconsin and northern Illinois: geographic distribution and risk factor analysis.
Authors: Guerra M A , Walker E D , Kitron U
Published: May 2017

A seroprevalence survey for Borrelia burgdorferi was conducted among the healthy canine pet population in selected counties of Wisconsin and northern Illinois to determine the distribution of Lyme disease and associated risk factors. Information obtained for each dog included place of residence, Lyme disease vaccination status, history of travel and tick exposure, signalment, and medical history. Serum samples were screened by enzyme-linked immunosorbent assay and confirmed by an immunoblot procedure. Seroprevalence by county ranged 0-40%, with the highest estimates from west-central Wisconsin. The spatial pattern was significantly correlated with human incidence of Lyme disease and with abundance of the tick vector, Ixodes scapularis. A geographic information system (GIS) was used to integrate environmental data with the location of the residences of the dogs to determine environmental risk factors. Seropositivity among dogs was positively associated with increased tick exposure and time spent outdoors and negatively associated with vaccination against Lyme disease. Seropositivity was also associated with living in forested and urban areas, and on sandy, fertile soils. A canine surveillance system is a useful method for assessing the geographic distribution of Lyme disease, and in combination with a GIS, it can be effective in determining environmental factors associated with I. scapularis endemicity.
Detection of Leishmania causing visceral leishmaniasis in the Old and New Worlds by a polymerase chain reaction assay based on telomeric sequences.
Authors: Chiurillo M A , Sachdeva M , Dole V S , Yepes Y , Miliani E , Vazquez L , Rojas A , Crisante G , Guevara P , AÃ±ez N , Madhubala R , RamÃ­rez J L
Published: May 2017

We present a new polymerase chain reaction assay based on telomeric sequences of Leishmania donovani. When this assay was used in dilutions of purified L. donovani DNA, a strong amplification signal was observed with 1 fg of DNA. In a specificity test that used purified DNA from Old World and New World Leishmania, the assay recognized all parasites isolated from patients with visceral leishmaniasis, except for 2 isolates of Leishmania colombiensis from Venezuela and 1 isolate from Brazil. All Leishmania major and Leishmania tropica isolates tested were negative, except for one isolate in each species. We also used the assay on fresh and archive bone marrow samples recovered from Giemsa-stained slides and from dried blood stains.
Identification of cryptic coinfection with Plasmodium falciparum in patients presenting with vivax malaria.
Authors: Mayxay M , Pukritrayakamee S , Chotivanich K , Imwong M , Looareesuwan S , White N J
Published: May 2017

In Thailand, approximately 8% of patients treated for vivax malaria are found subsequently to have coinfection with Plasmodium falciparum. A P. falciparum histidine rich protein 2 (PfHRP-2) dipstick test was evaluated as a predictor of mixed infections with subpatent P. falciparum in a prospective study of 238 patients admitted to the hospital with acute vivax malaria. Of these, 23 (10%) had subsequent development of falciparum malaria without reexposure. Patients with cryptic P. falciparum infection had a significantly lower mean (standard deviation) hematocrit than those with P. vivax alone: 29.6 (7.6%) versus 37.2 (6.4%) (P < 0.0001). Using microscopic appearance of P. falciparum after the start of treatment as the reference standard, the PfHRP-2 test was 74% sensitive and 99% specific in predicting mixed infections with subpatent P. falciparum parasitemia at presentation. The PfHRP-2 dipstick test may be a useful adjunct to microscopy in areas where mixed infections are common.
Virulence and viremia characteristics of 1992 epizootic subtype IC Venezuelan equine encephalitis viruses and closely related enzootic subtype ID strains.
Authors: Wang E , Bowen R A , Medina G , Powers A M , Kang W , Chandler L M , Shope R E , Weaver S C , _ _
Published: May 2017

Following a 19-year hiatus, Venezuelan equine encephalitis (VEE) reemerged in western Venezuela in December 1992. This outbreak is important in understanding VEE emergence because phylogenetic studies imply that sympatric, enzootic, subtype ID VEE viruses mutated to generate the epizootic/epidemic. Although the 1992-1993 strains belong to subtype IC, a serotype implicated in extensive outbreaks during the 1960s and in 1995, relatively small numbers of human and equine cases occurred in 1992-1993. We, therefore, evaluated the pathogenicity of these Venezuelan enzootic ID and epizootic IC viruses to determine 1) if they exhibit phenotypes like those described previously for more distantly related enzootic and epizootic strains, and 2) if the 1992-1993 outbreak was limited by the inability of these IC viruses to exploit equines as amplification hosts. All strains were virulent in mice and guinea pigs, but were benign for cotton rats, natural hosts of enzootic viruses. However, only the IC strains produced equine disease, with mean peak viremias of 10(5) suckling mouse 50% lethal doses per mL serum, and some titers exceeding 10(7). These viremias approximate those observed previously with VEE strains isolated during more extensive epizootics, suggesting that efficient equine amplification did not limit the scope and duration of the 1992-1993 outbreak. Enzootic ID virus infection protected all horses from challenge with epizootic strain P676, supporting the hypothesis that epizootics bypass regions of enzootic transmission due to natural immunization of equines by enzootic VEE viruses.
Association of helminth infections with increased gametocyte carriage during mild falciparum malaria in Thailand.
Authors: Nacher M , Singhasivanon P , Silachamroon U , Treeprasertsu S , Krudsood S , Gay F , Mazier D , Looareesuwan S
Published: May 2017

The objective of this study was to determine whether pre-existing helminth infections could affect sexual forms of Plasmodium falciparum. A cross-sectional case record study compared 120 mild P. falciparum malaria cases with patent gametocyte carriage and 187 without gametocytes for helminth exposure. Relevant crude odds ratios and potential confounders were included in a logistic regression model. Helminth infections were associated with the presence of gametocytes with a crude odds ratio of 1.9 (95% confidence interval = 1.1-3.3) (P = 0.01). A positive linear trend was observed between the odds of having patent gametocytemia and the number of different helminth species (P = 0.003). However, when adjusting for hemoglobin concentration the significance of the association between helminths and gametocytes disappeared (P = 0.15). Pre-existing helminth infections may increase the severity of malarial anemia and therefore increase the likelihood of carrying gametocytes. At a population level, helminth infections may thus have a significant influence on malaria transmission.
Endemic infectious diseases and biological warfare during the Gulf War: a decade of analysis and final concerns.
Authors: Hyams K C , Riddle J , Trump D H , Graham J T
Published: May 2017

Infectious diseases were one of the first health threats confronted by Coalition troops deployed to the Arabian desert in August 1990. On the basis of experiences in World War II, the major endemic infectious disease risks were thought to be sandfly fever, cutaneous leishmaniasis, diarrheal disease, and malaria. Although there was active surveillance, no case of sandfly fever and few other endemic infectious diseases were identified among over 500,000 U.S., British, and Canadian ground troops. In addition, there was no diagnosis of biological warfare (BW) exposure, and BW agents were not detected in clinical, environmental, or veterinary samples. The most common infectious disease problems were those associated with crowding (acute upper respiratory infections) and reduced levels of sanitation (travelers-type diarrhea). Only one endemic infectious disease has been confirmed as causing chronic health problems: visceral Leishmania tropica infection (viscerotropic leishmaniasis). However, this protozoan infection was diagnosed in only 12 U.S. veterans, and no new cases have been identified during the last 8 years. Infectious diseases were not a serious problem for Gulf War troops because of extensive preventive medicine efforts and favorable weather and geographic factors. Moreover, it is unlikely that an endemic infectious disease or a BW agent could cause chronic health problems and remain undetected over a 10-year period.
A safe, effective, herbal antischistosomal therapy derived from myrrh.
Authors: Sheir Z , Nasr A A , Massoud A , Salama O , Badra G A , El-Shennawy H , Hassan N , Hammad S M
Published: May 2017

Schistosomiasis is a widespread helminthic disease. Treatment of schistosomiasis is based on chemotherapy with praziquantel, which is the drug of choice. Since resistance to praziquantel has been demonstrated, alternative drugs must be considered. Myrrh is an oleo-gum resin from the stem of the plant Commiphora molmol. This study was carried out on 204 patients with schistosomiasis. The drug was given at a dose of 10 mg/kg of body weight/day for three days, and induced a cure rate of 91.7%. Re-treatment of cases who did not respond with a dose of 10 mg/kg of body weight/day for six days gave a cure rate of 76.5%, increasing the overall cure rate to 98.09%. The drug was well tolerated, and side effects were mild and transient. Twenty cases provided biopsy specimens six months after treatment and none of them showed living ova.