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## Complete Summary

#### GUIDELINE TITLE

Interim guidelines for the evaluation of infants born to mothers
infected with West Nile virus during pregnancy.

#### BIBLIOGRAPHIC SOURCE(S)

Interim guidelines for the evaluation of infants born to mothers
infected with West Nile virus during pregnancy. MMWR Morb Mortal Wkly
Rep 2004 Feb 27;53(7):154-7. \[6 references\]
[PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14985654)

#### GUIDELINE STATUS

This is the current release of the guideline.

### COMPLETE SUMMARY CONTENT

 SCOPE\
 METHODOLOGY - including Rating Scheme and Cost Analysis\
 RECOMMENDATIONS\
 EVIDENCE SUPPORTING THE RECOMMENDATIONS\
 BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS\
 QUALIFYING STATEMENTS\
 IMPLEMENTATION OF THE GUIDELINE\
 INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT
CATEGORIES\
 IDENTIFYING INFORMATION AND AVAILABILITY\
 DISCLAIMER

### SCOPE

#### DISEASE/CONDITION(S)

-   West Nile virus infection

-   Pregnancy

#### GUIDELINE CATEGORY

Evaluation\
Prevention

#### CLINICAL SPECIALTY

Family Practice\
Infectious Diseases\
Obstetrics and Gynecology\
Pediatrics

#### INTENDED USERS

Advanced Practice Nurses\
Nurses\
Physician Assistants\
Physicians

#### GUIDELINE OBJECTIVE(S)

To develop recommendations for evaluating infants born to mothers who
acquire West Nile virus infection during pregnancy

#### TARGET POPULATION

Infants born to mothers who acquire West Nile virus infection during
pregnancy

#### INTERVENTIONS AND PRACTICES CONSIDERED

**[Evaluation]{.underline}**

**Fetus**

1.  Ultrasound

2.  Amniotic fluid, chorionic villi, or fetal serum

**Infants Born to Mothers Who Were Infected During Pregnancy**

1.  Physical examination, including measurement of head circumference,
    length, weight, and assessment of gestational age

2.  Assessment for neurological abnormalities, dysmorphic features,
    splenomegaly, hepatomegaly, and rash or other skin lesion.
    Abnormalities photographed and specialist referral, if indicated

3.  Initial serum immunoglobulin M (IgM) and immunoglobulin G (IgG)
    testing from either the umbilical cord or directly from the infant
    within 2 days of birth

4.  Evaluation of hearing by evoked otoacoustic emissions testing or
    auditory brainstem response testing

5.  Referral to audiologist for infants with abnormal hearing screens

6.  Examination of the placenta by a pathologist

**Infants with Possible Congenital West Nile Virus (WNV) Infection**

1.  Computerized tomography (CT) scan of the head and brain and referral
    to a pediatric neurologist if indicated

2.  Pediatric ophthalmologic evaluation, including examination of the
    retina

3.  Complete blood count, platelet count, and liver function tests,
    including alanine aminotransferase and aspirate aminotransferase

4.  Examination of cerebrospinal fluid (CSF) and should include testing
    of CSF for IgM antibody to WNV

5.  Evaluation by a dysmorphologist or clinical geneticist

6.  Further evaluation of any congenital abnormalities to determine
    alternative causes, including genetic, infectious, or other
    teratogenic causes

7.  Additional hearing screen at age 6 months

8.  Careful evaluation of head circumference, physical characteristics,
    and developmental milestones throughout the first year of life

9.  Additional examination of infant serum for IgG and IgM antibody to
    WNV at age 6 months

10. Histopathologic examination of the placenta and umbilical cord,
    testing of frozen placental tissue and cord tissue for WNV nucleic
    acid, and testing of cord serum for IgM and IgG antibody to WNV

**[Prevention]{.underline}**

1.  Insect repellent

2.  Protective clothing

3.  Educate pregnant women to avoid outside at peak-mosquito time

#### MAJOR OUTCOMES CONSIDERED

Not stated

### METHODOLOGY

#### METHODS USED TO COLLECT/SELECT EVIDENCE

Searches of Electronic Databases

#### DESCRIPTION OF METHODS USED TO COLLECT/SELECT THE EVIDENCE

Not stated

#### NUMBER OF SOURCE DOCUMENTS

Not stated

#### METHODS USED TO ASSESS THE QUALITY AND STRENGTH OF THE EVIDENCE

Not stated

#### RATING SCHEME FOR THE STRENGTH OF THE EVIDENCE

Not applicable

#### METHODS USED TO ANALYZE THE EVIDENCE

Review

#### DESCRIPTION OF THE METHODS USED TO ANALYZE THE EVIDENCE

Not stated

#### METHODS USED TO FORMULATE THE RECOMMENDATIONS

Not stated

#### RATING SCHEME FOR THE STRENGTH OF THE RECOMMENDATIONS

Not applicable

#### COST ANALYSIS

A formal cost analysis was not performed and published cost analyses
were not reviewed.

#### METHOD OF GUIDELINE VALIDATION

Peer Review

#### DESCRIPTION OF METHOD OF GUIDELINE VALIDATION

Not stated

### RECOMMENDATIONS

#### MAJOR RECOMMENDATIONS

**Screening for West Nile Virus During Pregnancy**

No specific treatment for West Nile virus (WNV) infection exists, and
the consequences of WNV infection during pregnancy have not been well
defined. For these reasons, screening of asymptomatic pregnant women for
WNV infection is not recommended.

**Diagnosis of WNV Infection During Pregnancy**

Pregnant women who have meningitis, encephalitis, acute flaccid
paralysis, or unexplained fever in an area of ongoing WNV transmission
should have serum (and cerebrospinal fluid \[CSF\], if clinically
indicated) tested for antibody to WNV. If serologic or other laboratory
tests indicate recent infection with WNV, these infections should be
reported to the local or state health department, and the women should
be followed to determine the outcomes of their pregnancies.

**Evaluation of the Fetus in Pregnant Women with WNV Infection**

If WNV illness is diagnosed during pregnancy, a detailed ultrasound
examination of the fetus to evaluate for structural abnormalities should
be considered no sooner than 2 to 4 weeks after onset of WNV illness in
the mother, unless earlier examination is otherwise indicated. Amniotic
fluid, chorionic villi, or fetal serum can be tested for evidence of WNV
infection. However, the sensitivity, specificity, and predictive value
of tests that might be used to evaluate fetal WNV infection are not
known, and the clinical consequences of fetal infection have not been
determined. In case of miscarriage or induced abortion, testing of all
products of conception (e.g., the placenta and umbilical cord) for
evidence of WNV infection is advised to document the effects of WNV
infection on pregnancy outcome.

**Evaluation of Infants Born to Mothers Infected with WNV During
Pregnancy**

When an infant is born to a mother who was known or suspected to have
WNV infection during pregnancy, clinical evaluation is recommended.

-   Thorough physical examination, including careful measurement of the
    head circumference, length, weight, and assessment of gestational
    age

-   Evaluation for neurologic abnormalities, dysmorphic features,
    splenomegaly, hepatomegaly, and rash or other skin lesions. Any
    rash, skin lesions, or dysmorphic features should be photographed.
    If an abnormality is noted, consultation with an appropriate
    specialist is recommended.

-   Testing of infant serum for immunoglobulin M (IgM) and
    immunoglobulin G (IgG) antibody to WNV. The initial sample should be
    collected either from the umbilical cord or directly from the infant
    within 2 days of birth. If maternal WNV illness occurred
    [\<]{.underline}8 days before delivery and the initial infant serum
    sample is negative for WNV IgM antibody, a second infant serum
    sample should be obtained [\>]{.underline}2 weeks after the first
    sample. Free testing of samples by the Centers for Disease Control
    and Prevention (CDC) can be arranged by contacting state public
    health laboratories.

-   Evaluation of hearing by evoked otoacoustic emissions testing or
    auditory brainstem response testing, either before discharge from
    the hospital or within 1 month after birth. Infants with abnormal
    initial hearing screens should be referred to an audiologist for
    further evaluation.

-   Initial examination of the placenta by a pathologist is encouraged.
    Regardless of whether this is completed, the entire placenta, a
    sample of umbilical cord tissue, and a sample of serum from the
    umbilical cord should be retained for further evaluation if
    congenital WNV infection is identified or strongly suspected. A
    section of the placenta and umbilical cord should be frozen, and the
    remainder of the placenta should be preserved in formalin; a sample
    of umbilical cord blood should be centrifuged, and the serum should
    be refrigerated or frozen.

Further evaluation should be considered if any clinical abnormality is
identified or if laboratory testing indicates that an infant might have
congenital WNV infection\*.

-   Computerized tomography (CT) scan of the head and brain. If CT is
    abnormal, a pediatric neurologist should be consulted.

-   Pediatric ophthalmologic evaluation, including examination of the
    retina

-   Complete blood count, platelet count, and liver function tests,
    including alanine aminotransferase and aspartate aminotransferase.
    Examination of CSF should be considered and, if performed, should
    include testing of CSF for IgM antibody to WNV.

-   Evaluation by a dysmorphologist or clinical geneticist

-   Further evaluation of any congenital abnormalities to determine
    alternative causes, including genetic, infectious, or other
    teratogenic causes

-   Additional hearing screen at age 6 months

-   Careful evaluation of head circumference, physical characteristics,
    and developmental milestones throughout the first year of life

-   Additional examination of infant serum for IgG and IgM antibody to
    WNV at age 6 months

-   Histopathologic examination of the placenta and umbilical cord,
    testing of frozen placental tissue and cord tissue for WNV nucleic
    acid, and testing of cord serum for IgM and IgG antibody to WNV

\* The following laboratory results indicate possible congenital WNV
infection: 1) positive IgM to WNV in infant serum or cerebrospinal
fluid; 2) stable or increasing IgG to WNV in infant serum samples
obtained at delivery and at age 6 months; or 3) detectable WNV, WNV
nucleic acid, or WNV antigen in any infant clinical sample.

**Prevention of WNV Infection During Pregnancy**

Pregnant women who live in areas with WNV-infected mosquitoes should
apply insect repellent to skin and clothes when exposed to mosquitoes
and wear clothing that will help protect against mosquito bites. In
addition, whenever possible, pregnant women should avoid being outdoors
during peak mosquito-feeding times (i.e., usually dawn and dusk).

#### CLINICAL ALGORITHM(S)

None provided

### EVIDENCE SUPPORTING THE RECOMMENDATIONS

#### TYPE OF EVIDENCE SUPPORTING THE RECOMMENDATIONS

The type of supporting evidence is not specifically stated for each
recommendation.

### BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS

#### POTENTIAL BENEFITS

Effective evaluation of infants born to mothers infected with West Nile
virus during pregnancy

#### POTENTIAL HARMS

Not stated

### QUALIFYING STATEMENTS

#### QUALIFYING STATEMENTS

Use of trade names and commercial sources is for identification only and
does not imply endorsement by the United States Department of Health and
Human Services.

### IMPLEMENTATION OF THE GUIDELINE

#### DESCRIPTION OF IMPLEMENTATION STRATEGY

An implementation strategy was not provided.

### INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES

#### IOM CARE NEED

Getting Better\
Staying Healthy

#### IOM DOMAIN

Effectiveness

### IDENTIFYING INFORMATION AND AVAILABILITY

#### BIBLIOGRAPHIC SOURCE(S)

Interim guidelines for the evaluation of infants born to mothers
infected with West Nile virus during pregnancy. MMWR Morb Mortal Wkly
Rep 2004 Feb 27;53(7):154-7. \[6 references\]
[PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14985654)

#### ADAPTATION

Not applicable: The guideline was not adapted from another source.

#### DATE RELEASED

2004 Feb 27

#### GUIDELINE DEVELOPER(S)

Centers for Disease Control and Prevention - Federal Government Agency
\[U.S.\]

#### SOURCE(S) OF FUNDING

United States Government

#### GUIDELINE COMMITTEE

Not stated

#### COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

Not stated

#### FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

Not stated

#### GUIDELINE STATUS

This is the current release of the guideline.

#### GUIDELINE AVAILABILITY

Electronic copies: Available from the Centers for Disease Control and
Prevention (CDC) Web site:

-   [HTML Format](http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5307a4.htm)

-   [Portable Document Format
    (PDF)](http://www.cdc.gov/mmwr/PDF/wk/mm5307.pdf)

Print copies: Available from the Centers for Disease Control and
Prevention, MMWR, Atlanta, GA 30333. Additional copies can be purchased
from the Superintendent of Documents, U.S. Government Printing Office,
Washington, DC 20402-9325; (202) 783-3238.

#### AVAILABILITY OF COMPANION DOCUMENTS

None available

#### PATIENT RESOURCES

None available

#### NGC STATUS

This NGC summary was completed by ECRI on June 4, 2004.

#### COPYRIGHT STATEMENT

No copyright restrictions apply.

### DISCLAIMER

#### NGC DISCLAIMER

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© 1998-2008 National Guideline Clearinghouse

Date Modified: 11/10/2008