Epidemiology. The MTCT can occur with West Nile virus but appears to be rare. Although the data is limited, the CDC recorded pregnancy outcome of 77 women infected with West Nile virus from 2003 to 2004 in the United States. Three of the 72 infants followed had symptomatic West Nile disease.
Clinical manifestation
Maternal. Most infected individuals are asymptomatic. After an incubation period of 2 to 14 days, symptoms such as fatigue, weakness, myalgia, memory impairment, and balance issues may manifest. A morbilliform or maculopapular rash may be present. It tends to appear at the time of defervescence. More worrisome manifestations of West Nile virus include meningitis, encephalitis, or paralysis. Ophthalmic manifestation includes chorioretinitis, vitreitis, and retinal hemorrhage.
Congenital. Although there is some evidence that MTCT can occur with West Nile virus, there is no documented evidence of fetal abnormalities associated with maternal infection.
Diagnosis. Pregnant women with meningitis, encephalitis, paralysis, or inexplicable fever in West Nile endemic areas should have testing for IgM antibody to West Nile virus. Cerebrospinal fluid should also be tested in the presence of neurologic or ophthalmic symptoms.
Management
The mainstay of management is supportive. There is no clear evidence of invasive fetal testing.
Screening in asymptomatic pregnant women is not recommended.
Prevention. Protect from mosquito bites by wearing protective clothing outdoors and using DEET-containing insect repellents.
Epidemiology
Whereas Zika virus is primarily transmitted by mosquito bites, it can also be transmitted transplacentally and by sexual contact, blood transfusion, and organ transplantation.
Zika virus is currently endemic in Africa, Southeast Asia, and the Pacific Islands. As the outbreak pattern is dynamic, the most current geographical distribution of Zika virus may be viewed at the CDC's Web site on Zika: https://www.cdc.gov/zika/geo/index.html.
Clinical manifestation
Maternal. Symptoms include fever, pruritic rash (erythematous maculopapular rash in the face, extremities, and trunk), joint pain, myalgia, and conjunctivitis. Guillain-Barré syndrome has also been associated with Zika virus infection.
Congenital. Congenital Zika syndrome may be identified in the fetuses/neonates of a subset of mothers infected with Zika virus. Microcephaly, other CNS abnormalities such as ventriculomegaly, intracranial calcifications, atrophy or hypoplasia of cerebral tissue, fetal growth restriction, miscarriage, stillbirth, and hydrops fetalis all have been documented.
Diagnosis
All pregnant women should be screened for possible Zika virus exposure by inquiring about recent travel or sexual contact with a person who traveled to or lives in an area with ongoing Zika transmission.
Testing guidance has been updated frequently because more data are available regarding the current epidemic. The testing algorithms can be found at https://www.cdc.gov/pregnancy/zika/testing-follow-up/testing-and-diagnosis.html.
Management
Management focuses on symptomatic support consisting of hydration and antipyretic.
It is important to note that nonsteroidal anti-inflammatory drugs should be avoided until dengue infection has been ruled out, in order to reduce the risk of hemorrhage.
Prevention
Travel. The current CDC recommendation is for pregnant women to avoid traveling to areas where Zika virus is ongoing. The most current travel advisory data can be found on the CDC's Web site: https://wwwnc.cdc.gov/travel/page/world-map-areas-with-zika.
Mosquito bite prevention. It is recommended that women in endemic areas wear clothes that provide coverage of arms and legs. In addition, they should wear DEET-containing insect repellents.
Sexual. It is recommended that women in endemic areas use barrier protection if sexually active. The World Health Organization also recommend that individuals who have travelled to endemic areas abstain from sex for at least 3 months before engaging in unprotected sex regardless of presence of symptoms.