By Jessica Mondani, DO
In early 2015, an outbreak of Zika virus was identified in northeast Brazil. Zika virus is transmitted primarily by Aedes aegypti mosquitoes. Aedes albopictus mosquitoes might also transmit the virus. Both mosquitoes are found throughout much of the Americas, including parts of the United States, and also transmit dengue and chikungunya viruses. Please see map of highlighted affected areas.
In addition to mosquito-to-human transmission, Zika virus infections have been documented through intrauterine transmission resulting in congenital infection, intrapartum transmission from a viremic mother to her newborn, sexual transmission, blood transfusion and laboratory exposure.
An estimated 80% of persons who are infected with Zika virus are asymptomatic. Symptomatic disease generally is mild and characterized by acute onset of fever, maculopapular rash, arthralgia or nonpurulent conjunctivitis. Symptoms usually last about one week. No specific antiviral treatment is available for Zika virus disease. Treatment is generally supportive and can include rest, fluids, and use of analgesics and antipyretics. So, if severe disease is uncommon and fatalities are rare, then why are the CDC, WHO, and PAHO posting travel alerts?
In September 2015, health authorities began to receive reports from physicians in Brazil of an increase in the number of infants born with microcephaly. During an investigation, a link between maternal Zika virus infection during pregnancy and fetal and newborn microcephaly was found. So far, a small cohort of 35 microcephalic infants born to mothers living in or visiting Zika virus affected areas is being closely evaluated. Other congenital infections that cause microcephaly have been ruled out. Cerebral spinal fluid has been collected from these patients for Zika virus testing, but results are not yet available. A task force to investigate the possible association of microcephaly with Zika virus infection during pregnancy has been established and will continue to monitor ongoing cases of infant microcephaly. While the investigation is ongoing, many health organizations have posted travel warnings and prevention measures for women who may become pregnant, pregnant women, and lactating women.
Our responsibility is to educate at-risk women planning travel to areas in which Zika virus transmission is being reported. Because there is neither a vaccine nor prophylactic medications available to prevent Zika virus infection, the CDC recommends that all pregnant women consider postponing travel to areas where Zika virus transmission is ongoing. If a pregnant woman travels to an area with Zika virus transmission, then preventative measure should be strictly observed. Mosquitoes that spread Zika virus bite both indoors and outdoors, are aggressive daytime biters, but also bite at night. Wearing long-sleeved shirts and long pants, using an Environmental Protection Agency (EPA)–registered insect repellent, using permethrin-treated clothing and gear, and staying and sleeping in screened-in or air-conditioned rooms can help protect people traveling through these areas.
Healthcare providers should ask all pregnant women about recent travel. Pregnant women with a history of travel to an area with Zika virus transmission and who report two or more symptoms consistent with Zika virus disease during or within two weeks of travel, or who have ultrasound findings of fetal microcephaly or intracranial calcifications, should be tested for Zika virus infection in consultation with their state or local health department.