More on Zika

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Last week I touched on the “epidemic” caused by the Zika virus and the WHO. This came about after the World Health Organization (WHO) chaired a meeting to assess the level of threat. 18 experts and advisers looked in particular at the strong association, in time and place, between infection with the Zika virus and a rise in detected cases of congenital malformations and neurological complications. The experts agreed that a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, though not yet scientifically proven. All agreed on the urgent need to coordinate international efforts to investigate and understand this relationship better.

I pointed out last week that this resulted in one of these where the WHO is sliding down a knife edge, as if the microcephaly issue turns out not to be a Zika effect, the WHO becomes accused of scaremonger tactics for having brought attention to it. If however it is shown to be a vector in the condition, the WHO becomes accused of not giving the world enough of a warning! Damned if you do and Damned if you don’t.

The Center for Disease Control (CDC) now recommends that all pregnant women consider postponing travel to areas in which the transmission of the Zika virus remains active. The infection is currently most prevalent in Central America and South America.

Aedes aegypti mosquitoes bite mostly during the daytime. Persons who must travel to areas of active Zika infections should practice advanced mosquito prevention strategies. The authors note that insect repellants containing DEET, picaridin, and IR3535 are safe to use during pregnancy.

Healthcare providers should query all pregnant women about recent travel. However, only symptomatic women with symptoms within 2 weeks of travel should be tested for infection with the Zika virus. These women should be evaluated for dengue and chikungunya virus as well.

There are no commercially available tests for the Zika virus infection. Available tests use RT-PCR technology as well as antibody testing. State and local health departments may be necessary to help interpret test results.

Fetal ultrasonography should be ordered regardless whether the test result for the Zika virus is positive among symptomatic women. Ultrasonography should also be performed among asymptomatic women with a history of travel to areas of active Zika virus infection.

If microcephaly or intracranial calcifications are present on fetal ultrasound, women should have the option to undergo amniocentesis and counseling. The Zika virus can be isolated from amniotic fluid, but the sensitivity and specificity of this testing are unknown.

If results on fetal ultrasonography are normal in a woman with a positive test result for the Zika virus, the clinician and patient should consider serial fetal ultrasounds every 3 to 4 weeks to monitor fetal anatomy and growth.

Any positive test result for the Zika virus should prompt a referral to a maternal-fetal medicine specialist or an infectious disease specialist with expertise in pregnancy.

After delivery in a case of maternal Zika virus infection, the placental and cord tissue and cord serum should be tested for the Zika virus. The CDC is developing guidelines for the management of infants infected with the Zika virus.

There is no treatment for infection with the Zika virus beyond supportive care.

Approximately 80 percent of individuals infected with the Zika virus remain asymptomatic. The duration of symptoms is usually less than 1 week in the remainder of infected patients, and hospitalization and mortality are rare with Zika infection.

The current guidelines by the CDC suggest that pregnant women avoid travel to areas of active Zika virus infection. For those individuals who must travel to such areas, insect repellants can be safe during pregnancy. Women who return from areas of active Zika virus infection should undergo fetal ultrasonography to detect cranial abnormalities, but only symptomatic women and women with abnormal ultrasound findings should undergo serologic testing for the Zika virus.

Travel history is not typically at the forefront of issues in completing the history of prenatal patients, but the potentially devastating effects of the Zika virus infection mean that the healthcare team should be actively searching for at-risk patients.

The above is again jumping the gun – it has not yet been proved there is a causal relationship!