The first cluster of microcephaly cases just outside Angola’s capital city was noticed in September of this year, marking nine months since tests in January had confirmed the virus in a sick adult, and in a stillborn infant with neurological defects. A WHO bulletin now says cases in the area had surfaced in May and June, contributing to a total, by the end of last month, of 42 cases — 39 among newborn babies, and three among stillborn infants.
Still with just 15 blood specimens collected from microcephalic newborns or their mothers, and all of those negative, officials can’t confirm that what they call “a gradually increasing number” of babies showing neurological defects is linked to Zika infection, although the virus has been confirmed to cause microcephaly as well as other severe nervous system damage. Otherwise, “no evidence” that the virus is being spread exists. And, because of limited surveillance and testing, they add that “the true magnitude of the event is not well understood.”
What health officials do know is that the negative test results don’t mean that mothers of the affected infants were not infected during pregnancy. They know that all of the cases have been found in areas outside the city that were most affected by the 2016 outbreak of yellow fever — a virus transmitted by the Aedes aegypti mosquito, which also transmits Zika, as well as Dengue and Chikungunya. They note needs for heightened surveillance, with emphasis on early detection, and on communication, education, and mosquito control. With 10 cases in November alone, the bulletin notes that microcephaly incidence “appears to be slowly but steadily rising” in Angola’s capital.