Zika Highlights Weaknesses In Public Health

This past week, Zika infections were also linked with more Guillain-Barré cases, a type of paralysis from an autoimmune reaction. Another neurologic bombshell was that Brazilian scientists have linked Zika with an autoimmune syndrome called acute disseminated encephalomyelitis, or ADEM, which causes symptoms mimicking multiple sclerosis. Zika seems to have an affinity for nerve cells (neurotropism), and has been linked with cases of encephalitis (brain inflammation) and myelitis (nerve inflammation) as well.

News about Zika keeps getting worse. First is growing evidence that Zika causes of the serious birth defect microcephaly (abnormally small brain and skull) and severe mental retardation. The CDC just announced their analysis that concludes Zika is the cause of many recent microcephaly cases, with CDC Director Dr. Thomas R. Frieden declaring, “There is no longer any doubt that Zika causes microcephaly.” He added, “Never before in history has there been a situation where a bite from a mosquito can result in a devastating malformation.” Studies supporting this conclusion were just published in the New England Journal of Medicine.

The final bit of recent bad news is that Zika is likely more often sexually transmitted than was previously believed. What was especially striking is that “semen had 630,914 times more ZIKV RNA in it than serum (316,209 times more than urine)–two weeks later! And in addition to the detection of viral RNA, infectious ZIKV could be isolated using cell culture of the semen sample,” as virologist Ian Mackay explains.

Zika is also again highlighting that politics trumps rational public health policy, especially given the growing range of serious neurologic abnormalities in both the fetus and now adults. Zika shows huge weaknesses in our public health infrastructure and ability to respond to infectious disease threats, as well as illustrating our Congress’ priorities. For example, Maryn McKenna’s post highlights how fragmented the insect control efforts are, and the lack of coordination between jurisdictions. These threats go well beyond Zika, and are urgently problematic for other mosquito and tick-borne diseases as well.