On February 1, 2016, the World Health Organization (WHO) declared Zika virus a health emergency of international concern, and a week later, the U.S. Centers for Disease Control and Prevention (CDC) elevated its response to the highest level 1. WHO estimates that 4 million people will be infected with Zika virus this year alone, and 30 countries have reported confirmed transmitted cases of Zika virus in the last 9 months, with that number increasing regularly. So what mortality risk does Zika virus carry in underwriting, and how concerned should we be?
Zika virus is a single stranded RNA virus transmitted by mosquitoes. It belongs to a family of viruses called flavavirus, which is known for producing other diseases such as yellow fever, West Nile virus, dengue and encephalitis. It is named after a forested area in Uganda, and is not a new virus—cases have been identified since the 1950s. Originally limited to Asia and Africa, 2014 saw the first case that was found in the Western Hemisphere. In May 2015, dramatic increases of Zika virus transmission were found in Brazil, and now most countries in South and Central America and the Caribbean report multiple cases.
While commonest in contact with affected carrying mosquitoes, Zika virus now is known to have multiple routes of transmission. These include sexual intercourse, blood transfusions, and in what has become the most alarming finding, mother to child transmissions. In Brazil, reported cases of fetal microcephaly (small head) expanded ten-fold in the second half of 2015. Although Zika virus can be transmitted through breast milk, no known transmission through breastfeeding has been documented at this time.
Most Zika virus transmissions in adults have little to no symptoms. The illness in those who contract the virus is generally mild and self-limited, and most manifestations (like with any other common virus) are gone within seven days. The most common serious manifestations are fever, headache and rash. More recent investigation is now appearing to confirm a link between Zika infection and the neurologic Guillain-Barre syndrome in adults. The reported incidence of this in Zika predominant regions is up to five times the normal occurrence.
The most serious consequences of Zika virus are currently amongst newborn children. Besides a higher rate of miscarriage in pregnant women with the virus, the diagnosis of microcephaly has been well documented. Affected children have a very small brain, lack of development of the brainstem, abnormally defined cerebral structures, and malformations in the spinal cord. The long term effects on these children are obviously quite ominous and will be borne out in years ahead.
At the moment there is no treatment for Zika virus, either in an affected adult or child. In adults the disease is self-limiting, and recovery even in more symptomatic cases is usually complete. The effects on children affected by Zika virus in utero are generally evident at the time of underwriting. Applicants from endemic areas who are attempting to insure children should have evidence from an APS of an unaffected child with normal growth milestones. No vaccine is yet available against Zika virus, but progress is being made toward that end and hopes for one by year end are promising.
