Dr. Ronald Sacher is a professor of internal medicine and pathology at the University of Cincinnati College of Medicine and director of the Hoxworth Blood Center.
The Zika virus was first isolated in 1947 in the Zika Forest in Uganda. There is a history of Zika cases in some parts of Africa and Asia, but it is becoming more widely known now because of this outbreak in Brazil. The specific virus category is the flavivirus and it is spread by way of the bite of an infected mosquito. This same variety of mosquito is also known to transmit other viruses in the same category, particularly dengue and yellow fever.
The Zika virus produces an illness that is generally very, very mild and is associated with headaches, malaise, joint pains, a rash and occasionally some vomiting. Sometimes these symptoms are mistaken for a flu-like illness.
The biggest risk from Zika is in pregnant women who have babies who develop microcephaly, which is a brain disorder where the top part of the brain does not develop and as a result, the head of the baby doesn’t mold properly. Strong circumstantial evidence exists linking the virus and the development of microcephaly and some other pregnancy-related issues. The highest risk for pregnant women is in the first trimester of pregnancy.
There are anecdotal reports of Zika being transmitted by sexual intercourse, but those reports are still being evaluated.
From a general public health point of view, there have been no reported cases of death attributed to Zika. That’s in contrast to other viruses in the same category that have been transmitted by the same mosquito, like the dengue virus.
The Best Defense
For people traveling to areas where the Zika virus is prevalent, the key thing is to protect oneself against mosquito bites. Well-known entomologists have validated that repellents with at least 25 percent DEET have been effective in repelling mosquitos, as has Picaridin, a repellent with more natural ingredients.
Picaridin is what I’m going to use when I go to Brazil later this month.
From a local prevention standpoint, public health authorities and physicians should take a travel history particularly in individuals who show symptoms of a flu-like illness. This should then be reported to the Department of Health and those people should be tested for the presence of the virus. There needs to be ongoing surveillance. Surveillance is the most important thing.
Hoxworth Takes Precautions
From the point of view of my position as the director of the Hoxworth Blood Center, there’s no evidence that Zika has been transmitted by a blood transfusion. But in the abundance of caution, Hoxworth is excluding individuals who have traveled to one of the affected areas for at least 30 days after their return from those areas. This is in line with recommendations from the national blood banking organizations.
In summary, people need to be vigilant. There needs to be ongoing surveillance by health authorities and medical practitioners who should take a good travel history, especially in individuals who show a flu-like illness, and then follow a procedure to report it to public health authorities and have the individual tested. Individuals going to affected areas should be prudent and use mosquito repellents. Women who are pregnant should avoid travel to endemic areas.