Aedes species mosquito

Reports from Florida are suggesting that local mosquitoes may have transmitted the Zika virus to two people. This is a new development that, if confirmed, validates the CDC’s prediction that local cases will be seen in warm weather states this summer.

As of July 20th, 46 states have reported more than 1400 cases of Zika infection, until now all travel-related. In the U.S. territory of Puerto Rico, however, there are almost 4000 cases, almost all locally-transmitted.

Although Zika poses the most risk to pregnant women and their fetuses, the virus continues to defy expectation as new and unusual cases mount. The viral disease, transmitted by Aedes mosquitoes, can attack brain and other nerve cells in fetuses, leading to microcephaly and other abnormalities  in growth and development. Zika has also been associated with nerve disorders in humans, including the paralysis-inducing Guillain-Barre Syndrome.

Investigators are trying to determine if two cases of Floridians with Zika virus were transmitted by local mosquitoes. In each case, there doesn’t seem to be a history of travel to the epidemic zone. Little is known, as of yet, of the Florida cases, other than their origin in the southern part of the state. Florida is a state particularly hard hit due to the favorable climate for Aedes mosquitoes. NYC, with its large Latin/Caribbean population and many visitors, is another area with a large number of cases.

While the major concern with Zika virus is its effect on the developing fetus, new cases are leading some to question what we really know about the virus. Rare, at least at present, they suggest that more people may be at risk than originally thought.

The CDC reports that, in New York City, a woman who contracted Zika during a trip to the epidemic zone has infected her male partner through sexual intercourse. Previously, Zika was seen as a purely male-to-female or male-to-male transmission. Now it’s possible that vaginal fluids might have the same ability as semen to spread the virus. If a female can also transmit the infection sexually, it widens the population at risk significantly.

For example, a woman travels to Brazil, gets Zika, and transmits it, through vaginal secretions, to her partner when she arrives home. Her partner has sex with others and transmits it through, say, seminal fluid.

Although Zika virus lasts only a short time in the blood, it’s thought that Zika virus exists in seminal fluid for 2 months or more due to what is termed “immune privilege”. Certain organs, like the testes, are relatively immune to your body’s defense mechanisms. This protection works to preserve the ability to reproduce but allows some viruses to “hide” there. What, however,  if it lasts longer?

What if Zika virus lasts longer than two months in seminal fluid? Ebola virus lasts 6 months or more there. Is even six months long enough to avoid sex or use protection? We don’t know.

In Utah, an elderly man dies of complications due to Zika virus. Was there some other medical issue that made it a fatal event? He was found to have more than 100,000 times the usual amount of virus in his system. Why? Did he get a particularly bad strain? How many strains are there? Zika is certainly acting differently here than in Africa, where there was no obvious trend towards birth defects (there were, however, some affected newborns in French Polynesia). Did Zika mutate, like viruses often do?

Now, The New York Times and others report that a family caregiver of the Utah man is found to have been infected. How did it happen? Exposure to blood? Air-borne droplets? Handling the bedpan? No one really knows.

Does this now mean that we have to treat the virus as contagious by casual contact between humans, as opposed to requiring an infected mosquito bite or intimate relations? Should we, then, revamp our contagion protocols for medical professionals?

Recently, CNN reported that researchers in Brazil has found Zika in local Culex mosquitoes, a more common species than Aedes. The Culex mosquito can live in temperate climates. Are more northern U.S. states at risk? We don’t know.

All this may seem like paranoia. Zika doesn’t even cause symptoms in 80% of cases, and most infected babies are born without microcephaly. But the fact that it’s a “silent” infection in many might be the most concerning aspect of the infection.

A pregnant woman with an asymptomatic Zika infection won’t know her fetus is affected until ultrasounds tests reveal poor growth of the fetal head or other signs of damage. An asymptomatic male or female won’t know bodily fluids are contaminated and may spread the disease through sexual relations.

Here’s another question: Are there long-term effects of Zika virus on the development of infected but otherwise normal-appearing babies? We won’t know until milestones, like walking and talking, are delayed or fail to be reached. How many millions of dollars will be needed to test and, perhaps, provide care for the effects? The answer might not be known for years.

Zika is not Ebola. People aren’t dropping dead in the streets, so a calm, reasoned approach to this virus is important.

We have much to learn about Zika virus. Funds are needed to study it, develop vaccines, and aid efforts at mosquito control in communities at risk. Partisan bickering, however, has slowed needed appropriations that might make a difference in the spread of the epidemic disease.

We can’t allow politics to “infect” the Zika debate. Politicians should support the researchers that are trying to make sure that this mysterious disease doesn’t become a medical crisis in the U.S., now or in the future.

It may already be too late to avoid the complications of Zika Virus in the U.S. this summer. It is already an epidemic in Puerto Rico.  If we’re smart, though, we’ll facilitate the research needed to truly understand it and its short- and long-term effects.

Joe Alton MD is a disaster/epidemic preparedness expert and NYT/Amazon bestselling author of books in the genre, including “The Zika Virus Handbook”.

zika book cover

The Zika Virus Handbook