Zika update: Should I be concerned in Pa.?

It has been over a year since reports of complications of microcephaly in neonates born from Zika infected mothers began to appear in the Americas. Since then, Guillain Barre-syndrome, a paralyzing autoimmune disease has also been associated with mosquito borne Zika virus infections. These two major complications led the World Health Organization to issue a "public health emergency of international concern" in February this year. But what has happened to Zika virus infections since then, and what have learned that can help us treat or prevent the sometimes devastating consequences of infection?

Zika virus disease was first reported in Africa, but only sporadic cases were described until 2014, when the virus was tracked to migrate from Africa to the South Pacific and finally to the Americas. Brazil is the largest country in which a Zika epidemic has been reported. Indeed, so far, there are now approximately 50 countries that have reported active transmission of Zika virus, mostly in the Americas. There have been millions of documented cases of infection, and there have been thousands of cases of microcephaly and hundreds of cases of Guillain-Barre syndrome reported to this date.

As you know, intraunterine transmission of Zika virus infection from a pregnant woman to her fetus has been documented. Before or after birth transmission can also occur. One study determined that neonates are most susceptible to microcephaly when the mother is infected during the first trimester or earlier in pregnancy.

Zika virus in children and adults usually causes a mild illness characterized by low grade fever, pink eye, arthralgias (a type of joint pain), and skin rash. Recently, a case of uveitis, an inflammation of the middle layer of the eye, was reported in a 40 year old man who contracted Zika-virus infection.  Another report of probable transfusion transmitted infection was reported to have occurred in Brazil.

Are there recommendations for local pregnant women?

Women in the Philadelphia area who are pregnant are advised not to travel to Zika infected areas. They are also cautioned against having sexual intercourse with individuals who have returned from Zika infected areas. This is because Zika infection has been found to be passed along through sexual transmission.

If a pregnant woman from Philadelphia has no choice but to travel to a Zika infected area, then the proper precautions to avoid mosquito bites should be adhered to, including wearing light colored clothing and covering up arms and legs, avoiding standing water, using the appropriate mosquito repellants and using mosquito nets, air-conditioning and closing windows at night.

With regard to the Aedes Aegypti mosquito, the primary vector of transmission of Zika virus, it was originally believed that this mosquito did not live in such northern climates as Pennsylvania. However, a recent map from the Centers for Disease Control and Prevention indicates that these mosquitoes may be present in a limited area in the South Eastern part of Pennsylvania. While these areas are not highly populated with the Aedes Aegypti mosquitoes, those who pregnant in these areas should take the above precautions to avoid mosquito bites.

What are the concerns with Rio de Janiero Olympic Games?

With the rapid approach of the Olympic Games, which go from August 5-21, along with the paraOlympic games which go from September 7-18, there is obviously concern about travel to Brazil. The latest CDC recommendations are for pregnant women not to travel to the Olympics, and if they must, then to take precautions to avoid mosquito bites. Moreover, the CDC recommends that women who are pregnant and their male partners refrain from sexual intercourse. Epidemiologists have calculated that the chance of contracting Zika virus while traveling to Brazil this summer (winter in Brazil) is low, though not impossible. Several Olympic athletes have already said that they would not participate in the Games because of fears of Zika virus infection, but it is unclear if there are other motivating factors for the choices of these few individuals.

What else should I know?

New recommendations from the CDC regarding breast feeding are based on detection of Zika virus in breast milk.  However, Zika virus infection transmitted through breast feeding has not yet been reported. The CDC encourages mothers who have Zika virus infection and those living in areas with active infection continue to breast feed their infants, as the benefits of breast feeding outweigh the potential risk of transmission of Zika virus through breastfeeding.

There is still no vaccine for Zika virus. The bottom line is that there is still much to learn about the virus – such as why only some neonates develop microcephaly, and what kind of immunity one acquires after infection. The guidelines for when to perform diagnostic testing in adults and neonates is still a work in progress, and are very complicated. Here is more CDC information on Zika in the US.

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