Last month I wrote about Zika basics in this article. At that time, there had been no confirmed cases of Zika being transmitted by mosquitos in the United States. There had been some cases of Zika found in people returning from countries where mosquitos are spreading the virus. There had been a few cases of people returning with Zika and spreading the virus by sexual transmission. 
There has been a growing link between Zika infection during pregnancy and babies with microcephaly, but no clinical studies to confirm the link. Zika was only a problem for pregnant women. For everyone else, Zika was a mild cold-like event. I did mention that Zika was an evolving and moving target. Well, Zika has moved and evolved. Time for an update. 
Preliminary Report on Zika and Pregnancy: New England Journal of Medicine:
This is not encouraging. Researchers confirmed Zika infection in 72 pregnant Brazilian women. Pregnancies ranged from 5 to 38 weeks. Ultrasound fetal evaluations were done in 42 of these women. Serious problems were found in 29 percent of the pregnancies. These included microcephaly, fetal deaths, growth restrictions, and other brain defects. Zika appears to be a devastating complication for pregnancy. 
More Travel Associated Cases in the United States:
As of March, there have been 153 cases of people returning to the US with documented Zika infection. Twenty-nine states have confirmed cases. This may be the tip of a small ice berg, since symptoms are mild and testing is not routinely available. There are probably a lot more cases that are going undiagnosed. Although there are still no known cases of mosquitos transmitting the virus in the States, there are now over 100 cases in Puerto Rico and one in the Virgin Islands. Even if we never have a big epidemic here, it seems inevitable that some mosquitos will become infected and will spread the virus in the States. 
An Increasing Danger for Sexual Transmission:
Although pregnant women in the United States may still be safe from mosquitos, they may not be safe from sexual partners who have brought the virus home with them. The CDC now reports two confirmed cases of Zika spread to women through sex with an infected partner. There are also foure probable cases. Several of these women were pregnant when they became infected. CDC now says, sexual transmission is more likely than previously believed. 
Zika Danger for People Not Pregnant:
There is a growing link for Zika virus infection and a dangerous neurological condition called Guillain-Barre syndrome. Eight countries where Zika is common (endemic) are seeing a rise in this syndrome. Guillain-Barre is an autoimmune disease. That means something triggers a person’s immune system to attack normal cells. In Guillain-Barre, the normal cells are the nervous system. This can cause weakness, paralysis, and in rare cases, death. 
Most people recover from Guillain-Barre, but there is no cure for those who don’t. The exact cause of Guillain-Barre is not known, but it is known to be triggered by some infections. Zika virus infection may be the latest known trigger for the syndrome. 
What to Do?
There is still no need to panic. If you are not travelling in an area where Zika is endemic, you are still quite safe. But you do need to start worrying about sexual contact with people who are returning from an endemic area, especially if you are pregnant. We still don’t have a commonly available way of testing for Zika, so the true numbers are unknown. Other diseases carried by the same mosquitos that carry Zika have not spread significantly into the United States, but Zika is proving to be a stealthy target. [1,4]
For now: [1,4]
- Avoid travel to areas where Zika is active if you are pregnant or may become pregnant. To get the latest travel advisory on areas to avoid, check the CDC website here.
- If you have travelled or live in an area where Zika is active, and you are or may be pregnant, talk to your doctor. Symptoms of Zika include fever, rash, headache, and joint pain. But most people have Zika without any symptoms. Your doctor may recommend doing a blood test to see if you have been infected. If you are pregnant, you may have more frequent ultrasounds to make sure your baby is developing normally.
- If you are a pregnant woman with a sexual partner who has been travelling in an area where Zika is endemic, avoid having sex until you can talk to your health care provider about safe sex and possible testing for the virus.
- New England Journal of Medicine, Zika Virus in the Americas – Yet Another Arbovirus Threat.
- New England Journal of Medicine, Zika Virus Infection in Pregnant Women in Rio de Janeiro – Preliminary Report.
- CDC, Zika virus disease in the United States, 2015-2016.
- CDC, Transmission of Zika Virus Through Sexual Contact with Travelers to Areas of Ongoing Transmission – Continental United States, 2016.
- World Health Organization, Zika situation report.
- World Health Organization, Guillain-Barre syndrome.