The Zika virus, which is spread by the Aedes aegypti mosquito, is strongly suspected to be linked to a new wave of microcephaly cases in Brazil. Babies born with this birth defect have smaller heads and sometimes brains that aren't fully developed, which can result in life-long developmental problems.
Zika is currently spreading through Central and South America and the Caribbean, and with the high volume of news about the virus, it's tough to stay up-to-date. Check out our full coverage, or read our daily recaps.
Here are five updates, opinions and developments to know about now:
1. Pregnant Americans infected with Zika virus experienced a range of outcomes
The U.S. Centers for Disease Control and Prevention released a report Friday with details surrounding nine pregnant U.S. travelers with lab-confirmed Zika virus. Of the nine women, two had early pregnancy losses, two had abortions, two remain pregnant, and three gave birth.
At least one of the miscarried fetuses tested positive for Zika virus when researchers analyzed expelled tissue. Frieden pointed out, however, that because about 20 percent of pregnancies end in miscarriage, there's no way to know whether Zika virus caused the miscarriage.
One of the two aborted fetuses was diagnosed with brain abnormalities via ultrasound, while no information was given on the second. Of the three live births, one infant was born with severe microcephaly, while the other two babies appear to be healthy. The remaining two pregnancies appear to be healthy and without complication.
In a press conference to discuss the findings, CDC director Dr. Thomas Frieden said Friday that scientists may not know for years whether apparently healthy babies who were exposed to Zika virus in the womb will grow up to have other health problems. He also said that scientists don’t yet know which stage of the pregnancy, if any, is most vulnerable for a fetus exposed to Zika virus.
2. Zika virus may also cause stillbirths
Brazilian researchers have detailed a single case in which a mother, infected with Zika virus but asymptomatic, had a late-term stillbirth. While it’s unclear if Zika virus caused the stillbirth, doctors said the fetus had severe microcephaly and its brain was completely absent, reports Reuters. The skull, as well as parts of the lungs and abdomen, were filled with fluid. They also found that the fetus may have had arthrogryposis, a condition in which joints are stuck in place and can’t move.
While it is just one case, the researchers noted it was unusual, and that other doctors should watch out for stillbirth as a possible consequence of Zika virus infection. The mother tested negative for other known causes of microcephaly.
3. Argentina reports a case of Zika virus possibly acquired by sexual transmission
A woman in Argentina tested positive for Zika virus, despite the fact that she had not traveled to an area with ongoing and active transmission, reports Reuters. Health officials in the country say it could be yet another apparent case of sexual transmission, as the country is not experiencing locally-acquired Zika virus cases.
4. Experts say Brazil may be exaggerating their Zika crisis
A group of 14 Brazilian and American researchers published a letter Wednesday in the Annals of Internal Medicine that said Brazil’s government is being too presumptive about the link between Zika virus and microcephaly, and that their approach to the health crisis is creating a global panic, reports the Associated Press.
Some of the complaints in the letter include the fact that Brazil may have been severely underreporting microcephaly cases before the Zika virus epidemic, which means there’s no reliable way to tell if microcephaly numbers truly spiked after the disease broke out in Brazil. The group also points out that because the microcephalic births are highly concentrated in the country’s poor northeast region, there may be some underlying co-factor or accomplice responsible for these severe birth defects, in addition to or instead of Zika virus.
U.S. experts at the CDC and the National Institutes of Health, as well as global experts with the World Health Organization, concede that no causal relationship has been proven yet, but that evidence is mounting about the link between Zika virus and microcephaly. Among that evidence: an autopsy of a fetus that suggested the virus was replicating in its brain, as well as the presence of the virus in the amniotic fluid of pregnancies where the fetuses were diagnosed with microcephaly via ultrasound.
5. CDC issues travel advice about the 2016 Summer Olympics
Brazil is set to host the 2016 Summer Olympics this August, as well as the Paralympic Games in September.
But because of the country's ongoing Zika virus epidemic, as well as the disease's potential causal link to severe birth defects, the CDC recommends that pregnant women consider not attending the games. Pregnant women who must go to the Olympics should discuss the travel with their doctor first, and then follow strict mosquito bite prevention protocol throughout the trip.
If the male partner in a pregnant couple is going to the Olympics, the couple should use condoms consistently and correctly every time, or practice abstinence during pregnancy. The virus can remain in semen for an unknown amount of time, and U.S. health officials are now investigating several cases of sexual transmission of the disease.
Couples who are trying to become pregnant while visiting Brazil during the Olympics should discuss plans with their doctor and be vigilant against mosquito bites.