The Centers for Disease Control and Prevention (CDC) has compiled its research and recommendations on Zika virus in a new Pediatrics article released today.
“We wanted to have a place where busy pediatric health care providers could have information in one place that would give them what they needed to counsel women who might be considering traveling to places where there might be ongoing transmission as well as providing care for kids and their families that are concerned about Zika virus infections,” said Sonja A. Rasmussen, M.D., M.S., FAAP, co-author of the article “Zika Virus Disease: A CDC Update for Pediatric Health Care Providers” (Karwowski MP, et al. Pediatrics. March 21, 2016, http://pediatrics.aappublications.org/content/early/2016/03/22/peds.2016-0621).
Zika, a mosquito-borne Flavivirus, dates back to 1947, but it wasn’t until last year that it started spreading to the Americas. The introduction of the virus coincided with increasing numbers of microcephaly cases in Brazil. More than 5,000 suspected microcephaly cases were reported there from October 2015 through February 2016, according to the CDC. The number far surpasses Brazil’s average of 150-200 cases per year.
Researchers now are studying associations between the virus in pregnant women and these cases of microcephaly as well as other neurological disorders in their babies, although a causal link has not yet been proven.
“I think every week we become more concerned and have more information suggesting that link is real,” said Dr. Rasmussen, one of the leaders of the CDC’s Pregnancy and Birth Defects Task Force.
World Health Organization (WHO) Director-General Margaret Chan, M.D., M.Sc. expressed similar sentiments in a March 22 press briefing.
“Though the associations are not yet scientifically proven … there is now scientific consensus that Zika virus is implicated in these neurological disorders,” Dr. Chan said. “The kind of urgent action called for by this public health emergency should not wait for definitive proof.”
Zika now is being spread in more than 38 countries and territories in Latin America and the Caribbean, according to the WHO.
As summer gets closer, officials say it likely will spread to the continental U.S., particularly in areas that are home to the primary vectors, the Aedes aegypti mosquitoes and possibly Aedes albopictus mosquitoes. In rare cases, Zika also may be spread through sexual contact.
For the 20% of those infected who display symptoms, the illness is mild and may include fever, rash, joint pain and conjunctivitis. The top concern, Dr. Rasmussen said, is for babies born to mothers who may have contracted Zika during their pregnancy. The CDC in collaboration with the Academy released guidance on identifying infants and children who may have become infected.
- Infants should be tested for Zika if they are born with microcephaly or intracranial calcifications and their mother spent time in an affected area while pregnant or had sexual contact with a male partner who traveled to such areas.
- Infants should be tested for Zika if their mother had a positive or inconclusive test for Zika even if birth defects are not detected prenatally or at birth.
- Infants whose mother tested negative for Zika or was not tested and who are not born with microcephaly or intracranial calcifications should receive routine well-child preventive care.
- Zika should be suspected in infants with two of the aforementioned symptoms in their first two weeks of life if their mother traveled to one of the affected areas within two weeks of delivery.
- Zika should be suspected in children who display at least two symptoms within two weeks of traveling to an affected area. Adolescents also may be exposed through sexual contact with a male who spent time in an affected area.
The virus is a nationally notifiable disease and should be reported to local, state or territorial health departments to facilitate testing. CDC leaders say they are working to improve the availability of diagnostic tests, but none are available commercially.
For infants and children who contract Zika through mosquitoes, the disease typically is mild just as it is for adults, and treatment involves supportive care, according to the CDC. Two teen deaths tentatively have been associated with the virus, but at least one teen had a pre-existing condition. Researchers also are exploring possible associations between Zika and Guillain-Barré syndrome.
Zika RNA has been found in breast milk, but no infant cases of the virus related to breastfeeding have been reported. The CDC recommends mothers diagnosed with Zika who live in an area where the virus is spreading continue to breastfeed.
“We don’t have any evidence of transmission (through breast milk), and we know there are so many benefits to breastfeeding,” Dr. Rasmussen said.
Health officials recommend that pregnant women avoid travel to areas where Zika virus is spreading as no vaccines are available. All travelers to areas where Zika is being transmitted should take steps to avoid mosquito bites.
“We all expect that there will be some local transmission of Zika virus in the continental U.S., so pediatricians should start talking to their patients,” Dr. Rasmussen said.
While the Pediatrics article provides a primer on Zika, research is evolving quickly. Pediatricians should check www.cdc.gov/zika regularly for the latest information.