CDC MMWR Early Release: Zika Spread & Possible Association With Microcephaly

Credit MMWR

#10,922


Coming off a 2pm embargo, the CDC has published two Early Release MMWR reports on the rapidly emerging Zika virus; one on the potential link between Zika and Microcephalic birth defects and the other on the rapid spread of the virus to new regions around the world.

Due to their combined length, I've only presented the link, a short description, and the summary for each MMWR report.  

Follow the link to read each in its entirety.

Possible Association Between Zika Virus Infection and Microcephaly — Brazil, 2015

JANUARY 22, 2016

An outbreak of Zika virus infection was first recognized in northeastern Brazil in early 2015. By September, a sharp increase in microcephaly cases was reported from affected areas. The Brazil Ministry of Health developed a case definition for Zika virus–related microcephaly, and established a task force and a registry to investigate Zika virus–related cases of microcephaly and to describe the clinical characteristics of cases.

Summary

What is already known about this topic?

 An outbreak of Zika virus infection, a flavivirus transmitted by Aedes mosquitoes, was first recognized in northeastern Brazil in early 2015. In September, a sharp increase in the number of reported cases of microcephaly was reported in areas affected by the outbreak.

What is added by this report?
The Brazil Ministry of Health developed a case definition for Zika virus–related microcephaly (head circumference ≥2 standard deviations [SD] below the mean for sex and gestational age at birth). A task force and registry were established to investigate Zika virus–related cases of microcephaly and to describe the clinical characteristics of cases. Among the first 35 cases of microcephaly reported to the registry, 74% of mothers reported a rash illness during pregnancy, 71% of infants had severe microcephaly (>3 SD below the mean), approximately half had at least one neurologic abnormality, and among 27 who had neuroimaging studies, all were abnormal. Cerebrospinal fluid from all infants is being tested for Zika virus; results are not currently available.

What are the implications for public health practice?
The increased occurrence of microcephaly associated with cerebral damage characteristically seen in congenital infections in Zika virus-affected areas is suggestive of a possible relationship. Additional studies are warranted to confirm the association and to more fully characterize the phenotype. In addition to removing potential breeding areas for mosquitoes, pregnant women in Zika-affected areas should wear protective clothing, apply a U.S. Environmental Protection Agency (EPA)-approved insect repellent, and sleep in a screened room or under a mosquito net.

Zika Virus Spreads to New Areas — Region of the Americas, May 2015–January 2016
 
JANUARY 22, 2016
 
In May 2015, the World Health Organization reported the first local transmission of Zika virus in the Americas, with autochthonous cases identified in Brazil. In December, the Ministry of Health estimated that 440,000–1,300,000 suspected cases of Zika virus disease had occurred in Brazil in 2015

Summary

What is already known on this topic?

Zika virus is a mosquito-borne flavivirus transmitted primarily by Aedes aegypti mosquitoes. Most infections are asymptomatic, and symptomatic disease generally is mild. In May 2015, the first local transmission of Zika virus in the Region of the Americas was reported in Brazil. Following the spread of Zika virus in Brazil, there has been a marked reported increase in the number of infants born with microcephaly; it is not known how many of these cases are associated with Zika virus infection.

What is added by this report?

By mid-January 2016, local Zika virus transmission had been reported to the Pan American Health Organization from 20 countries or territories in the Region of the Americas; spread to other countries in the region is likely. Although local transmission of Zika virus has not been documented in the continental United States, infections have been reported among travelers visiting or returning to the United States, and  these likely will increase. Imported cases might result in local transmission in limited areas of the continental United States.

What are the implications for public health practice?

The best way to prevent Zika virus infection is to avoid mosquito bites by avoiding exposure and eliminating mosquito breeding areas. Until more is known, pregnant women should consider postponing travel to any area with ongoing Zika virus transmission. Health care providers should contact their state or local health department about testing patients with symptoms of Zika virus infection and a compatible travel history.