Though reports of fatal Zika virus infections are very rare, researchers from Colombia today profiled four of them, including one patient who suffered brain hemorrhage and two others with ischemic brain lesions detected on autopsy.
In other Zika developments, a new survey suggested Americans still have knowledge gaps about the threat, and US officials announced that they would keep the comment period open for another month on a proposed pilot project in Florida that would involve genetically modified mosquitoes.
Cases spotlight disease spectrum
Several clinical questions remain about Zika virus, which causes a typically mild disease and is thought to be asymptomatic in nearly 80% of patients. Very little is known about deaths from the virus, and so far, Colombia had recorded only one other, in a girl who had sickle cell disease. Brazil is the only other country to report fatalities—three known ones.
Researchers from Colombia yesterday reported clinical details of four deaths related to Zika virus infection that occurred in October 2015 in Tolima, located in the central part of the country. They published their findings in a letter to The Lancet Infectious Diseases.
Since Sep 22 and through the middle of March, Colombia has had 58,838 Zika cases, 2,361 of them lab confirmed, the group noted.
The patients who died were a 2-year-old girl, a 30-year-old woman, a 61-year-old man, and a 72-year-old woman. The two older patients had underlying medical conditions that were well-controlled with medications. After death, the two younger ones were found to likely have had acute leukemia.
All of the patients had fever to some extent, and three had dehydration and three had severe thrombocytopenia. Some had mucosal hemorrhage, and typically they experienced respiratory distress and shock. All had anemia, and three had low white blood cell counts.
The 30-year-old woman had lower- and upper-extremity rash, and in 10 days her deteriorating condition included intracerebral and subarachnoid hemorrhages.
Dengue tests were negative for all patients, and the man tested positive for chikungunya on a serology test. All four tested positive for Zika virus infection on reverse transcriptase polymerase chain reaction (RT-PCR) tests.
The patients died from 48 hours to 12 days after symptoms began. Autopsy findings for the two older patients included ischemic brain lesions. The man also had areas of liver necrosis and spleen inflammation, and samples of those tissues were positive for Zika virus on RT-PCR.
The authors said the cases point out the need for more evidence-based clinical guidance for managing patients and are a reminder that atypical and severe cases can occur.
Zika poll uncovers knowledge gaps
Though about three quarters of Americans know at least a little about Zika virus and its link to birth defects, few are aware of testing and whether there are vaccines or medicine available to treat it, suggesting that more work needs to be done to inform the public, according to a recent survey from the Associated Press and the NORC Center for Public Affairs Research at the University of Chicago.
The findings are based on responses from a randomly drawn, nationally representative sample of 1,004 adults who participated in Web-based or telephone survey from Mar 17 and Mar 21, according to a press release yesterday from the University of Chicago.
Among other findings, the poll revealed that although 90% of those who know about Zika are aware that mosquitoes spread the virus, only 57% are aware that it can spread sexually. About 25% believe American athletes should withdraw from the Summer Olympics slated for Rio de Janeiro in Brazil.
Caitlin Oppenheimer, senior vice president and director of public health at NORC, said in the press release, "As the Zika virus unfolds, it will be critically important to communicate effective prevention strategies to Americans." She added that the survey and other measures can help build Zika awareness and target topics that require more communication efforts.
In late March a Harvard-led study found that many Americans, including families with pregnant women, weren't aware of key facts about Zika virus, including the link to birth defects and the risk of sexual spread.
- The US Food and Drug Administration (FDA) yesterday announced that it was extending the public comment period for a recent draft environmental assessment and preliminary report on the investigational use of Oxitec genetically modified Aedes aegypti mosquitos for a field trial in the Florida Keys. Based on requests from the public, the comment period is now open until May 13.
- The US Centers for Disease Control and Prevention (CDC) posted a Morbidity and Mortality Weekly Report item today on a survey of Puerto Rico's blood collection and use, which the agency used for its efforts to maintain the safety and availability of the territory's blood supply. Most of Puerto Rico's blood supply is collected locally, posing a Zika transmission risk via transfusion. Local blood collection ceased on Mar 1, based on FDA guidance, but collections there on Apr 2 resumed after the FDA approved an investigational new test to screen the donations.
- The Pan American Health Organization announced today that it would provide technical support to countries that want to conduct pilot studies on new mosquito control technologies, such as Wolbachia bacteria and genetically modified mosquitoes.
- The CDC will host a clinician's conference call on Apr 12 with experts to review updated clinical guidance for reproductive-age women and men, sexual transmission, and the US Zika pregnancy registry.
Apr 7 Lancet Infect Dis letter
Apr 7 University of Chicago press release
Mar 29 CIDRAP News story "Americans lack awareness of Zika spread, birth defects"