CDC updates Zika testing recommendations for pregnant women
The US Centers for Disease Control and Prevention (CDC) today updated its recommendations for testing pregnant women for Zika virus, mainly because one of the most frequently used tests—which detected immunoglobulin B (IgM) antibodies—is more likely to yield a false positive result, especially as incidence of the disease in the Americas decreases.
The CDC detailed the new guidance today in an early online edition of Morbidity and Mortality Weekly Report (MMWR).
Health officials emphasized that health providers should continue to ask pregnant women at each prenatal visit about possible Zika exposure and possible symptoms of the illness before and during the current pregnancy. Nucleic acid and serologic testing are still recommended for symptomatic pregnant women within 12 weeks of illness onset.
However, for asymptomatic women with ongoing possible exposure, the CDC no longer routinely recommends routine IgM testing, due to the test's limitations and difficulty interpreting results. Recent studies have down that Zika IgM antibodies might be detected for months after infection, limiting the ability to tell if the infection occurred before or during pregnancy.
However, they note that in areas with ongoing possible Zika transmission, nucleic acid testing should be offered at the start of prenatal care, with follow-up testing based on local Zika transmission trends.
The CDC will host a Clinician Outreach and Communication Activity (COCA) call to explain and field questions about the new guidance on Jul 27 at 2 pm eastern time.
Jul 24 MMWR early release report
CDC COCA call information
Ebola RNA detected in semen more than 2 years after symptom onset
In about 8% of men, Ebola virus RNA can be detected in semen samples more than 2 years after symptom onset, according to a new study published in Open Forum Infectious Diseases.
The study was based on samples donated by 137 men diagnosed as having Ebola virus disease (EVD). Previous research has shown that within approximately 3 months of acute EVD, as many as 28% to 100% have Ebola RNA in semen, and sexual transmission of Ebola has taken place up to 6 months after infection. This was the first study to measure prevalence of Ebola RNA through the 2-year mark, when 11 of the men, or 8%, had detectable Ebola RNA in their semen.
Volunteers were recruited in Monrovia, Liberia, and donated semen samples every 90 days for the duration of the study. The longest time from EVD onset to detectable Ebola in semen was 965 days. The men who had Ebola RNA in their semen the longest were on average older and more likely to report vision problems than men who cleared the RNA earlier.
Currently, the World Health Organization recommends that men who've been diagnosed as having EVD practice abstinence or use condoms for 12 months after recovery. The study authors suggest their work should prompt a revised discussion of the timeline for sexual transmission of Ebola.
Jul 22 Open Forum Infect Dis study
In other research news, investigators who published a study in PLoS Neglected Tropical Diseases said that young children, the elderly, and rural patients were more likely to die from Ebola infections, and there was a decreasing trend in the case-fatality rate during Liberia's 2014-16 Ebola outbreak.
The researchers used 16,370 lab samples from Liberia, and identified 3,897 confirmed EVD cases and 3,975 Ebola RNA–negative suspected cases. Patients with Ebola who were 6 to 30 years old were more likely to survive the infection, as were urban versus rural patients. The case-fatality rate dropped from 80% in 2014 among confirmed cases to 63% at the study's end.
Jul 21 PLoS Negl Trop Dis study
More H5N8 outbreaks reported in Italy, South Africa
Italy and South Africa recently reported more highly pathogenic H5N8 avian flu outbreaks, according to separate updates from the World Organization for Animal Health (OIE).
In Italy, two events were reported in Lombardy region in the north central part of the country, and both began on Jul 19. One occurred at a commercial turkey farm and the other was detected in backyard birds. Between the two locations, the virus sickened 18,874 of 20,563 birds, killing 1,692 of them. Culling was planned for the remaining poultry, along with disinfection of the bands, movement controls, and enhanced screening.
Italy was among several countries to report several H5N8 outbreaks over the winter and spring, and its last outbreak was reported in May, also affecting poultry in Lombardy region.
South Africa reported two more H5N8 outbreak, both affecting wild birds, the country's agriculture officials said in a notification today to the OIE. Both detections occurred in provinces that have already reported the virus in poultry. In the new events, tests on two southern masked weavers—a type of perching bird—found dead in Mpumalanga province on Jun 30 tested positive for the virus.
Also, the virus turned up in tests on birds from two locations Gauteng province. The outbreaks there began between Jul 11 and Jul 13, affecting a yellow-billed duck and an Egyptian found dead in the city of Tshwane and in hobby geese at a backyard holding in the city of Emfuleni.
Jul 21 OIE report on H5N8 in Italy
Jul 24 OIE report on H5N8 in South Africa
New polio case confirmed in Afghanistan
The Global Polio Eradication Initiative (GPEI) last week confirmed another case of wild polio virus type 1 in Afghanistan. The nation, along with Pakistan and Nigeria, is one of three in the world in which wild polio is still transmitted.
Afghanistan now has 5 confirmed polio cases in 2017. The most recent case reported an onset of paralysis on Jun 19 in Kandahar.
On Jun 21, officials reported an environmental sample collected in Nangarhar tested positive for wild polio virus type 1. This is the seventh positive environmental sample collected in the country this year.
GPEI also noted the four cases of vaccine-derived poliovirus type 2 detected last week in Syria. That country has seen 27 vaccine-derived polio cases this year. On Saturday, a vaccination campaign targeting 448,000 children younger than 5 years began in Syria.
Jul 19 GPEI update