News Scan for Apr 28, 2016

Memphis measles outbreak
;
Yellow fever in Africa
;
Ebola update
;
Severe adenovirus illnesses
;
MCR-1 in Brazil’s livestock

Six measles cases reported in Memphis area

Six measles cases have been confirmed in the Memphis, Tenn., area, according to news services and health officials, signaling what is apparently the largest US measles outbreak since more than 100 cases were linked to Disney theme parks in California early in 2015.

The Tennessee Department of Health (TDH) reported six cases in Shelby County, home to Memphis, on Apr 25. In a statement, TDH Commissioner John Dreyzehner, MD, MPH, said health workers were tracing patients’ contacts but warned that the outbreak would "likely get worse before it gets better."

The source of the outbreak has not been pinpointed, according to a USA Today story yesterday. A Memphis infectious disease specialist, Manoj Jain, MD, told the newspaper that the virus was probably brought home from abroad by an unvaccinated traveler. None of the six patients in the outbreak had been vaccinated, the story said.

County health officials have identified more than a dozen places, including a thrift store and a pharmacy, that people who were later found to have measles visited, according to the newspaper. The story did not identify the places.

Under Tennessee law, parents can request an exemption for their children from required vaccinations, including the measles, mumps, and rubella shot, for religious reasons, USA Today said. Citing a report from the Centers for Disease Control and Prevention (CDC), it said that close to 96% of Tennessee children in 2014 had had at least one measles vaccine dose.

The biggest US measles outbreak of 2015 involved 131 cases, 42 of which were directly linked to exposures at Disneyland or Disney Adventure Park in Anaheim, Calif.
Apr 25 TDH press release
Apr 27 USA Today story
Apr 17, 2015, CIDRAP News item on California measles outbreak


Yellow fever totals rise in Angola, DRC, and Uganda

Case totals in Angola's yellow fever continue to climb, with 2,023 suspected cases, 653 of them confirmed, and 258 fatalities, the World Health Organization (WHO) said today in an update that was added to a Zika virus report.

The country's outbreak is still of high concern because of persistent local transmission and the exportation of cases to China, the Democratic Republic of Congo (also experiencing an outbreak), and Kenya, the agency said

Over the last 2 weeks, vaccination campaigns have reached 59% and 70% of target populations in Huambo and Benguela provinces, but the rates need to be increased to interrupt transmission.

Based on the threat of spread from Angola into Namibia and Zambia—which share a porous border with Angola—the latter two countries have asked the WHO for help and for yellow fever vaccine for travelers in the border areas.

The DRC government declared its yellow fever outbreak on Apr 23, and so far 37 cases have been reported, including 16 confirmed cases, all linked with travel to Angola. The WHO added that at least two locally acquired cases have been reported and that a field study found a high risk of local yellow fever transmission in the DRC.

Elsewhere, clusters of yellow fever cases in Uganda don't appear to be related to Angola's outbreak, the WHO said. As of yesterday, the country had reported 39 suspected cases in seven districts.
Apr 28 WHO statement

 

Ebola cluster in Guinea and Liberia winds down

Only one patient is still in treatment for Ebola in a recent flare-up in Guinea and Liberia that was likely triggered by persistent virus in a survivor, the WHO said in another update included in today’s Zika virus report.

The remaining patient is a 2-year-old Liberian boy who is healthy but is awaiting a second consecutive negative test before discharge.

Guinea's last case-patient tested negative for a second time on Apr 19, starting a 42-day countdown before the country can be declared free of the virus again, slated for May 31 if no new cases are detected.

More than 1,000 contacts were linked to the 13 recent cases, 9 of them fatal, in Guinea and Liberia, and as of Apr 27, all had completed their 21-day monitoring periods, the WHO said. The outbreaks triggered a ring vaccination campaign with VSV-EBOV, and in Guinea, more than 1,500 people were immunized.

The WHO lifted the public health emergency of international concern (PHEIC) for Ebola on Mar 29. Overall in the three countries, 28,616 confirmed, probable, and suspected cases were reported, 11,310 of them fatal.
Apr 28 WHO statement

 

Asian adenovirus strain detected in Oregon outbreak

A study investigating a human adenovirus (HAdV) outbreak in Oregon in early 2014 identified a strain that can cause severe disease and was previously known to circulate only in Asia, which may be gaining a foothold in the United States. The team from Oregon and the CDC reported their findings on Apr 26 in Emerging Infectious Diseases.

With data gathered from three major hospital systems in Oregon, they identified 198 patients with HAdV infections between October 2013 and July 2014. Molecular subtyping of 109 specimens found HAdV-B7 to be the most common strain (59%); the next closest was HAdVs -C1, -C2, -C5 at 26%.

Pneumonia was reported in 32% of patients with HAdV. Fever was also present in 75% of the patients, and other prevalent symptoms were cough (61%), shortness of breath (26%), nausea or vomiting (24%), and rhinorrhea (22%).

Patients with HAdV-B7 were hospitalized longer than those with other strains, with a median of 6.5 days, compared to 5.0 days for HAdVs-B3 or –B21. Another key finding was that HAdV-B7 was more likely to be detected in adults than in children.

Currently there is no HAdV vaccine available for patients although there is a live oral one for military use. While the disease has been more common in Asia, the study argues that the impact of the Oregon outbreak may suggest that HAdV-B7 may be reemerging and that clinicians should be more conscious of it during clinical workup of patients with respiratory infections.
April 26 Emerg Infect Dis study

 

MCR-1 gene detected in Brazilian livestock

A study of bacterial isolates collected in Brazil since 2000 for antibiotic-resistance surveillance revealed that Escherichia coli harboring the MCR-1 gene has been present in food-producing animals since at least 2012. The Brazil-based researchers reported their findings today in Eurosurveillance.

Chinese scientists first described MCR-1, which disables the antibiotic colistin, in November 2015, and since then several groups have found the gene in their bacterial collections, mainly in food and agricultural sources, but sometimes in patients. Colistin is an older drug often used in raising food animals, but for humans it is considered a last-line treatment for multidrug-resistant infections.

In the Brazilian study, the team looked at 4,620 Enterobacteriaceae isolates collected from humans, animals, food, and the environment between 2000 and 2016. Sixteen were positive for the MCR-1 gene: 2 from fecal samples collected from healthy pigs in 2012 and 14 from fecal samples collected in 2013 from healthy chickens. Most of the isolates also produced extended-spectrum beta-lactamase (ESBL) resistance enzymes.

The authors said it's clear that MCR-1-producing strains are already established in South America, adding that their findings support a previous report on the possible detection of the gene in European travelers who had visited Bolivia, Colombia, and Peru. They also raised concerns about the wide use of colistin sulphate as a growth promoter in Brazilian livestock, given the country's population and its large global role in chicken production.
Apr 28 Eurosurveill report

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