News Scan for Apr 19, 2018

News brief

WHO identifies international cities most at risk for yellow fever

The World Health Organization (WHO) released a new assessment of international cities most at risk for yellow fever transmission, and Miami made the cut.

The study used flight data from 2016 to track cities that play host to both the Aedes aegypti mosquito (the vector that carries yellow fever) and visitors from yellow fever–endemic areas.

Researchers found that 45.2 million international air travelers departed from yellow fever–endemic areas of the world, and 11.7 million of those travelers went to 472 cities in which yellow fever was not endemic but had the potential for virus transmission. Almost two thirds of travelers (7.7 million or 65.7%) were not required to provide proof of yellow fever vaccination upon arrival.

Miami does not require proof of yellow fever vaccination status, and the WHO said such a requirement is up to each country's discretion. The vast majority of cities (89%) included in the study that have yellow fever endemicity do require proof of vaccination, including major cities in Brazil, India, and China.

"With more than 3 billion domestic and international passengers now boarding commercial flights each year, humans have become the primary agents for the global spread of mosquito-borne viruses such as dengue, chikungunya, Zika and yellow fever. Our findings on yellow fever virus transmission provide countries with insights into contemporary vulnerabilities to international spread of the virus," the authors wrote.
Apr 11 WHO assessment

African rotavirus vaccine study reassures over bowel obstruction concerns

In a study based in Africa to explore postlicensing reports in middle- and high-income countries of an association between rotavirus vaccination and intussusception, a type of bowel obstruction, researchers yesterday reported that the risk is no higher than the background level. A team from African nations, the World Health Organization (WHO), and the US Centers for Disease Control and Prevention (CDC) reported its findings today in the New England Journal of Medicine.

In children younger than 5 years, rotavirus is responsible for about 37% of deaths from diarrhea each year, with the impact disproportionately high in sub-Saharan Africa. Associations between the vaccine and intussusception led to the withdrawal of an older version of the rotavirus vaccine, and the WHO has recommended careful monitoring during clinical trials of two newer vaccines, which found an increased risk, but not enough to outweigh the benefits of the vaccine.

For the new study, the researchers analyzed surveillance data from February 2012 through December 2016 from hospitals in seven sub-Saharan African countries that were among the first to start using the vaccine: Ethiopia, Ghana, Kenya, Malawi, Tanzania, Zambia, and Zimbabwe. They based their findings on 717 infants who had intussusception and confirmed rotavirus vaccination.

The risk of developing the condition 1 to 7 days after the first vaccine dose was not higher than the background risk, and findings were similar within a week of receiving the second dose. When they looked at the 21-day windows after both doses, they also found no higher risk than the background level.

In a press release today from the WHO Regional Office for Africa, Felicitas Zawaira, MD, who directs its family and reproductive health cluster, said the absence of the intussusception risk in African countries is reassuring, "particularly given the large public health benefits of rotavirus vaccination as demonstrated by ongoing rotavirus vaccine impact evaluation."

Matshidiso Moeti, MD, the office's regional director, said "These studies conducted in the African Region can serve as a model for other regions where wide-scale rotavirus vaccine introductions are just beginning and surveillance is ongoing as part of the WHO-coordinated Global Rotavirus Surveillance Network."
Apr 19 N Engl J Med study
Apr 18 WHO Regional Office for Africa press release

Food Outbreak Scan for Apr 19, 2018

News brief

Romaine-linked E coli outbreak expands to 5 more states as cases rise to 53

An Escherichia coli O157:H7 outbreak linked to chopped romaine lettuce has sickened 18 more people, with five more states reporting illnesses, the US Centers for Disease Control and Prevention (CDC) said yesterday in an update.

The new cases lift the outbreak total to 53 in 16 states. The newly affected states are Alaska, Arizona, California, Louisiana, and Montana. Nine more patients have been hospitalized, including two who developed hemolytic uremic syndrome (HUS), a potential fatal kidney complication. Overall, 31 people have been hospitalized for their illnesses and 5 have developed HUS.

The latest illness onset is Apr 6, but the CDC said infections that occurred after Mar 29 might not be reported yet because of the delay between when a patient gets sick and when the illness is reported.

Health officials still suspect that chopped romaine from the Yuma, Az., growing area is the source of the outbreak, but so far no specific grower, supplier, distributor, or brand has been identified. Interviews with patients sickened in the outbreak found that, of 43 people, 41 (95%) ate romaine lettuce the week before they became ill. For comparison, a survey of healthy people found that only 46% ate romaine the week before they were interviewed.
Apr 18 CDC outbreak update

FDA probe finds biosecurity problems at Salmonella outbreak egg farm

A Food and Drug Administration (FDA) inspection of a North Carolina egg farm linked to a multistate Salmonella Braenderup outbreak found an ongoing problem with rodent control and sanitation conditions and employee practices that could have contributed to contamination of egg processing equipment and eggs.

The agency on Apr 17 posted details of the investigation that took place from Mar 26 to Apr 11 in a 483 inspection form posted on its website. The outbreak has sickened 23 people from nine states and led to the recall of 206 million eggs from Rose Acre Farms that were produce at its facility in Hyde County, N.C.

During the inspection, the FDA reviewed the farm's pest control records from September 2017, which reflected an ongoing rodent infestation. During the visit, the FDA saw live rodents in multiple areas of eight poultry houses. Also, FDA officials saw flying insects throughout the facility that landed on food, food contact surfaces, and food production equipment.

A review of sanitation procedures found that one cleaning steps wasn't implemented and employees bypassed another step. In another instance, during a walk-through of cleaning procedures, FDA investigators observed that the farm didn't use a sanitizing step after the wash step. Authorities saw condensation dropping from ceilings and pipes, down walls, onto production equipment, and pooling on paths that had foot and forklift traffic. Also, they saw instances in which employees or equipment touched food contact surfaces after touching nonfood-contact surfaces.
Apr 17 FDA 483 inspection report