Study in pregnant women hints at pertussis protection from flu vaccination
A post hoc study in South African pregnant women who took part in a flu vaccine study in 2011 and 2012 found that flu vaccination may have had a protective effect against Bordetella pertussis. Researchers described their findings today in a letter to the New England Journal of Medicine.
The initial trial involved the trivalent inactivated vaccine, and it included 2,116 women—1,062 who received the flu vaccine and 1,054 who were in the placebo group. Researchers followed the women weekly for any respiratory illnesses from study enrollment, through pregnancy, and through 24 weeks postpartum. In women without HIV, the vaccine was 50.4% effective in preventing lab-confirmed flu.
Given that some studies suggest flu can enhance susceptibility to come bacterial infections, the researchers wanted to explore if there was a relationship between influenza virus and pertussis used archived samples from the earlier study to assess levels of pertussis. Scientists had 3,583 respiratory samples from 1,361 women, and they tested 3,125 (87.2%) samples for pertussis. Specimens from 11 flu vaccine recipients tested positive for pertussis, compared with 26 from placebo recipients. Also, test results were indeterminate for 10 women in the flu vaccine group and 16 in the placebo group.
The researchers acknowledged the limits of a post hoc study, but they said it's not likely that flu vaccination would alter the ability to diagnose pertussis and that their observations warrant further investigation.
Mar 29 N Engl J Med letter
More than 200 new yellow fever cases reported in Brazil
The Brazilian Ministry of Health yesterday noted 211 newly confirmed yellow fever cases, including 38 more deaths.
From Jul 1, 2017, to Mar 28, 2018, officials have confirmed 1,131 cases of yellow fever and 338 deaths. During the same period in 2016-17, the number was much lower, at 660 cases and 210 deaths.
The Ministry of Health said the increase correlates with the arrival of yellow fever in Brazil's biggest cities, where approximately 35.8 million Brazilians have not until recently been recommended to receive the yellow fever vaccine. In the previous season, only 9.8 million Brazilians were at risk for the virus.
An additional 77.5 million Brazilians should be vaccinated against yellow fever this year, as the government is now recommending that every citizen get vaccinated. The move to vaccinate all citizens is preventive and should be completed by April 2019, the ministry said.
Mar 28 Brazilian Ministry of Health update
South African Listeria outbreak tied to processed meat grows
The World Health Organization (WHO) yesterday reported a total of 978 laboratory-confirmed listeriosis cases in a South African outbreak that's been linked to a popular ready-to-eat processed meat product called polony, akin to bologna. The outbreak is now the largest ever reported to the WHO.
Among cases with known outcomes, 183 have died. The case-fatality rate is 27%, comparable to other listeriosis outbreaks worldwide, the agency said. Forty-two percent of patients are newborns who were infected during pregnancy or delivery, the WHO said.
Whole-genome sequencing collected from patients showed that 91% of the Listeria strains belonged to a type found in polony products. The South African Ministry of Health announced this connection on Mar 4, and all implicated polony products have been recalled in 15 African countries.
Listeria has a long incubation period, up to 70 days, so officials said more cases are to be expected.
"Following the identification of the source of this outbreak, WHO is now concerned that the export of implicated products may have resulted in listeriosis cases in other countries," the WHO said. "Detailed information on the implicated product batches exported to each of the identified 15 countries should be shared with WHO and the International Food Safety Authorities Network (INFOSAN) Secretariat."
Mar 28 WHO statement
Case report details possible family meningococcal disease transmission
A team from Colorado and the US Centers for Disease Control and Prevention described a possible instance of meningococcal transmission in a family, despite postexposure prophylaxis (PEP) that occurred within a 15-month interval between the two cases. The report appears today in Morbidity and Mortality Weekly Report (MMWR).
The index patient was a 75-year-old woman who was hospitalized in April 2015, where she was diagnosed as having Neisseria meningitidis serogroup C and recovered after treatment. Seven of her family members were advised to receive PEP to curb nasal carriage and prevent secondary infections, but it's not known if they complied.
Fifteen months later, the woman's 3-month-old grandson, who lived with and was cared for by the woman during the day, was hospitalized with a meningococcal serogroup C infection from which he also recovered. The family was again advised to take PEP.
Whole-genome sequencing revealed that the two isolates were closely related.
The researchers said the cases represent possible family transmission, though the mechanism is unclear. They said the N meningitidis strain could have come from an unidentified family contact, that the strain could have been circulating symptomatically in the community, or that PEP failed to eradicate carriage within the family. The 15-month time lag between related infections is longer than earlier similar reports, but some studies limited their definition of secondary cases to a specific time window.
The authors added that more studies to estimate household attack rates and improve documentation of PEP compliance would help assess the existing public health recommendations, which currently don't include vaccination of close contacts in patients who have sporadic disease.
Mar 29 MMWR report
Finland, Slovakia report H5N6 avian flu in wild birds
Two European countries—Finland and Slovkia—today reported more highly pathogenic H5N6 avian influenza detections in wild bird, according to separate reports from the World Organization for Animal Health (OIE).
The report from Finland marks the country's first detection of the strain, which has turned up in other European countries over the past few months, mainly in wild birds.
The event involves a white-tailed eagled found unable to fly on Mar 20 near the city of Pargas in the far southwest archipelago area. The bird was taken to a wild animal shelter, where tests revealed H5N6. The eagle was euthanized because it was very sick, and the shelter also culled five other wild birds, as well.
In Slovakia, officials detected H5N6 in a black-headed gull found dead in Trnava region in the southwest. The OIE report said the last detection of the virus in Slovenia was in June 2017.
Mar 29 OIE report on H5N6 in Finland
Mar 29 OIE report on H5N6 in Slovakia