Avian Flu Scan for Aug 17, 2016

News brief

WHO report on Chinese H7N9 cases notes possible human-to-human spread in cluster

After five human cases of avian influenza A (H7N9) appeared in China earlier this month, the World Health Organization (WHO) has said that limited human-to-human transmission cannot be ruled out for some that are part of a family cluster. Three of the five recent cases in humans appear to be in a cluster, the WHO said today in a statement.

Two of the five cases had direct exposure to poultry, but there were no reports of direct exposure in the other three cases. The WHO said the three patients with no exposure to poultry were family members.

"Investigations are on-going, at this stage human-to human-transmission cannot be ruled out, however to date no further transmission has been reported," the WHO said in a statement today.

According to Hong Kong's Centre for Health Protection (CHP), China's agriculture ministry reported positive poultry market samples from 10 of China's provinces between January 2015 and May 2016. H7N9 is now enzootic on China’s mainland. The five cases raise the global H7N9 cases to 807, according to FluTrackers, an infectious disease news message board.
Aug 17 WHO statement
Aug 12 CIDRAP News scan
FluTrackers H7N9 case list

H5N6 isolated from China poultry market air sample

A sample collected during bioaerosol surveillance at three live poultry markets in Zhongshan, a city in China's southern Guangdong province, yielded the H5N6 avian influenza strain, the first report of a viable virus from the strain from an air sample. Chinese researchers reported their findings in an Aug 9 letter to the Journal of Infectious Diseases.

Of 243 air samples collected, 19 were initially positive for influenza A RNA. One sample that was inoculated in chicken eggs yielded H5N6, based on reverse-transcriptase polymerase chain reaction (RT-PCR) testing and genome sequencing. Sequencing showed that the virus was similar to other recent H5N6 strains in poultry, with some gene segments that were similar to H5N6 strains that have infected humans.

The teams said the findings suggest that the strain they found could be transmitted from poultry to humans through the airborne route and that if aerosol transmission is confirmed, it would add to the complex ecology of influenza A. They also said biosafety measures for those with occupational exposure to poultry should be reexamined and that more study is needed on airborne avian influenza viruses in live poultry markets.

The first human infection involving the novel virus was reported by China in 2014, and the country has now reported 15 such cases. China and a few other Asian countries have reported H5N6 in poultry, but China is the only country to report human cases.
Aug 9 J Infect Dis letter

News Scan for Aug 17, 2016

News brief

Genetic analysis yield new clues in 1979 Soviet anthrax accident

Deep genome sequencing of two autopsy specimens from people who died in a 1979 accident at a Soviet anthrax production facility revealed that the Bacillus anthracis is similar to a wild type strain from Russia and shows no evidence of genetic manipulation for drug resistance or other characteristics. A team based at Northern Arizona University published its findings yesterday in bioRxiv, a prepublication Web portal for scientific studies.

In one of the largest known human anthrax outbreaks, a problem with an air filter at the Soviet defense ministry's lab in Sverdlovsk led to the release of a plume of anthrax spores that spread downwind, killing at least 66 people within about 2 miles and animals as far as 30 miles away.

From formalin-fixed tissue samples, researchers generated a draft genome sequence of the strain and compared it to other B anthracis samples in an effort to further the investigation into the Sverdlovsk event and to add reference information for future probes. They found few differences from ancestors used to make vaccine strains, and though Soviet scientists were known to have manipulated B anthracis to evade vaccines and antibiotics, they didn't find any evidence of it in the production strain involved in the accident.

Researchers said because culturing and selection for drug resistance is known to reduce the virulence of B anthracis, that Soviet scientists probably identified a suitable weapons-grade strain and maintained minimally manipulated stocks to preserve its virulence.
Aug 16 BioRxiv abstract

Mass polio vaccination begins in Nigeria after 2 cases detected

Nigerian health officials launched a polio vaccination campaign in the northern state of Borno on Aug 15, targeting 999,956 children under the age of 5 years.

Last week the World Health Organization (WHO) reported that two children in Borno were paralyzed after contracting polio. These were the first cases of polio reported in Nigeria in more than 2 years. Much of Borno is under the rule of the terrorist organization Boko Haram, making routine vaccination and surveillance a challenge, according to a report in Science.

On the first day of the campaign, health workers in 5 local government areas (LGAs) of Borno had vaccinated 201,290 children, with 662 receiving their zero or first time oral polio vaccine polio (OPV) dose, the WHO said today in an update.

Deputy Governor of the Gwoza LGA, Usman Mamman Durkwa, said "the Borno State government is determined and committed to the total eradication of polio and will do everything within its power to achieve this goal," according to the WHO.

In addition to the vaccination campaign, the WHO in a separate statement yesterday announced yesterday plans to place an external surveillance team in Nigeria to monitor the country’s acute flaccid paralysis (AFP) surveillance system.

Detecting AFP is the gold standard for surveillance according to guidelines set by the Global Polio Eradication Initiative (GPEI). The assessment team will be in Nigeria from Aug 15 to Aug 25 to hunt for the source of polio in Borno, Kaduna, Kano and Sokoto states.
Aug 15 Science story
Aug 17 WHO story
Aug 16 WHO surveillance story

Steep chikungunya rise in Americas reflects Brazil rise

In its latest update on chikungunya, the Pan American Health Organization (PAHO) reported 32,492 more cases in the Americas, raising the total to 247,656 for the year. The increase is sharply higher than for recent weeks, with the bulk of the new cases—30,449—related to a month's worth of confirmed cases in Brazil, the Aug 12 update said.

Central American countries such as Costa Rica, El Salvador, and Guatemala reported small rises in cases, as did other nations such as the Dominican Republic and Colombia. Several of the smaller Caribbean countries and territories have not reported on chikungunya cases so far this year.

The number of deaths from chikungunya also rose sharply, by 21, putting the total for 2016 at 50. Most of the new fatalities were from Brazil.

The Americas' outbreak began in December 2013 on the island of St. Martin in the Caribbean.
Aug 12 PAHO update