News Scan for Sep 07, 2017

News brief

Saudi Arabia reports new MERS case in Riyadh

The Saudi Arabian Ministry of Health (MOH) reported another new case of MERS-CoV in Riyadh today.

A 48-year-old male expatriate from the capital city was diagnosed as having MERS-CoV (Middle East respiratory syndrome coronavirus) after presenting with symptoms of the virus. He is in critical condition. The man's source of infection is listed as "pimary," meaning it's unlikely he contracted the virus from another person.

Saudi Arabia's MERS-CoV case count since 2012 has now reached 1,720, including 693 deaths. Nine patients are still being treated, according to the MOH.
Sep 7 Saudi MOH report

 

Study: Zika damages ganglion cells in retina, leading to vision problems

A study today in JAMA Ophthalmology suggests that congenital infection with the Zika virus interferes with the correct formation of the retina's ganglion cell layer (GCL), leading to lasting vision problems.

To conduct the study researchers compared eight infants who had confirmed congenital Zika syndrome (CZS) to eight infants with cobalamin C deficiency (cblC), an inherited disorder that affects the body's ability to process vitamin B12. All study participants had two eye evaluations.

The infants with CZS had severe thinning of the ganglion cell region that lines the retina, in addition to increased retinal backscatter and severe structural disorganization. The central retinal degeneration was similar to that of cblC deficiency.

"The findings provide the first, to date, in vivo evidence in humans for possible retinal maldevelopment with a predilection for retinal GCL loss in CZS," the authors wrote.

This is the first study to observe changes to the ganglion cells in the retina, and the authors said this malformation suggest a particular vulnerability of the inner retina to the Zika virus.
Sep 7 JAMA Ophthalmol study

 

WHO seeks input on health worker PPE for viral hemorrhagic fever

The World Health Organization (WHO) recently released a draft of a preferred product profile for personal protective equipment (PPE) for frontline health workers responding to Ebola and other viral hemorrhagic fever outbreaks.

In its initial estimate, the WHO said health workers in West Africa's Ebola outbreak were 21 to 32 times more likely to contract Ebola when compared to the general adult population. High levels of infections during the outbreak revealed challenges in training and problems with PPE use, suggesting that improved PPE design and training might help cut the risk to responders.

Since the outbreak, the WHO has convened experts to advise about PPE use, and a 2015 workshop led to the formation of a WHO Advisory Committee for Innovative PPE, which drafted the PPE preferred product profile. They suggest reviewing and modifying PPE that's currently on the market and designing innovative new systems.

Now the group is asking for stakeholder input, and the comment period began yesterday and is open through Sep 28. In its materials, the committee said it hopes to approve final guidance in October 2017.
Sep 6 WHO draft PPE preferred product notification
WHO draft PPE preferred product profile and comment instructions

 

Brazil declares end of yellow fever outbreak

Brazil's MOH confirmed yesterday that the country's yellow fever outbreak, which began last December, is over. A total of 777 cases of yellow fever were confirmed during the outbreak, including 261 deaths. No new cases have been detected since June.

There are still 213 cases under investigation, the MOH said. A total of 2,270 potential cases were ruled out, and 307 cases were declared inconclusive. The case-fatality rate among confirmed cases was approximately 34%.

More than 98% of confirmed cases (764 of 777) were found in the country's southeastern states, including Minas Gerais, Rio de Janeiro, Sao Paulo, Espirito Santo, and Bahia. The disease never took hold in the country's large cities, though sporadic zoonotic cases were reported outside of Sao Paulo and Rio de Janeiro. The Aedes aegypti mosquitoes were also never implicated in the transmission cycle of this outbreak.

Throughout the outbreak, health officials conducted several yellow fever vaccination campaigns, using 36.7 million doses of the vaccine. The MOH said another 10 million doses are ready for use in 2018.
Sep 6 Brazil MOH press release
Sep 7 Xinhua
news story

 

New polio case reported in Pakistan

Pakistan now has four cases of wild polio type virus 1 this year, with the latest case reported in Karachi, according to the Global Polio Eradication Initiative's (GPEI's) weekly update.

The new patient had onset of paralysis on Aug 11. Pakistan, along with neighboring Afghanistan as well as Nigeria, is one of three countries where wild polio virus type 1 is still endemic.

According to the GPEI, small-scale vaccination campaigns were carried out in July in the core polio reservoirs and other high-risk areas, aiming to reach 10.1 million children who are still unvaccinated against the virus.
Sep 6 GPEI
update

Avian Flu Scan for Sep 07, 2017

News brief

H5N8-H5N1 avian flu combo virus shows increased virulence in mice

In the latest gain-of-function (GOF) study, South Korean researchers have substituted genes from H5N1 avian influenza onto an H5N8 avian flu virus and found that it caused greater pathogenicity and up to a 1,000-fold greater virulence in mice.

Writing in the journal Virulence, the investigators did not alter the virus by serial passaging it in lab animals, as has often been the case with GOF studies. Instead, they generated reassortant viruses in the lab using an H5N8 backbone virus from South Korea in 2014 and then substituting individual genes from an H5N1 virus that was obtained in South Korea in 2006 so they could understand the contribution of each individual gene to virulence in mammals.

They found that substituting the PB2 gene segment or the NA gene segment from the H5N1 virus resulted in significantly enhanced pathogenicity in lab mice compared with the parental H5N8 virus. Notably, substituting the PB2 gene segment resulted in a 1,000-fold increase in virulence in mice compared with the parental virus. The reassortant virus with that substitution also induced the highest virus titers in lungs at all test intervals and the greatest inflammatory cytokine response among all viruses tested.

The authors conclude, "Our study demonstrates that a single gene substitution from other avian influenza viruses can alter the pathogenicity of recent H5N8 viruses, and therefore emphasizes the need for intensive monitoring of reassortment events among co-circulating avian and mammalian viruses."

South Korea had extensive H5N8 outbreaks in poultry over the winter and into the spring of this year.

GOF studies enhance the pathogenicity, transmissibility, or host range of a pathogen to learn more about it. They have triggered "dual-use" concerns—worries that research meant for beneficial purposes could be used to create bioterror threats or for other ill purposes.
Sep 5 Virulence abstract

 

Wrap-up of China's fifth H7N9 waves highlights dominance of new lineage

The number of towns, provinces, and regions that reported human cases in China's unprecedented fifth wave of H7N9 avian influenza activity, which began in October 2016, is higher than the previous four waves combined, researchers from the US Centers for Disease Control and Prevention and their collaborators in China reported today in the latest edition of Morbidity and Mortality Weekly Report (MMWR).

In their wrap-up of the latest epidemiologic and genetic sequencing information, the group said 759 illnesses were reported in the fifth wave, 281 of them fatal, and that among several new developments over the past months, the newly emerged Yangtze River Delta low pathogenic lineage accounted for most of the activity and scores as having the highest potential pandemic risk (moderate to high) on the CDC's Influenza Risk Assessment Tool. In February, World Health Organization (WHO) flu vaccine advisors recommended new candidate vaccine viruses for the Yangtze River Delta lineage, for which current H7N9 candidate vaccine viruses show limited protection.

Other notable features of the fifth wave were the emergence of the highly pathogenic strain in poultry, which was found in 27 of 759 cases and was most often seen in those from rural areas, people with early hospital admission, and in those who had been exposed to sick or dead poultry, according to the report.

Despite the wider geographic spread, the patterns of spread from poultry to humans and from human to humans haven't changed much, the group said. Fourteen clusters of two or three people were reported to the WHO in the fifth wave, compared to an average of nine in each of the earlier waves.  Transmission from poultry is rare and the virus doesn't pass easily among people, but when infections do occur, they are linked to severe and fatal infections, requiring close vigilance, they added.
Sep 8 MMWR report

 

More avian flu outbreaks reported in Taiwan, Italy

In separate notifications over the last 2 days, the World Organization for Animal Health (OIE) detailed more events regarding ongoing highly pathogenic avian influenza activity, one in Taiwan and the other in Italy.

In Taiwan, another H5N2 outbreak was detected, this time at a slaughterhouse in Taipei City. The virus was found after authorities saw signs of disease in carcasses of native chickens on Aug 18 during the postmortem inspection, which prompted testing. Ten carcasses were destroyed, and a trace back investigation is underway to find the farm that sourced the poultry. Taiwan has been battling several outbreaks involving H5N2, as well as other strains, since early 2015.

Elsewhere, Italy reported another H5N8 outbreak at a turkey farm in the Lombardy region in the north central part of the country. The event began on Sep 2, killing 45 of 23,193 susceptible birds. The rest of the flock is slated for culling. H5N8 has surfaced in a few European countries over the warmer summer months, but Italy has been hardest hit, especially commercial turkey producers.
Sep 6 OIE report on H5N2 in Taiwan
Sep 7 OIE report on H5N8 in Italy

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