Hong Kong initiates border monitoring, quarantine over H7N9 case
Authorities are monitoring incoming travelers for disease and have quarantined 17 close contacts of the first H7N9 avian flu patient identified in Hong Kong, its Centre for Health Protection (CHP) said today in a statement.
"All border control points (BCPs) have implemented disease prevention and control measures. Thermal imaging systems are well in place at BCPs for body temperature checks of inbound travellers," a spokesman for Hong Kong's Department of Health said in the statement.
Officials have identified 17 close contacts and more than 220 other contacts, the CHP statement said. The close contacts include 10 home contacts, including 4 with nonspecific symptoms, a friend who traveled to Shenzhen with the case-patient, and 6 patients who stayed in the same cubicle with the female 36-year-old H7N9 patient in Tuen Mun Hospital.
The close contacts were prescribed the antiviral drug oseltamivir (Tamiflu) as a precaution, and all tested negative for H7N9 on preliminary lab tests. Asymptomatic close contacts will live in a designated quarantine village for 10 days since their last contact with the index patient, who is a domestic helper from Indonesia.
The other contacts are being monitored and have been offered oseltamivir, the CHP said.
The agency said travelers who return to Hong Kong with a fever or respiratory symptoms, especially from H7N9-affected areas, should seek medical attention.
In a separate government statement today, Ko Wing-man, MBBS, secretary for food and health, said the risk of a community H7N9 outbreak in Hong Kong was low.
Dec 4 CHP statement
Dec 4 Hong Kong government statement
Tests weigh threat from former H2N2 pandemic flu virus
Experiments involving an avian H2N2 flu virus that caused a pandemic in the late 1950s and still circulates in birds found that it can infect mammalian cells and spread in ferrets, though it lacks the genetic markers for human adaptation, according to a study in the Journal of Virology. The goal was to assess the risk of the H2N2 virus, which hasn't been seen in humans since 1968.
Researchers from St. Jude Children's Research Hospital in Memphis analyzed 22 H2N2 viruses obtained from domestic and wild poultry from 1961 to 2008, the most comprehensive analysis so far of the virus. They found that the viruses haven't changed much since when H2N2 circulated as a pandemic strain. Most of the isolates they looked at replicated in mouse and human bronchial epithelial cells but showed little ability to replicate in swine tissues.
Several isolates replicated well in ferrets, and three spread through direct contact in the animals. Researchers classified one of the three strains, which was isolated in 1979 from a duck in Hong Kong, as having high pandemic potential. But no ferret-transmissible H2N2 strains spread by the airborne route.
Isolates still had a preference for cells in avian respiratory tracts, the team wrote, and the team's antiviral susceptibility tests found that all of the viruses were susceptible to neuraminidase inhibitors and adamantanes.
Co-author Jeremy Jones, PhD, said in a St. Jude press release that although the viruses appear avian, the study found that they can behave like mammalian flu strains. "That is troubling, because some of the H2N2 pandemic viruses looked avian when the pandemic began in 1957, but in a few short months, all of the isolated viruses had picked up the genetic signatures of adaptation to humans," he said. Jones added that the pattern could recur if the viruses jump from birds to humans again.
The group concluded that the greatest threat would be to people under age 50 who have no previous exposure to the virus. They also observed that isolates' close similarity to an H2N2 pandemic vaccine candidate could suggest that another outbreak in humans might be mitigated by a vaccine, though the changes in the virus warrant close surveillance.
Dec 2 St Jude press release
Nov 13 J Virol abstract
Low-path avian flu outbreaks reported in Taiwan, Germany, Portugal
Three outbreaks of low-pathogenic avian flu have affected poultry in Taiwan, Germany, and Portugal, according to reports filed with the World Organization for Animal Health (OIE).
In Taiwan, "third round surveillance" detected low-pathogenic H5N3 avian flu viruses in 20 ducks yesterday at a meat-type farm of 10,000 birds in Yuli township of Hualien County. Surveillance was being conducted after an August H5N3 outbreak in the vicinity.
The ducks showed no signs of clinical illness, and no culling was done to prevent disease spread.
In Germany, 20 laying hens tested positive for H5N3 on a farm of 130 birds in Baden-Wurttemberg state. The hens were culled yesterday, and ostriches on the farm will also be destroyed, according to the OIE report.
In Portugal, a low-pathogenic H7 strain was detected in Baixo Alentejo province during routine surveillance in a backyard flock of 63 birds—36 broilers, 18 chickens, 6 guinea fowl, and 3 ducks. All birds were destroyed, and a 1-kilometer restriction zone has been established.
Dec 3 OIE report on Taiwan
Dec 3 OIE report on German outbreak
Dec 2 OIE report on Portugal