H7N9 hospitalizes 2 in Shanghai; study estimates transmission risk
Shanghai health officials reported two new H7N9 avian influenza cases, in a 52-year-old man and a 37-year-old woman, the first infections reported in the city since the middle of February.
Hong Kong's Centre for Health Protection (CHP) said yesterday in a statement that the man is hospitalized in stable condition. No details were available about how he may have been exposed to the virus. The agency said so far 619 human cases have been reported on China's mainland, more than half of them from Guangdong and Zhejiang provinces.
The woman's infection was reported today in a statement from Shanghai's health department that was translated and posted by FluTrackers, an infectious disease news message board. The report said the woman is from Jiangsu province and is hospitalized in critical condition.
The two illnesses appear to be the 46th and 47th cases reported from Shanghai since the virus emerged in China 2 years ago.
Though it's unclear exactly how many H7N9 infections China has had in the third wave of illnesses that began in October, a case list kept by FluTrackers, which compiles official reports, puts the global total from the disease for all three waves at 646.
Apr 5 CHP statement
Apr 6 FluTrackers thread
FluTrackers H7N9 case list
In related developments, an analysis of surveillance systems in Cambodia, Laos, Thailand, and Vietnam suggests that severe human H7N9 infections in humans hasn't likely occurred, because the virus hasn't spread to the countries or that it has a lower incidence than H5N1 avian flu. The report, by researchers from the US Centers for Disease Control and Prevention and their counterparts in the four countries, appeared today in Emerging Infectious Diseases.
Though H7N9 may have already spread from China to poultry in other countries, poultry surveillance isn't likely to detect the virus until it becomes widespread, and possibly wouldn't be detected unless a human case surfaces, the investigators noted.
The authors said all four countries have the capacity to detect H7N9, along with well-developed hospital-based surveillance systems. They added that all but Laos have passive pneumonia surveillance systems that cover a wide area, and the group pointed out that Vietnam and Cambodia have detected H5N1 in humans since H7N9 emerged, suggesting that severe H7N9 infections haven't occurred or that they are less common than H5N1.
The team concluded that sporadic travel-related human infections might crop up, but they won't likely contribute to the spread in humans, as long as person-to-person transmission remains limited. They warned, though, that vulnerabilities remain, given the growth of trade networks and economic integration.
Mar 6 Emerg Infect Dis report
Canine flu outbreak strikes Chicago area
A canine influenza outbreak under way in the Chicago area has sickened more than 1,000 dogs so far and has been linked to 5 canine deaths, the Chicago Veterinary Medical Association (CVMA) said in an Apr 3 statement. The group is urging dog owners to take steps to protect the animals from exposure to canine infectious respiratory disease (CIRD), which is responsible for an increase in severe infections.
Donna Alexander, DVM, director of Cook County Department of Animal and Rabies Control (CCDARC), said in the statement that preliminary data from local veterinarians through Mar 31 suggests that 73% of animal hospitals have reported an increase in CIRD, and though the age of the dogs varies, the most severe cases of CIRD are being reported in dogs under 1 year old and those older than 7 years old.
She added that the majority of specimens submitted have been negative, but some results are still pending. Of samples that have tested positive, 93% were positive for canine influenza, suggesting that canine influenza may be the primary cause of the increasing number of severe respiratory infections that Chicago-area veterinarians are seeing.
Canine influenza is extremely contagious, and some infected dogs show no symptoms and can transmit the disease to other dogs. The CVMA is urging owners to keep their dogs from socializing with other dogs or from participating in group training activities. Pet owners are also being urged to refrain from boarding their dogs at kennels and to avoid doggie daycare, dog parks, and grooming facilities.
The CCDARC said the CIRD outbreak could last for several weeks. It said the condition is distinguished from "kennel cough" by its severity, possible consequences, and diagnostic confirmation. Symptoms include persistent cough, lethargic behavior, poor appetite, and fever. The agency added that the disease isn't transmitted to humans or other household pets, and because the virus can live on surfaces, people can avoid passing the virus to dogs by thoroughly washing their hands after touching or petting a dog.
A vaccine for CIRD is available and can be administered by a veterinarian.
According to the American Veterinary Medical Association (AMVA), canine influenza is caused by the novel influenza A H3N8 subtype, first seen in 2004 in racing greyhounds in Florida. Since then cases have been detected in 30 states and Washington, D.C. The disease is endemic in parts of Colorado, Florida, New York, and Pennsylvania.
Apr 3 CVMA statement