Avian Flu Scan for Feb 04, 2015

News brief

China reports new H7N9 case in Zhejiang province

Chinese officials have reported another H7N9 avian flu illness, in Zhejiang province, and Hong Kong's Centre for Health Protection (CHP) today noted 49 cases that have occurred in recent weeks, but it's difficult to determine if any of them are new.

The Zhejiang case involves a 49-year-old woman who is hospitalized in critical condition, according to a district health board notice translated and posted yesterday by FluTrackers, an infectious disease news message board. She has a history of a serious underlying medical condition.

The woman was hospitalized for a cough, body aches, and other symptoms on Jan 25. Testing confirmed H7N9 on Jan 28. Officials did not mention contact with poultry or other risk factors, but they said they are following up with 20 of the woman's close contacts.

The new case brings the outbreak total to 544, according to a list compiled by FluTrackers.

Today's Hong Kong CHP notice, meanwhile, said that China's Health and Family Planning Commission and Guangdong province's health commission have reported 49 cases in the past 6 weeks: 30 from Fujian, 10 from Zhejiang, and 7 from Jiangsu provinces, as well as 1 each from Guangdong province and Xinjiang Uyghur Autonomous Region. They involve 38 men and 11 women from 1 to 88 years old, and 9 proved fatal.

A post today from FluTrackers, however, notes, "Most of these 'new' cases are previously known. We have documented that the CHP was behind by 38 cases. Apparently there are an additional 11 cases but there is no visibility into who these cases are." It adds that Guangdong has recently confirmed two new cases that the CHP has not noted, but today's CHP report includes only one new case.

In other H7N9 news, the European Centre for Disease Prevention and Control (ECDC) today updated its risk assessment of the disease in light of two cases recently imported into Canada, but the agency did not elevate the risk level.
Feb 3 FluTrackers post
FluTrackers H7N9 case list
Feb 4 CHP press release
Feb 4 FluTrackers post
Feb 4 ECDC news release on risk assessment

More avian flu in Washington state, H5N8 in wild birds

The Washington State Department of Agriculture (WSDA) said yesterday that an unknown strain of avian flu has struck a backyard flock of about 100 birds in Okanogan County, while a report posted yesterday by the World Organization for Animal Health (OIE) notes H5N8 infections in wild birds in Washington and three other western states.

The outbreak in Washington compelled the WSDA to establish the state's third concurrent quarantine related to avian flu in backyard flocks. The other outbreaks both involve H5N2 avian flu; one announced on Jan 29, also in Okanogan County, involves almost 5,000 birds, and the other, announced Jan 16, involves an unknown number of birds in Clallam County.

The latest outbreak involved a "flock of mixed poultry and other birds" in Oroville, the WSDA said in a news release. The quarantine zone includes premises within 6 miles of the affected site. Tests on Jan 31 confirmed avian flu in infected birds, and further testing is under way to identify the strain, the WSDA said.

The OIE report, meanwhile, confirms highly pathogenic H5N8 in wigeons in Whatcom County, Wash., and Butte County, Calif.; a gyrfalcon in Kootenai County, Idaho; and a mallard in Lincoln County, Neb. The gyrfalcon is a captive wild bird, while all the ducks were shot by hunters. The findings in Nevada, from samples taken Jan 30, appear to be the same results reported by the media on Feb 2.
Feb 3 WSDA news release
Feb 3 OIE report

News Scan for Feb 04, 2015

News brief

Duration of MRSA colonization might be shorter than thought

The median duration of colonization with community-based methicillin-resistant Staphylococcus aureus (MRSA) in ambulatory patients is 21 days, shorter than the previously thought duration of 6 to 9 months, and treatment with clindamycin is associated with more rapid clearance of the infection, say findings of a study published yesterday in Clinical Infectious Diseases.

The authors, many of them from academic centers and hospitals in Philadelphia, carried out a prospective cohort study of 243 community-based patients presenting at any of five academic hospitals in Pennsylvania between Jan 1, 2010, and Dec 31, 2012, with skin soft-tissue infection (SSTI) that was found to be MRSA.

Patients and their household members (total, 803) performed self-sampling (or, for children, sampling by parents) from the nares, axillae, and groin for MRSA colonization every 2 weeks for 6 months. Clearance of the organism was defined as negative results in two consecutive sampling periods.

The median duration of MRSA colonization, defined as the period from diagnosis to clearance, was 21 days (95% confidence interval [CI], 19 to 24). In 19.8% of patients, MRSA had not been cleared at 6 months.

Clindamycin treatment of SSTI was associated with earlier clearance (hazard ratio [HR], 1.72; 95% CI, 1.28 to 2.30; P < 0.001). Older age was associated with longer colonization (HR, 0.99; 95% CI, 0.98 to 1.00; P = 0.010). An increasing number of colonized household members was associated to a borderline-significant degree with a longer duration of colonization of the index case (HR, 0.85; 95% CI, 0.71 to 1.01; P = 0.064).

The authors say future studies "should examine the predictors of persistent colonization, the impact of prolonged duration of colonization on development of MRSA reinfection, and the potential role of total household decolonization in adults and children" as well as further elucidate the role of clindamycin as treatment.
Feb 3 Clin Infect Dis study abstract

Trial: One dose of H3N2v vaccine immunogenic in most adults

An experimental vaccine provided protection against variant H3N2 influenza (H3N2v) after one dose in healthy adults 18 years and older, according to a study yesterday in the Journal of Infectious Diseases.

H3N2v viruses first emerged in 2011, but concern spiked in the summer of 2012 when the US Centers for Disease Control and Prevention (CDC) reported 306 cases. The incidence of known cases has since declined dramatically.

The study comprised 211 people, 104 of whom were 18 to 64 years old, and 107 of whom were age 65 and older. Researchers administered two doses of the H3N2v vaccine (15 micrograms of hemagglutinin per dose) 21 days apart to measure serum hemagglutinin inhibition (HAI) titers, neutralizing antibody (Neut Ab) titers, and memory B cell response.

HAI titers at or greater than 40 were present in 87% (95% CI, 79%-93%) of those under 65 and 73% (95% CI, 63%-81%) of those 65 and older after 21 days. HAI seroconversion occurred in 51% (95% CI, 41%-61%) of the younger group and 52% (95% CI, 41%-62%) of the older group, but neither seroconversion rate was statistically significant.

A Neut Ab response occurred in 91% (95% CI, 84%-96%) of the younger group, and 59% (95% CI, 49%-69%) of this group seroconverted after 21 days. In older group, 82% (95% CI, 73%-89%) had Neut Ab titers, and 67% (95% CI, 57%-77%) seroconverted after 21 days.

The authors said that, because 93% of the study population already had antibodies to H3N2v prior to vaccination, one dose of the vaccine should prove effective for a healthy adult population.
Feb 3 J Infect Dis study

Study: H3N2 viruses isolated from canine nasal swabs

Chinese researchers found two H3N2 influenza subtypes in pet dogs that contain both human and swine characteristics, according to a study yesterday in Virology Journal.

Researchers obtained 261 nasal swabs and 315 blood samples from pet dogs in eight Chinese provinces during 2013. After identifying influenza A canine isolate virus (CIV) in 35 nasal swabs from dogs in Guangxi province, subtyping showed the presence of H3N2 in two samples.

During subtyping, the viruses clustered with the human H3N2 Moscow/10/99 strain and most swine flu viruses. All blood samples were negative for CIV.

The findings suggest that dogs may be regarded as intermediate H3N2 hosts, even though the virus has not firmly established itself in canine populations, the authors said.
Feb 3 J Virol study