Flu Scan for May 31, 2016

H5N6 case in China
;
H5N1 in Cameroon
;
H7N9 transmission
;
Flu bacterial co-infections

China reports human H5N6 case in Hunan province

Chinese officials last week reported a human case of H5N6 avian flu, according to a post today on FluTrackers, an infectious disease message board.

The case involves a 50-year-old man from Jishou city in Hunan province's Xiangxi autonomous prefecture, FluTrackers said. He is hospitalized in critical condition.

The new case is the second H5N6 infection to have occurred in Hunan province, and it lifts the global case total to 15 since the virus emerged in April 2014. Nine H5N6 cases have been reported in China this year, FluTrackers said.
May 30 FluTrackers post
FluTrackers H5N6 case list

 

Cameroon reports H5N1 outbreak in poultry

Cameroon reported a recent H5N1 avian flu outbreak on a poultry farm, according to a May 27 report to the World Organization for Animal Health (OIE).

Cameroon's H5N1 outbreak began May 20 on a large farm in the capital city of Yaounde, located in the country's Centre region. Of the 33,000 breeders, boilers, and layers on the farm, 15,000 died from the infection, and the remaining 18,000 were culled to prevent the spread of the virus, the OIE said.

The outbreak was detected when officials observed high mortality among breeding birds during routine surveillance. Control measures, including disinfection and quarantine, have been implemented, the OIE said.
May 27 OIE
report

 

Study shows chickens readily transmit H7N9 to quail

Meanwhile, a recent study in Virology found that chickens transmit H7N9 avian flu poorly to other chickens but can infect nearby quail.

Researchers from Colorado State University and the US Department of Agriculture National Wildlife Research Center were able to characterize aspects of H7N9 avian flu transmission by simulating a live-animal market containing chickens, common quail, pigeons, and rabbits, according to findings published last week in Virology.

Four domestic chickens inoculated with the H7N9 virus were unable to produce an infection and viral shedding in two chickens caged with them. All four quail housed in cages directly below the infected chickens, however, seroconverted and began shedding virus between 3 and 11 days following exposure. Oral shedding in the quail was more than 10 times greater than titers observed in directly infected chickens, the authors said.

Pigeons and cottontail rabbits housed near the infected chickens showed no sign of infection. Environmental testing on 120 fecal and 100 water samples produced negative results for live virus, the authors said.

Given the findings, live-animal markets should not place cages of chickens and quail in proximity, the authors said.
May 26 Virology study

 

Review: Wide range of bacterial co-infections found in flu patients

The prevalence of bacterial co-infections in patients hospitalized with influenza ranges from 2% to 65%, a variation that highlights the importance of conserving antibiotic treatment for only those bacterial cases diagnosed by a positive test, according to a May 27 study in Influenza and Other Respiratory Diseases.

Researchers conducted a meta-analysis of 27 studies published since 1982 and comprising 3,215 patients hospitalized with lab-confirmed flu. The prevalence of bacterial co-infection was from 2% in a population of US newborns to 65% in French adults, the authors said. When seven studies accounting for more than half of the variation were excluded, the range of co-infection prevalence among 2,058 patients narrowed to 11% to 35%.

Rates of bacterial co-infection were similar for children and adults and rose only slightly for patients in the intensive care unit. Four studies that examined comorbidities found that co-infection was associated with flu severity, older age, diabetes, and sepsis, the authors said.

Among the eight studies that identified causes of co-infection, cases were most commonly due to Streptococcus pneumoniae (35% of cases) and Staphylococcus aureus (28%); other identified species included Pseudomonas aeruginosa, Streptococcus pyogenes, Haemophilus influenzae, and Klebsiella pneumonia, among others. Findings of significant species variation support the use of broad-spectrum antibiotics for flu-related pneumonia, the authors said, adding that routine testing for methicillin-resistant S aureus is advisable, especially for cases of community-acquired pneumonia.

Six studies found that providers may have underestimated the frequency of bacterial co-infection because of prior antibiotic use in 12% to 50% of flu patients, and one study found that previous antibiotic use made flu patients more likely to acquire an atypical bacterial infection, the authors said.

The authors cautioned providers to refrain from assuming that hospitalized flu patients require antibiotics and instead treat underlying viral illness and to confirm bacterial infection with routine cultures before initiating treatment. Additionally, more studies are needed to better characterize the frequency and diversity of bacterial infections in non-hospitalized flu patients, the authors said.
May 27 Influenza Other Respir Viruses study

Newsletter Sign-up

Get CIDRAP news and other free newsletters.

Sign up now»

OUR UNDERWRITERS

Unrestricted financial support provided by

Bentson Foundation 3MAccelerate DiagnosticsGilead 
Grant support for ASP provided by

  Become an underwriter»