NEWS SCAN: Bacterial co-infection in H1N1, tracking flu vaccine effectiveness, new BSE cow details, monkeypox scare, honing disease surveillance

Apr 27, 2012

Bacterial co-infection patterns in H1N1 pneumonia patients
An analysis from Spain of 128 consecutive patients hospitalized with 2009 H1N1 influenza and community-acquired pneumonia (CAP) showed that a third of them had bacterial co-infection and that the two most common predictors for the complication were chronic obstructive pulmonary disease (COPD) and increased platelet count. The study, published yesterday in the Journal of Infection, involved patients hospitalized at two facilities—one in Valencia and one in Barcelona—from May 2009 to February 2010. Patients went through a diagnostic protocol to identify 2009 H1N1 infection and to determine what type of pathogens were involved in cases involving bacterial co-infection. Of 677 patients hospitalized with CAP in the two facilities, 128 (19%) were found to have 2009 H1N1 influenza. Of these, 42 (33%) had bacterial co-infection. The authors noted that this rate is slightly higher than rates with seasonal flu. When the authors looked at mortality patterns, they found no difference between patients with only 2009 H1N1 pneumonia and those with co-infection. The two most common bacterial pathogens were Streptococcus pneumoniae and, unexpectedly, Pseudomonas aeruginosa. The researchers suggested that the high rate of P aeruginosa could relate to the high proportion of patients with severe CAP and COPD in the bacterial co-infection group. The role of platelets in the host defense system may contribute to their role as a marker for bacterial infections, the group wrote.
Apr 26 J Infect abstract

Canadian flu surveillance system tracked H3N2 mismatch
An enhanced sentinel flu surveillance system in four of Canada's biggest provinces helped health officials sort out a rise in the number of long-term-care facility outbreaks, including higher-than-expected infection rates in vaccinated staff, that occurred during the 2010-11 flu season, according to a study published yesterday in Clinical Infectious Diseases. The country's sentinel surveillance platform includes a negative case-control element and genetic analysis to help estimate annual vaccine effectiveness (VE). During that flu season, the first one after the 2009 H1N1 pandemic period, many Canadians received the split, nonadjuvanted trivalent inactivated flu vaccine. Ontario reported a threefold increase in the number of institutional outbreaks that season, with Quebec reporting a fivefold increase. Preliminary analysis found that two variant H3N2 viruses were circulating and that VE was suboptimal. The final analysis of 1,718 participants showed that VE among adults aged 20 to 49 years was 65% (95% confidence interval [CI], 8% to 87%) for 2009 H1N1, 66% (95% CI, 10% to 87%) for influenza B, and 39% (95% CI, 0 to 63%) for H3N2. Though hemagglutinin inhibition (HI) testing suggested all H3N2 isolates were matched to the vaccine strain, phylogenetic analysis identified two clades—Hong Kong/2121/2010 and Victoria/208/2009—that had multiple amino acid substitutions at antigenic sites compared with the vaccine strain. The researchers noted that the facility outbreak observations were consistent with the sentinel network findings, though not with conventional HI characterization. They concluded that the surveillance system they used helps health officials follow virus evolution and assess annual vaccine protection.
Apr 26 Clin Infect Dis abstract

Report: US BSE cow was lame before culling
A report yesterday from the US Department of Agriculture (USDA) to the World Organization for Animal Health (OIE) contained some new details about a California dairy cow that recently tested positive for an atypical form of bovine spongiform encephalopathy (BSE), the first US case detected since 2006. Earlier reports didn't say whether the cow had any signs of clinical disease or how old it was, but the OIE report says the cow was culled for lameness and that it was 10 years and 7 months old. The cow was tested for BSE after it was slaughtered as part of routine surveillance for the disease. The carcass was set to be rendered but will now be destroyed. The report said the source of the disease us unknown and could have resulted from a random mutation. The cow was from Tulare County, located in California's Central Valley south of Fresno. The cow's age means it was born after the United States first banned use of cattle protein in feed for cattle and other ruminants in 1997, but before a broader ban went into effect in 2009 that bars certain cattle materials from all animal feed. However, veterinary health experts said earlier this week that the very rare, atypical BSE the cow had isn't typically linked to consumption of contaminated feed. Health officials have said the California case poses no threat to the nation's food supply
Apr 26 OIE report
Apr 24 CIDRAP News story "US has first BSE case in 6 years"

Woman on grounded Chicago plane had bedbug bites, not monkeypox
Passengers on a Delta flight arriving at Midway Airport in Chicago were held on the plane while an emergency response team checked for possible monkeypox yesterday, according to a Minneapolis Star Tribune report and a notice on the Centers for Disease Control and Prevention (CDC) Web site. A 50-year-old woman on the plane, from Redwing, Minn., was returning home from a 4-month stay in Africa after other stops in Amsterdam and Detroit. The newspaper story says she had told her mother, who lives in Indiana, that one of the children she was preparing to adopt in Uganda had some pus-filled bumps and also that she had a rash. "Somewhere along the way things got confused," the story quotes her son as saying. The story says the woman's mother called a hospital asking what her daughter might do to treat sores she got in Uganda, while the CDC report says she expressed concern that the rash might be monkeypox. Chicago Emergency Medical Services met the plane and was in touch with the Chicago Department of Public Health and CDC medical staff. They determined, on the basis of the woman's symptoms and photographs of the rash, that the woman had been bitten by bedbugs.
Apr 26 Star Tribune story
Apr 26 CDC report

ECDC says disease surveillance needs honing in face of climate change
Surveillance practices for infections traditionally considered to be tropical diseases need enhancement in the European Union (EU) because of climate change and globalization, according to an article published today in Science magazine. The European Centre for Disease Prevention and Control (ECDC) was charged in 2009 by the European Commission with guiding a process to strengthen the EU's resilience to emerging and re-emerging infectious diseases. The agency conducted an evaluation of current surveillance systems, an extensive literature review, a weighted risk analysis of various diseases, and consultation with EU representatives. The seven diseases identified as most important for adjusted surveillance practices because of their sensitivity to climate change and their severity are Lyme disease, Vibrio infections (except for V cholerae 01 and 019), visceral leishmaniasis, Chikungunya fever, Rift Valley fever, dengue fever, and tick-borne encephalitis. Among suggested enhancements are better collaboration between the veterinary and public health communities and better monitoring of environmental precursors to disease.
Apr 27 ECDC report
Apr 27 summary of Science article

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