NEWS SCAN: H1N1 co-infections, low post-H1N1 immunity, sick hospital workers, food safety reform, Lassa fever case

Sep 15, 2010

Tamiflu-resistant seasonal H1N1 combined with pandemic H1N1 strains
Researchers have found that co-infection with oseltamivir (Tamiflu)–resistant seasonal H1N1 influenza and Tamiflu-susceptible pandemic 2009 H1N1 could produce reassortant viruses resistant to the common antiviral drug. The scientists, from St Jude Children's Research Hospital in Memphis, Tenn., and New Zealand and Australia, tested more than 1,000 pandemic H1N1 viral cultures for oseltamivir resistance using fluorometric-inhibition assay and polymerase chain reaction (PCR). In doing so, they discovered 11 cases of co-infection with oseltamivir-resistant seasonal H1N1, plus two samples that indicated co-infection on PCR but could not be confirmed. All samples were collected before pandemic vaccine was available. The authors conclude, "Although influenza co-infections are rare, we have shown that they occurred during the first stage of a pandemic when seasonal strains cocirculated. This cocirculation poses a risk for further reassortment for the pandemic strain, which could result in a new pandemic strain. Of particular concern is the potential generation of an oseltamivir-resistant pandemic strain."
Sep 15 Emerg Infect Dis study

Low immunity after novel H1N1 pneumonia may persist
A study of patients affected by pandemic H1N1 flu pneumonia found that their immunity may be decreased several months after they recover from their symptoms. The study, presented today at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy meeting in Boston, found that plasmocytoid dendritic cells (pDC), the main producers of natural antiviral substances in the body, were dramatically impaired during the acute phase of the disease. The researchers also found, however, that low pDC levels persisted months after patients recovered from their disease.

Survey reveals many hospital residents work while sick
A survey of medical residents during the 2008-2009 academic year found that three in five came to work sick at least once, which could have impaired their performance and exposed patients and colleagues to infections, according to Chicago researchers who reported their findings today in the Journal of the American Medical Association (JAMA). A third of the residents reported they worked sick more than once. The authors, from the University of Chicago Medical Center and Rush University, used data from a survey conducted by the American Council for Graduate Medical Education. It included 744 second- and third-year residents in 35 programs at 12 hospitals. The residents were asked if there were occasions when they should have taken time off for illnesses but didn't and if their schedule allowed them to see a physician regarding their health. More experienced residents were more likely to work when sick, but researchers found no differences by specialty, gender, or nationality. The authors suggested that because the pattern did not vary much by group, working while sick may be pervasive in hospital cultures. Factors that might contribute to the behavior may be misplaced dedication, inadequate staff coverage, and fear of letting teammates down, the authors speculated. They concluded that residency program directors should address the risks to patients and medical performance that can occur when residents work sick.
Sep 14 EurekAlert press release
Sep 15 JAMA research letter extract

Political squabbles slow passage of Senate food safety reform
Democrats in the US Senate say food safety legislation could be within 24 hours of passage, but the legislation is still hung up in the Senate Health, Education, Labor, and Pensions (HELP) committee, where Republican senators are voicing concerns about the bill's potential impact on the federal budget, the political news site Politico reported yesterday. The food safety reform legislation has languished in the Senate since July 2009, when the House passed its version. Calls for the Senate to complete work on its version of the bill have intensified in the wake of the national recall of eggs by two Iowa producers that was triggered by a surge in the number of Salmonella Enteritidis infections. Over the August recess the HELP committee made progress on the bill, releasing a manager's amendment with six bipartisan cosponsors. Democratic negotiators have said the Congressional Budget Office has listed the net cost of the bill as $1.4 billion over 5 years, but has said it complies with the Senate's pay-as-you-go rules and is "deficit neutral." However, Senate Republican aides told Politico that squabbles among Democrats are slowing progress on the bill.
Sep 14 Politico story

Imported Lassa fever case in Pennsylvania was 6th in US
A man who lives in Pennsylvania returned from a trip to his native Liberia with Lassa fever, marking the sixth case of the tropical disease imported into the United States and the first since 2004, according to the Centers for Disease Control and Prevention (CDC). The Lassa fever virus is endemic in West Africa and causes an illness that is fatal in 1% to 2% of cases, the agency noted in a report today in Emerging Infectious Diseases. The patient, 47, traveled to Liberia last January and stayed in his native village, sleeping in a hut infested with rats. He fell ill on the day of his departure from Liberia and sought treatment after returning to the United States, leading to 21 days in a hospital. The virus was identified on his fifth hospital day, but he was not given ribavirin, a recommended treatment, because he was improving by the time the virus was suspected. The man had 140 contacts who were given information about Lassa fever, but no secondary cases were found. The CDC says clinicians treating patients who have a fever after traveling to West Africa should obtain detailed histories to learn if they have been in rural areas where they risked exposure to rodents. Early treatment with ribavirin can greatly reduce death rates in patients with severe Lassa fever, the report says.
Sep 15 Emerg Infect Dis report

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