NEWS SCAN: Lab-acquired plague, XDR-TB in China, H5N1 outbreaks, foodborne investigation methods, high-dose flu vaccine

Feb 24, 2011

Ungloved hands may have led to first fatal case of lab-acquired plague
A 60-year-old researcher who contracted plague in 2009 was known to inconsistently wear gloves while handling Yersinia pestis cultures, according to an analysis today of the first reported fatal case of laboratory-acquired plague. The report, in Morbidity and Mortality Weekly Report (MMWR), details how the lab worker, part of a group working with an attenuated Y pestis strain not known to have caused lab-acquired infections, became ill in September 2009. He was evaluated in an outpatient clinic for fever, body aches, and cough of about 3 days' duration and was advised to seek emergency department (ED) care. He did not seek such care then, but was taken by ambulance to a Chicago ED 3 days later because of worsening symptoms. His respiratory distress required intubation 12 hours later, and he died of cardiac arrest an hour after that. Medical staff was unaware of the patient's potential for occupational Y pestis exposure until several days after his death. Blood tests later confirmed that he was infected with the Ypestis strain he had worked with. Follow-up investigation revealed no further plague cases, and the researcher's coworkers said he did not always follow protocol for wearing gloves. The report said the findings are consistent with septicemic plague, though pneumonic plague could not be entirely ruled out. His type 1 diabetes may have contributed to symptom severity. The CDC said the last reported US case of lab-acquired plague was in 1959.
Feb 25 MMWR report

Drug-resistant TB cases fairly high in Chinese study
A third of samples taken from a Chinese hospital specializing in tuberculosis (TB) care were found to be resistant to at least one first-line drug, while 11% were multidrug-resistant TB (MDR TB) and 2% were extensively drug-resistant TB (XDR TB), according to a study published yesterday. Researchers studied 989 Mycobacterium tuberculosis samples (860 new cases and 129 retreated cases) from Shandong Provincial Chest Hospital, which is China's only provincial hospital specializing in TB. Median patient age was 40. Of the isolates, 319 (32.3%) were resistant to at least one first-line drug, 107 (10.8%) were MDR TB, and 20 (2%) were XDR TB, or 10.8% of MDR TB cases. Recent surveillance data from Beijing and Shanghai found the proportion of XDR TB cases among MDR TB cases to be 6.3%. The authors conclude, "XDR TB is of major concern in China."
Feb 23 Emerg Infect Dis report

Japan and Bangladesh report more H5N1 outbreaks
Agriculture officials in Japan detected four more H5N1 avian influenza outbreaks in poultry and have identified the virus 17 more times in wild birds, according to reports they filed with the World Organization for Animal Health (OIE). The poultry outbreaks occurred in mid February in farms in Miyazaki, Wakayama, Aichi, and Mie prefectures. The virus killed a total of 100 birds on the farms, and the remaining 224,000 birds were destroyed to curb the outbreaks. The report detailing H5N1 in wild birds described findings in 11 prefectures: Nagasaki, Hokkaido, Hyogo, Kyoto, Oita, Miyazaki, Kagoshima, Tokushima, Fukushima, Tochigi, and Yamaguchi. The virus killed five peregrine falcons, four swan species, and three Mandarin ducks, along with a greater scaup, little grebe, hooded crane, Ural owl, and grey heron. Elsewhere, Bangladesh said the H5N1 virus hit 22 more poultry farms in five different states, according to a report to the OIE. Most of the outbreaks occurred on farms in Dhaka state, but H5N1 was also detected in farm flocks in Khulna, Rangpur, Sylhet, and Chittagong states. The disease killed 11,438 birds, and 78,840 more were culled during outbreak response activities.
Feb 24 OIE report on Japanese poultry outbreaks
Feb 24 OIE report on Japanese wild bird outbreaks
Feb 24 OIE report on Bangladesh outbreaks

New genome test shows promise for foodborne illness investigations
Investigators from the US Food and Drug Administration (FDA) used a new genome sequencing test to pinpoint spice rubs on certain salamis as the source of a Salmonella Montevideo outbreak in early 2010 that sickened nearly 300 people in 44 states and the District of Columbia, the FDA said today in a press release. In the earlier stages of the probe, laboratory experts using conventional testing methods had a difficult time distinguishing Salmonella isolates in spiced meat and clinical samples from earlier isolates associated with pistachios. The FDA's scientists used "next-generation sequencing" (NGS) to test 35 samples from a broad range of suppliers, patients, and places. NGS confirmed that the outbreak strain came from a single food facility and a single source, the spice rub, and it showed that a California isolate was not part of the outbreak even though its PFGE pattern showed it to match the outbreak strain. The FDA said the experience shows the value of good traceback investigations and that NGS will play an important role in future outbreak investigations. The FDA scientists who used the technique published their findings yesterday in the correspondence section of the New England Journal of Medicine.
Feb 24 FDA press release
Feb 23 New Engl J Med correspondence

Survey details complaint system use in foodborne outbreak detection
A study to determine how local health departments use consumer complaint systems for foodborne illness surveillance found that 81% have them, and though most collect a wide variety of information, few store it on an electronic database. The study by researchers from the University of Minnesota and the National Association of County and City Health Officials (NACCHO) appears in the March issue of the Journal of Food Protection. The group conducted two online surveys of 500 local health departments. They found a correlation between outbreak rates and complaint rates. Electronic databases and methods for reviewing complaints were linked to more frequent outbreak detections, which the researchers said suggests that proper investigation of complaints is a key to detecting outbreaks. They said their findings show that a surveillance infrastructure exists in most areas, but it's important to maximize its use to improve outbreak detection. Given their finding that 20% of health agencies covering populations of over 1,000,000 people did not find any outbreaks in the previous year, they concluded that more work is needed to refine foodborne illness surveillance, including the complaint system.
Mar J Food Prot abstract

Study sheds more light on effects of high-dose flu vaccine in elderly
A study published online yesterday by Vaccine provides further evidence that a high-dose influenza vaccine produces a stronger immune response in people over 65, whose immune systems may not respond effectively to standard-dose vaccines. In the study—a substudy within a larger clinical trail—49 elderly people were randomly assigned to receive either the high dose vaccine, containing 60 micrograms (mcg) of antigen for each of three flu strains, or a vaccine containing the standard 15 mcg per strain. Fifteen young adults received the standard vaccine. In the elderly volunteers, the high-dose vaccine generated higher antibody levels than the standard vaccine, but not as high as those induced by the standard vaccine in the young adults. The vaccines generated vaccine-specific circulating T cells producing interferon-gamma in all the groups, but the interferon responses didn't differ significantly between groups. The elderly group that received the standard vaccine had the highest proportion of people who showed no immune response. The vaccines used in the study were made by Sanofi Pasteur, maker of Fluzone High-Dose, which was approved in 2009 for use in US elderly people. The authors write that because the study involved healthy, active seniors, the findings "support the notion of a general decline in the immune capacity" of active elderly people and challenge the view that poor immune responses in the elderly are due to reduced health status.
Feb 23 Vaccine abstract
Dec 28, 2009, CIDRAP News story on Fluzone High-Dose approval

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