Study: Community-onset MRSA levels vary across US
A 4-year survey of methicillin-resistant Staphylococcus aureus (MRSA) at five medical centers across the United States found that the incidence of community-onset (CO) MRSA cases varied considerably, with trends in New York City and Los Angeles going in opposite directions, according to a report in Clinical Infectious Diseases.
Researchers from the five academic centers counted single-patient blood cultures that were positive for MRSA and methicillin-susceptible S aureus (MSSA) each year from 2008 through 2011. The cases were classified as CO or healthcare-onset (HO). Nationally, the report notes, CO MRSA rose from the 1990s through the 2000s, but HO rates have decreased recently.
A total of 4,171 episodes of bacteremia were counted at the five centers. Los Angeles had a 57% decline in CO MRSA rates from 2009 to 2011, from 0.42 to 0.18 per 1,000 patient-days, while CO MSSA rates remained stable, the report says.
In contrast, CO MRSA rates tripled at a center in New York City, from 0.11 to 0.34 cases per 1,000 patient-days. Three other institutions, in San Francisco, Chicago, and Raleigh-Durham, had a stable incidence of both CO MRSA and CO MSSA bacteremia, the authors found.
As for HO bacteremia, MRSA cases decreased and MSSA cases were stable at most of the centers. The authors also found that the virulent strain USA300 accounted for 52% (104 of 202) of genotyped MRSA isolates, but this varied by center, from 35% to 80%.
They concluded that enhanced infection control efforts are unlikely to explain the wide regional differences in CO MRSA rates and the contribution of USA300. "Bio-ecological and clinical explanations for geographical differences in CO-MRSA bacteremia rates merit further study," they write.
May Clin Infect Dis abstract
Jun 2 Los Angeles Biomedical Research Institute press release
Canada reports Salmonella outbreak tied to snakes, feeder rodents
Canada has identified 20 cases of salmonellosis in three provinces linked to snakes and rodents such as mice that are fed to reptiles, the Public Health Agency of Canada (PHAC) said yesterday.
PHAC and provincial officials are investigating 20 cases of Salmonella Typhimurium illness so far this year with the same genetic fingerprint. Of 15 patients with available information, 12 reported contact with snakes and feeder rodents. Sixteen cases are in Ontario, three in Quebec, and one in British Columbia.
Three patients were hospitalized but have recovered, and no deaths have been reported, the agency said. It did not specify illness-onset dates or patient ages but said children 5 years old and younger, pregnant women, the elderly, and those with weakened immune systems are particularly at risk.
Those who own pets should practice good hygiene while caring for and cleaning up after reptiles and feeder rodents. PHAC said it receives an average of 750 reports each year of sickness from Salmonella Typhimurium.
On May 20 the US Centers for Disease Control and Prevention (CDC) announced a similar outbreak that has sickened 37 people in 18 states, though it's not clear if the US and Canadian outbreaks are related.
Jun 2 PHAC notice
CDC advises US travelers on polio immunization
Americans traveling to a polio-affected country should have documentation of a polio booster to avoid travel delays, the Centers for Disease Control and Prevention (CDC) said yesterday in a Health Alert Network (HAN) advisory.
The advice comes on the heels of a May 5 World Health Organization (WHO) decision to declare the international spread of polio to be a public health emergency of international concern (PHEIC) under the authority of the International Health Regulations. The WHO at the time issued temporary vaccination requirements for travelers.
The recommendations will be reviewed and possibly revised by WHO's Emergency Committee in 3 months. The burden for enforcement of the WHO's requirements lies with polio-affected nations, the CDC said. "At this time, the United States government is not expected to implement requirements for entry into the United States," the agency added.
US clinicians should be aware of possible new requirements for patients planning to visit for more than 4 weeks countries with ongoing poliovirus transmission, the CDC said.
The WHO guidance names 10 countries, 3—Cameroon, Pakistan, and Syria—designated as exporting wild poliovirus that should ensure polio boosters 4 to 52 weeks before travel among all departing residents and long-term visitors (of more than 4 weeks). The agency recommends that 7 countries "infected with wild poliovirus" —Afghanistan, Equatorial Guinea, Ethiopia, Iraq, Israel, Somalia, and Nigeria—should encourage recent polio vaccination boosters among residents and long-term visitors.
The CDC says, "U.S. citizens who plan to travel to any of the polio infected countries should have documentation of a polio booster in their yellow International Certificate of Vaccination in order to avoid delays in transit."
Jun 2 CDC HAN advisory