NEWS SCAN: Antibiotic-resistant E coli, Key West dengue, pertussis vaccine gaps, polio in Pakistan

Mar 14, 2013

Study finds increasing drug-resistant E coli in nursing home residents
A study of 299 consecutive extraintestinal Escherichia coli isolates submitted to microbiology labs in Olmstead County, Minn., in February and March of 2011 found that 80 (27%) were sequence type ST131, an increasingly common strain often associated with fluoroquinolone resistance. Investigators published their findings in Infection Control and Hospital Epidemiology. The labs cover the main health facilities, of Rochester, Minnesota: the Mayo Clinic and Olmsted Medical Center. Researchers found that residence in a long-term-care facility was the strongest predictor of infection and was linked to an eight-times-greater risk of E coli ST131 infection compared with nonresidents. They also found that the sequence type was associated with older age, complicated infections, history of urinary tract infection, and prior antibiotic use. The team suggested that the high prevalence of the strain could be influenced by extensive antibiotic exposure, close contact with other antibiotic-exposed patients, age, and age-related changes in intestinal microbiota. Lead author Ritu Banerjee, MD, PhD, of the Mayo Clinic, said in a press release from the Society for Healthcare Epidemiology of America (SHEA) that expansion of ST131 has been recognized as a pandemic but has received little attention. "Alarmingly, the pace of new antibiotic development has not kept up with the emergence of antibiotic-resistant E coli, making development of strategies to halt further emergence and spread of these strains a public health priority," she said.
April Infect Control Hosp Epidemiol abstract
Mar 12 SHEA press release

Study: 2009-10 Key West dengue infections endemic
Sequencing of dengue virus type 1 (DENV-1) strains in Key West and elsewhere in Monroe County, Fla., indicate endemic transmission for more than 2 years of an American-African genotype, according to a report today in Emerging Infectious Diseases. Researchers from the Centers for Disease Control and Prevention in Puerto Rico and the Florida Department of Health analyzed 61 DENV-positive samples from Key West from 2009 and 2010, 31 from Monroe County, and 15 from six other Florida counties. They then sequenced the E gene of 12 DENV-1 strains—8 from Key West and 1 each from Dade, Broward, Orange, and Pinellas counties. They compared them with 23 DENV-1 E sequences published in GenBack, including 2010 Key West isolates from a blood donor and mosquito pool, to determine a phylogenetic tree. They found all isolates to be of American-African genotype, but Monroe County viruses were subgrouped among Central American viruses distinct from the Caribbean lineage found elsewhere in Florida. The authors conclude that the 2010 viruses appear to be a continuation of the 2009 outbreak, adding, "Collectively, these findings indicate that endemic DENV-1 was transmitted in Key West over a period of >2 years."
Mar 13 Emerg Infect Dis report
In response to the report, Monroe County Health Department Administrator Robert Eadie, JD, said the report may lead people to mistakenly believe that the dengue risk remains, when in fact the last reported case in the county was in October 2010. "We put a whole lot of effort into trying to eradicate the disease and it showed results," he told the Los Angeles Times yesterday. "Unfortunately that kind of gets lost in the report."
Mar 13 LA Times story

Another study finds protection gap for acellular pertussis vaccine
California researchers who explored how well different pertussis vaccine combinations protected children during a 2010 outbreak found a dramatic illness increase in kids who received the acellular version for all of their doses compared with those who received at least one dose of whole-cell vaccine. The study in Clinical Infectious Diseases used electronic data from Kaiser Permanente on 263,469 kids who were between the ages of 8 and 20 as of May 15, 2010. The United States had fully switched from the whole-cell vaccine to the acellular version by 2001, so the study group included children who received a mix of different vaccine types. Researchers identified 904 cases of pertussis in the study group. Kids who had received five doses of the acellular vaccine had a relative risk (RR) of 8.57 of contracting pertussus compared with those who had at least one dose of whole-cell vaccine. The RR was lowered to 3.55 when kids received a sixth booster dose (Tdap). The authors said their findings add to growing evidence that waning immunity from the acellular vaccine could play a role in ongoing pertussis outbreaks and that better vaccines are needed.
Mar 13 Clin Infect Dis abstract

UNICEF Pakistan publishes fatwas supporting polio vaccination
The United Nations Children's Fund (UNICEF) Pakistan has produced a booklet containing 24 fatwas, or religious decrees from prominent Muslim leaders, to encourage polio vaccination, The News International reported today. "This book would be provided to polio vaccinators during campaigns so that people who refuse drops for their children on religious grounds could be educated," a UNICEF official said. Pakistan's polio campaign has been interrupted several times in recent months by militants aiming to prevent vaccination on religious or anti-Western grounds. Several Pakistanis involved in vaccination campaigns have been killed.
Mar 14 News International story

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