Infectious Diseases News Brief - March 14, 2008

[Current Issue -Table of content]

Health officials hope to quell mumps outbreak - Canada

Fraser Health is reporting five lab-confirmed cases of mumps in Chilliwack, in the wake of larger outbreaks in Alberta. A mumps alert went out from Fraser Health offices last week warning Chilliwack residents to make sure their vaccinations are up to date. Older adults are more at risk for serious disease, if they're not immune through vaccination or through having had the disease. Those who are 18 years or younger, attending post-secondary, or child/health care workers born after 1956, are eligible for two free doses of Measles-Mumps-Rubella (MMR) vaccine. A total of 399 cases were reported in Alberta between Sept. 1, 2007 and March 4, 2008, with the majority of cases in the Chinook region of southern Alberta, and the rest in Calgary. There were also outbreaks in Nova Scotia.
Source: Chilliwack Progress, 10 March, 2008
http://www.bclocalnews.com/news/16450111.html

Health District notifies patients of potential exposure to hepatitis C urges testing for approximately 40,000 patients - United States

The Southern Nevada Health District announced it is notifying approximately 40,000 patients of a local medical clinic about potential exposure to hepatitis C following an investigation of several acute cases of the illness. The health district’s notification includes patients who had procedures at the clinic between March 2004 and January 11, 2008, and recommends they contact their primary care physicians or health care providers to get tested for hepatitis C as well as hepatitis B and HIV. The health district identified a cluster of three acute cases of hepatitis C in January 2008 and has identified a total of six cases to date. Five of the cases had procedures requiring injected anesthesia on the same day. Following a joint investigation with the Nevada State Bureau of Licensure and Certification (BLC) and with consultation from the U.S. Centers for Disease Control and Prevention, the health district determined that unsafe injection practices related to the administration of anesthesia medication might have exposed patients to the blood of other patients. The exposures did not result from the medical procedures performed. The joint investigation identified the re-use of syringes (not needles) and the use of single dose vials of anesthesia medication on multiple patients as the potential sources of contamination. The clinic took corrective action when notified by staff conducting the investigation. The health district is also recommending patients get tested for hepatitis B and HIV, as both of these diseases can be transmitted through the same unsafe injection practices identified as the likely source of transmission. However, the risk of transmission of hepatitis B and HIV is lower, and no associated cases of hepatitis B or HIV have yet been identified. The prompt identification of these infections is important, as there are treatment and/or medical management options available. Approximately 2 percent of the general population will test positive for hepatitis C and based on the average age of the patients at the clinic, it is expected that approximately 4 percent will test positive as many people have contracted the virus through other sources. Hepatitis C is more common among people who received blood transfusions or organ transplants prior to 1992 and intravenous drug users, therefore, it will not be possible to determine if patients who test positive were infected at the clinic.
Source: Southern Nevada Health District, 27 February 2008
http://www.southernnevadahealthdistrict.org/press_releases/2008/022708b.html

Universal Screening for Methicillin-Resistant Staphylococcus aureus at Hospital Admission and Nosocomial Infection in Surgical Patients

According to a study published in JAMA, universal screening at hospital admission for methicillin-resistant Staphylococcus aureus (MRSA) does not seem to reduce the rate of hospital-acquired infections in surgical patients. It is thought that in order to control MRSA, doctors and hospitals must identify patients with MRSA as early as possible. They also must use infection control measures to prevent patients from spreading the infection to other patients. The study, conducted by Stephan Harbarth, M.D., M.S. (University of Geneva Hospitals and Medical School, Geneva, Switzerland) and colleagues, aimed to determine the effect of an early detection strategy for MRSA on MRSA infections acquired in a hospital. These hospital-acquired infections like MRSA are termed nosocomial, and include infections that are secondary to the patient's original condition; urinary tract infections and pneumonia are common nosocomial infections. Harbath and colleagues studied 21,754 surgical patients at a Swiss teaching hospital, and used two MRSA control strategies: 1) rapid screening on admission plus standard infection control measures and 2) standard infection control alone. The researchers chose twelve surgical wards with various surgical specialties to enroll in the study that met requirements of a pre-determined protocol. Each ward was assigned to either the control (10,910 patients) or intervention (10,844 patients) group for a 9-month period. The groups then switched for a subsequent 9-month period. Upon or before admission to a surgical ward in the intervention group for more than 24 hours, a molecular technique for rapid, early detection of MRSA was applied to patients. About 94% (10,193 patients) of the intervention group received the rapid test during the intervention periods. There was a median time of 22.5 hours from admission screening to notification of test results. A total of 515 (5.1%) of the screened patients were diagnosed as MRSA-positive during the intervention periods. Sixty-five percent of these (337 patients) had not been previously identified as MRSA carriers. Without systematic screening upon admission, they would have been missed. According to estimates made by the authors, 30 patients would have to be checked in order to detect 1 previously unidentified MRSA carrier at admission. In the intervention periods, 93 patients (1.11 per 1,000 patient-days) developed nosocomial MRSA infection, whereas 76 patients (0.91 per 1,000 patient-days) developed infections it in the control periods. The authors did not find a significant change in the rate of MRSA surgical site infections and nosocomial MRSA acquisitions. Of the 93 infected patients in the intervention wards, 53 (57 percent) did not have MRSA upon admission but developed MRSA during hospitalization.
Source: The Journal of the American Medical Association
Vol. 299 No. 10, March 12, 2008