Minnesota Department of Health (MDH) Bug Bytes

January 21, 2005
Vol. 6: No. 1

Topics in this Issue:

1. Rodents and Typhimurium
2. Influenza Activity Picking Up
3. Pertussis Increase
4. Cover Your Cough

1. Rodents and Typhimurium
Since August we have been investigating a multistate outbreak of multidrug-resistant Salmonella Typhimurium. We were first alerted to this outbreak when a veterinarian called us about illness in hamsters at a local pet distributor. S. Typhimurium had been isolated from two hamsters submitted to the UM Veterinary Diagnostic Laboratory. S. Typhimurium isolates from ill hamsters were indistinguishable or nearly indistinguishable by PFGE to 27 human case-isolates from around the country from January 2004 to date. Thirteen of 22 interviewed cases were exposed to rodents (hamsters, fancy mice, rats) purchased from retail pet stores within 8 days prior to their illness. Two case-patients were secondary to primary rodent-associated cases. Seven of the interviewed cases had no identified rodent exposure. The 15 human cases with rodent exposure represent individuals in 10 states including one Minnesota resident. Human and rodent isolates are uniformly resistant to at least ampicillin, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline.

Traceback investigations of rodents from case households have identified multiple retail pet stores, distributors, and breeders. At one distributor, S. Typhimurium with an indistinguishable PFGE subtype was isolated from environmental cultures of rodent cages, bedding, and rat pellets. The ultimate source of this multi-state outbreak has not yet been identified. This is the first documented outbreak associated with small pet rodents.

Learn more about: Salmonella >>

2. Influenza Activity Picking Up
Although our first confirmed case was October 18, influenza activity in Minnesota didn’t significantly increase until the past three weeks. We received 35 reports of probable or possible influenza outbreaks in schools and 16 confirmed influenza outbreaks in nursing homes this previous week. Cumulatively, we’ve had 74 school outbreaks and 38 nursing home outbreaks of influenza this season. At this time last season, influenza activity was diminishing, having peaked around the second week of December. You can access more detailed information and subscribe to our Weekly Influenza Activity Update.

All of the influenza isolates that have been submitted to our Public Health Laboratory have been well matched to the strains that were in this season’s vaccine; approximately two thirds have been identified as A-Wyoming-like (H3) and approximately one third have been identified as B-Sichuan-like. The relatively large amount of influenza B this season differs from last season in which influenza A was circulating almost exclusively.

We continue to be interested in any critical or unusual cases of influenza. If you have an otherwise healthy patient who is hospitalized with influenza, please report by calling us at 651-201-5414 or by submitting a blue disease report card. Specimens from these cases should be sent to us.

Learn more about: Influenza >>

3. Pertussis Increase
The final count of reported pertussis cases for 2004 is expected to exceed 1,200. This number is more than twice the most recent peak of 575 reported cases in 2000, and is the highest number of reported cases since 1950 when 1,377 cases were reported. The increase is attributed to many factors including, the overall increasing trend since the early 1980’s, the natural three to five year cyclical peak in pertussis incidence, increased awareness among providers and the general public due to notifications from state and local health departments, and to media coverage of outbreaks in neighboring states and in Minnesota. We are analyzing 2004 data to identify anything significantly different about reported cases with regard to age, disease severity, drug susceptibility, molecular subtype of isolates of B. pertussis, or other factors.

We continue to receive new reports of cases in numbers higher than is typically seen at this time of year. Providers are reminded to consider pertussis, regardless of age or vaccination status, in persons presenting with paroxysmal coughing, or cough illnesses lasting more than seven days, or more than three days if a known exposure has occurred. Pertussis cases are potentially infectious during the first three weeks of coughing or until they have completed five days of appropriate antibiotics. Potentially infectious persons should be instructed to avoid exposing others by staying home from school, work, or other activities. Information for health care providers, school nurses, and the general public is at the MDH pertussis website.

Learn more about: Pertussis >>

4. Cover Your Cough
The Minnesota Cover Your Cough (CYC) campaign, in its second year, remains an effective resource to promote basic messages of respiratory etiquette and hand hygiene. Posters can be found in healthcare facilities, business offices, schools, universities and community settings in more than 35 states and several Canadian provinces.

This year, CYC was expanded to include two posters designed to help prevent the transmission of influenza and other respiratory illnesses. STOP: Protect Our Patients (for use in hospitals) and STOP: Protect Our Residents (for use in long-term care facilities). Limited copies have been mailed to Minnesota hospitals and long-term care facilities. Translations of the posters in Spanish, Somali, Hmong and Russian along with the English version are available at the Stop! Help Protect Our Patients/Residents Posters website.

Additionally, MDH in conjunction with APIC-MN has developed two full-barrier personal protective equipment (PPE) posters to assist healthcare workers in selecting, donning, doffing of appropriate PPE when caring for patients known or suspected to have diseases transmitted via the airborne and contact routes. Limited quantities of the Full Barrier Poster for Use with an N95 Respirator have already been sent to Minnesota hospitals and limited copies of the Full Barrier Poster for Use with a Powered Air Purifying Respirator (PAPR) will be mailed to Minnesota hospitals soon. Both posters can be downloaded from the MDH Personal Protective Equipment (PPE) for Infection Control website.

Learn more about: Personal Protective Equipment, Cover Your Cough, Infection Control

Bug Bytes is a combined effort of the Infectious Disease Epidemiology, Prevention and Control Division and the Public Health Laboratory Division of MDH. We provide Bug Bytes as a way to say THANK YOU to the infection control professionals, laboratorians, local public health professionals, and health care providers who assist us.

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Updated Friday, November 19, 2010 at 02:16PM