Minnesota Department of Health (MDH) Bug Bytes

Oct. 1, 2007
Vol. 8: No.2

Topics in this Issue:

1.  E. coli O157:H7 Picnic Cluster
2. Influenza Vaccination Recommendations Include Health Care Workers
3. Transfusion-associated Babesiosis
4. MRSA Recommendations
5. Recommended Reading
6. Emerging Infections in Clinical Practice and Public Health Conference

1. E. coli O157:H7 Picnic Cluster

We are investigating two pediatric cases of E. coli O157:H7 infection with isolates that are one band different by pulsed-field gel electrophoresis reported to us in the week following Labor Day.  Currently the only known link between the cases is attendance at an organized picnic held in a Hennepin County park on Labor Day.  No additional cases have been identified associated with the event, nor have there been any additional PFGE-matching cases. 

In 2006, 147 culture-confirmed cases of E. coli O157:H7 were reported.  Three outbreaks were identified; all three were foodborne.  One outbreak with 17 cases was associated with a church smorgasbord where ready-to-eat foods were likely cross-contaminated by ground beef that was used simultaneously to prepare meatballs for the event.  A second outbreak with 3 cases was associated with a restaurant where no specific vehicle could be confirmed, but all 3 cases had in common consumption of shredded lettuce.  A third outbreak resulted in 32 confirmed and probable cases in Minnesota and was associated with consumption of shredded lettuce served at four outlets of the same fast-food Mexican restaurant chain in Minnesota and Iowa.  The lettuce was traced back to a field in California and the same outbreak strain of E. coli O157:H7 was collected from dairy farms near the source fields for the contaminated lettuce.

To date in 2007, 133 confirmed cases of E. coli O157:H7 have been reported.  In addition to the picnic cluster described above, preliminary results show five other outbreaks including 26 cases (4 lab-confirmed and 22 probable) associated with a potluck with multiple food items likely contaminated by an ill child attendee, 8 cases associated with a single daycare home, 2 cases associated with cattle contact; 3 cases associated with steaks sold in retail chain stores, and 10 cases associated with ground beef purchased from grocery store chain retail markets.   

Learn more about: E. coli>>

2. Influenza Vaccination Recommendations Include Health Care Workers

The recommendations by the Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccine and antiviral agents were updated over the summer (see Prevention and Control of Influenza Recommendations of the Advisory Committee on Immunization Practices, 2007). The groups of persons for whom vaccination is recommended and the antiviral medications recommended for chemoprophylaxis or treatment (oseltamivir or zanamivir) have not changed.   Unfortunately however, vaccination coverage remains <50% among some groups for whom routine annual vaccination is recommended, including young children and adults with risk factors for influenza complications, health-care workers (HCWs), and pregnant women. Strategies to improve vaccination coverage, including use of reminder/recall systems and standing orders should be implemented or expanded.

The 2007 recommendations include new and updated information including: 1) reemphasizing the importance of administering two doses of vaccine to all children aged 6 months-8 years if they have not been vaccinated previously at any time with either live attenuated influenza vaccine (doses separated by >6 weeks) or trivalent inactivated influenza vaccine (doses separated by >4 weeks), with single annual doses in subsequent years; 2) recommending that children aged 6 months-8 years who received only one dose in their first year of vaccination receive two doses the following year, with single annual doses in subsequent years; 3) highlighting a previous recommendation that all persons, including school-aged children, who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others should be vaccinated; 4) emphasizing that immunization providers should offer influenza vaccine and schedule immunization clinics throughout the influenza season; and 5) recommending that health-care facilities consider the level of vaccination coverage among HCWs to be one measure of a patient safety quality program and implement policies to encourage vaccination (e.g., obtaining signed declination statements from HCWs who decline influenza vaccination).

The 2007-2008 trivalent vaccine contains viral strains A/Solomon Islands/3/2006 (H1N1)-like (new this season), A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like antigens.

Learn more about: Influenza>>

3. Transfusion-associated Babesiosis
Babesiosis is a rare malaria-like disease caused by Babesia microti, an intraerythrocytic protozoan transmitted by the bite of the deer tick (Ixodes scapularis) or, less frequently, by blood transfusion.  In 2002 we reported in the medical literature a 2000 case of transfusion-associated babesiosis from a fall 1999 blood donation.

In September 2006, an elderly, asplenic male resident of Minnesota with cancer was hospitalized for an acute febrile illness.  Tests for B. microti by polymerase chain reaction and blood smear were positive, and the patient died within a month of symptom onset.  The patient lived within Minnesota’s tick-borne disease endemic area and spent some time, albeit limited, in potential deer tick habitat.  Because of his history of recent blood transfusions, Memorial Blood Centers conducted a trace-back for 10 donors of blood transfused into the index case during spring-summer 2006.  All 10 donors submitted blood for B. microti antibody testing by immunofluorescent assay, conducted by the CDC.  One donor tested serologically positive for B. microti.  Red blood cells from the implicated donor were transfused into the index case about 2 weeks before symptom onset.  The implicated donor reported no history of babesiosis symptoms in the past year but frequently traveled to a deer tick endemic area in Minnesota.  Trace-back on other blood units donated by the implicated donor did not reveal any other B. microti antibody-positive recipients.

Although babesiosis is rare in Minnesota (50 reported cases, 2001-2006) compared to the state’s other deer tick-transmitted diseases (Lyme disease and human anaplasmosis), it can be severe or fatal in patients who are asplenic, elderly, or otherwise immune compromised.  Most B. microti infections in healthy individuals are sub-clinical, and parasitemia may persist for months.  Therefore, asymptomatic carriers who donate blood are a potential source of transfusion-transmitted babesiosis.  A large volume blood donor screening assay for B. microti does not exist; therefore, patients who undergo transfusions are at risk of acquiring B. microti infections from transfused blood.  Physicians should include babesiosis in their rule-out for patients who develop acute febrile illness and hemolytic anemia following a blood transfusion, especially those with asplenia, advanced age, or other immune compromise.

Learn more about: Babesiosis>>

4. MRSA Recommendations

The Minnesota Legislature passed a law in the 2007 legislative session which instructed MDH to develop recommendations for methicillin-resistant Staphylococcus aureus (MRSA) control in acute care settings. The final recommendation report is due to the State Legislature by January 15, 2008.  In developing the recommendations, MDH assembled the MRSA Recommendations Task Force (MRTF). The MRTF consisted of infection control experts including infection control practitioners and infectious disease physicians from across the state. The MRTF has completed a draft report and we are making the draft Recommendations for Prevention and Control of MRSA in Acute Care Settings available for comment beginning October 1, 2007. The purpose of the report is to provide standard recommendations for prevention of MRSA transmission in acute care facilities in Minnesota to prevent and control hospital-associated MRSA infections.

MDH invites all interested parties to review the draft Recommendations and submit comments at http://www.health.state.mn.us/divs/idepc/diseases/mrsa/rec/index.html. The comment period will run for one month. To be considered, comments must be submitted to MDH no later than November 1, 2007.

Learn more about: MRSA>>

5. Recommended Reading

Several of us were involved in the publication of a new book, “Infectious Disease Surveillance” which was just released last week.  One of the book’s co-editors was Dr. Ruth Lynfield, State Epidemiologist, and four other MDH staff were individual chapter authors.
The book provides practical information on surveillance systems in practice in the United States and around the world. It is designed for public health practitioners, epidemiologists, clinical microbiologists, and students of public health and epidemiology.
We receive no rewards or incentives so we can recommend you check it out.  It is published by Blackwell Publishing and more information is at http://www.blackwellpublishing.com/book.asp?ref=9781405142663&site=1.

6. Emerging Infections in Clinical Practice and Public Health Conference
On November 8 and 9 (half day) we will hold our Annual Emerging Infections in Clinical Practice and Public Health Conference.  Topics include emerging respiratory diseases, MRSA, new vaccines, and viral medications. Speakers include Drs. Yu-lung Lau from the University of Hong Kong, Carlene Muto from the University of Pittsburgh, Gregory Poland from the Mayo Clinic, and Jane Siegel from University of Texas.  A brochure and registration form is at http://www.cme.umn.edu/img/assets/24315/Emerging_brochure.pdf.

Learn more about: Emerging Infections>>


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Updated Tuesday, June 03, 2014 at 02:05PM