Minnesota Department of Health (MDH) Bug Bytes

December 22, 2011
Vol. 12: No. 2

Topics in This Issue:
Unusual Swine-Origin Influenza Strain (H3N2) Among Humans
2.  Unusual Influenza Strain (H1N2) Identified in Infant
3.  First Minnesota Case of Carbapenem-Resistant Enterobacteriacae due to NDM-1
4.  Said the Night Wind to the Little Lamb

1. Unusual Swine-Origin Influenza Strain (H3N2) Among Humans

In September 2011, CDC reported 2 influenza cases of a reassortant novel H3N2 influenza A; 1 in Indiana and 1 in Pennsylvania. The strains were similar to circulating influenza in swine, except that they also had a component that had originated from the 2009 pandemic H1N1 influenza strain. There was no contact between the cases. One had direct contact with swine; the other had indirect contact.

Since then, a total of 11 cases of a reassortant novel H3N2 influenza A have been identified including 3 cases from Iowa. The component from 2009 pandemic H1N1 is the M gene (matrix protein) which is in involved in the process of influenza entering a host cell. Changes in the M gene have been previously observed to impact transmissibility between humans. Potential person-to-person transmission has been observed in approximately half the cases. The majority of cases have been in children with a median age of 3 years, although there was a 58 year-old case. Most had mild disease consistent with influenza-like-illness or acute respiratory illness. Several individuals with co-morbidities were hospitalized.

No cases of this novel strain have occurred in Minnesota. CDC has asked all states to enhance surveillance particularly among children for a limited period of time to determine if additional cases are occurring. We are working with our Influenza Sentinel Site Surveillance partners to increase the number of specimens submitted for influenza testing.

Learn more about: Influenza>>

2. Unusual Influenza Strain (H1N2) Identified in Infant

In late October, a previously healthy infant from the Twin Cities area developed fever and cough. Rapid testing identified influenza A. The child completely recovered. As part of routine surveillance, the specimen was further tested at MDH Public Health Laboratory and CDC and identified as a strain of H1N2 on December 5. This specific strain of influenza has recently been identified in swine from the Upper Midwest; however, similar strains have been circulating in swine since the early 1990’s. While the family did not have contact with swine, a child who had contact with the infant had fever and cough a few days prior to the onset of the infant’s symptoms. No family members or other contacts have subsequently developed symptoms.

This represents the 5th case of human influenza associated with swine-origin influenza viruses in Minnesota in approximately 5 years. Cases of human influenza associated with swine-origin influenza viruses have likely occurred on a regular basis and have been identified in the last few years due to heightened influenza surveillance. Limited person-to-person transmission of similar swine viruses has previously been described. No further cases have been identified among the infant’s contacts. Surveillance in the subsequent month has not identified other cases due to this virus.

This is not the same swine-origin influenza virus that is mentioned above (H3N2 influenza A) and does not contain genes associated with 2009 pandemic H1N1. Swine-origin influenza has not been shown to be transmissible to people through eating properly handled and prepared pork or other products derived from pigs.

Both the H1N2 and the H3N2 swine-origin strains are a reminder of the importance of influenza surveillance. Clinicians should continue to submit specimens in the following circumstances:

  1. Persons who are hospitalized with influenza-like illness (ILI) or clinical suspicion of influenza OR deceased following ILI or clinical suspicion of influenza.
  2. Until this season's influenza strains are well-characterized, laboratories performing rapid testing methods (EIA, IFA, DFA, PCR, etc.) should submit UP TO TWO (2) patient specimens that are POSITIVE for influenza (either A or B) each week for surveillance purposes.
  3. Cluster investigations, after consultation with us.

For more information on current influenza surveillance, see:

Learn more about: Influenza>>

3. First Minnesota Case of Carbapenem-Resistant Enterobacteriacae due to NDM-1

In November, a clinical laboratory identified 2 highly resistant carbapenem-resistant Enterobacteriaceae (CRE) isolates that were referred to MDH Public Health Laboratory (PHL). The bacteria were identified as E. coli and Klebsiella spp. These isolates tested positive for a plasmid-borne resistance mechanism known as New Delhi Metallo-Beta-Lactamase-1 (NDM-1), which confers resistance not only to carbapenems, but also multiple other antibiotic classes. CDC reports that these are the 10th and 11th isolates nationwide to be confirmed in their laboratory with NDM-1, and the first time NDM-1 has been detected in Minnesota. The isolates were identified in urine from an outpatient who had recently traveled to India and was hospitalized there in the 2 weeks prior to specimen collection.  A history of healthcare exposure in India or Pakistan has been reported in other NDM-1 cases.

NDM-1 was first reported by CDC in June 2010. Because the resistance mechanism is on a plasmid, it is thought to be highly transmissible between bacterial species within a patient and the bacteria can be transmitted among patients. Treatment of infections caused by organisms with this type of resistance mechanism can be extremely challenging with few or even no antibiotics available to treat them. Morbidity and mortality among patients with CRE is much higher compared to patients with the same bacterial species that is not resistant to carbapenems. Contact Precautions are indicated during any medical care, including hospitalizations. Importantly, use of contact precautions is a very effective tool to control the spread of CRE and their use has stopped previous outbreaks.

Infection prevention and laboratory personnel should collaborate to identify and respond to these highly resistant organisms. Detailed infection prevention and control recommendations for hospitals and long-term acute care hospitals, as well as clinical laboratory surveillance testing guidelines are posted at: http://www.health.state.mn.us/divs/idepc/dtopics/cre/cre.html.

Clinicians should be alert to the travel history of patients in whom a CRE is detected, especially if the patient has received medical care in India or Pakistan within the past 6 months.  Minnesota health care providers should contact us (651-201-5414) for infection prevention and control consultation or the PHL (651-201-5073) to submit an isolate.

Additional Information on CREs can be found at:
MDH CRE Website: http://www.health.state.mn.us/divs/idepc/dtopics/cre/index.html
MLS Laboratory-specific CRE website:  http://www.health.state.mn.us/divs/phl/mls/diseaselinks.html#kpc
CDC. Detection of Enterobacteriaceae isolates carrying metallo-beta-lactamase-United States, 2010 MMWR 2010; 59:750.

Learn more about: CRE>>

4. Said the Night Wind to the Little Lamb

As a holiday reminder, we want to alert you of an unhealthy practice. In a recent MMWR article was a report of 2 lab-confirmed cases of Campylobacter jejuni enteritis among persons working at a Wyoming sheep ranch. Both cases had diarrhea, and 1 was hospitalized for 1 day. Both had participated in an event to castrate and dock tails of 1,600 lambs. Both reported having used their teeth to castrate some of the lambs. Among the 12 persons who participated in the event, the cases are the only 2 known to have used their teeth to castrate lambs. During the multiday event, a few lambs reportedly had a mild diarrheal illness. Neither case reported consumption of poultry or unpasteurized dairy products, which are common sources of exposure to C. jejuni.

Animals at the ranch included sheep, cattle, horses, cats, and dogs. C. jejuni was isolated from 2 lambs; 1 isolate had a PFGE pattern indistinguishable from the 2 human isolates. C. jejuni is transmitted via the fecal-oral route; this is the first reported association of C. jejuni infection with exposure during castration of lambs.

As did the Wyoming Department of Health, we recommend against the use of your teeth to castrate lambs.

Learn more about: Campylobacter>>

We wish all of you happy, healthy and peaceful holidays, and hope that you have a wonderful 2012!



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 Wednesday, December 21, 2011 at 09:33AM