Minnesota Department of Health (MDH) Bug Bytes

March 18, 2010
Vol. 11: No.1

Topics in This Issue:
1. Invasive GAS Cluster
2. H1N1 Slows
3. World TB Day
4. Parechovirus Myocarditis Death
5. Pepper and Salami

1. Invasive GAS Cluster

Through our Emerging Infections Program, we conduct active, laboratory-based surveillance for invasive infections due to group A streptococcus (GAS), including antimicrobial susceptibility testing of isolates by our Public Health Laboratory. We recently noticed that 3 GAS isolates from September and December 2009 exhibited the same unusual multidrug resistance pattern (resistant to erythromycin, clindamycin, and tetracycline, and a high MIC to telithromycin; no breakpoints have been established for telithromycin but all 3 isolates had MICs greater than 4 mcg/ml). Each patient had invasive disease, but for two, soft tissue involvement occurred initially.

Patterns for 2 isolates were indistinguishable by PFGE and the third differed by only 1 band. Upon further investigation, we determined all 3 cases were men who have sex with men (MSM) and 2 were also methamphetamine users (1 was known to inject drugs).

Because invasive cases may represent only a small component of all GAS disease, including non-invasive disease, be alert to potential additional cases of GAS infection among patients who are MSM or using methamphetamine or injecting drugs. In addition, the 3 invasive isolates were resistant to erythromycin and clindamycin, antibiotics that may be used to treat GAS, and tetracycline which may be used empirically in skin and soft tissue infections when CA-MRSA is considered. The isolates were susceptible to penicillin.

Although only invasive GAS is required to be reported to us, we are interested in hearing about skin and soft tissue infections or pharyngitis in patients who may be MSM or injecting drug users particularly in circumstances where a GAS isolate is available to be sent to our laboratory. This will help us better understand the scope of a possible GAS outbreak, and determine whether ongoing transmission of this strain is occurring.

Learn more about: group A streptococcus (GAS)>>
Learn more about: CA-MRSA>>

2. H1N1 Pandemic Slows

The novel H1N1 influenza pandemic has slowed nationally and in Minnesota. We have seen little to no outbreaks in schools or long term care facilities in the last month and few confirmed novel H1N1 tests among hospitalized patients.

We have begun to analyze the tremendous amount of data we collected. Preliminary results show that there were 1,809 confirmed novel H1N1 hospitalized cases, including 260 in the summer wave through August 31, and 1,549 in the current fall/winter wave beginning September 1. The median age in the summer wave was 11.8 years and in the fall/winter wave was 26.5 years. The median length of hospital stay was 3 to 4 days depending on age. One fifth were admitted to the ICU in each wave. Sixty-six were pregnant women and 83% had one or more underlying chronic health conditions such as asthma, obesity, or diabetes. Fifty-five of the hospitalized cases died, and there were an additional 6 out-of-hospital H1N1-confirmed or influenza type A, subtype-unspecified deaths. Non-whites represented an astonishing 31% of hospitalized cases.

We want to gratefully thank all the clinicians, infection preventionists, and laboratorians who reported cases, collected specimens, and provided other assistance to us in tracking this historic influenza pandemic. Great partners make for great public health in Minnesota!

Learn more about: influenza (flu)>>
Learn more about: Pandemic Influenza Planning>>

3. World TB Day

March 24 is World TB Day in honor of Dr. Robert Koch who discovered the tubercle bacillus and gave his famous lecture on "The Etiology of Tuberculosis" on March 24, 1882. He won the Nobel Prize for Physiology or Medicine in 1905 for his TB work. In his acceptance speech he said this: "Hardly a country remains where, in one way or another, the struggle against tuberculosis has not been taken up, and it is extraordinarily gratifying to see how the campaign is now waged quite generally and with considerable vigor against this dangerous enemy. ...The struggle has caught hold along the whole line and enthusiasm for the lofty aim runs so high that a slackening is no longer to be feared. If the work goes on in this powerful way, then the victory must be won." Unfortunately, the struggle goes on.

A century later TB continues to be one of the deadliest diseases worldwide. TB kills nearly 2 million people every year, including an average of 3 in Minnesota and over 600 in the United States. Following a decade of increasing numbers, TB incidence in Minnesota has now decreased for 2 consecutive years with 161 cases being reported in 2009. While this decrease is encouraging, we must remain vigilant. There were two large TB outbreaks in Minnesota in 2008. TB continues to affect children (18 children were diagnosed in 2009). Multidrug-resistant TB and extensively drug-resistant TB have also occurred here.

For every person with active TB, dozens more have latent TB infection (LTBI). One-tenth of them will develop active TB unless they receive preventive treatment. MDH encourages screening and treatment of persons at high risk for LTBI. A variety of resources and tools for the diagnosis and treatment of LTBI are available from us (www.health.state.mn.us/tb) and we will supply LTBI medication at no cost to any resident of Minnesota.

A recent MMWR (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5908a3.htm?s_cid=mm5908a3_e) reported on 17 cases of severe adverse events (SAEs) from LTBI therapy. Isoniazid (INH) remains the recommended therapy. Although SAEs are rare, patients should be educated about the symptoms of liver toxicity and told to stop INH immediately and report them to their provider if they occur. We are unaware of any SAEs occurring in Minnesota. If this should occur, please report them to us and FDA's MedWatch system (https://www.accessdata.fda.gov/scripts/medwatch.

Learn more about: Tuberculosis>>

4. Parechovirus Myocarditis Death

We recently received a report through our Unexplained Deaths and Critical Illness Program of a 3 year-old previously healthy male who died in an emergency department after sudden cardiac arrest. He had a 3-4 day history of fever, vomiting, and some mild nasal congestion; his lungs were clear. He had 2 siblings with similar symptoms. He was noted to have increasing somnolence and eventually became unresponsive at home. On arrival at the ED, his temperature was 36.4, heart rate 44, respirations 44, and blood pressure 93/67.  Intermittent seizure activity and decreased level of consciousness was noted. His heart rate remained unstable and he suffered complete cardiac arrest during a seizure.

On autopsy he was found to have extensive myocarditis with lymphocytic inflammatory infiltrates within all layers of the heart and destruction of the myocytes in every section of the heart. Post-mortem cultures of the lung and spleen were negative. We ran our own respiratory pathogen panel including PCR targets for influenza A & B, parainfluenza 1-4, adenovirus, RSV, picornavirus, human bocavirus, human metapneumovirus, Chlamydia pneumoniae, Haemophilus influenzae A & B, Legionella spp., Streptococcus pneumoniae, and Mycoplasma pneumoniae. A nasopharyngeal (NP) swab and trachea tissue were tested and both were found to be PCR positive for S. pneumoniae and parainfluenza 1 but not considered to be causative. A brain swab was also obtained and viral culture performed with negative results. The CDC Infectious Diseases Pathology Branch (IDPB) tested heart tissue and found it to be PCR positive for parechovirus 2. Additional tissue is being evaluated by IDPB.

This is the first known Minnesota fatality related to parechovirus 2, previously known as echovirus 23. A recently published article (Feb. 1 CID) documented the occurrence of parechovirus 3 from lung, colon, and NP swabs from 2 child decedents from the Milwaukee area with evidence suggesting it contributed to their deaths. Much remains unknown about the prevalence and scope of disease due to these viruses, but they can cause severe complications in certain cases, most commonly myocarditis and encephalitis.

Learn more about: Unexplained Deaths and Critical Illness Program>>

5. Pepper and Salami

Since January, we have been collaborating on a multistate Salmonella Montevideo outbreak investigation. To date, a total of 249 cases have been reported from 44 states and District of Columbia since July 1, 2009; this includes 6 Minnesota cases. Cases range in age from < 1 year to 93 years old; the median age is 37 years. Forty-nine persons were hospitalized, but there have been no deaths.

Multiple states conducted a case-control study by comparing foods eaten by 41 ill and 41 well persons. Preliminary analysis suggested salami as a possible source of illness. Sixteen cases were identified who purchased the same type of sliced salami variety pack at different stores before becoming ill; 3 additional ill persons were identified who purchased a similar type of sliced salami deli tray before becoming ill. The salami was produced by Daniele International Inc. in Rhode Island which has initiated an extensive recall of over 1.2 million pounds of several of its salami products.

Testing by the Rhode Island Department of Public Health found the same PFGE strain of S. Montevideo in samples of black pepper and red pepper intended for use in the production of Italian-style meats at Daniele. On February 25, Wholesome Spice, Brooklyn, NY, recalled crushed red pepper sold between April 6, 2009 and January 20, 2010.  Wholesome Spice sells spices directly to commercial customers, who may have incorporated them into their own products. On March 5, 2010, Mincing Overseas Spice Company of Dayton, NJ, recalled two lots of black pepper due to possible Salmonella contamination. Black pepper was not distributed at the retail level.

The initial recall followed isolation of S. Senftenberg by a private laboratory from a retail sample of Daniele salami; this product was different than the sliced salami variety pack mentioned above, but the same product purchased by 3 ill persons. The Washington State Department of Health subsequently tested the bacterial culture provided by the private laboratory (the salami was not provided) and identified two different Salmonella serotypes: both S. Senftenberg, and S. Montevideo indistinguishable by PFGE from the outbreak strain. In addition, the Iowa Department of Public Health investigated a case of S. Montevideo with an indistinguishable outbreak strain and tested an open sliced salami variety pack frozen from this case's home and confirmed that the Salmonella isolated from this leftover salami was indistinguishable from the outbreak strain of S. Montevideo. In addition, the Illinois Department of Public Health tested unopened salami and found that the product contained the same S. Senftenberg strain.

Nationally, 8 cases whom had illness caused by S. Senftenberg with matching PFGE patterns between July 1, 2009 and now have been identified. Six of these cases have been interviewed and two reported purchasing a recalled salami product during the week before their illness began. These 8 cases are not included in the overall case count reported above.

Salami which has been properly aged or fermented generally is a low risk vehicle for salmonellosis. This salami product was a high end product which was coated with pepper on the outside. Daniele believes that black pepper is the likely source of Salmonella contamination. Pepper has been associated with pathogenic organisms before. Black pepper is from the unripe berries of the pepper plant. Sometimes ground pepper is irradiated for pests before importation but not always, so it is a raw ready-to-eat product.

Learn more about: Salmonella>>

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