Minnesota Department of Health (MDH) Bug Bytes
September 17, 2001
Vol. 2: No. 17
1. Measles Case
A case of measles was reported on August 31 and confirmed by positive IgM serology performed at MDH. The case was a 10-year-old Somali child who arrived in Minnesota on August 22 and then resided in Minneapolis. The child presented at a hospital clinic on August 30 with a history of fever, cough, conjunctivitis, and rash. Rash onset occurred on August 29; therefore, the child is not considered to have been infectious during travel. Measles exposure and vaccination history are unknown. The child was hospitalized over the Labor Day weekend.
Eight extended family members (including three adults who were living in Minneapolis prior to the child's arrival, the child's father, and four older siblings who traveled with her) all had positive IgG serology, indicating past infection. Secondary cases among other unidentified contacts are possible, as there were two additional clinic visits during the case's prodromal period, as well as the potential for community exposures near the child's residence. Cases could occur until September 20; however, rash onsets would have most likely occurred around September 10. Suspect cases should be reported immediately at 651-201-5414 or 1-877-676-5414.
2. HUS Death
On September 5, a 6-year-old died of hemolytic uremic syndrome (HUS), our third death this year (second in a child). Two siblings also had HUS at the same time. To date, all tests conducted at the hospital and at MDH have been negative for E. coli O157:H7; additional tests are pending. Other enterohemorrhagic E. coli also may cause HUS. Nineteen HUS cases have been reported to date for 2001; the mean annual number of cases reported during 1996-2000 was 17 (range, 12-29).
3. A Buffet of E.
On September 5 we became aware of a cluster of five cases of E. coli O157:H7 infection, in part due to the diligent reporting by an ICP in Douglas County (kudos to her!). All five cases were adults and were hospitalized. All case isolates had the same PFGE subtype. One person remains in critical condition with thrombotic thrombocytopenic purpura. Their onsets of illness ranged from August 24-27. All five cases had eaten at the same Chinese buffet-style restaurant within 5 days prior to their onset of illness. No single menu item could be implicated due to the nature of buffet style dining. The restaurant was inspected on September 6 and closed due to numerous violations including those allowing for multiple opportunities for cross contamination from raw to ready-to-eat foods. It was reopened on September 7, and reinspected on September 10 and 11. A reinspection on September 13 again revealed multiple critical violations so the restaurant was closed until at least September 17.
Confirmation of one or two additional cases is pending. Our investigation as to the source of contamination continues.
4. Treatment for Latent TB Infection:
In the August 31 issue of MMWR (at http://www.cdc.gov/mmwr/preview/
mmwrhtml/mm5034a1.htm Attention: Non-MDH link) is a report of 21 patients who were hospitalized due to severe hepatotoxicity associated with a 2-month regimen of rifampin and pyrazinamide (RIF-PZA) for the treatment of latent tuberculosis infection (LTBI). Sixteen of the patients recovered, and five died. CDC previously published a report of one fatal and one severe case of hepatotoxicity associated with RIF-PZA (at http://www.cdc.gov/mmwr/preview/
mmwrhtml/mm5015a3.htm Attention: Non-MDH link). Although the total number of patients treated with RIF-PZA for LTBI is unknown, the number of recent reports of severe hepatotoxicity associated with this regimen has been unexpectedly high since CDC and the American Thoracic Society (ATS) issued new guidelines in June 2000 recommending RIF-PZA as an acceptable alternative to isoniazid (INH) for treatment of LTBI.
As a result of these investigations, CDC and ATS have issued revised guidelines for LTBI treatment which limit the circumstances in which the 2-month RIF-PZA regimen is prescribed and strengthen the need for and level of monitoring and counseling recommended for patients receiving this regimen. Nine months of daily INH is the preferred treatment for LTBI in most instances. The 2-month RIF-PZA regimen may be useful for certain patients who are unlikely to complete a longer course of treatment and who can be monitored closely. CDC recommends that providers prescribe RIF-PZA with caution, particularly for patients taking other potentially hepatotoxic medications and those with alcoholism. RIF-PZA is not recommended for persons with underlying liver disease or those who have experienced hepatotoxicity associated with INH. The revised guidelines also amend the recommended dosage of PZA (<20 mg/kg/day, maximum 2 gm) in the RIF-PZA regimen and recommendations for clinical monitoring of patients, which now include measurement of serum aminotransferase and bilirubin at baseline and at 2, 4, and 6 weeks of treatment.
We are aware of only a few persons who have received the 2-month RIF-PZA regimen for treatment of LTBI in Minnesota; we have received no reports of hepatotoxicity associated with this regimen. We will be updating MDH guidelines for treatment of LTBI in Minnesota to be consistent with the revised national guidelines (at http://www.health.state.mn.us/tb).
5. Horse Positive for EEE
A second horse in Minnesota has tested positive for Eastern equine encephalitis (EEE) (see last issue of Bug Bytes). A horse from Kanabec County developed sudden neurological problems on September 2, died on September 3, and tested positive by PCR in our laboratory on September 13. Clinicians in the area should be alert for persons exhibiting neurological symptoms and call us for consultation. The ongoing risk from mosquitoes at this time of the year is now negligible as their populations are dropping substantially.
6. Terrorism and Public Health
We salute our colleagues at the New York City Department of Health who were a few blocks away from the World Trade Center. As with the thousands of others, their work was and continues to be heroic.
In the meantime, we ask you remain vigilant for the occurrence of unusual symptoms or signs, or a cluster of illnesses unusual for this time of year, which may be indicative of biological terrorism. If you have questions, please call 651-201-5414.
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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