Minnesota Department of Health (MDH) Bug Bytes
June 26, 2001
Vol. 2: No. 12
1. Anthrax Awareness
An interesting abstract concerning anthrax detection was presented at the General Meeting of the American Society for Microbiology in May To evaluate the ability of clinical labs to identify anthrax, the New Mexico Public Health Laboratory sent a blinded specimen of the Sterne strain of Bacillus anthracis to four labs in the state. Three of these reported the specimen as "Bacillus species, probable contaminant," and the fourth sent the isolate back to the state lab for identification, 9 days after initial screening. This failure to identify anthrax in a timely manner raises an important concern. If Bacillus anthracis were to be used in a bioterrorism attack, clinical labs may be the first to detect such an event. Consequently, it is critical for all labs to be prepared. If a non-hemolytic, non-motile, large gram positive, spore-forming rod is isolated from a human specimen, anthrax should be ruled out. The MDH Laboratory should be contacted immediately so that confirmatory testing can be conducted.
2. Minnesota Laboratory System
To assure Minnesota's bioterrorism preparedness, the MDH Laboratory recently received funds from the Association of Public Health Labs (APHL)/CDC to begin developing a statewide laboratory network. The vision for this Minnesota Laboratory System (MLS) is to have an informal, integrated network of public and private infectious disease testing laboratories to enhance infectious disease surveillance and outbreak response at the local and state level. When in place, such a system will markedly improve our collective statewide ability to address bioterrorism, emerging infections, food safety, antibiotic resistance, and other as yet undefined threats to the health of Minnesota's citizens. In the coming weeks we will be discussing the MLS with labs throughout the state. Please contact Paula Snippes at (612) 676-5258 if you have questions.
3. Meningococcal Disease Issues
Two fatal cases of meningococcal disease serogroup C occurred in students from the same high school in an Ohio town over Memorial Day weekend. The ACIP recommends that antibiotic chemoprophylaxis be given to close contacts, defined as household members, daycare/nursery school co-attendees and others with direct oral secretion contact with the case-patient (kissing, sharing a drink, etc.). Contacts of contacts are not considered to be at risk. Despite these recommendations, rifampin was given to approximately 37,000 persons in the community area of this high school. A few days later, a third teenager from a different high school in the area was diagnosed with meningitis (later confirmed as serogroup C). ACIP recommendations state that a meningococcal outbreak control vaccination program (vaccine covers serogroups A, C, Y, and W-135) be considered when 3 or more cases have occurred in less than three months and the attack rate exceeds 10 cases per 100,000 population. This criterion was not met in this situation since the first two cases are considered co-primary cases and are counted as one case. However, approximately 5,800 students and teachers at several high schools in the area were vaccinated in public health clinics. It's easy to second guess our colleagues and we recognize the tremendous pressure of concerned citizens when two teenagers have died. In last week's MMWR was an article describing recommendations when a case-patient with meningococcal disease has flown on a commercial airline (http://www.cdc.gov/mmwr/preview/
mmwrhtml/mm5023a2.htm Attention: Non-MDH link). It is recommended when a case-patient has been on a flight of 8 hours duration or longer (including ground time), antimicrobial prophylaxis should be considered for those sitting immediately next to the case-patient. Implementation of this recommendation is often very difficult. As a first step, we do query all of our case-patients for travel histories in the 14 days prior to their onset of illness. Please report suspect cases of meningococcal disease immediately to (612) 676-5414.
4. Lyme Disease Update
Last week the New England Journal of Medicine released several articles on its website related to Lyme disease that will be published in July (http://content.nejm.org/ Attention: Non-MDH link). Of note was an article demonstrating that a single 200 mg dose of doxycycline given within 72 hours after an I. Scapularis tick bite can prevent the development of Lyme disease. An accompanying editorial notes that the risk of Lyme disease after a known tick bite is low (3%) and most Lyme disease cases result from unrecognized tick bites. In the majority of circumstances in which the tick bite occurs in an area of low incidence for Lyme disease, in which the tick is not a nymphal tick, or in which the tick is not at least partially engorged, the risk of Lyme disease is so low that prophylaxis with doxycycline is not indicated.
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.
For concerns or questions regarding content, please use our Bug Bytes Feedback Form.
You can also subscribe to the MDH Bug Bytes newsletter.