Minnesota Department of Health (MDH) Bug Bytes
March 14, 2001
Vol. 2: No. 6
Neisseria meningitidis
2. Second Measles Case Seen
3. Chronic Wasting Disease of Deer and Elk
4. Foot and Mouth Disease
Neisseria meningitidis
Three cases of invasive meningococcal disease have been reported
in the last 2 weeks. The first, a 4-year old male, was initially
reported as a suspect case when he was admitted to the hospital
with purpura fulminans. His blood culture grew out Neisseria
meningitidis later, but prompt notification made it possible
to quickly determine which contacts should be treated with prophylactic
antibiotics. In addition to his immediate family and other close
contacts a local health department and we determined that approximately
40 preschool classroom and church school classroom contacts should
be given prophylaxis. The second case was a 49-year-old male with
abrupt onset of illness. He became hypotensive, developed a petechial
rash, had multisystem organ failure, and died within 24 hours of
his initial symptoms. The family was started on antibiotics at the
time of admission as a precautionary measure. The physician promptly
notified us when gram negative diplococci were identified in the
blood culture. A family member was interviewed about other possible
contacts who might need prophylaxis. Neisseria meningitidis
was subsequently isolated from blood culture. The third case was
a 20-year-old female admitted to a hospital with meningococcemia.
Prophylaxis was recommended to approximately 20 attendees of a party,
attended by the case-patient, who may have shared oral secretions
with her. Neisseria meningitidis was subsequently isolated
from blood culture. Isolates from all cases were sent to us for
serogrouping; the first two were serogroup Y and the third is pending.
There is no known connection between the first two cases and the
isolates have different pulsed-field gel electrophoresis patterns.
Approximately 40 sporadic cases of invasive meningococcal disease
are reported in Minnesota annually. In 1999, 56 cases were reported,
followed by 22 cases in 2000, and only 4 cases (including the 3
described here) have been reported so far in 2001. It is unknown
why there has been a drop in cases. It is important that MDH be
notified promptly of suspect cases of meningococcal disease. In
some instances it may not be possible to have culture confirmation
but chemoprophylaxis of contacts may be recommended based on the
case's clinical picture and related circumstances. The American
Academy of Pediatrics Red Book recommends that high risk contacts
begin chemoprophylaxis within 24 hours of diagnosis of the primary
case.
2. Second Measles Case Seen In the last issue of Bug Bytes we discussed an imported case of measles in an infant adopted from China. We now have another measles case with no association to the first case. On February 28, a clinic reported a suspect measles case in a 31-year old Hennepin County resident. He had symptoms of cough, coryza, and conjunctivitis beginning on February 25, and rash on February 26. Blood drawn on February 28 and was negative for IgG and IgM measles antibody (indicating his susceptibility to measles and an insufficient time for IgM antibody to develop). Although CDC recommends obtaining serology on the first day of rash, our experience indicates that waiting until day 3 (72 hours) is optimal to avoid false negative results. A second blood was drawn on March 5 and was positive IgM antibody. The patient traveled extensively for business to California and Texas, but we are unable to determine a specific exposure for him. Measles cases have been seen in 11 states in the last month. He believes he had received one dose of vaccine as a child. On a related note, we have seen no secondary spread from the first infant case, but cases are still possible at this point in time.
3. Chronic Wasting Disease of Deer and Elk
A common telephone call received lately involves whether or not venison
or elk is safe to eat, the caller having heard about "mad cow disease
in deer." In a previous (Dec.
1, 2000) Bug Bytes we discussed mad cow disease and Creutzfeldt-Jakob
disease. Chronic wasting disease (CWD) is another type of transmissible
spongiform encephalopathy (TSE) of deer and elk. First seen in 1967, among
free ranging wildlife, it is confined to mule deer, white-tailed deer,
and Rocky Mountain elk in northeastern Colorado, southeastern Wyoming,
and very recently in Nebraska. It has also been seen sporadically in farmed
elk herds in South Dakota, Nebraska, and Oklahoma. Fewer than 200 animals
have been diagnosed with CWD with an estimated prevalence of <5% in
wild deer and <1% in wild elk in the affected area. It has never been
found in Minnesota. Like other TSEs it is a progressive fatal neurodegenerative
disease. Its origin and mode of transmission is unknown. CWD is not known
to cross over to other species and humans are not thought to be at risk.
As a precautionary measure, Colorado health officials advise hunters to
not eat obviously ill animals; wear gloves when gutting a carcass; and
to not eat brain, spinal cord, eye, or lymph nodes where the transmissible
agent is thought to be present.
4. Foot and Mouth Disease
Another common telephone call received lately is about the foot and mouth
disease (FMD) epidemic being seen in the U.K. and several European countries.
FMD is a highly infectious viral disease of cloven-hooved animals, especially
cattle, pigs, sheep, and goats. The disease causes fever and blisters
in the mouth and on the feet of animals. It may lead to lameness, drop
in milk production, and weight loss in infected animals, with severe economic
consequences for the farmer. Very few human FMD infections have ever been
documented despite regular exposure throughout the world. It has been
found in those with direct contact to infected animals. Those few have
had a self-limiting mild influenza-like illness (headache, malaise, fever).
They also may exhibit symptoms similar to animals with vesicles appearing
on the fingers and hands, feet, and in the mouth, especially the tongue
and palate. It is not transmitted person-to-person or through food to
humans. It should not be confused with hand, foot, and mouth disease in
humans (a mild viral illness caused by a different enterovirus). With
this information in mind, we've been advising people not to cancel their
travel plans to Europe, but to use caution so as not to bring the virus
back to Minnesota farms. The Board of Animal Health recommends avoiding
visiting farms and zoos in Europe, and to wash clothes and shoes, and
to not visit farms for 7 days after returning to Minnesota. Information
about the foot and mouth outbreak is at http://www.maff.gov.uk/animalh/
diseases/fmd/default.htm Attention: Non-MDH link
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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