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Typhoid Fever. Reportable Diseases Surveillance & Investigation Louisville Metro Health Department Louisville, Kentucky, 40202. Typhoid Fever Outbreak. On Monday, May 3,2004, a positive blood culture for Salmonella typhi in a 12 y.o. female was reported by a local hospital
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Typhoid Fever Reportable Diseases Surveillance & Investigation Louisville Metro Health Department Louisville, Kentucky, 40202
Typhoid Fever Outbreak • On Monday, May 3,2004, a positive blood culture for Salmonella typhi in a 12 y.o. female was reported by a local hospital • Due to the uncommon occurrence of typhoid fever in the community an investigation was initiated to identify the source of infection as well as any activities associated with the spread of the infection • State Health Dept. notified. Sporadic cases occasionally occur and are not considered a cause for alarm unless additional cases are identified
Second Case Reported • On Tuesday, May 4, Salmonella (serotype unknown) cultured from the blood of a 39 yo male at a local hospital • Clinical presentation consistent with typhoid fever (fever 103, headache, mild diarrhea) • Newly employed as a manager-in-training at a local restaurant (Restaurant A) • Specimen sent to state lab for serotyping • Investigation started on the assumption that possible typhoid outbreak (2 or more cases associated by time and place) in progress
Clinical Manifestations of Salmonella typhi Disease (Typhoid fever) • Clinical course : a gradual onset of illness with fever, headache, malaise, anorexia, lethargy, abdominal pain, hepatomegaly, splenomegaly, and possibly a “rose spot” rash on the trunk or a nonproductive cough
Epidemiology of Typhoid Fever • Bacterial disease-Salmonella typhi • Humans are the only source of infection • Asymptomatic carrier state may follow illness, including subclinical infection • Occurrence • Estimated 17 million cases annually with approx. 600,000 deaths worldwide • Fewer than 500 cases annually in US • Fewer than 5 cases annually in Kentucky
Mode of Transmission • Fecal-oral • By food and water contaminated by feces and urine of patients and carriers (shellfish, raw fruits and vegetables, milk products) • Incubation period 3 days-1 month with a usual range of 8-14 days
Salmonella typhi Case Definition • a case that meets the clinical case definition and is confirmed by isolation of S. typhi from blood, stool or other clinical specimens
Interviews conducted • We conducted interviews to collect information regarding: • clinical data • demographic information • complications and treatment • epidemiological information
Results of Epidemiologic Investigation • Cases were investigated thoroughly to assess risk factors for acquiring illness, similarities in activities and risk of spread to the community • Onset dates (4/18/04 and 4/12/04) • Occupation (1 student, 1 food handler) • Travel (both denied personal travel , but had recent contact with immigrants) • Restaurant patronage (1 facility identified by both patients- Restaurant B)
Patient 1 • An interview was conducted with the mother of the 13 yo female • The interview process revealed: • a recent history of aiding Somolian refugees re-settle through church program • Stool specimens were negative • Ate at Restaurant B every Friday night
Patient 1 (cont.) • Attends a local middle school • LMHD issued an advisory to the school about Salmonella (did not specify type) and the importance of hand hygiene • A team of LMHD nurses visited the school to assess the hand washing facilities and procedures of the kitchen staff as well as the students and teaching staff
Patient 2 • An interview was conducted with the 39 yo male • Interview process revealed • Employed as a manager-in-training at a local restaurant-Restaurant A. Notified the environmental health/food hygiene office of LMHD to notify employer of exclusion from work until released by LMHD • Many co-workers in restaurant are recent immigrants from Senegal • Identified Restaurant B as a frequent choice for dining
Restaurant A (Employer of Patient 2) • Upon being notified of Pt. 2’s exclusion from work due to illness, restaurant obtained a contract physician to evaluate risk to the business • Contract physician (Dr. C.) obtained a consent for release of information from Pt. 2, and obtained hospital record • Dr. C. felt clinical presentation consistent with typhoid fever. Inquired about testing all restaurant staff. Decision made by KDPH to wait until serotype confirmed
Second Case Confirmed • Contract physician for Restaurant A notified that their employee (Pt. 2) confirmed to have S. typhi • Dr. C. recommends (as does CDC) to Restaurant A’s corporate office that all employees in Pt. 2’s store be screened for typhoid • Dr. C. travels to Louisville to personally instruct restaurant staff on stool specimen collection and to instruct staff about hygiene and the importance of reporting any illness • Specimens are sent to a private lab for evaluation per choice of Restaurant A.
Restaurant B. Investigated • Owner of Restaurant B. contacted and advised that his facility was identified as the only link between two ill citizens (exact nature of illness not revealed to prevent information leak and public panic) • Requested he arrange for staff to be present for lab specimen collection to screen for the source of illness • Assured that no mention of the situation will be made to the press at this time
Clinic Planned at Restaurant B. • Arrangements made for LMHD to arrive at Restaurant B. in the early morning in order to finish prior to restaurant’s opening for lunch at 11:00 a.m. • Supplies and staff organized to collect blood specimens and to distribute stool specimen collection kits • Health history questionnaire developed to screen for symptoms of typhoid fever as well as travel history and work history for past 2 years • Translators acquired as most of the staff at Restaurant B. spoke little English
Results of Restaurant Investigations • Restaurant A: Total of 86 staff • 55 voluntarily provided stool specimen • All specimens negative for S. typhi • Decision was made not to “require” staff to comply
Restaurant Results (Cont.) • Restaurant B: Total of 25 staff • 22 presented at on site clinic for health history and blood specimen collection • Stool collection kits distributed with instructions • All specimens negative for typhoid Vi antibody • 8 stool specimens returned- negative
Public Health Decisions • LMHD consulted KDPH throughout the course of the investigation • KDPH consulted CDC Enteric pathogens branch for advice about outbreak investigation • CDC recommended extensive histories on both patients as well as screening of employees at both restaurant facilities involved • Public Health Advisory issued to local ED’s to encourage increased index of suspicion for typhoid in patient’s with fever of unknown origin and rigors with or without GI symptoms
Laboratory Services • CDC made arrangement for serum of Restaurant B.’s employees to be tested for Typhoid Vi antibody at their lab, as well as PFGE testing of the cases’ specimens • KDPH made arrangements for stool specimens of Restaurant B.’s employees to be cultured at the state lab
Investigation Results • No source of infection for patients 1 or 2 was identified • No further cases of S. typhi reported
Lessons Learned • Use of Environmental Food Hygiene staff was beneficial due to established relationship with restaurant managers • Confidentiality was extremely difficult to maintain due to large number of people involved • Mom of patient 1 told several people her daughter’s diagnosis • A physician who is friend of mom informed her that he had seen another case of typhoid recently • Pt 2 discussed his diagnosis with others
Lessons (cont.) • Immigrant status of employees of Rest. B contributed to a fear of cooperating • Payment for laboratory services needs to be pre-arranged • 100% management/employee cooperation necessary in order to identify carrier or exclude facility as a possible source • Although no source was found, attempt was necessary for public safety.