Ehrlichiosis in a golf-oriented retirement community.

BACKGROUND: Ehrlichiosis due to Ehrlichia chaffeensis usually occurs sporadically or in small clusters, with an annual incidence estimated at 3 to 5 cases per 100,000 population in areas of endemic disease. The putative principal vector is the Lone Star tick (Amblyomma americanum). We investigated an outbreak of ehrlichiosis that occurred in June 1993 among members of a golf-oriented retirement community (community A) in Tennessee. The community is densely wooded and borders a wildlife-management area where deer are numerous. METHODS: We conducted a case-control study, using medical-history reviews, serologic testing, and testing with the polymerase chain reaction for E. chaffeensis infection. We also surveyed a sample of 10 percent of the households in community A and in another golf-oriented community (community B) more than 20 miles (32 km) from the wildlife-management area. Survey participants completed a questionnaire and provided specimens for serologic testing. In both communities, searches for ticks were undertaken. RESULTS: Eleven cases of symptomatic ehrlichiosis were identified in the case-control study, 10 of which were in community A (attack rate, 330 per 100,000). Of 311 surveyed residents of community A, 12.5 percent had serologic evidence of past E. chaffeensis infection, as compared with 3.3 percent of 92 in community B (relative risk in community A as compared with community B, 3.9; 95 percent confidence interval, 1.2 to 12.2). The risk of infection was associated with tick bites, exposure to wildlife, golfing, and among golfers, retrieving lost golf balls from the rough. Persons who never used insect repellent were more likely to have had infection than persons who did. In community A, thousands of Lone Star ticks were found; in community B, only three ticks were found. CONCLUSIONS: The high rate of E. chaffeensis infection in community A resulted from its proximity to a wildlife reserve. When outdoor recreational activities are common and concentrations of ticks are high, outbreaks of arthropod-borne zoonoses can be anticipated.

Coccidioidomycosis among visitors to a Coccidioides immitis-endemic area: an outbreak in a military reserve unit.

An outbreak of coccidioidomycosis occurred in a US Marine reserve unit based in Tennessee after a 3-week training exercise in California that involved substantial exposure to soil and dust. Interviews and serologic testing were done on three occasions (6, 11, and 15 weeks) after the men returned from California, and spherulin skin tests were done at 6 months. Of 27 men, 8 (30%) had evidence of recent coccidioidal infection. Of these, 7 (88%) had an illness consistent with coccidioidomycosis that, despite medical evaluation, was diagnosed incorrectly in 5 men (71%). Diagnosis of coccidioidal pneumonia outside an area in which Coccidioides immitis is endemic is unlikely unless the health care provider is aware that the patient traveled recently. Detection of coccidioidomycosis could be facilitated if organizations that regularly send people to C. immitis-endemic regions were to inform these persons about the risks of infection.

Immunization coverage among infants enrolled in the Tennessee Medicaid program.

OBJECTIVES: To determine immunization coverage of infants receiving Medicaid in Tennessee and to identify risk factors for failure to complete recommended vaccinations by 24 months of age. DESIGN: Retrospective cohort study. SUBJECTS: A total of 33,615 children born in one of three urban Tennessee counties from 1980 through 1989 who were enrolled in Medicaid throughout their first 24 months of life. MAIN OUTCOME MEASURES: Receipt of four diphtheria-tetanus-pertussis, three oral polio, and one measles-mumps-rubella vaccines by 24 months of age (up-to-date), as recorded in computerized county immunization records and Medicaid billing files. RESULTS: Overall, 45% of infants enrolled in Medicaid in the three urban counties completed the recommended vaccinations by 24 months. The proportion of infants up-to-date peaked at 50% for those born in 1982 and 1983, and decreased to 44% for those born in 1989. The only strong independent predictors of immunization completion were number of prior births for the mother, timing of the first immunization, and county of birth. The proportion up-to-date was 56% for first-born children compared with 27% for those whose mothers had at least three prior births; 55% for those whose first immunization was on time compared with 22% for those with a delay in the first immunization; and 63%, 52%, and 37% for infants born in the three respective counties. Maternal age, education, race, and marital status predicted immunization completeness only weakly or not at all. CONCLUSIONS: Of infants born in the three counties in the 1980s who were enrolled in the Tennessee Medicaid program, fewer than half completed their recommended childhood vaccinations by 24 months of age. The large differences in immunization levels between infants enrolled in the Medicaid program in the three counties, not accounted for by differences in demographics, suggest that factors related to the health care and vaccine delivery system have important effects on achieving adequate immunization of these infants.

The reporting of communicable diseases: a controlled study of Neisseria meningitidis and Haemophilus influenzae infections.

Surveillance systems for communicable diseases in the United States are primarily passive. We compared the passive reporting system for invasive disease caused by Neisseria meningitidis and Haemophilus influenzae with a concurrent, active laboratory-based system in the four metropolitan counties of Tennessee. The passive reporting system identified approximately 50% of all cases that were identified by the active system and accurately reflected trends in disease occurrence during the study period. Of all reported cases, physicians contributed fewer than 4%. Nearly 40% of all hospitals in the study area did not participate in the passive system. This lack of participation resulted in disproportionately increased reporting of disease among blacks. Inconsistencies in case definition within the state also contributed substantially to underreporting and lack of demographic representativeness of reported cases. The median reporting interval (the time from the onset of disease to transmission of the case report to the Centers for Disease Control and Prevention) was 24 days (range, 5-157 days). Efforts to improve surveillance of those infections for which isolation of a pathogen is tantamount to a diagnosis should concentrate on laboratory-based reporting and the use of currently available computer telecommunication systems.

Sustained transmission of mumps in a highly vaccinated population: assessment of primary vaccine failure and waning vaccine-induced immunity.

From January to July 1991, an outbreak of mumps occurred in Maury County, Tennessee. At the primarily affected high school, where 98% of students and all but 1 student with mumps had been vaccinated before the outbreak, 68 mumps cases occurred among 1116 students (attack rate, 6.1%). Students vaccinated before 1988 (the first year mumps vaccination was required for school attendance in Tennessee) may have been at greater risk of mumps than those vaccinated later (65[6.1%] of 1001 vs. 2[2.2%] of 89; risk ratio, 2.9; 95% confidence interval, 0.7-11.6). Of 13 persons with confirmed mumps who underwent serologic testing, 3 lacked IgM antibody in well-timed acute- and convalescent-phase serum specimens. Vaccine failure accounted for a sustained mumps outbreak in a highly vaccinated population. Most mumps cases were attributable to primary vaccine failure. It is possible that waning vaccine-induced immunity also played a role.

Nosocomial transmission of Salmonella gastroenteritis to laundry workers in a nursing home.

BACKGROUND: Outbreaks of salmonella gastroenteritis in nursing homes are common. Person-to-person transmission to nursing home personnel occurs occasionally, but infection of laundry staff as a result of handling soiled linen rarely has been reported. OBJECTIVE: To examine the nosocomial transmission of infection to laundry staff during an outbreak of salmonellosis in a nursing home. SETTING: A 250-bed nursing home in a rural Tennessee county. METHODS: Residents and staff of the nursing home were interviewed and cultures of stool samples examined for enteric pathogens. RESULTS: Stool cultures from 32 residents and 8 employees were positive for Salmonella hadar. Infection among the residents was food-borne, but infection among employees likely represented secondary transmission, as none of the employees ate food prepared in the kitchen and their onset of symptoms occurred seven to 10 days after that of ill residents. Three laundry personnel who had no contact with residents were infected. Most of the ill residents (81%) were incontinent, which led to an increase in both the degree of fecal soiling and the amount of soiled linen received by the laundry during the outbreak. Laundry personnel regularly ate in the laundry room, did not wear protective clothing, and did not wear gloves consistently while handling soiled laundry. CONCLUSIONS: This investigation implicates linen soiled with feces as the source of nosocomial S hadar infection in laundry workers and underscores the importance of using appropriate precautions when handling linen.

Rubella among the Amish: resurgent disease in a highly susceptible community.

Although the Amish make up less than 0.05% of the United States population, nearly all rubella reported in the United States in 1991 occurred in this population. In early 1991 a large rubella outbreak in a Tennessee Amish community that had experienced no rubella for 17 years afforded an opportunity to describe the epidemiology of rubella in this unique population. Structured interviews were conducted with 54 Amish families. Of 383 persons in the sample 85 (22%) had rubella. Illnesses were mild; 16% of cases lacked fever and 20% of cases reported no symptoms except rash. Children < 17 years of age were 7 times more likely than older individuals to be affected (77 of 214 vs. 8 of 165). All pregnant women in the community were > 20 years of age; none developed rubella. No congenital rubella syndrome was recognized. Although rubella is increasingly a disease of adolescents and young adults, in this outbreak, rubella was again a childhood disease. Illness in this community-based investigation was mild; rubella may be difficult to diagnose and report. Immunity after remote natural infection was durable since the community's last outbreak. Pregnant women probably were protected by the age distribution of immunity; this age distribution may not occur in other Amish populations. If preventable morbidity from rubella and other vaccine preventable diseases is to be avoided in this group, increased attention should be directed to encouraging vaccinations among Amish persons.

Salmonella enteritidis gastroenteritis transmitted by intact chicken eggs.

OBJECTIVE: To determine the source and to describe the clinical importance of a large outbreak of Salmonella enteritidis gastroenteritis in Tennessee, which is outside the geographic focus of the S. enteritidis pandemic. DESIGN: A case-control study and tracing of the source eggs. SETTING: A Tennessee community and a large layer farm in Indiana. PATIENTS: Case patients ate at the implicated restaurant and subsequently developed S. enteritidis gastroenteritis; controls ate with the case patients, but did not develop gastroenteritis. MEASUREMENTS: Eighty-one case patients were identified; 73 (90%) had eaten egg-containing sauces at a local restaurant on a given evening. The eggs were traced to their farm of origin in Indiana. The farm was inspected 5 weeks after the outbreak. MAIN RESULTS: Of 24 patients with culture-proved cases, 11 were hospitalized. Hollandaise and bernaise sauces prepared with intact, extra-large, grade-A eggs were strongly associated with illness (P less than 0.001). Salmonella enteritidis was isolated from specimens collected from chickens and the farm. Antimicrobial susceptibility patterns, phage typing, and plasmid profiles of isolates from the farm and from patients were indistinguishable. CONCLUSIONS: Salmonella enteritidis infection is a large and growing public health problem that is spreading beyond the northeastern United States. This study shows a direct link between infected poultry flocks and an outbreak of human illness.

Foodborne hepatitis A: evidence that microwaving reduces risk?

During July 1988, 68 persons in Chattanooga, Tennessee, developed serologically confirmed hepatitis A. Between 15 June and 3 July, 93% of case-patients ate at a specific restaurant compared with only 3% of the local community. An intravenous drug user who worked as a cook was identified as the source. A case-control study was done to identify the vehicle of transmission. Case-patients were more likely than controls to have eaten hamburger buns and pickles, the only foods routinely handled after cooking. Of the restaurant patrons included in the study, 12 microwaved their food before consumption; none developed clinical illness despite eating large amounts of food handled after cooking. Sandwiches that were not microwaved were significantly associated with illness (odds ratio = 9.6; P less than .02). This epidemiologic evidence suggests that microwaves inactivate hepatitis A virus in food.

A surgeon with AIDS. Lack of evidence of transmission to patients.

In January 1989 [corrected], the media reported the identity of a surgeon who was recently diagnosed with the acquired immunodeficiency syndrome (AIDS). Concern about surgeon-to-patient transmission of human immunodeficiency virus (HIV) persisted despite reassurances from health authorities. Therefore, HIV antibody testing was offered to the surgeon's patients. We identified 2160 patients operated on since 1982; none had been reported to Tennessee's AIDS registry. A total of 264 had already died; none were reported to have died of AIDS or other HIV-related diseases. Of the 1896 patients remaining, we contacted 1652; 616 (37%) were tested. Only one (an intravenous drug user) was HIV antibody positive, and his medical history suggested that he may already have had AIDS at the time of his surgery. These results support the concept that the risks to patients operated on by HIV-infected surgeons are most likely quite low and support recommendations for the individualized assessment of HIV-infected health care workers.

KIE: The authors attempted to notify and to offer HIV antibody testing to all patients who had been operated on by a Tennessee surgeon with AIDS during the seven years prior to his diagnosis. They found no evidence of HIV transmission to patients from the surgeon. Six hundred and sixteen former patients were screened for HIV; only one, an intravenous drug user, tested positive for HIV antibody. None of 2,160 former patients appeared on the Tennessee AIDS registry. None of 264 deceased patients were reported to have died of AIDS or of AIDS-related diseases. Mishu, et al. argue that their findings support the conclusion that risks to patients operated on by HIV-positive surgeons are probably quite low, and that each instance of a HIV-infected health worker should be assessed individually.

Mumps transmission in hospitals.

Although sporadic transmission of mumps within hospitals to patients and staff is well documented, outbreaks of mumps within hospitals have only rarely been reported. The widespread mumps outbreaks that occurred in Tennessee in 1986-1987 provided an opportunity to assess the extent of the problems caused by mumps in hospitals. Information was obtained from 146 (95%) of 154 infection control practitioners in the state. Infection control problems caused by mumps were reported from 17 (12%) of 146 hospitals. The 17 hospitals in which these incidents occurred were located in counties that accounted for 67% of the reported mumps cases statewide during this period. Although most cases of mumps in health care workers were community-acquired, six health care workers in three different hospitals developed mumps following nosocomial exposure. In two institutions, nine patients contracted mumps while hospitalized. Both were long-term-care facilities housing adolescents, who had substantial contact with a community where mumps outbreaks were ongoing. This study suggests that mumps poses a small but real risk to both patients and staff in hospitals, particularly in long-term-care facilities caring for adolescents and young adults. In communities where mumps activity is ongoing, hospitals should consider identifying potentially susceptible staff members at risk for infection and offering vaccine. Likewise, susceptible patients in long-term-care facilities should be immunized.

Fatal carbon monoxide poisoning at a motel.

One man died and four other persons required hospitalization following accidental exposure to carbon monoxide at a motel. In spite of prompt diagnosis of the index cases, a search for the source of exposure and for other possible victims was delayed more than ten hours. Subsequent investigation revealed that air conditioning units drew carbon monoxide from the gas heaters for the motel's indoor swimming pools into three adjacent guest rooms through structural defects in the walls. Emergency care providers must remember that in environmental exposures, other persons may continue to be at risk, and efforts must be made to identify them.

A large outbreak of mumps in the postvaccine era.

During a county-wide mumps outbreak in Nashville, Tennessee, 332 cases of mumps were identified at a public high school (attack rate, 18.8%). A pep rally 17 d before the peak of the outbreak at a single public high school may have provided an opportunity for point-source exposure. A case-control study demonstrated that vaccine efficacy was 75% (we used provider-verified records and excluded students with a history of mumps disease). Although school records were nonuniform, mumps immunization status was correct, compared with provider-verified records, in at least 85% of both cases and controls. Parental reports were much less reliable. The cost of the outbreak was estimated at $154/case. Receiving mumps vaccine at a vaccine clinic held after the outbreak had peaked was associated with a decrease in risk of mumps disease. Thus, these clinics may have a role in the control of such outbreaks.

An outbreak of organic dust toxic syndrome in a college fraternity.

An explosive outbreak of a febrile respiratory illness occurred among members of a college fraternity. The preponderant signs and symptoms were muscle aches, cough, and low-grade fever. All illnesses occurred within 1.3 to 13 hours of attendance at a party where there was a dense airborne dust from straw that had been laid on the floor. Of the 67 fraternity members who attended the party and answered a questionnaire, 55 became ill (attack rate, 82%). Risk of illness was higher for those who spent more time at the party. Duration of illness ranged from 4.5 hours to seven days. Results of serological studies did not demonstrate an allergic or viral cause for these illnesses. The clinical and epidemiologic features of this outbreak were characteristic of organic dust toxic syndrome, an acute respiratory illness caused by inhalation of molds growing on hay, silage, or other agricultural products.

Disease surveillance and emergency services at the 1982 World's Fair.

We designed a special surveillance system to detect health complaints of visitors to the 1982 World's Fair. Heat-related illness occurred during the first month of the Fair but was substantially reduced by public education, environmental modification, and provision of additional water fountains. There was no disruption of emergency health services in the communities surrounding the Fair. Advance planning and the provision of on-site medical services can minimize the public health impact of large gatherings.

An outbreak of staphylococcal skin infections among river rafting guides.

Outbreaks of staphylococcal skin infections among healthy adults are most unusual. The authors report an epidemic of skin infections due to Staphylococcus aureus that involved river rafting guides in Tennessee, South Carolina, and North Carolina in summer 1982. Infections occurred only among employees of the rafting companies that provided communal, on-site housing; carriage rates of S. aureus were as high as 89% at those companies. A case-control study found that having had an infected roommate was significantly associated with infection, as was working at the livery with the most crowded housing. This outbreak appeared to be due to two factors: frequent minor skin wounds acquired while rafting, and prolonged close contact among the persons with wounds. It is likely that crowding and exposure to infected wounds led to elevated S. aureus carriage rates, which in turn increased the probability that wounds would become infected. Repeated immersion in water likely enhanced the development of infections.

The detection of penicillin-resistant pneumococci. The compliance of hospital laboratories with recommended methods.

Isolations of pneumococci with diminished susceptibility to penicillin have been reported with increasing frequency in recent years. The first reported isolations of such organisms in Tennessee occurred in December 1982, and prompted a survey of acute-care hospitals to determine the methods being used to test pneumococcal isolates for penicillin susceptibility. All 77 acute-care hospitals in Tennessee with 100 or more beds were surveyed. Eighteen (23%) did not test the penicillin susceptibility of any pneumococcal isolates obtained from blood or cerebrospinal fluid. Thirty-eight hospitals (49%) tested some or all such isolates, but did not perform the tests in accord with established standards; 21 (27%) properly tested all such isolates. There was no correlation between the proper testing of pneumococcal isolates for penicillin susceptibility and the mode of governance, numbers of beds, or medical school affiliations of the respondent hospitals. It is recommended that appropriate pneumococcal isolates be tested for penicillin susceptibility. Such testing is most reliably performed by the disk diffusion method, using a 1-microgram oxacillin disk.