Outbreak of Legionnaires' disease associated with a display whirlpool spa.

BACKGROUND: Recognized outbreaks of Legionnaires' disease (LD) are rare; when they occur, they provide opportunities to understand the epidemiology of the illness and improve prevention strategies. We investigated a population-based outbreak. METHODS: After the confirmation of LD in October 1996 in five people in neighbouring towns in southwest Virginia, active surveillance for additional cases was undertaken. A case-control study was conducted to identify exposures associated with illness, followed by a cohort study among employees of the facility at which the source of the outbreak was located in order to assess unrecognized exposure and illness. Samples of likely sources of LD in the facility were cultured for LEGIONELLA: RESULTS: In all, 23 laboratory-confirmed cases of LD were eventually identified. Of the 15 cases in the case-control study, 14 (93%) reported visiting a home-improvement store, compared with 12 (27%) of 45 controls (matched odds ratio [MOR] = 23.3; 95% CI : 3-182). Among home-improvement centre patrons, 10 (77%) of 13 cases questioned recalled either visiting or walking by a display whirlpool spa, compared with 3 (25%) of 12 controls (MOR = 5.5; 95% CI : 0.7-256.0). Two cases' sputum isolates were an exact match, by monoclonal antibody subtyping and arbitrarily primed polymerase chain reaction, to a whirlpool spa filter isolate from the store. Employees reporting more exposure to the display spas were more likely to report symptoms of LD or to have an elevated titre. CONCLUSIONS: This investigation shows that LD can be transmitted from a whirlpool spa used for display only, and highlights the need for minimizing the risk of transmission of LD from all water-filled spas. Key messages This paper describes an investigation of a population-based outbreak of Legionnaires' disease (LD). A case-control study first identified a home-improvement store as the likely source of the outbreak. An environmental investigation later confirmed that finding, as two cases' sputum isolates were an exact match, by monoclonal antibody subtyping and arbitrarily primed polymerase chain reaction, to a whirlpool spa filter isolate from the store. The spa was intended and used for display only.

[Incidence and risk factors of the association of AIDS and tuberculosis in Spain]. / Incidencia y factores de riesgo de la asociación del sida y la tuberculosis en España.

BACKGROUND: Incidence of tuberculosis in persons coinfected with HIV is very high. The aim of this study was to determine the risk factors for tuberculosis in AIDS patients in Spain. PATIENTS AND METHODS: A study was carried into AIDS cases (1993 European AIDS case definition) over 12 years old, diagnosed in Spain in 1994. A comparison was run between cases with tuberculosis and the remaining reported AIDS cases on the register, by sex, age, transmission category and prison record. Multiple logistic regression was used to assess the independent effect of each variable, with the adjusted odds ratio (ORa) and their 95% confidence intervals. RESULTS: Annual incidence of AIDS and tuberculosis comorbidity was 8.9 per 100,000 inhabitants. Multivariate analysis revealed that tuberculosis in AIDS patients appeared with higher frequency in: males (ORa = 1.4; CI 95%, 1.3-1.6); the 13-29 age group (ORa = 1.3; CI 95%, 1.1-1.5) and the 30-39 year old group (ORa = 1.1; CI 95%, 1.0-1.3), injecting drug users (IDU) (ORa = 1.4; CI 95%, 1.2-1.6), and those patients with a prison record (ORa = 2.1; CI 95%, 1.9-2.4). CONCLUSIONS: In Spain, male AIDS patients, under age 40 years with a prison record and IDU have a higher risk of tuberculosis. Control measures for tuberculosis should therefore be intensified among these patients.

[Intervention in a measles outbreak]. / Intervención en un brote de sarampión.

BACKGROUND: The description of a community measles epidemic and the activities developed to control the same is presented. Vaccination efficacy was studied by a cases and controls study. METHODS: The study period of the epidemic was from August 1994 to March 1995 and the intervention was performed from January to March 1995. The activities were developed in two phases: the first directed at a descriptive study and control of the outbreak and in the second phase a cases and controls study was designed to evaluate vaccination efficacy (VE%) versus measles. RESULTS: A total of 325 cases of measles were registered over a period of 29 weeks. The greatest attack rate was found in the age group of 5 to 9 years with 5-91 cases/100. The surveillance system and the priorization of activities protocol designed for control of the outbreak were found to be useful. The result of the cases and controls study demonstrated VE% to be 93.5% (84.3-97.3%). CONCLUSIONS: Rapid intervention in the outbreaks of measles is considered fundamental to avoid propagation of the same among the susceptible population. The surveillance system versus the disease should therefore be optimized. Although vaccination efficacy was found to be good, the high rates of attack found in the theoretically vaccinated groups lead to the recommendation of the introduction of a second dosis of the vaccine and to vaccinate the existing non vaccinated sets.

[Study of an outbreak of hysteria after hepatitis B vaccination]. / Estudio de un brote de histeria después de la vacunación de hepatitis B.

BACKGROUND: The aim of this study was to describe an epidemic outbreak of mass hysteria among adolescents which occurred after the immunisation with vaccine against hepatitis B and to determine the association with social variables related to the students. SUBJECTS AND METHODS: All the available information was evaluated and a questionnaire was designed, which included sociodemographic, clinics and school environment variables. A case-control study was conducted. The data were analyzed and outbreak rate and odds ratio with their respective CI (95%) were calculated. RESULTS: 18 cases (among a set of 74 students of seventh of EGB) were clustered in time (10.30-11 h) and space (class of seventh B). There was a clear association between the cases and the female sex (odds ratio = 5.4; CI 95% 1.3 - 23.8). As for the sociological variables there was a association with increasing household members (odds ratio = 5.3; CI 95% 1.3 - 23.4) and with lower educational levels of the father (odds ratio = 10.6; CI 95% 1.2 - 239.9). Among the affected a more unfavorable opinion of the school was detected. CONCLUSIONS: This outbreak fulfils 8 of the 11 criteria classically admitted as usual characteristics of a mass psychogenic illness episode. The sensorial transmission remains demonstrated supporting the hypothesis of a chain reaction.

[Epidemic outbreak of 81 cases of brucellosis following the consumption of fresh cheese without pasteurization]. / Estudio de un brote epidémico de 81 casos de brucelosis consecutivo al consumo de queso fresco sin pasteurizar.

BACKGROUND: In spite of the great effort that has been made in recent years in Castilla-La Mancha to control brucelosis, a lack of awareness on the part of producers and consumers leads to major epidemic outbreak, such as the one described below. METHODS: A description of the outbreak is described and a study is conducted of cases and controls to determine the factors which are responsible for the epidemic. Unadjusted and adjusted Odds Ratios (O.R.) are obtained together with their confidence intervals, for the main epidemiological factors studied. RESULTS: A total of 81 cases of brucelosis were recorded in a period of 25 weeks. All the cases occurred in the same borough or were in some way linked to it. In the case and controls study no differences were found with regard to age, sex, contact with livestock or the consumption of pasteurised milk or cheese. A strong link was established between the illness and the consumption of home-made cottage cheese prepared by a small-scale producer in the borough, (O.R. = 311.9; C.I. = 95% = 41.48-12735)., whose livestock turned out to be infected with Brucella Mellitensis. CONCLUSIONS: This outbreak showed that in Spain, there is a risk of contracting brucelosis by consuming non-pasteurised dairy products, particularly cheese, when these are not subjected to the normal sanitary and health controls. The benefits of epidemiological research in the search for cases and determining the factors responsible for the outbreak are also demonstrated. An intensification of controls, the cleansing of the herds and flocks and health education in general, are suitable instruments for controlling this zoonosis in Spain.

Completeness of tuberculosis case reporting, San Juan and Caguas Regions, Puerto Rico, 1992.

Completeness of tuberculosis case reporting in Puerto Rico was assessed. Cases diagnosed among hospitalized, tuberculosis, and human immunodeficiency virus clinic patients during 1992 were retrospectively reviewed. Hospital discharge diagnoses, pharmacy listings of patients receiving anti-tuberculous medications, laboratory and acquired immunodeficiency syndrome registry data were used for case finding in selected hospitals and clinics. Identified cases were matched to the health department TB case registry to determine previous reporting through routine surveillance. Records of unreported cases were reviewed to verify tuberculosis diagnoses. Of 159 patients with tuberculosis, 31 (19.5%) were unreported. A case was defined according to the Centers for Disease Control and Prevention definition. Unreported cases were less likely than previously reported cases to have specimens that were culture positive for M. tuberculosis, 14 of 31 (45.2%) compared with 111 of 128 (86.7%). Excluding the laboratory, tuberculosis diagnoses in acquired immunodeficiency syndrome registry patients had the highest predictive value of finding tuberculosis (94.1%), followed by tuberculosis clinic records (71.7%), and pharmacy listings (45.6%). Tuberculosis discharge diagnoses, however, yielded the largest number of unreported cases (14). Health care providers should be educated regarding the importance of promptly reporting all suspected TB cases regardless of results of laboratory testing.

Drug-resistant tuberculosis in Puerto Rico, 1987-1990.

We conducted a proportional morbidity study to determine the factors associated with, patterns of, and proportion of cases of tuberculosis with drug resistance in Puerto Rico. We abstracted data from 279 report forms of new cases of tuberculoses reported to the Puerto Rico Health Department between 1987 and 1990 in which isolates had been tested for drug susceptibility. Overall, 55 (19.7%) of the 279 cases of tuberculosis were resistant to at least one drug, and 27 (9.7%) were resistant to more than one drug. Among the 59 patients with previous tuberculosis therapy, 20 (33.9%) had isolates that were drug-resistant. Among the 220 without previous therapy, 35 (15.9%) had isolates that were drug-resistant. For all 279, resistance to isoniazid (INH) was most common (11.1%) followed by streptomycin (SM) (10%), rifampin (RIF) (4.3%), ethambutol (EMB) (2.2%), and pyrazidimide (PZA) (1.1%). A history of previous tuberculosis therapy (odds ratio [OR] = 2.71, 95% confidence interval [CI] = 1.34-5.48) and being born outside the United States and Puerto Rico (OR = 4.76, CI = 1.69-13.39) were independently associated with drug resistance. Because of the high proportion of drug-resistant tuberculosis in Puerto Rico we recommend (1) that all persons in Puerto Rico in whom tuberculosis is diagnosed should initially receive four-drug therapy (INH, RIF, EMB, and PZA), (2) that susceptibility testing be done on initial Mycobacterium tuberculosis isolates from all patients, and (3) that those with a history of previous tuberculosis therapy or those who are foreign-born have very careful clinical and microbiologic follow-up.

Successes and failures in vaccine delivery: evaluation of the immunization delivery system in Puerto Rico.

The objective of this study was to evaluate immunization delivery and determine reasons for low coverage among preschool-age public clinic attendees in Puerto Rico. In 25 randomly selected clinics, coverage and missed immunization opportunities were assessed in 273 children aged 2 to 59 months, exist interviews were conducted with parents, and providers were interviewed. Two neighborhoods close to the clinics were surveyed to determine parental knowledge about immunizations, and the vaccination status of children in these neighborhoods was assessed. Two hundred seventy-three clinic attendees were interviewed. Among 229 (84%) with vaccination cards, only 126 (55%) had received all indicated vaccines by completion of the clinic visit. Forty-five percent of children with cards in the household survey were not up-to-date. Of 171 (75%) clinic attendees eligible for vaccination at the visit, 118 (69%) missed one or more immunizations at the visit. In addition, half of all children had previously missed one or more immunizations when they had received another vaccine. Missed opportunities occurred because of nonavailability of vaccines, lack of integration of services, provider misconceptions about contraindications, and failure to administer vaccines simultaneously. Other problems included barriers to immunization services and lack of information and education activities. It is concluded that deficiencies in immunization delivery substantially delay immunization and reduce coverage.

HIV wasting syndrome in the United States.

OBJECTIVE: To describe the characteristics of individuals > or = 13 years of age with HIV wasting syndrome in the United States and US territories. DESIGN: Retrospective review of national AIDS case surveillance data. METHODS: Data for the 147,225 individuals with AIDS reported to the Centers for Disease Control from 1 September 1987 to 31 August 1991 were reviewed. The frequency of HIV wasting syndrome and its association with demographic and exposure category variables and with other AIDS-indicator diseases were assessed. RESULTS: A total of 10,525 (7.1%) had wasting syndrome as the only AIDS-indicator condition, and 15,726 (10.7%) had wasting syndrome plus at least one other AIDS-indicator condition. Patients with wasting syndrome as the only AIDS diagnosis were more likely to be female, to be black or Hispanic, and to have a mode of HIV exposure reported as injecting drug use, heterosexual contact, or transfusion/hemophilia. The proportion of AIDS patients reported with wasting syndrome varied by geographic distribution, ranging from 11% in the northeastern United States to 47% in Puerto Rico. The association between HIV wasting syndrome and Hispanic ethnicity was due to the much higher prevalence of wasting syndrome reported in Puerto Rican AIDS patients. The other AIDS-indicator conditions most strongly associated with wasting syndrome were isosporiasis, pulmonary candidiasis, esophageal candidiasis, HIV encephalopathy, chronic mucocutaneous herpes simplex, and coccidioidomycosis. CONCLUSIONS: The association between HIV wasting syndrome and injecting drug use, and the significant racial/ethnic and geographic differences in prevalence of this AIDS diagnosis may reflect differences in diagnostic and reporting practices and/or access to medical care.

Risk factors associated with severe measles in Puerto Rico.

From January to April, 1990, 695 measles cases were reported to the Puerto Rico Health Department; there were 12 measles-associated deaths (case fatality ratio, 17/1000), more than in any year since 1967. We conducted a case-control study of risk factors for severe measles. We identified 16 children (ages 5 to 34 months) with severe measles and selected children with nonsevere measles as controls (39 hospitalized and 38 nonhospitalized). Controls were frequency matched to severe measles cases by region of residence. One case and two controls had been vaccinated. An underlying illness was present in 50% of cases and 16% of nonhospitalized controls (Mantel-Haenszel weighted odds ratio 5.3; 95% confidence interval 1.4, 20.2). In a multivariate analysis cases were significantly more likely than hospitalized controls to be from families with an annual income of < $5000 (odds ratio (OR), 26.9), to have a mother without a high school degree (OR 11.1), to be anemic (hemoglobin < 10 g/dl) (OR 15.9) and have an underlying illness (OR 18.3). During measles outbreaks preventing severe illness requires aggressive control measures and strategies to increase vaccine coverage of children with underlying illnesses and of low socioeconomic status.

Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients.

OBJECTIVE: To assess nosocomial transmission of tuberculosis (TB). DESIGN: A historical cohort study of hospitalized patients with the human immunodeficiency virus (HIV) and a purified protein derivative (PPD) tuberculin skin test survey of health care workers (HCWs). SETTING: A large public teaching hospital in San Juan, Puerto Rico. PATIENTS: For the cohort study, a case patient was defined as any patient in the HIV unit at the hospital who developed culture-positive TB from 31 days or more after admission through December 31, 1989. For the PPD survey, of 1420 HCWs from the hospital, 908 agreed to participate and had sufficient data for analysis. MAIN OUTCOME MEASURES: For the cohort study, to compare the risk of developing active TB among patients who were exposed to hospital roommates with infectious TB and the risk among nonexposed patients. For the HCW PPD survey, to determine the prevalence of and risk factors for tuberculous infection. RESULTS: Eight of 48 (9.7/10,000 person-days) exposed case patients vs four of 192 (0.8/10,000 person-days) nonexposed case patients developed active TB (relative risk [RR] = 11; 95% confidence interval [CI], 2.3, 50.3). Positive PPDs (greater than or equal to 10 mm of induration) in HCWs were associated with older age (P = .0001) and with history of community TB exposure (P = .0002). In a multivariable logistic model that adjusted for these variables, HIV unit nurses (nine of 19) and nurses in the internal medicine ward (45 of 90) had a higher proportion of positive PPDs than the reference group (clerical personnel on other floors: 35 of 188, P = .0005). CONCLUSIONS: These data suggest that patient-to-patient transmission of TB in HIV units can occur and that HCWs are at risk of acquiring TB infection.

Antibody response after a two-year intradermal booster of rabies human diploid cell vaccine.

A study was undertaken to evaluate the effectiveness of a low dose of rabies human diploid cell vaccine administered intradermally for preexposure booster inoculation. Seventy-six volunteers received a 0.1-ml dose of rabies human diploid cell vaccine intradermally, approximately 2 years after their primary series. Though only 25 (32.9%) had a titer less than 0.5 IU/ml before the booster, all had a postbooster titer of greater than or equal to 4.0 IU/ml 3 weeks later. Five of 73 (6.8%) reported an allergic reaction after the booster.