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The bacterium Lactococcus lactis is widely used in food production and in medical applications, and is considered safe for human and animal use. However, studies have also linked Lactococcus bacteria to infection. For example, certain variants of Lactococcus species have been associated with bovine mastitis (e.g., Lactococcus lactis and Lactococcus garvieae). In this study, we investigated an outbreak of bovine mastitis thought to be associated with Lactococcus bacteria by using microbiological and molecular techniques. We used bacterial isolation, next-generation sequencing, DNA fingerprinting, and other methods to test our hypothesis that Lactococcus microbes were the primary pathogen causing the mastitis outbreak. Twenty-eight Lactococcus isolates were obtained from mastitic milk of 28 dairy cows. The isolates were identified as L. lactis (27 isolates) and L. garvieae (1 isolate). Phylogenetic analysis based on 16S rDNA gene sequence comparison indicated similarity among the L. lactis isolates as well as between the isolates and reference sequences. The DNA fingerprinting analysis based on random amplified polymorphic DNA results of the 27 L. lactis isolates identified different random amplified polymorphic DNA profiles, which suggests they originated from multiple sources. Microbiome analysis determined Lactococcus to be the dominant genus in the majority of the mastitic milk samples, whereas it was found in low relative abundance in healthy milk samples. The Lactococcus genus was detected in all environmental samples tested, and sampling of bulk tank milk corroborated that Lactococcus was not abundant in healthy milk from the same dairy herd. In summary, our findings suggest that Lactococcus bacteria are a potential etiological agent in the mastitis outbreak studied. Further studies should be conducted to understand the importance of Lactococcus, especially L. lactis, as pathogenic microbes in veterinary medicine and food safety.

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Fresh produce increasingly is recognized as an important source of salmonellosis in the United States. In December 1999, the Centers for Disease Control and Prevention detected a nationwide increase in Salmonella serotype Newport (SN) infections that had occurred during the previous month. SN isolates recovered from patients in this cluster had indistinguishable pulsed-field gel electrophoresis (PFGE) patterns (which identified the outbreak strain), suggesting a common source. Seventy-eight patients from 13 states were infected with the outbreak strain. Fifteen patients were hospitalized; 2 died. Among 28 patients enrolled in the matched case-control study, 14 (50%) reported they ate mangoes in the 5 days before illness onset, compared with 4 (10%) of the control subjects during the same period (matched odds ratio, 21.6; 95% confidence interval, 3.53- infinity; P=.0001). Traceback of the implicated mangoes led to a single Brazilian farm, where we identified hot water treatment as a possible point of contamination; this is a relatively new process to prevent importation of an agricultural pest, the Mediterranean fruit fly. This is the first reported outbreak of salmonellosis implicating mangoes. PFGE was critical to the timely recognition of this nationwide outbreak. This outbreak highlights the potential global health impact of foodborne diseases and newly implemented food processes.

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OBJECTIVES: Workers in the steel industry are exposed to various severe hazards. This study investigated risk factors for non-fatal injury occurring in the workplace and during travel to and from work in steelworkers in Brazil. METHODS: Non-fatal work related injuries during employment from January 1977 to September 1992 were analysed in a cohort of 21 732 male workers in the steel plant of USIMINAS, Brazil. RESULTS: There were 14 972 non-fatal injuries during follow up, with 10 891 injuries in the workplace and 4081 during travel to and from work (travel to work injury). The rate of injury in the workplace was 5.6/100 person-years and that of travel to work injury was 2.1/100 person-years. The most common injuries were to hands, arms, and eyes, with 90% of the eye injuries caused by a foreign body. Both rates of workplace and travel to work injury increased significantly with the number of injuries previously experienced, and decreased with number of years in employment and calendar period. The rates of travel to work injury also seemed to decrease with age, but age was not an independent predictor of workplace injury when we controlled for duration of employment. The rate of workplace injury was increased eightfold for workers who had experienced more than six previous injuries compared with those with no previous workplace injuries after adjusting for duration of employment and calendar period. Labourers were most at risk of workplace injury, with about eight injuries per 100 person-years. Travel to work injury was most common among support workers, with nearly half of the travel to work injuries affecting the eyes. CONCLUSION: The rate of injury was high in these steelworks, both for workplace and travel to work injuries. Characteristics of the work areas and the employees can identify high risk groups; protective measures, safety, health training, and injury programmes should concentrate particularly on these groups. Prevention of eye injury needs special attention in steelworks.

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OBJECTIVE: To determine mortality in patients with congenital adrenal hyperplasia (CAH) compared with that in the general population. DESIGN: We identified 333 children with CAH, treated at several pediatric endocrinology departments in the United Kingdom since 1964, and monitored their mortality to mid 1996. Standardized mortality ratios were calculated, comparing mortality in the cohort with that in the general population, adjusted for sex, age, and calendar period. RESULTS: All-cause mortality in the cohort was 3 times that expected. Mortality was significantly increased at ages 1 to 4 years (standardized mortality ratio = 18.3) but not at older ages and was significantly increased in patients of Indian-subcontinent ethnicity (standardized mortality ratio = 20.4), particularly in girls. From case notes and death certificates, it appears that most deaths were caused by adrenal crisis, often after infection. CONCLUSIONS: Although survival of patients with CAH has greatly improved since steroid therapy has been used, this disease can still have fatal consequences. The high mortality rate in Indian ethnic girls may well reflect lack of parental acceptance and understanding of the disease, as well as of the action required when their child becomes acutely ill. Better communication with and education of parents of children with CAH, especially those from immigrant ethnic minorities, is important.

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OBJECTIVES: In a cohort of 21,816 Brazilian steelworkers we found mortality from motor-vehicle injury was twice that in the State population. A nested case-control study was therefore undertaken to investigate possible socio-demographic, medical and occupational risk factors for this increased risk. METHODS: Cases were defined as all steelworkers in the cohort who died of motor-vehicle injury during employment in the period 1977-1992. For each case, four controls were selected at random from workers in the cohort who were employed at the time of death of the case, and who were born in the same year as the case. Data on socio-demographic factors, and medical and occupational histories were obtained from personnel, industrial hygiene and medical records, and the relation of these factors to risk of motor-vehicle injury was analysed using conditional logistic regression. RESULTS: In a multivariate analysis, the risk of death from motor-vehicle injury was independently associated with being unmarried (odds ratio [OR] compared to married = 3.21, 95% confidence interval [CI]: 1.84-5.59), having a hearing defect (OR = 2.28, 95% CI: 1.10-4.74) and exposure to moderate (OR = 1.71, 95% CI: 1.03-2.83) or high (OR = 2.00, 95% CI: 1.18-3.39) levels of noise at work. The risk of fatal motor-vehicle injury increased with intensity of occupational noise exposure (P = 0.004). CONCLUSIONS: The raised risk of motor-vehicle injury death associated with single marital status is likely to relate to selective factors in the types of individual who remain single, and behaviours associated with being unmarried. The raised risks in relation to hearing defects and exposure to occupational noise, factors that do not appear to have been examined previously, imply that occupational noise exposures might be a cause of fatal motor-vehicle accidents outside the workplace. This finding may have widespread public health consequences since high levels of noise in the workplace and occupationally acquired hearing deficits are prevalent in several occupations. Further investigation is needed to confirm the associated and its mechanisms and, if it is causal, to develop preventive strategies.

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OBJECTIVES: To estimate the relative risk of death from work related injury in a steelworks, associated with exposure to various occupational hazards, sociodemographic factors, and medical history. MATERIAL AND METHODS: The study was a nested case-control design. It was based on a cohort of men employed in the steel plant of USIMINAS, Brazil between January 1977 and August 1990, who were followed up to November 1992. The cases were defined as all workers in the cohort who died from injury in the study period and whose death had been notified to the Brazilian Ministry of Labour as being related to work. Four controls per case, matched to cases on year of birth, were randomly selected from among workers employed in the plant at the time of death of the matching case. Data on potential risk factors for occupational injury were extracted from company records; for the controls these data were abstracted for the period preceding the death of the matching case. RESULTS: There were 37 deaths related to work injuries during the study period. Four surviving workers were selected as controls for each case, but for eight the personnel records were incomplete, leaving 140 controls in all. Significantly increased risk of fatal injury related to work was associated with exposure to noise, heat, dust and fumes, gases and vapours, rotating shift work, being a manual worker, and working in the steel mill, coke ovens, blast furnaces, and energy and water supply areas. Risk of fatal injury related to work increased with intensity of exposure to noise (P (trend) = 0.004) and heat (P < 0.001), and increased greatly with a hazard score that combined information on noise, heat, dust, and gas exposure (P < 0.001). Number of years of schooling (P = 0.03) and salary level (P = 0.03) were both negatively associated with risk. In a multivariate analysis including all these significant factors, only hazard score and area of work remained associated with death from injury related to work. The highest risks were for men exposed to all four environmental hazards (odds ratio (OR) 19.4; 95% confidence interval (95% CI) 1.1 to 352.1) and those working in the energy supply area (OR 18.0; 1.6 to 198.1). CONCLUSIONS: The study identified parts of the steelworks and types of hazard associated with greatly increased risk of fatal accident. Research and measures to prevent accidents need to concentrate on these areas and the people working in them. The use of a hazard score was successful in identifying high risk, and similar scoring might prove useful in other industrial situations.

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OBJECTIVES: Injury is the leading cause of death in the male working population of Brazil. An important fraction of these deaths are work related. Very few cohort studies of steel workers, and none from developing countries, have reported on mortality from injuries. This paper analyses mortality from work and non-work related injuries among Brazilian steel workers. METHODS: Deaths during employment from 1 January 1977 to 30 November 1992 were analysed in a cohort of 21,816 male steel workers. Mortality rates specific for age and calendar year among the workers were compared with those of the male population of the state where the plant is located. Work related injuries were analysed by comparing the mortality rates for different subgroups of the cohort. RESULTS: The number of deaths (391) was less than half that expected based on death rates of the general population. Over 60% (242) of deaths were due to injuries. Mortality from most causes was substantially below that in the general population, but that from unintentional injury, was 50% above that of the general population. Standardised mortality ratios (SMRs) were highest for the youngest and the oldest employees and for labourers and clerical workers. Mortality from motor vehicle injury was twice that expected from population rates (SMR = 209, 95% confidence interval (95% CI) 176-244). There was a 67% fall in the age adjusted mortality from occupational injuries in the study period. CONCLUSION: The healthy worker effect in this cohort was greater than that commonly found in studies of occupational groups in developed countries, probably because of a greater socioeconomic gap between employed and unemployed populations in Brazil, and unequal distribution of health care resources. Mortality was especially high for motor vehicle injuries. The fall in mortality from occupational injuries during the study period was probably due to improvement in safety standards, increased automation, and better medical care. There is a need to investigate risk factors for unintentional injuries among steel workers, especially those due to motor vehicle injuries. Prevention of occupational and nonoccupational injuries should be a main priority in Brazil.

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Thirty-one infants with clinical and radiographic evidence of a large left-to-right shunt across a patent ductus arteriosus underwent echocardiographic study to determine the magnitude of shunting. Seven patients were found to have a normal-left atrial dimensions and a normal left atrial/aortic root dimension at the time when physical and roentgenographic findings of a large PDA were most pronounced. In contrast, left ventricular end diastolic dimensions were excessive in these infants. After ductal closure (four, surgery; two, indomethacin, one, spontaneous) the left ventricular end diastolic dimension fell to the normal range. Optimal echocardiographic accuracy in infants with PDA should combine analysis of both atrial and ventricular dimensions; the former, used alone, may be misleading.

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