Tuberculosis in East Sussex. I. Outbreaks of tuberculosis in cattle herds (1964-1984).

The history and epidemiology of bovine tuberculosis in cattle herds in East Sussex are described. Since 1960, following the compulsory eradication scheme for tuberculosis, the incidence of herd infection has been low. The epidemiological features of herd infection have been sporadic incidents, with only small numbers of cattle becoming infected in the majority of incidents. There was no evidence of endemic Mycobacterium bovis infection in the cattle population in East Sussex in recent years, but a low risk of infection for cattle on the South Downs, from badgers, was apparent.     

Tuberculosis in East Sussex. II. Aspects of badger ecology and surveillance for tuberculosis in badger populations (1976-1984)

Following the disclosure of Mycobacterium bovis infection in badgers in East Sussex in 1976, badgers have been examined from and around farms on which cattle have become infected, but with no other attributable source of infection. These farms are confined to the downland of the south-west of the county and M. bovis has been confirmed in badger populations utilising their land. The available evidence indicates that M. bovis infection in badgers is also confined to this area. A detailed study in one area on the South Downs suggested that M. bovis is endemic in the badger population and therefore presents a continued risk for cattle occupying the area.     

Tuberculosis in East Sussex. II. Aspects of badger ecology and surveillance for tuberculosis in badger populations (1976-1984).

Following the disclosure of Mycobacterium bovis infection in badgers in East Sussex in 1976, badgers have been examined from and around farms on which cattle have become infected, but with no other attributable source of infection. These farms are confined to the downland of the south-west of the county and M. bovis has been confirmed in badger populations utilising their land. The available evidence indicates that M. bovis infection in badgers is also confined to this area. A detailed study in one area on the South Downs suggested that M. bovis is endemic in the badger population and therefore presents a continued risk for cattle occupying the area.     

Tuberculosis in East Sussex. IV. A systematic examination of wild mammals other than badgers for tuberculosis

A detailed investigation of the possible role of wild mammals, other than badgers, in the maintenance of Mycobacterium bovis in an area on the South Downs of East Sussex was carried out over 3 years. Estimates of population sizes were made where possible and minimum sample sizes were selected to be 95% certain of including at least one infected animal if the prevalence was at least 5%. Samples of wild mammals were taken from populations which had the highest potential direct or indirect contact rate with known infected badgers. M. bovis was not isolated from any of the 15 species of wild mammals. It was concluded that badgers are able to maintain M. bovis in an area independently of other species, and that in the area studied other species were not a source of infection for the cattle herds.     

Tuberculosis in East Sussex. IV. A systematic examination of wild mammals other than badgers for tuberculosis.

A detailed investigation of the possible role of wild mammals, other than badgers, in the maintenance of Mycobacterium bovis in an area on the South Downs of East Sussex was carried out over 3 years. Estimates of population sizes were made where possible and minimum sample sizes were selected to be 95% certain of including at least one infected animal if the prevalence was at least 5%. Samples of wild mammals were taken from populations which had the highest potential direct or indirect contact rate with known infected badgers. M. bovis was not isolated from any of the 15 species of wild mammals. It was concluded that badgers are able to maintain M. bovis in an area independently of other species, and that in the area studied other species were not a source of infection for the cattle herds.     

Tuberculosis in East Sussex. III. Comparison of post-mortem and clinical methods for the diagnosis of tuberculosis in badgers

Following epidemiological and ecological studies of a defined badger population in an area of East Sussex, removal of all badgers by cage trapping was attempted. Trapping was incomplete due to the activities of protesters. Forty-seven badgers were caught from the eight social groups. All badgers were examined clinically and samples of faeces, urine and tracheal aspirate were taken, together with swabs from any bite wounds, for bacteriological examinations. Forty-five animals were skin tested using whole killed cells of Mycobacterium bovis strain AN5, bovine PPD Weybridge and new human tuberculin. Skin test results were recorded after 24 and 72 h. All badgers were killed and subjected to a post-mortem and bacteriological examination. M. bovis was detected in 10 (21.3%) badgers at post-mortem and in 2 badgers from clinical samples. Four social groups were infected. Positive skin test results were recorded at 72 h with bovine PPD (2 micrograms and 20 micrograms/ml), strain AN5 (1 mg/ml) and human tuberculin (2 micrograms/ml), but not with human tuberculin at 20 micrograms/ml. Histological sections of the skin test reactions showed the cellular types typical of delayed-type hypersensitivity. The skin test reactions observed were neither sensitive nor specific enough to be of practical value.     

Tuberculosis in East Sussex. III. Comparison of post-mortem and clinical methods for the diagnosis of tuberculosis in badgers.

Following epidemiological and ecological studies of a defined badger population in an area of East Sussex, removal of all badgers by cage trapping was attempted. Trapping was incomplete due to the activities of protesters. Forty-seven badgers were caught from the eight social groups. All badgers were examined clinically and samples of faeces, urine and tracheal aspirate were taken, together with swabs from any bite wounds, for bacteriological examinations. Forty-five animals were skin tested using whole killed cells of Mycobacterium bovis strain AN5, bovine PPD Weybridge and new human tuberculin. Skin test results were recorded after 24 and 72 h. All badgers were killed and subjected to a post-mortem and bacteriological examination. M. bovis was detected in 10 (21.3%) badgers at post-mortem and in 2 badgers from clinical samples. Four social groups were infected. Positive skin test results were recorded at 72 h with bovine PPD (2 micrograms and 20 micrograms/ml), strain AN5 (1 mg/ml) and human tuberculin (2 micrograms/ml), but not with human tuberculin at 20 micrograms/ml. Histological sections of the skin test reactions showed the cellular types typical of delayed-type hypersensitivity. The skin test reactions observed were neither sensitive nor specific enough to be of practical value.     

Epidemiological features of bovine tuberculosis in cattle herds in Great Britain.

Particular epidemiological features of Mycobacterium bovis infection in cattle herds in Great Britain during the period 1972-8 were examined. During these seven years 1099 herds became infected, the mean annual incidence of herd infection being of the order of one infected herd per 1000 cattle herds. Infection in herds was predominantly a sporadic occurrence; 938 (85.4%) herds experienced only one incidence of infection which persisted for less than 12 months. The concentration of infected herds in localized areas of the south-west region of England, where infected badgers were the most significant attributed source of infection, is demonstrated. The risk of herd infection in relation to badger sett density was also examined in Cornwall, Gloucestershire/Avon and counties in England and Wales outside the south-west region of England. The numbers of herds at risk in six categories of badger sett density in these three areas were estimated from three random samples of herds drawn from the annual agricultural census. In Cornwall and Gloucestershire/Avon herd infection, associated with infected badgers or for which no source of infection could be found, was positively associated with badger sett density. A similar association between herd infection, not attributable to a source of infection, and badger sett density was found in counties in England and Wales outside the south-west region of England.     

Bovine tuberculosis in domestic and wild mammals in an area of Dorset. I. Tuberculosis in cattle

A major outbreak of tuberculosis occurred in cattle on a farm in Dorset between 1970 and 1976. Six hundred and twenty-six cattle were slaughtered either because they reacted to the tuberculin test or had been exposed to infection. No source of infection was found until 1974 when badgers infected with Mycobacterium bovis were first discovered. An analysis of the tuberculin test records of this herd and the six surrounding herds indicated that tuberculosis had been a sporadic problem since the early 1960's. Two peaks of infection occurred in the most severely affected herd in 1970 and 1974 when 20.8% and 27.3% of animals, respectively, reacted to the tuberculin test. These figures are exceptionally high. During the last 20 years there have been two periods when all the herds in the area had synchronous outbreaks consistent with a common source. Analysis indicated that cattle were at greatest risk in April and May and suggest that there was re-exposure to infection at this time each year. In addition the cattle were apparently exposed to M bovis, at sufficiently high levels for transmission to occur, for only a relatively short period of time.     

Bovine tuberculosis in domestic and wild mammals in an area of Dorset. I. Tuberculosis in cattle.

A major outbreak of tuberculosis occurred in cattle on a farm in Dorset between 1970 and 1976. Six hundred and twenty-six cattle were slaughtered either because they reacted to the tuberculin test or had been exposed to infection. No source of infection was found until 1974 when badgers infected with Mycobacterium bovis were first discovered. An analysis of the tuberculin test records of this herd and the six surrounding herds indicated that tuberculosis had been a sporadic problem since the early 1960''s. Two peaks of infection occurred in the most severely affected herd in 1970 and 1974 when 20.8% and 27.3% of animals, respectively, reacted to the tuberculin test. These figures are exceptionally high. During the last 20 years there have been two periods when all the herds in the area had synchronous outbreaks consistent with a common source. Analysis indicated that cattle were at greatest risk in April and May and suggest that there was re-exposure to infection at this time each year. In addition the cattle were apparently exposed to M bovis, at sufficiently high levels for transmission to occur, for only a relatively short period of time.     

Tuberculosis contact control in Brazil: a literature review (1984-2004)

This study aims to review plans for tuberculosis control through the analysis of measures for tuberculosis contact tracing in Brazil from 1984 to 2004. This article presents a literature review on tuberculosis control published in manuals of the Ministry of Health and the State Department of Health of Sao Paulo, and in Medline and Lilacs databases. There was a gap in the standardization of control measures in the decade from 1984 to 1994. It was concluded that health professionals need to incorporate TB control and prevention actions from the perspective of health surveillance and systematic monitoring.     

Epidemiological features of bovine tuberculosis in cattle herds in Great Britain

Particular epidemiological features of Mycobacterium bovis infection in cattle herds in Great Britain during the period 1972-8 were examined. During these seven years 1099 herds became infected, the mean annual incidence of herd infection being of the order of one infected herd per 1000 cattle herds. Infection in herds was predominantly a sporadic occurrence; 938 (85.4%) herds experienced only one incidence of infection which persisted for less than 12 months. The concentration of infected herds in localized areas of the south-west region of England, where infected badgers were the most significant attributed source of infection, is demonstrated. The risk of herd infection in relation to badger sett density was also examined in Cornwall, Gloucestershire/Avon and counties in England and Wales outside the south-west region of England. The numbers of herds at risk in six categories of badger sett density in these three areas were estimated from three random samples of herds drawn from the annual agricultural census. In Cornwall and Gloucestershire/Avon herd infection, associated with infected badgers or for which no source of infection could be found, was positively associated with badger sett density. A similar association between herd infection, not attributable to a source of infection, and badger sett density was found in counties in England and Wales outside the south-west region of England.     

A bacteriological survey of tuberculosis due to the human tubercle bacillus (Mycobacterium tuberculosis) in south-east England: 1984-91.

The occurrence and nature of bacteriologically confirmed tuberculosis due to Mycobacterium tuberculosis in South-East England in the period 1984-91 is reported and compared with the results of a study for 1977-83. Registered new cases reached a low of 1028 in 1988 but increased to 1252 in 1991. This appeared to be due to a halt in the previous decline in new cases of European patients, a small increase in the number of Indian subcontinent (ISC) patients and an increase in patients from Africa. A total of 122 patients, mostly of European ethnic origin, were known to be HIV positive. As in the 1977-83 study, disease in the ISC group affected younger patients than in the European group, tubercle bacilli were more frequently isolated from a non-pulmonary site in the ISC group (45%) than in the European group (19%) and there was a higher incidence of the South Indian variant of M. tuberculosis in the former group (17%) than in the latter (9%). The overall incidence of drug resistance has not altered significantly since the 1977-83 study but 46 strains resistant to 3 or more drugs were isolated from 4099 ISC patients, compared with 3 of 4594 strains from European patients. Six of the 122 isolates from HIV positive patients were drug-resistant but none was multi-drug resistant. The slight rise in registered bacteriologically proven cases of tuberculosis, the presence of multi-drug resistant strains, the occurrence of HIV-related tuberculosis and reports of the emergence of multi-drug-resistant HIV-related tuberculosis in other countries strongly indicate the need for continued careful surveillance.     

Outbreaks of hepatitis A among illicit drug users, Oklahoma, 1984-87.

Transmission of hepatitis A has been described in many settings, although few outbreaks have been reported among illicit drug users. We report six unrelated outbreaks of hepatitis A among users of marijuana and intravenously administered methamphetamine. Although the exact mode of transmission could not be determined, practices associated with illicit drug use may have facilitated transmission of hepatitis A. These outbreaks and other recent information indicate that illicit drug users may be at increased risk of acquiring hepatitis A infection.     

Twenty years of research on the quality of medical care: 1964-1984.

Since 1964 we have built on earlier work, with some refinements, particularly in the formulation of explicit criteria of process and outcome; the detailed standardization of case mix when outcomes signify quality; the prespecification of outcomes for follow-up, when adverse outcomes are only the occasion for later assessment of process; a greater emphasis on more subtle organizational characteristics in the study of structure; and the identification of the separate effects of structural attributes by multivariate analysis. We have also paid more systematic attention to questions of measurement, including the veracity and completeness of the record; the procedures of criteria formulation; and the reliability, validity, and screening efficiency of the criteria. A notable advance is the use of decision analysis to identify optimal strategies of care, including the introduction of patient preferences and monetary cost in the specification of such strategies, and the use of decisional algorithms to portray the criteria of quality.