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Background: A national survey of tuberculosis was conducted in England and Wales in 1998 to obtain detailed information on the occurrence of the disease and recent trends. This survey also piloted the methodology for enhanced tuberculosis surveillance in England and Wales and investigated the prevalence of HIV infection in adults with tuberculosis., Methods: Clinical and demographic data for all cases diagnosed during 1998 were obtained, together with microbiological data where available. Annual incidence rates in the population were estimated by age, sex, ethnic group, and geographical region using denominators from the 1998 Labour Force Survey. Incidence rates in different subgroups of the population were compared with the rates observed in previous surveys. The tuberculosis survey database for 1998 was matched against the Communicable Disease Surveillance Centre HIV/AIDS database to estimate the prevalence of HIV co-infection in adult patients with tuberculosis., Results: A total of 5658 patients with tuberculosis were included in the survey in England and Wales (94% of all formally notified cases during the same period), giving an annual rate of 10.93 per 100 000 population (95% CI 10.87 to 10.99). This represented an increase of 11% in the number of cases since the survey in 1993 and 21% since 1988. In many regions case numbers have remained little changed since 1988, but in London an increase of 71% was observed. The number of children with tuberculosis has decreased by 10% since 1993. Annual rates of tuberculosis per 100 000 population have continued to decline among the white population (4.38) and those from the Indian subcontinent, although the rate for the latter has remained high at 121 per 100 000. Annual rates per 100 000 have increased in all other ethnic groups, especially among those of black African (210) and Chinese (77.3) origin. Over 50% of all patients were born outside the UK. Recent entrants to the UK had higher rates of the disease than those who had been in the country for more than 5 years or who had been born in the UK. An estimated 3.3% of all adults with tuberculosis were co-infected with HIV., Conclusions: The epidemiology of tuberculosis continues to change in England and Wales and the annual number of cases is rising. More than one third of cases now occur in young adults and rates are particularly high in those recently arrived from high prevalence areas of the world. The geographical distribution is uneven with urban centres having the highest rates. The increase in the number of cases in London is particularly large. Tuberculosis in patients co-infected with HIV makes a small but important contribution to the overall increase, particularly in London. To be most effective and to make the most efficient use of resources, tuberculosis prevention and control measures must be based on accurate and timely information on the occurrence of disease. A new system of continuous enhanced tuberculosis surveillance was introduced in 1999, based on the methodology developed in this national survey.

In a study of 279 United Kingdom bakery workers a high prevalence of immunological response to storage mites was found. To determine whether this was the consequence of exposure to storage mites in bakery work, a population of salt packing workers was examined as a comparison group not at occupational risk of exposure to storage mites. Forty two per cent of both groups were atopic (had a positive skin prick response greater than negative controls to D pteronyssinus, grass pollen, or cat fur by 2 mm or more) and 33% had an immediate skin prick test response to at least one of four storage mites (L destructor, G domesticus, T putrescentiae, A Siro). A higher percentage of the salt packing workers than the bakery workers had a positive radioallergosorbent test (RAST) (greater than or equal to 0.35 PRU) to D pteronyssinus and to the four storage mites. Logistic regression analysis identified atopy as the most significant variable for a positive skin test and RAST response to storage mites in both groups of workers. RAST inhibition was used to analyse extracted area and personal air samples. Analysis of static area samples for aeroallergen showed immunological identity with flour but L destructor was found in only one of seven exposed filters. The concentration of airborne flour was related to exposure rank of perceived dustiness and gravimetric measurement of total dust. Nineteen out of 32 filters from workers in jobs with higher dust exposure (rank >/=6) had a level of > 10 microgram/m(3) flour whereas this concentrations was exceeded in only one of 23 filters from workers in low dust exposure (< rank 6). It is concluded that storage mites are not of special significance in allergic responses in bakery workers. The development of immunological (and airway) responsiveness to inhaled flour dust is increased in those exposed to higher concentrations of airborne allergen, which appears to be predominantly flour and not storage mites.

The effects of smoking on the development of work related asthma and on the production of specific IgE and IgG antibodies to antigen from a contaminated humidifier are described for a sample of 258 workers from a printing factory. Current smoking was associated with low production of IgG antibody but with higher production of IgE antibody. No dose response for either antibody was found when numbers of cigarettes or pack-years smoked were considered. Work related asthma was detected in 12 workers by peak flow recordings. Six were current smokers and one was an ex-smoker. One subject with work related asthma had a high (and one a marginal) concentration of specific IgE to humidifier antigen.

The long term effects of formaldehyde on the respiratory tract have been investigated in a group of 164 workers exposed daily to the chemical during the production of urea formaldehyde resin, together with 129 workers not exposed to free formaldehyde. Exposure was classified as high (corresponding to an eight hour time weighted exposure of more than 2.0 ppm), medium (0.6 to 2.0 ppm), or low (0.1 to 0.5 ppm). Twenty five per cent of workers had had high exposure at some time and 17% moderate exposure. Both the exposed and unexposed groups had an annual assessment that included lung function. The proportion with self reported respiratory symptoms was similar in the two groups, 12% and 16% reporting breathlessness on hurrying and 26% and 20% wheezing. The initial forced expiratory volume in one second (FEV1) was within 0.5 l (approximately one standard deviation (SD)) of the predicted value (by age and height) in 65% of the exposed and 59% of unexposed workers and more than 0.5 l below the predicted value in 9% of exposed and 11% of unexposed workers. The mean decline in FEV1 was 42 ml a year (SD 45) in the exposed group and 41 ml a year in the unexposed group (SD 40 ml a year). The rate of decline showed the expected association with smoking in the unexposed group, but in the exposed group the mean rate of decline in the never smokers was similar to that in current smokers. There were, however, relatively few never smokers and considerable variation in the rates of decline. In the exposed group no association was found between the rate of decline and indices of exposure to formaldehyde. Thus there is no evidence from this study of an excess of respiratory symptoms or decline in lung function in the workers exposed to formaldehyde. The similar rate of decline of FEV1 however in never smokers and smokers of the exposed group is consistent with findings of other studies for workers exposed to formaldehyde and to toluene di-isocyanate.

Allergic bronchopulmonary aspergillosis often requires treatment with oral corticosteroids to control the host response to Aspergillus fumigatus. In a double blind study 25 patients with allergic bronchopulmonary aspergillosis taking maintenance oral corticosteroids were randomly allocated to receive 5 mg natamycin or placebo by nebuliser twice daily for one year. The primary aim of the study was to assess the steroid sparing potential of natamycin. Standardised reductions in corticosteroid dosage were therefore undertaken every five weeks, unless clinically contraindicated. Five patients were withdrawn in the first four months: two (1 natamycin, 1 placebo) died, two (1 natamycin, 1 placebo) had suspected drug reactions, and one (natamycin) was non-compliant. The pretreatment characteristics of the 20 patients (10 in each group) who completed the study were similar, 17 (9 natamycin, 8 placebo) having evidence of recent disease activity. At the end of the study prednisolone dose had been reduced by a similar amount in each group (median natamycin 2.25 mg, placebo 2.5 mg). Evidence of disease activity during the study year (transient shadowing on the chest radiograph, blood eosinophilia, or increases in antibodies to A fumigatus, or any combination of these) was observed in similar numbers of patients in each group (5 natamycin, 7 placebo). There was no evidence that natamycin conferred benefit on these patients with allergic bronchopulmonary aspergillosis.

A survey of dust exposure, respiratory symptoms, lung function, and response to skin prick tests was conducted in a modern British bakery. Of the 318 bakery employees, 279 (88%) took part. Jobs were ranked from 0 to 10 by perceived dustiness and this ranking correlated well with total dust concentration measured in 79 personal dust samples. Nine samples had concentrations greater than 10 mg/m3, the exposure limit for nuisance dust. All participants completed a self administered questionnaire on symptoms and their relation to work. FEV1 and FVC were measured by a dry wedge spirometer and bronchial reactivity to methacholine was estimated. Skin prick tests were performed with three common allergens and with 11 allergens likely to be found in bakery dust, including mites and moulds. Of the participants in the main exposure group, 35% reported chest symptoms which in 13% were work related. The corresponding figures for nasal symptoms were 38% and 19%. Symptoms, lung function, bronchial reactivity, and response to skin prick tests were related to current or past exposure to dust using logistic or linear regression analysis as appropriate. Exposure rank was significantly associated with most of the response variables studied. The study shows that respiratory symptoms and sensitisation are common, even in a modern bakery.

In a randomised, controlled study alternate day prednisolone with an initial high dose phase ("prednisolone only series") has been compared with cyclophosphamide plus alternate day low dose prednisolone ("cyclophosphamide-prednisolone series") in 43 patients with previously untreated fibrosing alveolitis (five patients had received prednisolone in minimal dosage). In the prednisolone only series prednisolone 60 mg daily was given for one month and then reduced by 5 mg a week to 20 mg on alternate days or the minimum dose to maintain early improvement. Patients in the cyclophosphamide-prednisolone series received 100, 110, or 120 mg cyclophosphamide daily (depending on body weight) plus 20 mg prednisolone on alternate days. Treatment was continued indefinitely, or changed to the alternative regimen if the patient deteriorated, failed to improve, or developed drug toxicity. For response to treatment (as judged by change in breathlessness score, radiographic appearance, and lung function) patients were classified as improved, stable, or deteriorating. Deaths from cryptogenic fibrosing alveolitis were also analysed. Improvement had occurred at one or more assessments in seven of the 22 patients in the prednisolone only series and in five of the 21 patients in the cyclophosphamide-prednisolone series. At three years, however, only two of the 22 patients in the prednisolone only series were still improved and three stable, compared with one and seven of the 21 patients in the cyclophosphamide-prednisolone series (three of the seven had stopped treatment because of toxicity). Life table analysis suggested better survival in patients in the cyclophosphamide-prednisolone series but this was not significant. At three years 10 of 22 patients in the prednisolone only series had died compared with three of 21 patients in the cyclophosphamide-prednisolone series. With death or failure of first treatment regimen as outcome there was a significant advantage to the patients having cyclophosphamide-prednisolone. This advantage was explained in part by the better lung volumes in this group on admission. After allowance had been made for total lung capacity (TLC), no other factor was predictive of outcome. Analyses of subgroups according to TLC on admission showed that patients with a TLC below 60% predicted did badly and those with a TLC of 80% or more predicted did well with both regimens. Patients with an initial TLC of 60-79% predicted did better with the cyclophosphamide-prednisolone regimen. Side effects were uncommon in both series and those due to cyclophosphamide resolved when treatment was stopped. The combination of cyclophosphamide with prednisolone may be an alternative to prednisolone alone with an initial high dose phase. Many patients, however, failed to respond to either treatment.

Tables are presented showing estimates of the number of subjects which is required to give an 80% or 90% chance of detecting various differences in forced expiratory volume in one second, forced vital capacity, total lung capacity, transfer factor, and residual volume between the mean of two groups by means of Student's t test.

In two national surveys of tuberculosis notifications in England conducted in 1978/79 and 1983 the estimated annual notification rates for the Indian subcontinent (Indian, Pakistani, and Bangladeshi) ethnic groups were considerably higher than the rate for the white ethnic group. The mean annual decline in rates between the surveys appeared to be greater for the Indian and the Pakistani and Bangladeshi ethnic groups, 15% and 16% respectively, than for the white ethnic group (7%). Data from two small sample population surveys, the National Dwelling and Housing Survey in 1978 and the Labour Force Survey in 1983, were used to calculate the rates. However, comparison of the estimates for the population of Indian subcontinent ethnic origin in England from these surveys revealed discrepancies between them. Additional information from the Labour Force Survey on the year of first entry to the United Kingdom (UK) permitted the calculation of new estimates for the 1978 population, and based on these estimates the annual notification rates for 1978/79 were 287 per 100,000 for the Indian and 286 per 100,000 for the Pakistani and Bangladeshi ethnic groups. The rates for 1983 were 178 and 169 respectively, and the mean annual decline between the surveys was 11% for the Indian and 12% for the Pakistani and Bangladeshi ethnic groups. There were important changes in the characteristics of the population of Indian subcontinent ethnic origin in England between 1978 and 1983, and therefore the rates for both surveys have been standardised by the method of direct standardisation to a common reference population. Standardizing for year of entry to the UK, place of birth (UK or abroad), age, and sex reduced the mean annual decline in the notification rate to 4% for the Indian and 9% for the Pakistani and Bangladeshi ethnic groups. The much greater reduction in the rate of decline in the Indian ethnic group is due to the substantial decline between the surveys in the proportion of recent immigrants, the group with the highest annual notification rate, in that population. Future trends will continue to be influenced by immigration patterns, but it will also be important to monitor the rates among the increasing proportion of the population born in the UK or resident in England for more than five years.

Since the early 1960s notification rates for tuberculosis in England and Wales for the whole population have been influenced by high rates in certain ethnic groups. Using data based on country of birth from the British (Thoracic and) Tuberculosis Association surveys of 1965 and 1971, and based on ethnic origin from the Medical Research Council surveys in 1978/79 and 1983, rates for the white ethnic group have been estimated at those four times, and compared with the published rates for the whole population in 1953, when only a very small proportion was of non-white ethnic origin. Between 1953 and 1983 the notification rate for the white ethnic group fell from 122.2 to 11.3 per 100,000 for males, an annual decline of 7.7%, the corresponding rates for females being 90.1 and 5.8, an annual decline of 8.8%. The greatest annual declines occurred between 1953 and 1965, 9.4% for males and 11.2% for females. The annual declines in the most recent period, 1978/79 to 1983, were 6.9% for males and 7.3% for females. In both sexes the decline was greatest in the 15-24 year age group and least in the oldest age group, and this has led to a change in the age pattern of annual notification rates. The highest rates in both sexes occurred in young adults in 1953 but in the oldest age groups in 1983. There is however no evidence of any cohort experiencing an increase in notification rate with increasing age.