Scottish national survey of tuberculosis notifications 1993 with special reference to the prevalence of HIV seropositivity

Risk factors for TB and HIV coinfection in Scotland, 2001 to 2010

The number of patients with tuberculosis (TB) increased steadily in Scotland between 2005 and 2010. Human immunodeficiency virus (HIV) infection has been a contributory factor to increases in TB in a number of comparable industrialised countries. This study investigated the extent of, and risk factors for, TB and HIV coinfection in Scotland from 2001 to 2010. Patients with TB in the national TB database were linked to those in the national HIV database using probabilistic data linkage. Patient records were anonymised to maintain confidentiality. From 2001 to 2010, 106/4, 097 (2.6%, 95% CI: 2.1 to 3.1) TB patients matched with HIV patients, equating to a 10-year incidence of 2.1 cases per million population. Patients with both TB and HIV were more often born outside the United Kingdom,were of black African ethnicity, had refugee status and had extra-thoracic lymph node involvement or cryptic/disseminated TB disease. Individuals with TB and HIV coinfection were younger and symptomatic for a shorter time before their diagnosis of TB, compared with TB patients without HIV. TB and HIV coinfection was relatively uncommon in Scotland in the study period. Clinicians should recognise the potential for HIV infection among TB patients and the importance of offering an HIV test to all TB patients.

Pulmonary tuberculosis and deprivation in hospitalised patients in Scotland

During the last decades tuberculosis re-emerged in almost all over the world, in both developed and developing countries. Many risk factors were implicated to explain the re-emergences including the HIV epidemic. The aim of the study was to explore if tuberculosis is related with poverty in Scotland utilising routinely collected hospital discharge data for patients with pulmonary tuberculosis and postcode-derived Carstairs deprivation scores. The Carstairs and Morris index is composed of four indicators which were judged to represent material disadvantage in the population. A positive correlation was found between the cumulative incidence rate for hospitalised patients within each Health Board and the Carstairs deprivation score (r = 0.76, p < 0.01). A similar correlation was found between the cumulative incidence rate and the deprivation scores within each postcode sector (r = 0.47, p < 0.0001). These results supports findings by other researchers that poverty and tuberculosis are related, and might be one explanation for the recent re-emergence of tuberculosis.

The management of pulmonary tuberculosis in adults notified in Scotland in 1993

The management of pulmonary tuberculosis (TB) in Scotland in 1993 was studied by asking the physicians responsible for all 321 adult cases of the disease notified that year to complete a standardized questionnaire relating to drug treatment and bacteriology. The response rate to the questionnaire was 100%. Isoniazid and rifampicin were used together in initial therapy in 98.4% of cases, while pyrazinamide was prescribed in 90.3% of cases, broadly in keeping with existing treatment guidelines. However, considerable variability was observed both in the drug regimens employed, and in the duration of initial and continuation phases of chemotherapy. Treatment regimens were therefore frequently at variance with published recommendations. Among patients prescribed drug regimens other than those recommended satisfactory completion of therapy was less common. Microbiological confirmation was provided for 84% of cases in which clinical samples were submitted. However, in approximately 11% of cases, no clinical samples were submitted. Closer adherence to existing treatment guidelines and more rigorous pursuit of microbiological confirmation should further improve the overall management of pulmonary TB in Scotland.

Notification of tuberculosis in a university hospital

The aim of this study was to evaluate completeness of tuberculosis notification in Bichat Claude-Bernard University Hospital and to evaluate whether misclassification of atypical mycobacterial infection could have contributed to the inaccuracy of tuberculosis notification. Data from Microbiology Laboratory of the hospital and statutory notifications were compared. From 1 January 1994 to 31 December 1995, 299 tuberculosis cases were diagnosed in the Microbiology Laboratory and 316 cases were notified as tuberculosis. Notification rate for laboratory-documented tuberculosis was 57.5%, was significantly higher in cases with positive acid fast bacilli smear (75%) than without this feature (45%) and was similar in HIV-positive (59.4%) and HIV-negative (63.5%) patients. Among notified cases, diagnosis was established by laboratory proofs in only 54.4% and by clinical signs in 45.6%. Three cases with positive smear and culture growing atypical mycobacteria were wrongly notified. Notification of laboratory-documented tuberculosis was higher than that observed in a previous study in the same hospital, suggesting that the rise of tuberculosis incidence reported in our country could be partially artificial. Nevertheless, extent of notification remains insufficient and needs to be improved by combining microbiological data with current system of notification.

HIV-testing study of immigrants with pulmonary tuberculosis

The increasing prevalence of tuberculosis (TB) and human immunodeficiency virus (HIV), particularly in Africa and Asia, led us to investigate the prevalence of HIV infection in immigrants with pulmonary TB at the time of arrival in the UK. We performed anonymous HIV testing of stored sera from 39/65 immigrants referred to our unit between January 1991 and December 1994, who had culture-positive pulmonary TB. None of the 39 patients tested was positive for either HIV-1 or HIV-2, and the characteristics of the 26 patients for whom no serum was available were similar to those of the tested group. Despite the need to consider concomitant HIV infection in any patient with TB, particularly those from an area of HIV endemnicity, the present data do not suggest that recently arrived refugees, asylum seekers, immigrants or long-term visitors to the UK constitute a group in whom dual infection of HIV and Mycobacterium tuberculosis is common.

Increasing incidence of tuberculosis in the young and the elderly in Scotland

BACKGROUND

Since 1987 there has been an arrest in the previously established decline of tuberculosis notifications in Scotland. A study was undertaken to determine whether age contributed to this phenomenon.

METHODS

Notifications of tuberculosis in Scotland were quantified by year and age group for the years 1981-92 from national statistics supplied by the Information and Statistics Division. Population data were obtained from the 1981 and 1991 national censuses.

RESULTS

Age group analysis of pulmonary tuberculosis notifications showed that, in the 0-14 age group, incidence (per 10(5) population) decreased from 7.4 in 1981 to 2.6 in 1987, rising by an estimated 12.6% per annum to 3.7 in 1992. In the 65+ age group incidence declined from 30.1 in 1981 to 17.3 in 1988, and rose by an estimated 4.1% per annum to 22.2 in 1992. In the age groups 15-44 and 45-64 a continuous decrease in notification rate was seen over the period of the study.

CONCLUSIONS

The plateauing of the incidence of tuberculosis in Scotland is associated with significant increases since 1987 of tuberculosis in the young and elderly. Contributions from ethnic minorities and those infected with HIV are negligible. An ageing population over the decade, with the highest tuberculosis rates seen in the older age group, may explain these findings.