Procedures for developing a simple scoring method based on unsophisticated criteria for screening children for tuberculosis.

OBJECTIVE: To develop a scoring system for screening children for tuberculosis (TB) and for selecting suspects for further investigation in tuberculosis control programmes. Application of the score model, which would not require sophisticated or expensive technology, would be directed towards resource-poor countries with high prevalences of tuberculosis, where health care workers have to deal with diagnostic problems away from district hospitals or diagnostic facilities. DESIGN: Based on contributions from members of an IUATLD task group from 10 countries on the use of diagnostic criteria in childhood tuberculosis, criteria were selected to be used as elements in a score model. Data were collected by standardised questionnaire on 879 subjects aged under 15 years. Of these, 794 were considered probable or confirmed cases of tuberculosis by the diagnosing doctors. From each record, the criteria/procedures used in the diagnosis of probable/confirmed TB and regarded by the doctors as relevant criteria were selected. Bacteriology, histology and chest radiography were used either singly or collectively as the definitive reference (gold standard) against which the more subjective criteria (symptoms, clinical signs, skin test) would be evaluated. The latter criteria cited as relevant were then ranked and further explored for inclusion in the score model. The relative importance of each criterion to every other criterion on the list was expressed as weights, determined by employing a logarithmic least squares method to solve the ratio scale estimation problem which underlies decision-making involving more than one criterion. The resultant values were then assigned to each criterion in the final score model. RESULTS: The five clinical criteria thought to be most relevant as predictors of disease in children were history of contact with a case of tuberculosis, positive skin test, persistent cough, low weight for age, and unexplained/prolonged fever. In selecting the optimal cut-off points for the model at which tuberculosis would be suspected, low sensitivity and specificity (below 70%) but reasonably good positive predictive values (60%-77%) were obtained, depending on age group and epidemiological setting. In low tuberculosis prevalence settings, heavy reliance is placed by the model on a history of contact with a household case of tuberculosis and on a positive skin test, both of which have to be true. For high prevalence settings, more or less equal weighting is assigned to all five elements. Case contact and skin tests are less important, with low body weight, prolonged fever and cough being more indicative of tuberculosis. CONCLUSION: The model provides for epidemiological differences between target populations and should prove successful as a screening tool to select children for further investigation by radiography and bacteriology.

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.

Surveillance of tuberculosis in Europe. Working Group of the World Health Organization (WHO) and the European Region of the International Union Against Tuberculosis and Lung Disease (IUATLD) for uniform reporting on tuberculosis cases.

Consensus-based recommendations have been developed by a Working Group of the World Health Organization (WHO) and the European Region of the International Union Against Tuberculosis and Lung Disease (IUATLD) on uniform reporting of tuberculosis surveillance data in the countries of Europe. A uniform case definition and a minimum set of variables for reporting on each case have been agreed which, when collated on a national basis, will allow comparison of the epidemiology of tuberculosis in different European countries. The Working Group recommends that the case definition includes "definite" cases, where the diagnosis has been confirmed by culture (or supported by microscopy findings in countries where diagnostic culture facilities are not available), and "other than definite cases" based on a clinical diagnosis of tuberculosis combined with the intention to treat with a full course of antituberculosis therapy. Both "definite" and "other than definite" cases should be notified by physicians and, in addition, laboratories should be required to report "definite" cases. The minimum set of variables to be collected on each case of tuberculosis should include: date of starting treatment, place of residence, date of birth, gender, and country of origin, to characterize the patient. Recommended disease-specific variables include: site of disease, bacteriological status (microscopy and culture), and history of previous antituberculosis chemotherapy. The minimum set of variables should be collated on all patients and should be as complete as possible. Additional variables may be collected for individual, local or national purposes, but, in general, completeness of reporting on cases is likely to be better if the information requested is kept to a minimum. Timely reporting of cases is essential for appropriate public health action. Cases should be reported to the health authority at the local and/or regional level within 1 week of starting treatment. Individual-case based information should be reported to the national level by the local or regional level. Feedback to reporters is essential. At the national level, preliminary quarterly reports should be produced and final reports should be published annually.

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.

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

BACKGROUND: The study sought to determine the contribution of HIV seropositivity to the arrest of decline in tuberculosis notifications in Scotland. METHODS: Survey forms relating to each tuberculosis notification in 1993 were completed by the notifying consultant. Voluntary anonymous HIV testing of tuberculosis cases aged under 65 was requested. Age, sex, ethnic status, country of birth, employment status, occupation, previous tuberculosis, contact status, risk factors for HIV infection, HIV serostatus of cases aged under 65, site, radiological extent, and bacteriological status of tuberculous disease were determined. RESULTS: Five hundred and seventy four cases of tuberculosis were originally notified, of which 77 (14%) subsequently proved to be non-tuberculous and were therefore denotified. Of the 497 cases 423 (85%) were white and 58 (12%) were from the Indian subcontinent. Eighty five per cent of patients from the Indian subcontinent were aged < 55 years whereas 64% of white patients were aged > 55 years. Pulmonary disease was found in 74%, non-pulmonary in 22%, and combined disease in 4% of patients. Of 242 HIV tests performed, three were positive and five other HIV positive patients were known, giving an HIV positivity rate of 1.6% of all tuberculosis notifications in 1993. Annual notification rates for Scotland were 9.7 per 10(5) before and 8.7 per 10(5) after exclusion of previously treated cases; rates were 8.4 per 10(5) for the white population and 179 per 10(5) for those from the Indian subcontinent. CONCLUSIONS: The study documents the distribution of tuberculous disease in Scotland by age, sex, site, and ethnic group for the first time. Notification practices, with respect to denotification, need to be improved. Infection with HIV is presently uncommon in cases of tuberculosis in Scotland but continued vigilance is essential.

Why disease due to Mycobacterium tuberculosis is less common than expected in HIV-positive patients in Edinburgh.

By December 1993, only five cases of tuberculosis were observed in the 1030 HIV-positive patients in Edinburgh, U.K., although, on the basis of historical tuberculin skin test data, between four and eight new cases of tuberculosis were expected per year. Of 310 HIV-positive patients, none of the 19 (6.1%) who were tuberculin skin test positive had developed tuberculosis after 87 months (average) of follow-up. It is suggested that new or re-infection is a more common cause of tuberculosis in HIV-positive patients than reactivation. Restriction fragment length polymorphism typing of Mycobacterium tuberculosis strains could confirm this hypothesis and support currently suggested additional infection control procedures.

Death in notified cases of tuberculosis in Edinburgh: 1983-1992.

Between 1983-1992, 730 cases of tuberculosis were notified in the Edinburgh area (population 6 x 10(5)). A review of available records identified 79 deaths (10.9% of all notifications). Thirty-seven patients (5.1%) died in the year following notification, 14 of these (five females, nine males; median age 71 years) due to tuberculosis. Five of these 14 deaths occurred within 7 days of starting chemotherapy and three deaths were due to miliary disease. Of 41 deaths (58%) before notification, 29 (19 females, 10 males; median age 77 years) were due to tuberculosis (autopsy rate 27/29) and 13 of these 29 deaths, all autopsied, were due to cryptic miliary disease. These findings reinforce continuing concerns about failure to diagnose tuberculosis, particularly cryptic miliary disease, in life.

The outcome of contact procedures for tuberculosis in Edinburgh, Scotland 1982-1991.

We have reviewed the records of 632 (80%) of the 788 index cases of tuberculosis notified in Edinburgh from 1982-1991 to assess the value of contact procedures for tuberculosis. Screening was by tuberculin testing and radiological follow-up for 6 months. Fifty (7.9%) of 632 notifications were detected by contact procedures and a further 35 contacts had recent infection qualifying for chemoprophylaxis. Tuberculosis was diagnosed at the first clinic visit in 38 (76%) cases and a further 11 (22%) were diagnosed at 3 months. Twenty-seven (54%) contacts with tuberculosis were in the 0-14 year age group. BCG vaccination offered 59% protection. Forty-two (84%) cases of tuberculosis were in contacts of sputum smear-positive respiratory index cases. Contact procedures continue to be effective in identifying new cases of tuberculosis in Edinburgh. Most cases occur in children who are close contacts of smear-positive respiratory index cases and are identified within 3 months of initiating screening. Screening of close contacts other than those of smear-positive respiratory disease is usually unnecessary.

Pulmonary tuberculosis in overseas students of higher education is increasing in Edinburgh.

In Edinburgh in 1991 a relative excess of pulmonary TB cases in the 15-34 year age group was recorded. Five of 17 notifications in this age group were of overseas students of higher education: three aged 21-29 from Central Africa, one 27-year-old Asian and one 26-year-old Western European. One of the African students was seropositive for HIV infection. Disease presented clinically on average 31 months after entry to the U.K. (range 6-48 months). Four students had smear positive disease. Two patients had had normal chest radiographs 1 and 2 years previously on entry to the U.K.; three students had not previously been radiologically screened. We suggest that students from countries with a high prevalence of tuberculosis should be screened on entry to their course of education and that student health services should develop and maintain a high index of suspicion for tuberculosis in these students.

Audit of procedures related to outcome of chest clinic consultation.

We audited the case records of 493 new patients referred to a chest clinic to determine for eight consultants and five middle-grade staff the average number of investigations performed, the follow-up rate and prolixity (the length of the letter written to the general practitioner). The outcome of the consultation was assessed by a questionnaire administered to the patients' general practitioners. Practitioner mean investigation rates varied from 0.1 to 8.7 investigations per patient, follow-up rate from 45 to 100% and average prolixity from 53 to 200mm. The prolixity of the eight consultants was significantly related to their investigation and follow-up rates. Consultation outcome was at least satisfactory for 97.4% of patients. We conclude that considerable potential exists for savings of laboratory, clinic and secretarial time and costs by reducing investigation and follow-up rates and writing shorter letters to general practitioners.

Miliary tuberculosis in Edinburgh--a comparison between 1984-1992 and 1954-1967.

We have reviewed the records of 29 patients notified with miliary tuberculosis in Edinburgh from 1984 to 1992 and compared our findings with those for the 40 patients previously reported in Edinburgh from 1954 to 1967. The incidence of miliary tuberculosis has not changed. Respiratory symptoms of cough and dyspnoea were commoner in 1984-1992 (P < 0.001) perhaps reflecting the increase in mean age at presentation (73.5 vs. 59.4 years; P < 0.001). Mortality was 50% in 1984-1992, significantly higher (P < 0.05) than the 25% recorded in 1954-1967. Forty percent of cases in both time periods were of cryptic miliary disease. The diagnosis of cryptic disease tended to be made more often post-mortem and less often by a trial of anti-tuberculosis chemotherapy in 1984-1992. Our findings emphasize the current poor outcome associated with a diagnosis of miliary tuberculosis. It is important to consider this diagnosis in elderly patients with unexplained pyrexia and implement a trial of specific anti-tuberculosis chemotherapy to confirm it.

Extra-pulmonary tuberculosis in Lothian 1980-1989: ethnic status and delay from onset of symptoms to diagnosis.

We have retrospectively determined the incidence and delay in diagnosing extrapulmonary tuberculosis (ETB) by ethnic group in Lothian, Scotland, from 1980-1989. One hundred and sixteen (13.3%) of 874 TB notifications were for ETB. Eighty-seven records were available for analysis: 59 with a mean age of 57.9 years (range 10-90) were Caucasian (C) and 28 with a mean age of 30.3 years (range 10-86) were non-Caucasian (NC). There were 42 cases of lymphatic TB; 23 (7M,16F) with a mean age of 62 years (range 10-82) were C and 19 (14M,5F) with a mean age of 29 years (range 10-60) were NC. Lymphatic TB was a significantly commoner ETB site in NC (67.9%) cf C (39%) (P < 0.01). Of 24 cases of genito-urinary TB, 23 (14M,9F) with a mean age of 54 years (range 24-82) were C compared to one NC male aged 29 years. Genito-urinary TB was a significantly commoner ETB site in C (39%) cf NC (3.6%) (P < 0.001). Bone and joint TB was found in 11 (5M,6F) C with a mean age of 55 years (range 28-86) compared to five (3M,2F) NC with a mean age of 36 years (4-47). Five cases of abdominal TB (2C,3NC) were also identified. Delay from onset of symptoms to diagnosis for lymphatic TB was significantly longer for NC (mean 26 weeks, range 0-156) than for C (mean 9 weeks, range 2-28) (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Reactivation disease: the commonest form of tuberculous pleural effusion in Edinburgh, 1980-1991.

From 1980-1991 82 (7.2%) of 1134 tuberculosis notifications in Edinburgh were for pleural effusion. Study of the available records of 62 cases satisfying defined diagnostic criteria identified 14 cases (6 M, 8 F) with a mean age of 27.6 years (range 11-51 years) of primary tuberculous effusion and 25 cases (21 M, 4 F) with a mean age of 51 years (range 19-79 years) with pleural effusion due to reactivation disease. Twenty-three patients (19 M, 4 F) with a mean age of 48.9 years (range 25-85 years) defied classification. Symptoms, associated and diagnostic test findings were similar in all three groups of patients. Parenchymal radiographic shadowing was seen in 1/14 primary, 16/25 reactivation and 3/25 unclassified pleural effusions. Twenty-three of 30 patients treated with corticosteroids showed no residual radiographic abnormality compared to 17/30 not so treated (P < 0.06). Reactivation disease is currently a commoner cause of tuberculous pleural effusion than primary disease in Edinburgh. We suggest that the unclassified cases, so similar in age and sex to the defined reactivation disease cases, also represent largely extrapulmonary reactivation disease occurring in middle age.