Use of QuantiFERON-TB Gold test in the investigation of unexplained positive tuberculin skin tests.

OBJECTIVES: To investigate the use of new gamma-interferon (IFN-gamma)-based blood tests to determine whether or not a higher-than-expected proportion of positive tuberculin skin tests (TSTs) were due to tuberculosis infection. STUDY DESIGN: When an unexpectedly high proportion of children in a high school in Leeds were found to have positive TSTs, a cohort study was undertaken based on blood tests and long-term follow-up of the affected children. IFN-gamma-based blood tests are reported to be more specific for tuberculosis infection than TSTs. METHODS: One hundred and ninety children, aged 13-14 years, were screened and 28 (15%) had a positive TST. None had any known risk factor for tuberculosis infection. Parental consent was requested for testing with QuantiFERON-TB Gold (Cellestis, Carnegie, Victoria, Australia). Active cases of tuberculosis with any possible connection to the school or the children were sought through the routine diagnosis and reporting service over the next 36 months. RESULTS: Consent was given for 26 children with Heaf Grade 2 results to be tested using QuantiFERON-TB Gold, and blood was obtained from 24 of these children. All tested negative. None of these children developed active tuberculosis, and no cases of active tuberculosis were identified with any connection to the children or the school. CONCLUSION: QuantiFERON-TB Gold testing appeared to identify false-positive TSTs correctly in this group. This supports the recent recommendation to use IFN-gamma-based blood tests in people with positive TSTs to confirm or refute the diagnosis of tuberculosis infection.

Faecal contamination on children's hands and environmental surfaces in primary schools in Leeds.

Gastro-intestinal diseases continue to be a major health problem in primary schools in the UK. This study, which took place in 20 primary schools in the Leeds area, investigated the presence of faecal indicator bacteria on children's hands and environmental surfaces. Faecal streptococci were used as an indicator of faecal contamination. A handwashing knowledge score was developed for each child. Those children with good hygiene knowledge had less faecal contamination on their hands (relative risk: 1.4, 95% CI = 1.09-1.81, P = 0.005). Those schools with higher hand counts were more likely to have had a reported outbreak of gastroenteritis in the past. Values of the Townsend Deprivation Index, an indicator of deprivation, were compared with the hand results and those schools in high deprivation areas had higher hand counts. Of the swabs taken from surfaces in the toilet areas and classrooms, the carpets in the classrooms were the most frequently contaminated surfaces.

Does exposure to rubella virus generate endocrine autoimmunity?

Rubella virus is a possible environmental agent which may be involved in triggering autoimmunity to pancreatic islet cells, leading to Type 1 diabetes. Autoantibody responses were determined in 239 10-year-old girls who received live attenuated rubella vaccine, of whom 61 (26%) had no pre-existing rubella immunity. Islet cell antibodies (ICA greater than 5 Juvenile Diabetes Foundation (JDF) units) were present in seven (2.9%) girls before vaccination, and they appeared in three more 6 weeks after vaccination (4.2%). However, the ICA levels were low in all cases and of the three girls who developed ICA greater than 5 JDF units 6 weeks post-vaccination, none had detectable ICA 18 months later. IgG-insulin autoantibodies were present in 17 (7.1%) girls before vaccination, and their prevalence decreased after vaccination (5.4%). Thyroid antibodies (thyroglobulin and microsomal) were present in 2% and 1%, respectively, of the girls before vaccination and none appeared afterwards. Thus, rubella vaccination did not elicit widespread endocrine autoantibody production and viral triggering of endocrine autoimmunity in susceptible subjects remains an open question.

Diphtheria and tetanus vaccine: a comparative study of reactogenicity.

One hundred and eighty children aged between four and six years were intensively followed-up after receiving diphtheria/tetanus vaccine. A daily diary was used as the method of assessment to elicit as many transient effects as possible. The results confirm the predicted profile of these vaccines with a high incidence of local effects but little general disturbance. The two vaccines used were essentially similar in results, showing a peak incidence of effects on Days 2-4 followed by a rapid decline in adverse effects. All the side effects reported were transient, self-limiting and did not require medical assistance.

Differences in rate of uptake of immunisation among ethnic groups.

In the Bradford health district ethnic origin is associated with appreciable differences in morbidity and mortality. In view of these differences a study was undertaken to determine whether there were differences among the ethnic groups in utilisation of the National Health Service, as reflected in the rate of uptake of immunisation, which is offered to all children. Significant differences were found between the British group and some other ethnic groups--notably Pakistani, Indian, and half Negro groups. The rate of uptake of immunisation was nearer the optimum in the Indian group than in the British group. The most unsatisfactory rate of uptake of immunisation overall was found in the half Negro group. No clear explanation of the differences has been shown, they are likely to be due to various factors in the National Health Service and in the community.