BACKGROUND: An inverse association between tuberculin responses and atopy has been observed in Japanese children, indicating that BCG immunisation, subclinical exposure to Mycobacterium tuberculosis without clinical disease, or host characteristics may influence the T helper (Th) lymphocyte balance with decreased atopy as a result. This study was undertaken to determine whether tuberculin reactivity is inversely related to atopy in young adults vaccinated with BCG at the age of 14. METHODS: Men and women aged 20-44 years were tested using the adrenaline-Pirquet test with Norwegian produced synthetic medium tuberculin (n = 891). In addition, their serum total and specific IgE antibodies against mite, cat, timothy grass, mould and birch were measured. RESULTS: Of the 574 subjects with complete examinations, 64% had a positive adrenaline-Pirquet tuberculin test (> or =4 mm) and 27% exhibited IgE antibodies (> or =0.35 kU/l) to one or more of the five specific allergens. The geometric mean of total serum IgE in the population was 30.2 kU/l. Tuberculin reactivity and log IgE were not correlated (r = 0.043, p = 0.30). The mean tuberculin reactivity was 4.6 mm, 4.9 mm, and 5.0 mm in the lower, middle and upper tertile of IgE distribution (61 kU/l). The prevalence of atopy, as assessed by either the presence of any of the five specific IgE antibodies or by each specific IgE antibody separately, did not differ between subjects with a positive and those with a negative tuberculin test. These results persisted after adjustment for age, sex, and smoking status in multivariate logistic regression analyses. CONCLUSIONS: In this young adult population, BCG vaccinated at the age of 14, no significant relationship between a positive tuberculin reaction and atopy was observed. If a true relationship had been found, our study suggests that it may be limited to populations immunised in early childhood when a substantial modulation of the immune system can occur.
Primary care clinic for refugee claimants, Montreal, Canada.
To identify factors linked to the acceptance of the tuberculin skin test (TST), and assess completion of treatment for latent tuberculosis infection (LTBI).
Asylum seekers consulting for a medical complaint or medical immigration examination between February and October 1999 were assessed for eligibility. Personal and clinical information was gathered prospectively by questionnaire. Hospital files were reviewed to assess completion of LTBI treatment.
In our study, 296 subjects (72.4% of 409 eligible) were offered TST, of whom 227 accepted (76.7%). Of these, 49 (24.9%) had a TST > or = 10 mm and 24 (49%) completed 6 months of LTBI treatment. Logistic regression models showed that patients who had never had a TST (OR 3.2, 95%CI 1.34-7.6) or had no temporary exclusion criteria (OR 4.0, 95%CI 1.6-9.9) were more likely to accept TST. Perceiving tuberculosis as a severe disease (OR 0.29, 95%CI 0.09-0.91) and consulting for an immigration examination (OR 0.42, 95%CI 0.18-0.98) was associated with refusal of TST. Increasing age was found to be independently associated with a positive TST (OR 1.06, 95%CI 1.01-1.12). Variability in the proportion of positive results was found between TST readers.
This study supports the feasibility of screening refugee claimants for LTBI during medical consultation and of developing organizational links to ensure completion of LTBI treatment.
The paper describes the introduction of Mycobacterium bovis into Swedish deer herds and its possible consequences. The different control strategies applied are summarized as well as their shortcomings under the conditions of the Swedish outbreak. An alternative control, to be used in extensive deer herds, based only on slaughter and meat inspection is described. Finally, the efficiency of the implemented control and surveillance systems are discussed and possible improvements suggested.
To compare trends in direct annual risk of tuberculous infection (ARTI) during 1991-2005 in relation to tuberculosis (TB) incidence and to indirect estimates of ARTI derived from the prevalence of tuberculin skin test (TST) positivity in schoolchildren in Orel Oblast, Russia.
In 2005, we abstracted annual TST results and vaccination histories from a representative sample of schoolchildren in Orel Oblast, Russia, where bacille Calmette-Guerin (BCG) vaccination and annual TST of children are nearly universal. We calculated direct ARTI based on the percentage of children tested with TST conversions each year, excluding conversions following BCG vaccination.
We analysed records from 13 206 children, with a median of 10 recorded TST results per child. The ARTI increased from 0.2% in 1991 to 1.6% in 2000, paralleling trends in TB incidence. Similar results were observed when the ARTI was estimated based on prevalence of infection among children aged 3-5 years using a 12 mm cut-off to define TST positivity. Results differed substantially when 10 or 15 mm cut-offs were used or when prevalence was determined among children aged 6-8 years.
ARTI measured through TST conversion increased as TB incidence increased in Orel Oblast. ARTI measured through serial TSTs can thus provide an indicator of changing trends in TB incidence.
An outbreak of tuberculosis in pigs and cattle caused by Mycobacterium africanum produced lesions in the pigs similar to those caused by M tuberculosis, M bovis and M avium, with caseation in the lymph nodes of the head and in the jejunal lymph nodes. Bacteriological examination of the dysgonic mycobacteria isolated showed that they were M africanum I. The intradermal tuberculin test was very reliable in pigs, differentiating between mammalian and avian reactions, and the results of the test were in accordance with the lesions found at meat inspection. No clinical signs were observed during the outbreak, and the infection was neither serious nor progressive. There were no lesions in the tuberculin-positive cattle. The source of the infection remains unknown.
Because of deterioration of epidemiological situation by tuberculosis, individuals from tuberculous infection foci and social risk group require special care. It is important to integrate efforts of phthisiatric and general therapeutic and prophylactic services in detection of tuberculosis in children and adolescents, to create controlled conditions for conduction of antituberculous measures.