Differential avian and human tuberculin skin testing in non-tuberculous mycobacterial infection

OBJECTIVE—To determine the sensitivity of differential avian and human delayed-type hypersensitivity skin testing in the diagnosis of non-tuberculous mycobacterial lymphadenitis.METHOD—Retrospective review of all patients with culture proved non-tuberculous mycobacterial lymph node infections who also had differential avian and human skin testing performed over a 10year period from 1986 to 1996.RESULTS—One hundred and twenty four patients had non-tuberculous mycobacteria isolated from lymph nodes over this period, 59 of whom had differential skin testing performed. The sensitivity of a response of ? 10 mm to the avian precipitin was 58 of 59. No patient had both a negative human and avian Mantoux. The sensitivity of the human Mantoux alone for diagnosing non-tuberculous mycobacterial infection was 81% for a response of ? 5 mm and 66% for ? 10 mm. Ten patients had a 0 human response. Fifty five of the 59 patients had an avian response at least 2 mm greater than the human response.CONCLUSION—The avian Mantoux is a very sensitive method of diagnosing non-tuberculous mycobacterial infection in children. The human Mantoux is not sensitive enough to be used alone as a surrogate to diagnose non-tuberculous mycobacterial infection.     

Differential avian and human tuberculin skin testing in non-tuberculous mycobacterial infection.

OBJECTIVE: To determine the sensitivity of differential avian and human delayed-type hypersensitivity skin testing in the diagnosis of non-tuberculous mycobacterial lymphadenitis. METHOD: Retrospective review of all patients with culture proved non-tuberculous mycobacterial lymph node infections who also had differential avian and human skin testing performed over a 10 year period from 1986 to 1996. RESULTS: One hundred and twenty four patients had non-tuberculous mycobacteria isolated from lymph nodes over this period, 59 of whom had differential skin testing performed. The sensitivity of a response of >/= 10 mm to the avian precipitin was 58 of 59. No patient had both a negative human and avian Mantoux. The sensitivity of the human Mantoux alone for diagnosing non-tuberculous mycobacterial infection was 81% for a response of >/= 5 mm and 66% for >/= 10 mm. Ten patients had a 0 human response. Fifty five of the 59 patients had an avian response at least 2 mm greater than the human response. CONCLUSION: The avian Mantoux is a very sensitive method of diagnosing non-tuberculous mycobacterial infection in children. The human Mantoux is not sensitive enough to be used alone as a surrogate to diagnose non-tuberculous mycobacterial infection.     

药物代谢酶单核苷酸多态性与异烟肼致肝损害研究现状

【摘要】异烟肼（INH）是抗结核治疗最主要的一线药物,其最常见、最严重的副作用是肝损害（Anti-tuberculosis drug-induced heaptotoxicity ,ATDIH）。ATDIH的发病率约为2%-28%,严重限制了抗结核药的应用,使治疗被迫中断,导致治疗失败。在异烟肼致肝损害的过程中,药物代谢酶的含量和活性直接影响毒性中间代谢物的产生。由于遗传变异决定了药物代谢酶含量和活性的差异,导致了不同个体对药物的反应不同,从而引起肝损害个体差异。因此,药物代谢酶的基因多态性作为影响肝损害发病的主要因素之一,有待进一步深入研究,以最终实现抗结核药物个体化治疗,在减少ATDIH的发生并提高抗结核药的疗效方面有重要意义。本文系统的回顾了异烟肼致肝损害的代谢酶基因多态性及其在不同种族的分布情况,探讨宿主药物代谢酶单核苷酸多态性对ATDIH的影响,展望其未来的研究目标和方向。     

Unintended consequences of programmatic changes to infant and young child feeding practices in Bangladesh

BRAC, an international development organization, implemented a home‐fortification programme from 2014 to 2018 in Bangladesh. This study aimed to understand the unintended consequences of programmatic changes that occurred during the implementation of the programme on the prevalence of good infant and young child feeding (IYCF) practices and other associated factors. We used pooled data from eight cross‐sectional surveys and data from a series of qualitative investigations carried out as part of a mixed‐methods evaluation approach. A total of 6,479 caregivers of children aged 6 to 23 months participated in the surveys. The prevalence of good IYCF practices increased from baseline (42.1%) to midline (45.3%), but it decreased at the endline survey (31.9%). Qualitative investigations identified several reasons for low IYCF practices at the programme level, such as the withdrawal of community health worker (CHW) incentives for promoting IYCF, providing incentives for the home‐fortification of micronutrient powder (MNP) and changing the focus from IYCF promotion to MNP promotion. A multivariable generalized estimating equation model for pooled data revealed that caregivers were 28% (adjusted risk ratio [ARR]: 0.72, 95% CI [0.67, 0.78]) less likely to maintain good IYCF practices during the period when CHWs were not incentivized to promote IYCF compared to the period when CHWs were incentivized to promote it. The prevalence of good IYCF practices decreased from both baseline and midline to the endline survey due to the unintended consequences of the programmatic changes. An integrated intervention strategy to promote the home‐fortification of MNP and IYCF could be helpful to avoid unintended negative consequences of programmatic changes.     

Influence of MPR revaccination on tuberculin and sensitin skin reactions in children

ABSTRACT. Many viral diseases, as well as viral vaccines, have a transient effect in depressing cell-mediated immunity. The study group consisted of 52 children, aged 6.0–6.3 years. Thirty (57%) of them had been revaccinated against measles, parotitis and rubella (MPR vaccination). In MPR-revaceinated children, the mean skin reaction sizes were 4.7 mm, 4.1 mm, 4.3 mm and 2.1 mm to tuberculin, Mycobacterium avium, M. scrofulaceum and M. fortuitum sensitins, respectively. In non-revaceinated children ( n = 22), the respective mean skin reaction sizes were 3.0 mm, 2.8 mm, 2.9 mm and 0.8 mm. The difference between re- and non-revaccinated children was statistically significant with regard to reactions to M. fortuitum sensitin ( p <0.05). These results suggest that the influence of viral revaccination is different from natural infection or primary vaccination. The mechanism of stimulation of cell-mediated immunity—ither specific or non-specific—is unknown.     

Amanita bisporigera ingestion: mistaken identity, dose-related toxicity, and improvement despite severe hepatotoxicity

Ingestion of wild mushrooms has led to unintentional poisonings caused by mistaken identity. We report 3 cases of exposure to Amanita bisporigera, demonstrating dose-related toxicity. The use of nasobiliary drainage as a novel approach to interrupting the enterohepatic circulation of amatoxins is illustrated. Pathophysiology and treatment of Amanita poisoning are reviewed.     

Dissociation between tuberculin skin test and in vitro IFN-gamma responses following neonatal BCG vaccination

The in vitro IFN-gamma response to tuberculin was recently proposed as a correlate of vaccine-induced immunity to tuberculosis. IFN-gamma also plays a central role in the tuberculin skin test (TST), commonly used as a marker of mycobacterial infection. However, the use of TST as a marker of immunity to tuberculosis is limited for reasons ascribed mainly to interference by environmental mycobacteria. We prospectively investigated the relationship between the TST and cytokine responses to BCG in early infancy, a cohort with relatively low exposure to environmental mycobacteria. Neonatal BCG vaccination induced positive TST responses and predominant IFN-gamma responses to tuberculin in most newborns. However, the production of IFN-gamma, IL-5 and IL-13 was similar in TST responders and non-responders, and there was no significant correlation between the size of TST response and cytokine production. These results indicate that the IFN-gamma assay provides different information than TST in BCG-vaccinated newborns and could be a better marker of vaccine-induced immunity.     

No association between tuberculin skin test and atopy in a bacillus Calmette-Guérin vaccinated birth cohort

Previously, an inverse association was suggested between mycobacterial infection and atopy. We aimed to determine the association between tuberculin skin test (TST) and allergic manifestations in a birth cohort where all infants were vaccinated with bacillus Calmette-Guérin (BCG) at birth. Newborns were enrolled randomly and prospectively followed up for a period of 5 yr. Information on family history and environmental factors was obtained at birth, International Study of Asthma and Allergies in Childhood asthma questionnaire, physical examination, skin prick test to common inhalant and food allergens and TST were performed at 2 and 5 yr of age. Positive TST reactivity was defined as an induration of ≥10 mm. A total of 399 newborns were enrolled, 293 and 125 were available for a followup visit at 2 and 5 yr of age respectively. The prevalence of ever asthma, rhinitis and allergen sensitization tended to increase while eczema decreased with time. No significant association was found between TST reactivity and ever and current wheeze, doctor diagnosed asthma or atopic sensitization both at 2 and 5 yr of age. This prospectively designed birth cohort study did not confirm the previously suggested inverse correlation between TST reactivity and atopic sensitization or any allergic manifestations in Turkish children vaccinated with BCG at birth.