Zinc Cream and Reliability of Tuberculosis Skin Testing

In 50 healthy Peruvian shantytown residents, zinc cream applied to tuberculosis skin-test sitescaused a 32% increase in induration compared with placebo cream. Persons with lower plasma zinc had smaller skin-test reactions and greater augmentation with zinc cream. Zinc deficiency caused false-negative skin-test results, and topical zinc supplementation augmented antimycobacterial immune responses enough to improve diagnosis

Screening for latent TB, HIV, and hepatitis B/C in new migrants in a high prevalence area of London, UK: a cross-sectional study.

BACKGROUND: Rising rates of infectious diseases in international migrants has reignited the debate around screening. There have been calls to strengthen primary-care-based programmes, focusing on latent TB. We did a cross-sectional study of new migrants to test an innovative one-stop blood test approach to detect multiple infections at one appointment (HIV, latent tuberculosis, and hepatitis B/C) on registration with a General Practitioner (GP) in primary care. METHODS: The study was done across two GP practices attached to hospital Accident and Emergency Departments (A&E) in a high migrant area of London for 6 months. Inclusion criteria were foreign-born individuals from a high TB prevalence country (>40 cases per 100,000) who have lived in the UK ≤ 10 years, and were over 18 years of age. All new migrants who attended a New Patient Health Check were screened for eligibility and offered the blood test. We followed routine care pathways for follow-up. RESULTS: There were 1235 new registrations in 6 months. 453 attended their New Patient Health Check, of which 47 (10.4%) were identified as new migrants (age 32.11 years [range 18-72]; 22 different nationalities; time in UK 2.28 years [0-10]). 36 (76.6%) participated in the study. The intervention only increased the prevalence of diagnosed latent TB (18.18% [95% CI 6.98-35.46]; 181.8 cases per 1000). Ultimately 0 (0%) of 6 patients with latent TB went on to complete treatment (3 did not attend referral). No cases of HIV or hepatitis B/C were found. Foreign-born patients were under-represented at these practices in relation to 2011 Census data (Chi-square test -0.111 [95% CI -0.125 to -0.097]; p < 0.001). CONCLUSION: The one-stop approach was feasible in this context and acceptability was high. However, the number of presenting migrants was surprisingly low, reflecting the barriers to care that this group face on arrival, and none ultimately received treatment. The ongoing UK debate around immigration checks and charging in primary care for new migrants can only have negative implications for the promotion of screening in this group. Until GP registration is more actively promoted in new migrants, a better place to test this one-stop approach could be in A&E departments where migrants may present in larger numbers

Predictors of Multidrug- and Extensively Drug-Resistant Tuberculosis in a High HIV Prevalence Community

BACKGROUND: Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) have emerged in high-HIV-prevalence settings, which generally lack laboratory infrastructure for diagnosing TB drug resistance. Even where available, inherent delays with current drug-susceptibility testing (DST) methods result in clinical deterioration and ongoing transmission of MDR and XDR-TB. Identifying clinical predictors of drug resistance may aid in risk stratification for earlier treatment and infection control. METHODS: We performed a retrospective case-control study of patients with MDR (cases), XDR (cases) and drug-susceptible (controls) TB in a high-HIV-prevalence setting in South Africa to identify clinical and demographic risk factors for drug-resistant TB. Controls were selected in a 1:1:1 ratio and were not matched. We calculated odds ratios (OR) and performed multivariate logistic regression to identify independent predictors. RESULTS: We enrolled 116, 123 and 139 patients with drug-susceptible, MDR, and XDR-TB. More than 85% in all three patient groups were HIV-infected. In multivariate analysis, MDR and XDR-TB were each strongly associated with history of TB treatment failure (adjusted OR 51.7 [CI 6.6-403.7] and 51.5 [CI 6.4-414.0], respectively) and hospitalization more than 14 days (aOR 3.8 [CI 1.1-13.3] and 6.1 [CI 1.8-21.0], respectively). Prior default from TB treatment was not a risk factor for MDR or XDR-TB. HIV was a risk factor for XDR (aOR 8.2, CI 1.3-52.6), but not MDR-TB. Comparing XDR with MDR-TB patients, the only significant risk factor for XDR-TB was HIV infection (aOR 5.3, CI 1.0-27.6). DISCUSSION: In this high-HIV-prevalence and drug-resistant TB setting, a history of prolonged hospitalization and previous TB treatment failure were strong risk factors for both MDR and XDR-TB. Given high mortality observed among patients with HIV and drug-resistant TB co-infection, previously treated and hospitalized patients should be considered for empiric second-line TB therapy while awaiting confirmatory DST results in settings with a high-burden of MDR/XDR-TB

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A guide to UPS and power quality products (issue 2)

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Diagnosis of sputum-scarce HIV-associated pulmonary tuberculosis in Lima, Peru.

Sputum induction, bronchoalveolar lavage, or gastric aspiration are often needed to produce adequate diagnostic respiratory samples from people with HIV in whom tuberculosis is suspected. Since these procedures are rarely appropriate in less-developed countries, we compared the performances of a simple string test and the gold-standard sputum induction. 160 HIV-positive adults under investigation for tuberculosis, and 52 asymptomatic HIV-positive control patients underwent the string test followed by sputum induction. The string test detected tuberculosis in 14 patients in whom this disease was suspected; sputum induction detected only eight of them (McNemar's test, p=0.03). These preliminary data suggest that the string test is safe and effective for retrieval of useful clinical specimens for diagnosis of pulmonary tuberculosis, and is at least as sensitive as sputum induction

Tuberculosis transmission risk and infection control in a hospital emergency department in Lima, Peru.

BACKGROUND: Overcrowded emergency departments (EDs) are used by undiagnosed tuberculosis (TB) patients. TB infection control measures are seldom prioritized, making EDs potential foci of unrecognised nosocomial transmission. OBJECTIVE: To quantify TB infection risk among health care workers in an ED in a high TB-burden setting, Lima, Peru, and to evaluate TB infection control measures. METHODS: Consenting ED staff were tested for TB infection at baseline and after 1 year using the QuantiFERON-TB Gold In-Tube (QFT-G). In parallel, sputum for TB culture was requested from patients spending >2 h in the ED, irrespective of presenting complaint. Infection control measures were documented and room ventilation measured. RESULTS: Over 1 year, there were 2246 TB patient-hours of exposure in the ED from 153 different patients. At baseline, 56% of the 70 staff recruited were QFT-G-positive; 27 of 31 baseline-negatives consented to follow-up after 1 year, and eight (30%, all clinical staff) tested positive. Annual incidence of infection was 1730 per 100,000 population. TB infection control measures were sub-optimal, with no patient screening, no isolation rooms, inadequate ventilation and sporadic respirator use. CONCLUSIONS: ED staff were exposed to an unexpectedly large TB burden in the workplace, resulting in a high rate of TB infection. TB infection control should be prioritized in EDs, especially in high-prevalence settings