Katherine Fielding

How Soon after Infection with HIV Does the Risk of Tuberculosis Start to Increase? A Retrospective Cohort Study in South African Gold Miners

BACKGROUND Infection with human immunodeficiency virus (HIV) increases the risk of tuberculosis (TB), but no study has assessed how this risk changes with time since HIV seroconversion. METHODS The incidence of pulmonary TB was estimated in miners with and those without HIV infection in a retrospective cohort study. HIV test results were linked to routinely collected TB, demographic, and occupational data. The rate ratio (RR) for the association between HIV status and TB was estimated by time since HIV seroconversion, calendar period, and age. RESULTS Of the 23,874 miners in the cohort, 17,766 were HIV negative on entry, 3371 were HIV positive on entry, and 2737 seroconverted during follow-up (1962 had a seroconversion interval of < or =2 years). A total of 740 cases of TB were analyzed. The incidence of TB increased with time since seroconversion, calendar period, and age. TB incidence was 2.90 cases/100 person-years at risk (pyar) in HIV-positive miners and was 0.80 cases/100 pyar in HIV-negative miners (adjusted RR, 2.9 [95% confidence interval {CI}, 2.5-3.4]). TB incidence doubled within the first year of HIV infection (adjusted RR, 2.1 [95% CI, 1.4-3.1]), with a further slight increase in HIV-positive miners for longer periods, up to 7 years. CONCLUSION The increase in the risk of TB so soon after infection with HIV was unexpected. Current predictive models of TB incidence underestimate the effect of HIV infection in areas where TB is endemic.

Antidepressant drugs and generic counselling for treatment of major depression in primary care: randomised trial with patient preference arms

Abstract Objectives: To compare the efficacy of antidepressant drugs and generic counselling for treating mild to moderate depression in general practice. To determine whether the outcomes were similar for patients with randomly allocated treatment and those expressing a treatment preference. Design: Randomised controlled trial, with patient preference arms. Follow up at 8 weeks and 12 months and abstraction of GP case notes. Setting: 31 general practices in Trent region. Participants: Patients aged 18–70 who met research diagnostic criteria for major depression; 103 patients were randomised and 220 patients were recruited to the preference arms. Main outcome measures: Difference in mean Beck depression inventory score; time to remission; global outcome assessed by a psychiatrist using all data sources; and research diagnostic criteria. Results: At 12 months there was no difference between the mean Beck scores in the randomised arms. Combining the randomised and patient preference groups, the difference in Beck scores was 0.4 (95% confidence interval −2.7 to 3.5). Patients choosing counselling did better than those randomised to it (mean difference in Beck score 4.6, 0.0 to 9.2). There was no difference in the psychiatrists overall assessment of outcome between any of the groups. 221/265 (83%) of participants with a known outcome had a remission. Median time to remission was shorter in the group randomised to antidepressants than the other three groups (2 months v 3 months). 33/221 (15%) patients had a relapse. Conclusions: Generic counselling seems to be as effective as antidepressant treatment for mild to moderate depressive illness, although patients receiving antidepressants may recover more quickly. General practitioners should allow patients to have their preferred treatment. What is already known on this topic Antidepressants and specific psychological interventions are effective in major depression. Generic counselling has not previously been compared with antidepressants in primary care What this study adds 12 months after starting treatment, generic counselling is as effective as antidepressants Patients treated with antidepressants may recover more quickly Given a choice, more patients opt for counselling Patients who choose counselling may benefit more than those with no strong preference

Influence of Mycobacterium bovis bacillus Calmette-Guérin on antibody and cytokine responses to human neonatal vaccination

The immaturity of the immune system increases the susceptibility of young infants to infectious diseases and prevents the induction of protective immune responses by vaccines. We previously reported that Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccination induces a potent Th1 response to mycobacterial Ags in newborns. In this study, we evaluated the influence of BCG on the response to unrelated vaccines given in early life. Newborns were randomly allocated to one of three study groups receiving BCG at birth, when infants received their first dose of hepatitis B and oral polio vaccines; at 2 mo of age, when infants received their first dose of diphtheria and tetanus vaccines; or at 4.5 mo of age, when immune responses to vaccines were measured. Administration of BCG at the time of priming markedly increased the cellular and Ab responses to the hepatitis B vaccine, but had only a limited influence on the cytokine response to tetanus toxoid and no effect on the Ab responses to tetanus and diphtheria toxoids. Although BCG induced a potent Th1-type response to mycobacterial Ags, it promoted the production of both Th1- and Th2-type cytokines in response to unrelated vaccines. The effect of BCG was apparent at the systemic level, as it increased the Ab response to oral polio vaccine. These results demonstrate that BCG influences the immune response to unrelated Ags in early life, likely through its influence on the maturation of dendritic cells.

Evaluation of the WHO criteria for antiretroviral treatment failure among adults in South Africa.

Objective:To assess the performance of WHO clinical and CD4 cell count criteria for antiretroviral treatment (ART) failure among HIV-infected adults in a workplace HIV care programme in South Africa. Design:Cohort study. Methods:We included initially ART-naive participants who remained on first-line therapy and had an evaluable HIV viral load result at the 12-month visit. WHO-defined clinical and CD4 cell count criteria for ART failure were compared against a gold standard of virological failure. Results:Among 324 individuals (97.5% men, median age 40.2, median starting CD4 cell count and viral load 154 cells/μl and 47 503 copies/ml, respectively), 33 (10.2%) had definite or probable virological failure at 12 months, compared with 19 (6.0%) and 40 (12.5%) with WHO-defined CD4 and clinical failure, respectively. CD4 criteria had a sensitivity of 21.2% and a specificity of 95.8% in detecting virological failure, and clinical criteria had sensitivity of 15.2% and specificity of 88.1%. The positive predictive value of CD4 and clinical criteria in detecting virological failure were 36.8 and 12.8%, respectively. Exclusion of weight loss or tuberculosis failed to improve the performance of clinical criteria. Conclusion:WHO clinical and CD4 criteria have poor sensitivity and specificity in detecting virological failure. The low specificities and positive predictive values mean that individuals with adequate virological suppression risk being incorrectly classified as having treatment failure and unnecessarily switched to second-line therapy. Virological failure should be confirmed before switching to second-line therapy.

A Four-Month Gatifloxacin-Containing Regimen for Treating Tuberculosis

BACKGROUND Shortening the course of treatment for tuberculosis would be a major improvement for case management and disease control. This phase 3 trial assessed the efficacy and safety of a 4-month gatifloxacin-containing regimen for treating rifampin-sensitive pulmonary tuberculosis. METHODS We conducted a noninferiority, randomized, open-label, controlled trial involving patients 18 to 65 years of age with smear-positive, rifampin-sensitive, newly diagnosed pulmonary tuberculosis in five sub-Saharan African countries. A standard 6-month regimen that included ethambutol during the 2-month intensive phase was compared with a 4-month regimen in which gatifloxacin (400 mg per day) was substituted for ethambutol during the intensive phase and was continued, along with rifampin and isoniazid, during the continuation phase. The primary efficacy end point was an unfavorable outcome (treatment failure, recurrence, or death or study dropout during treatment) measured 24 months after the end of treatment, with a noninferiority margin of 6 percentage points, adjusted for country. RESULTS A total of 1836 patients were assigned to the 4-month regimen (experimental group) or the standard regimen (control group). Baseline characteristics were well balanced between the groups. At 24 months after the end of treatment, the adjusted difference in the risk of an unfavorable outcome (experimental group [21.0%] minus control group [17.2%]) in the modified intention-to-treat population (1356 patients) was 3.5 percentage points (95% confidence interval, -0.7 to 7.7). There was heterogeneity across countries (P=0.02 for interaction, with differences in the rate of an unfavorable outcome ranging from -5.4 percentage points in Guinea to 12.3 percentage points in Senegal) and in baseline cavitary status (P=0.04 for interaction) and body-mass index (P=0.10 for interaction). The standard regimen, as compared with the 4-month regimen, was associated with a higher dropout rate during treatment (5.0% vs. 2.7%) and more treatment failures (2.4% vs. 1.7%) but fewer recurrences (7.1% vs. 14.6%). There was no evidence of increased risks of prolongation of the QT interval or dysglycemia with the 4-month regimen. CONCLUSIONS Noninferiority of the 4-month regimen to the standard regimen with respect to the primary efficacy end point was not shown. (Funded by the Special Program for Research and Training in Tropical Diseases and others; ClinicalTrials.gov number, NCT00216385.).

Active tuberculosis in Africa is associated with reduced Th1 and increased Th2 activity in vivo

Activation of Th1 lymphocytes, IFN‐γ production and macrophage activation are crucial in defense against Mycobacteria. In developing countries, Th2 activation and IL‐4 production have been associated in vitro with tuberculosis and with poor clinical outcome after treatment. Serological markers of Th1 [soluble lymphocyte activation gene (LAG)‐3] and Th2 (IgE, solubleCD30, and CCL22/macrophage‐derived chemokine) activity were measured in 414 HIV‐negative tuberculosis patients from The Gambia and Guinée and in 414 healthy household and community controls. Measurements were repeated during treatment to assess the effect of therapy on Th1/Th2 ratio. At diagnosis, sLAG‐3 levels were lower in patients than in community controls (p<0.0001), but were higher in household controls exposed to contact with patients than in community controls (p<0.0001). In comparison with community controls, patients had consistently higher levels of IgE, sCD30, and CCL22 (p<0.0001), whereas household controls had lower levels of indicators of Th2 activity (p<0.0001). After treatment, cured patients had higher levels of Th1 (p<0.0001) and lower levels of Th2 (p<0.0001) activity than patients who were not successfully treated or interrupted therapy. In Africa, tuberculosis is associated with low Th1 and high Th2 activity in vivo, whereas close exposure to tuberculosis is associated with a high Th1/Th2 ratio. Patients with favorable outcome after treatment exhibit a higher Th1/Th2 ratio compared to patients with poor clinical outcome.

Large-Scale Evaluation of Enzyme-Linked Immunospot Assay and Skin Test for Diagnosis of Mycobacterium tuberculosis Infection against a Gradient of Exposure in The Gambia

The purified protein derivative (PPD) skin test for Mycobacterium tuberculosis infection lacks specificity. We assessed 2 more specific M. tuberculosis antigens (ESAT-6 and CFP-10) by enzyme-linked immunospot assay (ELISPOT) compared with PPD by ELISPOT and skin test in The Gambia. Of 735 household contacts of 130 sputum smear-positive tuberculosis cases, 476 (65%) tested positive by PPD ELISPOT, 300 (41%) tested positive by PPD skin test, and 218 (30%) tested positive by ESAT-6/CFP-10 ELISPOT. Only 15 (2%) had positive ESAT-6/CFP-10 results and negative PPD results by ELISPOT. With increasing M. tuberculosis exposure, the percentage of subjects who were PPD skin test positive/ESAT-6/CFP-10 ELISPOT negative increased (P<.001), whereas the percentage of subjects who were PPD skin test negative/PPD ELISPOT positive decreased (P=.011). Eighteen (31%) ESAT-6/CFP-10 ELISPOT-positive subjects in the lowest exposure category had negative PPD skin test results. ESAT-6/CFP-10 ELISPOT probably offers increased specificity in the diagnosis of M. tuberculosis infection in this tropical setting of endemicity, at the cost of some sensitivity.

Vitamin D Receptor Polymorphisms and Susceptibility to Tuberculosis in West Africa: A Case-Control and Family Study

Vitamin D receptor (VDR) gene polymorphisms have been implicated in susceptibility to tuberculosis (TB), but reports have been inconsistent. We genotyped the VDR single-nucleotide polymorphisms (SNPs) FokI, BsmI, ApaI, and TaqI in 1139 case patients and control subjects and 382 families from The Gambia, Guinea, and Guinea-Bissau. The transmission-disequilibrium test on family data showed a significant global association of TB with SNP combinations FokI-BsmI-ApaI-TaqI and FokI-ApaI that were driven by the increased transmission to affected offspring of the FokI F and ApaI A alleles in combination. The ApaI A allele was also transmitted to affected offspring significantly more often than expected. Case-control analysis showed no statistically significant association between TB and VDR variants. BsmI, ApaI, and TaqI showed strong linkage disequilibrium. The significance of the family-based associations found between TB and FokI-BsmI-ApaI-TaqI and the FA haplotype supports a role for VDR haplotypes, rather than individual genotypes, in susceptibility to TB.

That is why I stopped the ART: Patients' & providers' perspectives on barriers to and enablers of HIV treatment adherence in a South African workplace programme

BackgroundAs ART programmes in African settings expand beyond the pilot stages, adherence to treatment may become an increasing challenge. This qualitative study examines potential barriers to, and facilitators of, adherence to ART in a workplace programme in South Africa.MethodsWe conducted key informant interviews with 12 participants: six ART patients, five health service providers (HSPs) and one human resources manager.ResultsThe main reported barriers were denial of existence of HIV or of ones own positive status, use of traditional medicines, speaking a different language from the HSP, alcohol use, being away from home, perceived severity of side-effects, feeling better on treatment and long waiting times at the clinic. The key facilitators were social support, belief in the value of treatment, belief in the importance of ones own life to the survival of ones family, and the ability to fit ART into daily life schedules.ConclusionGiven the reported uncertainty about the existence of HIV disease and the use of traditional medicines while on ART, despite a programme emphasising ART counselling, there is a need to find effective ways to support adherence to ART even if the individual does not accept biomedical concepts of HIV disease or decides to use traditional medicines. Additionally, providers should identify ways to minimize barriers in communication with patients with whom they have no common language. Finally, dissatisfaction with clinical services, due to long waiting times, should be addressed.

Hepatotoxicity in an African antiretroviral therapy cohort: The effect of tuberculosis and hepatitis B

Objective:Hepatotoxicity is a significant complication of antiretroviral therapy (ART). We assessed the incidence of and risk factors for hepatotoxicity among HIV-infected individuals on ART in South Africa. Design:We conducted a retrospective cohort study in a workplace HIV care program in South Africa which uses a first-line regimen of efavirenz, zidovudine, and lamivudine and provides routine clinical and laboratory monitoring. Methods:We included subjects with baseline and follow-up alanine transaminase and aspartate aminotransferase tests. Severe hepatotoxicity cases were identified during the first 12 months of ART. Potential risk factors, including concomitant medication use, tuberculosis, and hepatitis B and C, were determined from clinical records, database queries, and serological testing. Associations with hepatotoxicity were investigated using Cox proportional hazards modeling. Results:Of the 868 subjects (94% male, median age 41 years), the median nadir CD4 cell count was 136/μl, 25% received concomitant tuberculosis treatment during ART, and 17% of a randomly selected subset were positive for hepatitis B surface antigen (HBsAg). We identified 7.7 episodes of severe hepatotoxicity per 100 person-years. Tuberculosis treatment increased risk 8.5 fold, positive HBsAg 3.0 fold, and nadir CD4 cells count < 100/μl 1.9 fold. Importantly, the fraction of patients with severe hepatotoxicity on ART (4.6%) was similar to the fraction with liver enzyme elevations > 5 times the upper limit of normal before starting ART (4%). Conclusions:In this African ART cohort, we found a low incidence of and minimal morbidity due to hepatotoxicity. HBsAg and concomitant tuberculosis therapy significantly increased the risk of hepatotoxicity.