Implementing tuberculosis patient cost surveys in resource-constrained settings: lessons from Tanzania.

Tuberculosis (TB) disproportionally affects persons and families who are economically and socially disadvantaged. Therefore, a patient cost survey was conducted in Tanzania to evaluate the costs incurred by patients and their households before and after the diagnosis of TB. It was the first survey in Tanzania to ascertain baseline information and experience for subsequent surveys. This paper aims to share the experience encountered during the survey to ensure a standardized approach and elimination of potential barriers for the implementation of future surveys. A total of 777 TB patients from 30 clusters selected based on probability proportional to the size were interviewed during the study period. As the sample size was calculated based on notification data from the previous year, some health facilities experienced an inadequate number of TB patients during the study to meet the allocated cluster size for the survey. Most facilities had poor recording and recordkeeping in TB registers where deaths were not registered, and some patients had not been assigned district identification numbers. Fixed days for TB drug refills in health facilities affected the routine implementation of the survey as the interviews were conducted when patients visited the facility to pick up the drugs. Tablets used to collect data failed to capture the geographic location in some areas. The households of TB patients lost to follow-up and those who had died during TB treatment were not included in the survey. When planning and preparing for patient costs surveys, it is important to consider unforeseen factors which may affect planned activities and findings. During the survey in Tanzania, the identified challenges included survey logistics, communications, patient enrollment, and data management issues. To improve the quality of the findings of future surveys, it may be reasonable to revise survey procedures to include households of TB patients who were lost to follow-up and those who died during TB treatment; the households of such patients may have incurred higher direct and indirect costs than households whose patient was cured as a result of receiving TB treatment.

The second national anti-tuberculosis drug resistance survey in Tanzania, 2017-2018.

OBJECTIVE: To determine the levels and patterns of resistance to first- and second-line anti-tuberculosis (TB) drugs among new and previously treated sputum smear positive pulmonary TB (PTB) patients. METHODS: We conducted a nationally representative cross-sectional facility-based survey in June 2017-July 2018 involving 45 clusters selected based on probability proportional to size. The survey aimed to determine the prevalence of anti-TB drug resistance and associated risk factors among smear positive PTB patients in Tanzania. Sputum samples were examined using smear microscopy, Xpert MTB/RIF, culture and drug susceptibility testing (DST). Logistic regression was used to account for missing data and sampling design effects on the estimates and their standard errors. RESULTS: We enrolled 1557 TB patients, including 1408 (90.4%) newly diagnosed and 149 (9.6%) previously treated patients. The prevalence of multidrug-resistant TB (MDR-TB) was 0.85% [95% confidence interval (CI): 0.4-1.3] among new cases and 4.6% (95% CI: 1.1-8.2) among previously treated cases. The prevalence of Mycobacterium tuberculosis strains resistant to any of the four first-line anti-TB drugs (isoniazid, rifampicin, streptomycin and ethambutol) was 1.7% among new TB patients and 6.5% among those previously treated. Drug resistance to all first-line drugs was similar (0.1%) in new and previously treated patients. None of the isolates displayed poly-resistance or extensively drug-resistant TB (XDR-TB). The only risk factor for MDR-TB was history of previous TB treatment (odds ratio = 5.7, 95% CI: 1.9-17.2). CONCLUSION: The burden of MDR-TB in the country was relatively low with no evidence of XDR-TB. Given the overall small number of MDR-TB cases in this survey, it will be beneficial focusing efforts on intensified case detection including universal DST.

Phylogenetic lineages of tuberculosis isolates and their association with patient demographics in Tanzania.

BACKGROUND: Mycobacterium tuberculosis presents several lineages each with distinct characteristics of evolutionary status, transmissibility, drug resistance, host interaction, latency, and vaccine efficacy. Whole genome sequencing (WGS) has emerged as a new diagnostic tool to reliably inform the occurrence of phylogenetic lineages of Mycobacterium tuberculosis and examine their relationship with patient demographic characteristics and multidrug-resistance development. METHODS: 191 Mycobacterium tuberculosis isolates obtained from a 2017/2018 Tanzanian drug resistance survey were sequenced on the Illumina Miseq platform at Supranational Tuberculosis Reference Laboratory in Uganda. Obtained fast-q files were imported into tools for resistance profiling and lineage inference (Kvarq v0.12.2, Mykrobe v0.8.1 and TBprofiler v3.0.5). Additionally for phylogenetic tree construction, RaxML-NG v1.0.3(25) was used to generate a maximum likelihood phylogeny with 800 bootstrap replicates. The resulting trees were plotted, annotated and visualized using ggtree v2.0.4 RESULTS: Most [172(90.0%)] of the isolates were from newly treated Pulmonary TB patients. Coinfection with HIV was observed in 33(17.3%) TB patients. Of the 191 isolates, 22(11.5%) were resistant to one or more commonly used first line anti-TB drugs (FLD), 9(4.7%) isolates were MDR-TB while 3(1.6%) were resistant to all the drugs. Of the 24 isolates with any resistance conferring mutations, 13(54.2%) and 10(41.6%) had mutations in genes associated with resistance to INH and RIF respectively. The findings also show four major lineages i.e. Lineage 3[81 (42.4%)], followed by Lineage 4 [74 (38.7%)], the Lineage 1 [23 (12.0%)] and Lineages 2 [13 (6.8%)] circulaing in Tanzania. CONCLUSION: The findings in this study show that Lineage 3 is the most prevalent lineage in Tanzania whereas drug resistant mutations were more frequent among isolates that belonged to Lineage 4.

Economic burden of tuberculosis in Tanzania: a national survey of costs faced by tuberculosis-affected households.

BACKGROUND: Although tuberculosis (TB) care is free in Tanzania, TB-associated costs may compromise access to services and treatment adherence resulting in poor outcomes and increased risk of transmission in the community. TB can impact economically patients and their households. We assessed the economic burden of TB on patients and their households in Tanzania and identified cost drivers to inform policies and programs for potential interventions to mitigate costs. METHODS: We conducted a nationally representative cross-sectional survey using a standard methodology recommended by World Health Organization. TB patients of all ages and with all types of TB from 30 clusters across Tanzania were interviewed during July - September 2019. We used the human capital approach to assess the indirect costs and a threshold of 20% of the household annual expenditure to determine the proportion of TB-affected households experiencing catastrophic cost. We descriptively analyzed the cost data and fitted multivariable logistic regression models to identify potential predictors of catastrophic costs. RESULTS: Of the 777 TB-affected households, 44.9% faced catastrophic costs due to TB. This proportion was higher (80.0%) among households of patients with multi-drug resistant TB (MDR-TB). Overall, cost was driven by income loss while accessing TB services (33.7%), nutritional supplements (32.6%), and medical costs (15.1%). Most income loss was associated with hospitalization and time for picking up TB drugs. Most TB patients (85.9%) reported worsening financial situations due to TB, and over fifty percent (53.0%) borrowed money or sold assets to finance TB treatment. In multivariable analysis, the factors associated with catastrophic costs included hospitalization (adjusted odds ratio [aOR] = 34.9; 95% confidence interval (CI):12.5-146.17), living in semi-urban (aOR = 1.6; 95% CI:1.0-2.5) or rural areas (aOR = 2.6; 95% CI:1.8-3.7), having MDR-TB (aOR = 3.4; 95% CI:1.2-10.9), and facility-based directly-observed treatment (DOT) (aOR = 7.2; 95% CI:2.4-26.6). CONCLUSION: We found that the cost of TB care is catastrophic for almost half of the TB-affected households in Tanzania; our findings support the results from other surveys recently conducted in sub-Saharan Africa. Collaborative efforts across health, employment and social welfare sectors are imperative to minimize household costs due to TB disease and improve access to care, patient adherence and outcomes.

The association of Schistosoma and geohelminth infections with ß-cell function and insulin resistance among HIV-infected and HIV-uninfected adults: A cross-sectional study in Tanzania.

OBJECTIVES: Data on the role of helminths on diabetes in Africa are limited. We investigated whether Schistosoma and geohelminth infections are associated with ß-cell function and insulin resistance among adults. METHODS: A cross-sectional study was conducted among adults during 2016-2017. Demography, Schistosoma and geohelminth infections, HIV and insulin data were collected. Insulin during an oral glucose tolerance test (fasting, 30, and 120-min), overall insulin secretion index, insulinogenic index, HOMA-ß, and HOMA-IR were main outcome measures for ß-cell function and insulin resistance, respectively. Generalized estimating equations and generalized linear models assessed the association of Schistosoma and geohelminth infections with outcome measures separately by HIV status. Outcomes were presented as marginal means with 95% CI. RESULTS: Data were obtained for 1718 participants. Schistosoma infection was associated with higher 30-min insulin (24.2 mU/L, 95% CI: 6.9, 41.6) and overall insulin secretion index (13.3 pmol/L/mmol/L; 3.7, 22.9) among HIV-uninfected participants but with lower fasting insulin (-0.9 mU/L; -1.6, -0.2), 120-min insulin (-12.0 mU/L; -18.9, -5.1), and HOMA-IR (-0.3 mmol/L; -0.6, -0.05) among HIV-infected participants not yet on antiretroviral therapy (ART). Among HIV-infected participants not on ART, geohelminth infection was associated with lower fasting insulin (-0.9 mU/L; -1.6, -0.2), 120-min insulin (-9.1 mU/L; -17.3, -1.0), HOMA-ß (-8.9 mU/L)/(mmol/L; -15.3, -2.6) and overall insulin release index (-5.1 pmol/L/mmol/L; -10.3, 0.02), although this was marginally significant. There was no association among those on ART. CONCLUSIONS: Schistosoma infection was associated with higher ß-cell function among HIV-uninfected participants whereas Schistosoma and geohelminth infections were associated with reduced ß-cell function among HIV-infected participants not on ART.

ß-cell dysfunction and insulin resistance in relation to pre-diabetes and diabetes among adults in north-western Tanzania: a cross-sectional study.

OBJECTIVE: Studies on phenotypes of diabetes in Africa are inconsistent. We assessed the role of ß-cell dysfunction and insulin resistance on pre-diabetes and diabetes. METHODS: We included 1890 participants with mean age of 40.6 (SD11.9) years in a cross-sectional study among male and female adults in Tanzania during 2016 to 2017. Data on C-reactive protein (CRP), alpha-acid glycoprotein (AGP), HIV, oral glucose tolerance test (OGTT), body composition and insulin were collected. Insulinogenic index and HOMA-IR were used to derive an overall marker of ß-cell dysfunction and insulin resistance which was categorised as follows: normal ß-cell function and insulin sensitivity, isolated ß-cell dysfunction, isolated insulin resistance, and combined ß-cell dysfunction and insulin resistance. Pre-diabetes and diabetes were defined as 2-hour OGTT glucose between 7.8-11.0 and ≥ 11.1 mmol/L, respectively. Multinomial regression assessed the association of ß-cell dysfunction and insulin resistance with outcome measures. RESULTS: ß-cell dysfunction, insulin resistance, and combined ß-cell dysfunction and insulin resistance were associated with higher pre-diabetes risk. Similarly, isolated ß-cell dysfunction (adjusted relative risk ratio (aRRR) 4.8 (95% confidence interval (CI) 2.5, 9.0), isolated insulin resistance (aRRR 3.2 (95% CI 1.5, 6.9), and combined ß-cell dysfunction and insulin resistance (aRRR 35.9 (95% CI 17.2, 75.2) were associated with higher diabetes risk. CRP, AGP and HIV were associated with higher diabetes risk, but fat mass was not. 31%, 10% and 33% of diabetes cases were attributed to ß-cell dysfunction, insulin resistance, and combined ß-cell dysfunction and insulin resistance, respectively. CONCLUSIONS: ß-cell dysfunction seemed to explain most of diabetes cases compared to insulin resistance in this population. Cohort studies on evolution of diabetes in Africa are needed to confirm these results.

Diabetes prevalence by HbA1c and oral glucose tolerance test among HIV-infected and uninfected Tanzanian adults.

BACKGROUND: The burden of diabetes is increasing in sub-Saharan Africa, including among people living with HIV. We assessed the prevalence of diabetes and the roles of HIV, antiretroviral therapy (ART) and traditional risk factors among adults in Tanzania. METHODS: We analysed diabetes-relevant baseline data from 1,947 adult participants in the CICADA study in Mwanza, Tanzania: 655 HIV-uninfected, 956 HIV-infected ART-naïve, and 336 HIV-infected persons on ART. WHO guidelines for haemoglobin A1c (HbA1c) and oral glucose tolerance test (OGTT) were used to define diabetes and prediabetes. Risk factors were evaluated using multinomial logistic regression analysis. Relative risk ratios (RRR) were generated comparing participants with diabetes and prediabetes against the reference of those with no diabetes. RESULTS: Mean age was 41 (SD 12) years; 59% were women. The prevalence of diabetes was 13% by HbA1c and 6% by OGTT, with partial overlap among participants identified by the two tests. Relative to HIV-uninfected, HIV-infected ART-naïve persons had increased relative risks of diabetes (HbA1c: RRR = 1.95, 95% CI 1.25-3.03; OGTT: RRR = 1.90, 95% CI 0.96-3.73) and prediabetes (HbA1c: RRR = 2.89, 95% CI 1.93-4.34; OGTT: RRR = 1.61, 95% CI 1.22-2.13). HIV-infected participants on ART showed increased risk of prediabetes (RRR 1.80, 95% CI 1.09, 2.94) by HbA1c, but not diabetes. CD4 count < 200 cell/µL at recruitment increased risk and physical activity decreased risk of diabetes by both HbA1c and OGTT. CONCLUSIONS: The prevalence of diabetes was high, especially among HIV-infected ART-naïve adults. Being more physically active was associated with lower risk of diabetes. HbA1c and OGTT identified different participants as having diabetes or prediabetes. Overall, the finding of high burden of diabetes among HIV-infected persons suggests that health systems should consider integrating diabetes screening and treatment in HIV clinics to optimize the care of HIV patients and improve their health outcomes.

HIV treatment is associated with a two-fold higher probability of raised triglycerides: Pooled Analyses in 21 023 individuals in sub-Saharan Africa.

BACKGROUND: Anti-retroviral therapy (ART) regimes for HIV are associated with raised levels of circulating triglycerides (TG) in western populations. However, there are limited data on the impact of ART on cardiometabolic risk in sub-Saharan African (SSA) populations. METHODS: Pooled analyses of 14 studies comprising 21 023 individuals, on whom relevant cardiometabolic risk factors (including TG), HIV and ART status were assessed between 2003 and 2014, in SSA. The association between ART and raised TG (>2.3 mmol/L) was analysed using regression models. FINDINGS: Among 10 615 individuals, ART was associated with a two-fold higher probability of raised TG (RR 2.05, 95% CI 1.51-2.77, I2=45.2%). The associations between ART and raised blood pressure, glucose, HbA1c, and other lipids were inconsistent across studies. INTERPRETATION: Evidence from this study confirms the association of ART with raised TG in SSA populations. Given the possible causal effect of raised TG on cardiovascular disease (CVD), the evidence highlights the need for prospective studies to clarify the impact of long term ART on CVD outcomes in SSA.

Pharmacokinetics of Isoniazid, Pyrazinamide, and Ethambutol in Newly Diagnosed Pulmonary TB Patients in Tanzania.

Exposure to lower-than-therapeutic levels of anti-tuberculosis drugs is likely to cause selection of resistant strains of Mycobacterium tuberculosis and treatment failure. The first-line anti-tuberculosis (TB) regimen consists of rifampicin, isoniazid, pyrazinamide, and ethambutol, and correct management reduces risk of TB relapse and development of drug resistance. In this study we aimed to investigate the effect of standard of care plus nutritional supplementation versus standard care on the pharmacokinetics of isoniazid, pyrazinamide and ethambutol among sputum smear positive TB patients with and without HIV. In a clinical trial in 100 Tanzanian TB patients, with or without HIV infection, drug concentrations were determined at 1 week and 2 months post initiation of anti-TB medication. Data was analysed using population pharmacokinetic modelling. The effect of body size was described using allometric scaling, and the effects of nutritional supplementation, HIV, age, sex, CD4+ count, weight-adjusted dose, NAT2 genotype, and time on TB treatment were investigated. The kinetics of all drugs was well characterised using first-order elimination and transit compartment absorption, with isoniazid and ethambutol described by two-compartment disposition models, and pyrazinamide by a one-compartment model. Patients with a slow NAT2 genotype had higher isoniazid exposure and a lower estimate of oral clearance (15.5 L/h) than rapid/intermediate NAT2 genotype (26.1 L/h). Pyrazinamide clearance had an estimated typical value of 3.32 L/h, and it was found to increase with time on treatment, with a 16.3% increase after the first 2 months of anti-TB treatment. The typical clearance of ethambutol was estimated to be 40.7 L/h, and was found to decrease with age, at a rate of 1.41% per year. Neither HIV status nor nutritional supplementations were found to affect the pharmacokinetics of these drugs in our cohort of patients.

Increased level of acute phase reactants in patients infected with modern Mycobacterium tuberculosis genotypes in Mwanza, Tanzania.

BACKGROUND: There is increasing evidence to suggest that different Mycobacterium tuberculosis lineages cause variations in the clinical presentation of tuberculosis (TB). Certain M. tuberculosis genotypes/lineages have been shown to be more likely to cause active TB in human populations from a distinct genetic ancestry. This study describes the genetic biodiversity of M. tuberculosis genotypes in Mwanza city, Tanzania and the clinical presentation of the disease caused by isolates of different lineages. METHODS: Two-hundred-fifty-two isolates from pulmonary TB patients in Mwanza, Tanzania were characterized by spoligotyping, and 45 isolates were further characterized by mycobacterium interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR). The patients' level of the acute phase reactants AGP, CRP and neutrophil counts, in addition to BMI, were measured and compared to the M. tuberculosis lineage of the infectious agent for each patient. RESULTS: The most frequent genotype was ST59 (48 out of 248 [19.4%]), belonging to the Euro-American lineage LAM11_ZWE, followed by ST21 (CAS_KILI lineage [44 out of 248 [17.7%]). A low degree of diversity (15.7% [39 different ST's out of 248 isolates]) of genotypes, in addition to a high level of mixed M. tuberculosis sub-populations among isolates with an unreported spoligotype pattern (10 out of 20 isolates [50.0%]) and isolates belonging to the ST53 lineage (13 out of 25 [52%]) was observed. Isolates of the 'modern' (TbD1-) Euro-American lineage induced higher levels of α1-acid glycoprotein (ß = 0.4, P = 0.02; 95% CI [0.06-0.66]) and neutrophil counts (ß = 0.9, P = 0.02; 95% CI [0.12-1.64]) and had lower BMI score (ß = -1.0, P = 0.04; 95% CI[-1.89 - (-0.03)]). LAM11_ZWE ('modern') isolates induced higher levels of CRP (ß = 24.4, P = 0.05; 95% CI[0.24-48.63]) and neutrophil counts (ß = 0.9, P = 0.03; 95% CI[0.09-1.70]). CONCLUSION: The low diversity of genotypes may be explained by an evolutionary advantage of the most common lineages over other lineages combined with optimal conditions for transmission, such as overcrowding and inadequate ventilation. The induction of higher levels of acute phase reactants in patients infected by 'modern' lineage isolates compared to 'ancient' lineages may suggest increased virulence among 'modern' lineage isolates.

Nutritional supplementation increases rifampin exposure among tuberculosis patients coinfected with HIV.

Nutritional supplementation to tuberculosis (TB) patients has been associated with increased weight and reduced mortality, but its effect on the pharmacokinetics of first-line anti-TB drugs is unknown. A cohort of 100 TB patients (58 men; median age, 35 [interquartile range {IQR}, 29 to 40] years, and median body mass index [BMI], 18.8 [17.3 to 19.9] kg/m(2)) were randomized to receive nutritional supplementation during the intensive phase of TB treatment. Rifampin plasma concentrations were determined after 1 week and 2 months of treatment. The effects of nutritional supplementation, HIV, time on treatment, body weight, and SLCO1B1 rs4149032 genotype were examined using a population pharmacokinetic model. The model adjusted for body size via allometric scaling, accounted for clearance autoinduction, and detected an increase in bioavailability (+14%) for the patients in the continuation phase. HIV coinfection in patients not receiving the supplementation was found to decrease bioavailability by 21.8%, with a median maximum concentration of drug in serum (Cmax) and area under the concentration-time curve from 0 to 24 h (AUC0-24) of 5.6 µg/ml and 28.6 µg · h/ml, respectively. HIV-coinfected patients on nutritional supplementation achieved higher Cmax and AUC0-24 values of 6.4 µg/ml and 31.6 µg · h/ml, respectively, and only 13.3% bioavailability reduction. No effect of the SLCO1B1 rs4149032 genotype was observed. In conclusion, nutritional supplementation during the first 2 months of TB treatment reduces the decrease in rifampin exposure observed in HIV-coinfected patients but does not affect exposure in HIV-uninfected patients. If confirmed in other studies, the use of defined nutritional supplementation in HIV-coinfected TB patients should be considered in TB control programs. (This study has the controlled trial registration number ISRCTN 16552219.).

Diabetes is associated with lower tuberculosis antigen-specific interferon gamma release in Tanzanian tuberculosis patients and non-tuberculosis controls.

BACKGROUND: Diabetes is increasingly common in TB endemic regions and plays a role as a possible risk factor for increased progression from latent TB infection (LTBI) to active TB disease. Although the pathophysiological mechanisms are not fully understood, the immune system is weakened in diabetes patients and therefore the validity of interferon gamma release assays (IGRA) may be compromised. The aim of the present study was to assess the association between diabetes and Mycobacterium tuberculosis (Mtb) antigen-specific interferon gamma (IFN-γ) release in a TB endemic area among culture-confirmed TB patients and non-TB controls. METHODS: Culture-confirmed pulmonary TB patients (n = 187) and healthy non-TB neighbourhood controls (n = 190) from Mwanza, Tanzania were tested for the presence of circulating T cells recognizing Mtb antigens using an IGRA. The diabetes status of all participants was assessed using a standard oral glucose tolerance test. The impact of diabetes on the performance of the IGRA was estimated using robust linear and logistic regression. RESULTS: Compared to normal glucose tolerance, diabetes was associated with reduced levels of Mtb-specific IFN-γ. Increasing levels of fasting blood glucose (B - 0.3, 95% confidence interval - 0.6 to - 0.03, p = 0.033) was negatively associated with IFN-γ. Although TB patients had higher specific and lower unspecific mitogen IFN-γ responses compared to non-TB controls, the association between diabetes and IFN-γ did not depend on TB status. CONCLUSION: Diabetes is associated with lower levels of Mtb antigen-specific IFN-γ, and the validity of IFN- γ tests for LTBI may be questionable in individuals with diabetes.

Vitamin D status among pulmonary TB patients and non-TB controls: a cross-sectional study from Mwanza, Tanzania.

BACKGROUND: Little is known about vitamin D status in low-income populations burdened with infectious diseases. Hence, there is a need for data on correlates of serum 25-hydroxy vitamin D (S-25(OH)D) and its validity during infections. OBJECTIVE: To assess the role of pulmonary TB (PTB) and HIV as correlates of S-25(OH)D. DESIGN: Age-sex-matched cross-sectional study among PTB patients and non-TB controls. METHODS: PTB patients were categorized as sputum negative (PTB-) and positive (PTB+) by culture. Non-TB controls were randomly selected among age-sex-matched neighbours to PTB+ patients. Height, weight, arm circumference and triceps skinfold were measured, and body mass index (BMI), arm fat (AFA) and muscle area (AMA) computed. HIV status, and S-25(OH)D, C-reactive protein (S-CRP) and α1-acid glycoprotein (S-AGP) were determined. Linear regression analysis with controls and PTB patients combined was used to identify correlates of S-25(OH)D. RESULTS: S-25(OH)D data were available on 97.8% (1570) of 1605 participants. Mean (SD) S-25(OH)D was 84.4 (25.6) nmol/L with 39.6% <75 nmol/L among 347 non-TB controls. Time of recruitment, sex, PTB and HIV, and elevated S-AGP were correlates of S-25(OH)D. S-25(OH)D was 24.8 (95% CI 18.6;30.9) nmol/L higher in PTB compared to controls among females, but only 9.8 (95% CI:4.5;15.2) nmol/L among males (interaction p<0.0001). Females had 13.8 (95% CI:8.2;21.9) nmol/L lower S-25(OH)D than males, and HIV infected individuals had 8.5 (95% CI:4.9;12.1) higher S-25(OH)D compared to uninfected. Elevated S-AGP was a positive correlate of S-25(OH)D. Low BMI was associated with S-25(OH)D, but not with infections or S-AGP in the model. CONCLUSION: While S-25(OH)D may decline transiently during a mild acute phase response, it may increase if the acute phase response leads to loss of fat. The validity of S-25(OH)D as a marker of vitamin D status may be affected by infections.

Diabetes is a strong predictor of mortality during tuberculosis treatment: a prospective cohort study among tuberculosis patients from Mwanza, Tanzania.

OBJECTIVE: Strong evidence suggests diabetes may be associated with tuberculosis (TB) and could influence TB treatment outcomes. We assessed the role of diabetes on sputum culture conversion and mortality among patients undergoing TB treatment. METHODS: A total of 1250 Tanzanian TB patients were followed prospectively during TB treatment with sputum culture after 2 and 5 months. Survival status was assessed at least 1 year after initiation of treatment. At baseline, all participants underwent testing for diabetes and HIV, and the serum concentration of the acute phase reactant alpha-1 glycoprotein (AGP) was determined. RESULTS: There were no differences between participants with and without diabetes regarding the proportion of positive cultures at 2 (3.8% vs. 5.8%) and 5 (1.3% vs. 0.9%) months (P > 0.46). However, among patients with a positive TB culture, relatively more patients with diabetes died before the 5-month follow-up. Within the initial 100 days of TB treatment, diabetes was associated with a fivefold increased risk of mortality (RR 5.09, 95% CI 2.36; 11.02, P < 0.001) among HIV uninfected, and a twofold increase among HIV co-infected patient (RR 2.33 95% CI 1.20; 4.53, P = 0.012), while diabetes was not associated with long-term mortality. Further adjustment with AGP did not change the estimates. CONCLUSION: Diabetes considerably increases risk of early mortality during TB treatment. The effect may not be explained by increased severity of TB, but could be due to impaired TB treatment response. Research is needed to clarify the mechanism and to assess whether glycaemic control improves survival.

The prevalence of latent Mycobacterium tuberculosis infection based on an interferon-γ release assay: a cross-sectional survey among urban adults in Mwanza, Tanzania.

INTRODUCTION: One third of the world's population is estimated to be latently infected with Mycobacterium tuberculosis (LTBI). Surveys of LTBI are rarely performed in resource poor TB high endemic countries like Tanzania although low-income countries harbor the largest burden of the worlds LTBI. The primary objective was to estimate the prevalence of LTBI in household contacts of pulmonary TB cases and a group of apparently healthy neighborhood controls in an urban setting of such a country. Secondly we assessed potential impact of LTBI on inflammation by quantitating circulating levels of an acute phase reactant: alpha-1-acid glycoprotein (AGP) in neighborhood controls. METHODS: The study was nested within the framework of two nutrition studies among TB patients in Mwanza, Tanzania. Household contacts- and neighborhood controls were invited to participate. The study involved a questionnaire, BMI determination and blood samples to measure AGP, HIV testing and a Quantiferon Gold In tube (QFN-IT) test to detect signs of LTBI. RESULTS: 245 household contacts and 192 neighborhood controls had available QFN-IT data. Among household contacts, the proportion of QFT-IT positive was 59% compared to 41% in the neighborhood controls (p = 0.001). In a linear regression model adjusted for sex, age, CD4 and HIV, a QFT-IT positive test was associated with a 10% higher level of alpha-1-acid glycoprotein(AGP) (10(B) 1.10, 95% CI 1.01; 1.20, p = 0.03), compared to individuals with a QFT-IT negative test. CONCLUSION: LTBI is highly prevalent among apparently healthy urban Tanzanians even without known exposure to TB in the household. LTBI was found to be associated with elevated levels of AGP. The implications of this observation merit further studies.

Sex, smoking, and socioeconomic status are associated with body composition among tuberculosis patients in a deuterium dilution cross-sectional study in Mwanza, Tanzania.

Underweight is common among tuberculosis (TB) patients. However, there is little information on determinants of body composition at TB treatment initiation in high-TB-burdened countries. This study aimed to determine factors associated with body composition at commencement of TB treatment in Mwanza, Tanzania. A cross-sectional study was conducted from 2007 to 2008 among newly diagnosed TB patients. Fat and fat-free mass were determined using a deuterium dilution technique and fat and fat-free mass indices were computed. Correlates were assessed using multiple regression analysis. A total of 201 pulmonary TB patients were recruited; of these, 37.8% (76) were female, 51.7% (104) were HIV infected, 65.3% (126) had sputum-positive TB, and 24.4% (49) were current smokers. In multiple regressions analysis, males had a 2.2-kg/m(2) [(95% CI = 1.6, 2.9); P < 0.0001] lower fat mass index but 1.5 kg/m(2) [(95% CI = 0.9, 2.0); P < 0.0001] higher fat-free mass index compared with females. Sputum-positive TB was associated with a lower fat mass index among HIV-uninfected patients [-1.4 kg (95% CI = -2.5, -0.4); P = 0.006] but not among HIV-infected patients (P-interaction = 0.09). Current smokers had a 0.7-kg/m(2) [(95% CI = 0.02, 1.5); P = 0.045] lower fat mass index, but smoking did not affect fat-free mass. High socioeconomic status (SES) was associated with higher fat as well as fat-free mass. HIV infection, cluster of differentiation 4 count, and antiretroviral therapy were not correlates. Sex, smoking, and SES were associated with body composition of TB patients at treatment commencement. Prospective studies are needed to determine the role of these factors on weight gain, functional recovery, and survival during and after treatment.

Health workers' performance in the implementation of Patient Centred Tuberculosis Treatment (PCT) strategy under programmatic conditions in Tanzania: a cross sectional study.

BACKGROUND: Patient Centred Tuberculosis Treatment (PCT) is a promising treatment delivery strategy for Mycobacterium tuberculosis (TB). It aims to improve adherence to treatment by giving patients the choice of having drug intake supervised at the health facility by a medical professional or at home by a supporter of their choice. METHODS: A cross-sectional survey was undertaken in three districts of Tanzania during October 2007, one year after PCT was rolled out nationally. Semi-structured questionnaires were used to assess whether key elements of the PCT approach were being implemented, to evaluate supporters' knowledge, to capture opinions on factors contributing to treatment completion, and to assess how treatment completion was measured. Transcripts from open-ended responses were analysed using framework analysis. RESULTS: Interviews were conducted with 127 TB patients, 107 treatment supporters and 70 health workers. In total, 25.2% of TB patients were not given a choice about the place of treatment by health workers, and only 13.7% of those given a choice reported that they were given adequate time to make their decision. Only 24.3% of treatment supporters confirmed that they were instructed how to complete patients' treatment cards. Proper health education was the factor most frequently reported by health workers as favouring successful completion of TB treatment (45.7%). The majority of health workers (68.6%) said they checked returned blister packs to verify whether patients had taken their treatment, but only 20.0% checked patients' treatment cards. CONCLUSIONS: The provision of choice of treatment location, information on treatment, and guidance for treatment supporters need to be improved. There is a requirement for regular re-training of health workers with effective supportive supervision if successful implementation of the PCT approach is to be sustained.

BCG protects against tuberculosis irrespective of HIV status: a matched case-control study in Mwanza, Tanzania.

While BCG vaccine protects against severe tuberculosis (TB) in children, its effect against adult TB is questionable. Furthermore, it is not known if HIV co-infection modifies the effect of BCG. Among 352 pairs of Tanzanian TB cases and matched controls, the BCG scar was associated with a reduced risk of TB (OR 0.3, 95% CI 0.2 to 0.7, p=0.005), irrespective of HIV status (interaction, p=0.623). BCG vaccination considerably reduced the risk of TB, both among individuals with and without HIV infection.