Development of treatment-decision algorithms for children evaluated for pulmonary tuberculosis: an individual participant data meta-analysis.

BACKGROUND: Many children with pulmonary tuberculosis remain undiagnosed and untreated with related high morbidity and mortality. Recent advances in childhood tuberculosis algorithm development have incorporated prediction modelling, but studies so far have been small and localised, with limited generalisability. We aimed to evaluate the performance of currently used diagnostic algorithms and to use prediction modelling to develop evidence-based algorithms to assist in tuberculosis treatment decision making for children presenting to primary health-care centres. METHODS: For this meta-analysis, we identified individual participant data from a WHO public call for data on the management of tuberculosis in children and adolescents and referral from childhood tuberculosis experts. We included studies that prospectively recruited consecutive participants younger than 10 years attending health-care centres in countries with a high tuberculosis incidence for clinical evaluation of pulmonary tuberculosis. We collated individual participant data including clinical, bacteriological, and radiological information and a standardised reference classification of pulmonary tuberculosis. Using this dataset, we first retrospectively evaluated the performance of several existing treatment-decision algorithms. We then used the data to develop two multivariable prediction models that included features used in clinical evaluation of pulmonary tuberculosis-one with chest x-ray features and one without-and we investigated each model's generalisability using internal-external cross-validation. The parameter coefficient estimates of the two models were scaled into two scoring systems to classify tuberculosis with a prespecified sensitivity target. The two scoring systems were used to develop two pragmatic, treatment-decision algorithms for use in primary health-care settings. FINDINGS: Of 4718 children from 13 studies from 12 countries, 1811 (38·4%) were classified as having pulmonary tuberculosis: 541 (29·9%) bacteriologically confirmed and 1270 (70·1%) unconfirmed. Existing treatment-decision algorithms had highly variable diagnostic performance. The scoring system derived from the prediction model that included clinical features and features from chest x-ray had a combined sensitivity of 0·86 [95% CI 0·68-0·94] and specificity of 0·37 [0·15-0·66] against a composite reference standard. The scoring system derived from the model that included only clinical features had a combined sensitivity of 0·84 [95% CI 0·66-0·93] and specificity of 0·30 [0·13-0·56] against a composite reference standard. The scoring system from each model was placed after triage steps, including assessment of illness acuity and risk of poor tuberculosis-related outcomes, to develop treatment-decision algorithms. INTERPRETATION: We adopted an evidence-based approach to develop pragmatic algorithms to guide tuberculosis treatment decisions in children, irrespective of the resources locally available. This approach will empower health workers in primary health-care settings with high tuberculosis incidence and limited resources to initiate tuberculosis treatment in children to improve access to care and reduce tuberculosis-related mortality. These algorithms have been included in the operational handbook accompanying the latest WHO guidelines on the management of tuberculosis in children and adolescents. Future prospective evaluation of algorithms, including those developed in this work, is necessary to investigate clinical performance. FUNDING: WHO, US National Institutes of Health.

Mortality and Cause of Death in Children With Presumptive Disseminated Tuberculosis.

BACKGROUND AND OBJECTIVES: Children experience high tuberculosis (TB)-related mortality but causes of death among those with presumptive TB are poorly documented. We describe the mortality, likely causes of death, and associated risk factors among vulnerable children admitted with presumptive TB in rural Uganda. METHODS: We conducted a prospective study of vulnerable children, defined as <2 years of age, HIV-positive, or severely malnourished, with a clinical suspicion of TB. Children were assessed for TB and followed for 24 weeks. TB classification and likely cause of death were assessed by an expert endpoint review committee, including insight gained from minimally invasive autopsies, when possible. RESULTS: Of the 219 children included, 157 (71.7%) were <2 years of age, 72 (32.9%) were HIV-positive, and 184 (84.0%) were severely malnourished. Seventy-one (32.4%) were classified as "likely tuberculosis" (15 confirmed and 56 unconfirmed), and 72 (32.9%) died. The median time to death was 12 days. The most frequent causes of death, ascertained for 59 children (81.9%), including 23 cases with autopsy results, were severe pneumonia excluding confirmed TB (23.7%), hypovolemic shock due to diarrhea (20.3%), cardiac failure (13.6%), severe sepsis (13.6%), and confirmed TB (10.2%). Mortality risk factors were confirmed TB (adjusted hazard ratio [aHR] = 2.84 [95% confidence interval (CI): 1.19-6.77]), being HIV-positive (aHR = 2.45 [95% CI: 1.37-4.38]), and severe clinical state on admission (aHR = 2.45 [95% CI: 1.29-4.66]). CONCLUSIONS: Vulnerable children hospitalized with presumptive TB experienced high mortality. A better understanding of the likely causes of death in this group is important to guide empirical management.

Population Pharmacokinetics and Significant Under-Dosing of Anti-Tuberculosis Medications in People with HIV and Critical Illness.

Critical illness from tuberculosis (TB) bloodstream infection results in a high case fatality rate for people living with human immunodeficiency virus (HIV). Critical illness can lead to altered pharmacokinetics and suboptimal drug exposures. We enrolled adults living with HIV and hospitalized with sepsis, with and without meningitis, in Mbarara, Uganda that were starting first-line anti-TB therapy. Serum was collected two weeks after enrollment at 1-, 2-, 4-, and 6-h post-dose and drug concentrations quantified by validated LC-MS/MS methods. Non-compartmental analyses were used to determine total drug exposure, and population pharmacokinetic modeling and simulations were performed to determine optimal dosages. Eighty-one participants were enrolled. Forty-nine completed pharmacokinetic testing: 18 (22%) died prior to testing, 13 (16%) were lost to follow-up and one had incomplete testing. Isoniazid had the lowest serum attainment, with only 4.1% achieving a target exposure over 24 h (AUC0-24) of 52 mg·h/L despite appropriate weight-based dosing. Simulations to reach target AUC0-24 found necessary doses of rifampin of 1800 mg, pyrazinamide of 2500-3000 mg, and for isoniazid 900 mg or higher. Given the high case fatality ratio of TB-related critical illness in this population, an early higher dose anti-TB therapy should be trialed.

Surveillance of Plasmodium falciparum pfcrt haplotypes in southwestern uganda by high-resolution melt analysis.

BACKGROUND: Chloroquine (CQ) resistance is conferred by mutations in the Plasmodium falciparum CQ resistance transporter (pfcrt). Following CQ withdrawal for anti-malarial treatment, studies across malaria-endemic countries have shown a range of responses. In some areas, CQ sensitive parasites re-emerge, and in others, mutant haplotypes persist. Active surveillance of resistance mutations in clinical parasites is essential to inform treatment regimens; this effort requires fast, reliable, and cost-effective methods that work on a variety of sample types with reagents accessible in malaria-endemic countries. METHODS: Quantitative PCR followed by High-Resolution Melt (HRM) analysis was performed in a field setting to assess pfcrt mutations in two groups of clinical samples from Southwestern Uganda. Group 1 samples (119 in total) were collected in 2010 as predominantly Giemsa-stained slides; Group 2 samples (125 in total) were collected in 2015 as blood spots on filter paper. The Rotor-Gene Q instrument was utilized to assess the impact of different PCR-HRM reagent mixes and the detection of mixed haplotypes present in the clinical samples. Finally, the prevalence of the wild type (CVMNK) and resistant pfcrt haplotypes (CVIET and SVMNT) was evaluated in this understudied Southwestern region of Uganda. RESULTS: The sample source (i.e. Giemsa-stained slides or blood spots) and type of LCGreen-based reagent mixes did not impact the success of PCR-HRM. The detection limit of 10- 5 ng and the ability to identify mixed haplotypes as low as 10 % was similar to other HRM platforms. The CVIET haplotype predominated in the clinical samples (66 %, 162/244); however, there was a large regional variation between the sample groups (94 % CVIET in Group 1 and 44 % CVIET in Group 2). CONCLUSIONS: The HRM-based method exhibits the flexibility required to conduct reliable assessment of resistance alleles from various sample types generated during the clinical management of malaria. Large regional variations in CQ resistance haplotypes across Southwestern Uganda emphasizes the need for continued local parasite genotype assessment to inform anti-malarial treatment policies.

Prevalence, associated factors and clinical features of congenital syphilis among newborns in Mbarara hospital, Uganda.

BACKGROUND: While congenital syphilis is a significant public health problem that can cause severe disabilities, little is known about the situation in Uganda. We describe prevalence, associated factors and clinical presentation of congenital syphilis in Mbarara, Uganda. METHODS: A cross sectional study was carried out among mother- newborn dyads from the postnatal ward of Mbarara Regional Referral Hospital (MRRH). After obtaining informed consent, a structured questionnaire was used to capture data on risk factors for congenital syphilis. A finger prick was performed on the mothers for Treponema Pallidum Haemagglutination Assay (TPHA). If TPHA was positive, a venous blood sample was collected from the mother to confirm active infection using Rapid Plasma Reagin (RPR). Venous blood was drawn from a newborn if the mother tested positive by TPHA and RPR. A newborn with RPR titres 4 times higher than the mother was considered to have congenital syphilis. We fit logistic regression models to determine factors associated with congenital syphilis. RESULTS: Between June and September 2015, we enrolled 2500 mothers and 2502 newborns. Prevalence of syphilis was 3.8% (95% CI 3.1-4.6) among newborn infants and 4.1% (95% CI 3.4-5.0) among their mothers. Maternal age <25 years, past history of genital ulcer, a past history of abnormal vaginal discharge, and not receiving treatment of at least one of genital ulcer, genital itching, lower abdominal pain and abnormal vaginal discharge in the current pregnancy were the risk factors associated with congenital syphilis. The most common clinical feature was hepatosplenomegaly. CONCLUSIONS: We found higher-than-expected syphilis sero-prevalence rates in a high risk population of postnatal mothers and their newborns in Uganda. Bridge populations for syphilis may include mothers not tested during pregnancy, who are usually married and not treated. In accordance with our results, the national policy for syphilis control in Uganda should be strengthened to include universal syphilis screening amongst mother-newborn pairs in postnatal clinics with subsequent partner notification.

Clinical Conditions of Hospitalized Older Adult Patients and Their Outcomes in a Regional Referral Hospital in Southwestern Uganda.

BACKGROUND: Recent advances in medicine have caused positive impact on the life expectancy of most countries, resulting in increased older adult population. Aging comes with a number of health challenges. This study investigated health conditions of older adults at admission and clinical outcomes in a regional referral hospital in southwestern Uganda. METHODS: A retrospective study reviewed clinical data of older adult patients admitted between January 2016 and December 2017. Demographic data, cause of admission, length, and outcomes of hospitalization are described. RESULTS: Up to 813 patient files were reviewed. The patients had been hospitalized to emergency, 371 (45.6%); medical, 355 (43.7%); surgical, 84 (10.3%); psychiatry, 2 (0.3%); and obstetrics and gynecology, 1 (0.1%) wards. The majority, 427 (52.5%), of the patients were females. Cancer was the most common reason for hospitalization, 130/889 (14.6%), followed by stroke, 94/889 (10.6%); heart failure, 76/889 (8.6%); chronic obstructive pulmonary disease, 56/889 (6.3%); pneumonia, 47/889 (5.3%); and head injury, 45/889 (5.1%), whilst 560 (68.9%) of the hospitalized patients were discharged, 197 (24.2%) died, 18 (2.2%) were referred for advanced care, and 38 (4.7%) escaped from the facility. The emergency ward had the highest deaths, 101 (51.3%), then medical, 56 (28.4%), and surgical, 39 (19.8%), wards. Mortality of those who died was admitted with stroke, 30 (15.2%), cancer, 21 (10.7%), head injury, 16 (8.1%), heart failure, 14 (7.1%), sepsis, 14 (7.1%), and renal disease, 12 (6.1%). On average, patients were admitted for 5 days (IQR: 3-8). CONCLUSIONS: The high proportion of mortality in this group is worrying and requires further investigations.

Effect of high-dose rifampicin on efavirenz pharmacokinetics: drug-drug interaction randomized trial.

BACKGROUND: High-dose rifampicin is considered to shorten anti-TB treatment duration but its effect on antiretroviral metabolism is unknown. OBJECTIVES: To assess the effect of doubling the rifampicin dose (to 20 mg/kg/day, R20) on efavirenz pharmacokinetics (PK) in HIV/TB coinfected patients. METHODS: Open-label Phase 2 drug-drug interaction randomized trial. Pulmonary TB, ART-naive adults were randomized to R20 and either efavirenz 600 mg (EFV600) or 800 mg (EFV800), or rifampicin 10 mg/kg/day (R10) and EFV600 with a 1:1:1 ratio. Patients were first started on TB treatment and 2-4 weeks later started on ART. They were switched to R10 and EFV600 after 8 weeks. Full PK sampling was done 4 weeks (on rifampicin) and 24 weeks (off rifampicin) after ART initiation. Transaminases, plasma HIV-1 RNA and sputum cultures were monitored. The efavirenz geometric mean ratio (GMR) of AUC at 4 and 24 weeks after ART initiation within the same patient was calculated in each arm and its 90% CI was compared with a preset range (0.70-1.43). RESULTS: Of 98 enrolled patients (32 in the R20EFV600 arm, 33 in the R20EFV800 arm and 33 in the R10EFV600 arm), 87 had full PK sampling. For the R20EFV600, R20EFV800 and R10EFV600 arms, GMRs of efavirenz AUC were 0.87 (90% CI: 0.75-1.00), 1.12 (90% CI: 0.96-1.30) and 0.96 (90% CI: 0.84-1.10). Twelve weeks after ART initiation, 78.6%, 77.4% and 72.4% of patients had HIV-1 RNA below 100 copies/mL and 85.7%, 86.7% and 80.0% had Week 8 culture conversion, respectively. Two patients per arm experienced a severe increase in transaminases. CONCLUSIONS: Doubling the rifampicin dose had a small effect on efavirenz concentrations and was well tolerated.

Evaluation of OMNIgene Sputum and Ethanol Reagent for Preservation of Sputum Prior to Xpert and Culture Testing in Uganda.

Xpert MTB/RIF (Xpert) and culture are the most reliable methods for tuberculosis diagnosis but are still poorly accessible in many low-resource countries. We aimed to assess the effects of OMNIgene Sputum (OM-S) and ethanol in preserving sputum for Xpert and OM-S for mycobacterial growth indicator tube (MGIT) testing over periods of 15 and 8 days, respectively. Sputum samples were collected from newly diagnosed smear-positive patients. For Xpert, pooled samples were split into 5 aliquots: 3 for Xpert on days 0, 7, and 15 without additive and 2 with either OM-S or ethanol at day 15. For MGIT, 2 aliquots were tested without preservative and 2 with OM-S at 0 and 8 days. Totals of 48 and 47 samples were included in the analysis for Xpert and culture. With Xpert, using day 0 as a reference, untreated samples stored for 7 and 15 days showed concordances of 45/46 (97.8%) and 46/48 (95.8%). For samples preserved with OM-S or ethanol for 15 days compared with untreated samples processed at day 0 or after 15 days, OM-S concordances were 46/48 (95.8%) and 47/48 (97.9%), while those of ethanol were 44/48 (91.7%) and 45/48 (93.8%). With MGIT, concordances between untreated and OM-S-treated samples were 21/41 (51.2%) at day 0 and 21/44 (47.7%) at day 8. In conclusion, Xpert equally detected tuberculosis in OM-S-treated and untreated samples up to 15 days but showed slightly lower detection in ethanol-treated samples. Among OM-S-treated samples, MGIT positivity was significantly lower than in untreated samples at both time points.

Further evidence of Mycobacterium tuberculosis in the sputum of culture-negative pulmonary tuberculosis suspects using an ultrasensitive molecular assay.

BACKGROUND: Rapid diagnosis of pulmonary tuberculosis (TB) is critical to TB control. However, many patients with paucibacillary TB disease remain undiagnosed. Current TB elimination goals require new tools to diagnose early disease. We evaluated performance of the Totally Optimized PCR (TOP) TB assay, a novel ultrasensitive molecular test. METHODS: We assessed analytical specificity against nontuberculous mycobacteria (NTM), and estimated the diagnostic accuracy of TOP in a pilot study in Brazil (n = 46) and a cross-sectional study in Boston (n = 60). We compared TOP results to culture and a composite reference standard (CRS). RESULTS: TOP exhibited no cross-reactivity against NTM. We tested 132 respiratory specimens from 106 patients with suspected pulmonary TB. The pilot demonstrated feasibility and 100% (95% CI 85-100) sensitivity in predominantly smear-positive specimens; TOP's specificity against solid media culture was low (58%, 37-77) but improved against a CRS (93%, 68-100). Similarly, when using the CRS in the Boston study, TOP (88%, 1-99) had greater sensitivity than solid or liquid media culture (25%, 3-65) and similar specificity (both 100%, 93-100). CONCLUSIONS: The TOP assay enables detection of M. tuberculosis in culture-negative paucibacillary disease. While the use of TOP for the diagnosis of paucibacillary disease will require further clinical validation, its high sensitivity indicate a more immediate utility as a rule out TB test.

Xpert MTB/RIF diagnosis of childhood tuberculosis from sputum and stool samples in a high TB-HIV-prevalent setting.

The Xpert MTB/RIF assay is a major advance for diagnosis of tuberculosis (TB) in high-burden countries but is limited in children by their difficulty to produce sputum. We investigated TB in sputum and stool from children with the aim of improving paediatric TB diagnosis. A prospective cohort of children with presumptive TB, provided two sputum or induced sputum at enrolment in a regional referral hospital in Uganda. Stool was collected from those started on TB treatment. All specimen were tested for Xpert MTB/RIF, mycobacteria growth indicator tube (MGIT), Lowenstein Jensen cultures and microscopy (except stool). We compared TB detection between age categories and assessed the performance of Xpert MTB/RIF in sputum and stool. Of the 392 children enrolled, 357 (91.1%) produced at least one sputum sample. Sputum culture yield was 13/357 (3.6%): 3/109 (2.6%), 3/89 (3.2%), 3/101 (2.6%) and 4/44 (8.2%) among children of < 2, 2-5, ≥ 5-10 and > 10 years, respectively (p = 0.599). Xpert MTB/RIF yield was 14/350 (4.0%): 3/104 (2.9%), 4/92 (4.3%), 3/88 (2.9%) and 4/50 (.0%), respectively (p = 0.283). Sensitivity and specificity of Xpert MTB/RIF in sputum against sputum culture were 90.9% (95% CI 58.7-99.8) and 99.1% (99.1-99.8). In stool, it was 55.6% (21.2-86.3) and 98.2% (98.2-100) against Xpert MTB/RIF and culture in sputum. Only a minority of children had microbiologically confirmed TB with a higher proportion in children above 10 years. Although sensitivity of Xpert MTB/RIF in stool was low, with good optimization, it might be a good alternative to sputum in children.

Outcome of Children With Presumptive Tuberculosis in Mbarara, Rural Uganda.

BACKGROUND: Mortality among children with presumptive tuberculosis (TB) empiric TB treatment can be high. We describe the predictors of death among children with presumptive TB, and the relation between treatment and mortality. METHODS: A prospective cohort of children with presumptive TB who underwent clinical assessment, chest radiograph, tuberculin skin test and sputum bacterial tests for TB was followed up for 3 months. TB diagnosis was based on mycobacterial, clinical and radiologic findings. Predictors of deaths were determined using cox regression model. RESULTS: Of 360 children included in the analysis, 31.4% were younger than 2 years; 31.6% were HIV infected and 11.3% were severely malnourished. One hundred forty (38.9%) were diagnosed with TB, 18 (13%) of whom were bacteriologically confirmed. At 3 months of follow up, 25 of 360 (6.9%) children had died: 15 of 140 (10.7%) were receiving TB treatment versus 10 of 220 (4.5%) were not receiving treatment (P = 0.025). Severely malnourished children [adjusted hazard ratio (aHR), 9.86; 95% confidence interval (CI): 3.11-31.23] and those with chest radiographs suggestive of TB (aHR, 4.20; 95% CI: 0.93-19.01) were more likely to die. Children receiving empiric TB treatment had an increased risk of death (aHR, 2.37; 95% CI: 1.01-5.55) compared with children without treatment after adjustment for age, sex, HIV status and Bacillus Calmette-Guérin (BCG) vaccination. CONCLUSIONS: The high mortality in children receiving empirically TB treatment highlights the difficulty in diagnosing childhood TB, the increased likelihood of starting treatment in critically ill children and in children with chronic disease, and the possibility of misdiagnosis. It strengthens the need to invest further in early TB detection and diagnosing nonsevere illness.

Detection of Plasmodium Species by High-Resolution Melt Analysis of DNA from Blood Smears Acquired in Southwestern Uganda.

Microscopic diagnosis of malaria using Giemsa-stained blood smears is the standard of care in resource-limited settings. These smears represent a potential source of DNA for PCR testing to confirm Plasmodium infections or for epidemiological studies of archived samples. Therefore, we assessed the use of DNA extracts from stained blood smears for the detection of Plasmodium species using real-time PCR. We extracted DNA from archived blood smears and corresponding red blood cell pellets collected from asymptomatic children in southwestern Uganda in 2010. We then performed real-time PCR followed by high-resolution melting (HRM) to identify Plasmodium species, and we compared our results to those of microscopy. We analyzed a total of 367 blood smears and corresponding red blood cell pellets, including 185 smears (50.4%) that were positive by microscopy. Compared to microscopy, PCR-HRM analysis of smear DNA had a sensitivity of 93.0% (95% confidence interval [CI], 88.2 to 96.2%) and a specificity of 96.7% (95% CI, 93.0 to 98.8%), and PCR-HRM analysis of pellet DNA had a sensitivity of 100.0% (95% CI, 98.0 to 100.0%) and a specificity of 94.0% (95% CI, 89.4 to 96.9%). Identification of positive PCR-HRM results to the species level revealed Plasmodium falciparum (92.0%), Plasmodium ovale (5.6%), and Plasmodium malariae (2.4%). PCR-HRM analysis of DNA extracts from Giemsa-stained thick blood smears or corresponding blood pellets had high sensitivity and specificity for malaria diagnosis, compared to microscopy. Therefore, blood smears can provide an adequate source of DNA for confirmation of Plasmodium species infections and can be used for retrospective genetic studies.

Evaluation of the Deki Reader™, an automated RDT reader and data management device, in a household survey setting in low malaria endemic southwestern Uganda.

BACKGROUND: Early diagnosis of suspected malaria cases with a rapid diagnostic test (RDT) has been shown to be an effective malaria control tool used in many resource-constrained settings. However, poor quality control and quality assurance hinder the accurate reporting of malaria diagnoses. Recent use of a portable, battery operated RDT reader (Deki Reader™, Fio Corporation) has shown to have high agreement with visual inspection across diverse health centre settings, however evidence of its feasibility and usability during cross sectional surveys are limited. This study aimed to evaluate the performance of the Deki Reader™ in a cross-sectional survey of children from southwestern Uganda. METHODS: A two-stage, stratified cluster sampling survey was conducted between July and October 2014 in three districts of southwestern Uganda, with varying malaria transmission intensities. A total of 566 children aged 6-59 months were included in the analysis. Blood samples were collected and tested for malaria using: the SD Bioline Malaria Ag Pf/Pan RDT and microscopy. Results were compared between visual inspection of the RDT and by the Deki Reader™. Diagnostic performance of both methods were compared to gold-standard microscopy. RESULTS: The sensitivity and specificity of the Deki Reader™ was 94.1% (95% CI 69.2-99.6%) and 95.6% (95% CI 93.4-97.1%), respectively. The overall percent agreement between the Deki Reader™ and visual RDT inspection was 98.9% (95% CI 93.2-99.8), with kappa statistic of 0.92 (95% CI 0.85-0.98). CONCLUSIONS: The findings from this study suggest that the Deki Reader™ is comparable to visual inspection and performs well in detecting microscopy-positive Plasmodium falciparum cases in a household survey setting. However, the reader's performance was highly dependent on ensuring adequate battery life and a work environment free of dirt particles.

Prevalence of antibodies to Brucella species in commercial raw bovine milk in Southwestern Uganda.

OBJECTIVES: The purpose and objective of this research was to explore the prevalence of antibodies against Brucella species in raw milk samples collected in Southwestern Uganda, one of the biggest milk producing regions in the Country. We hypothesized that there is a high level of antibodies in milk samples from this region. This builds more evidence to other studies in the region on the level contamination of raw milk. RESULTS: A total of 185 raw milk samples, collected from dairy farms and factories in southwestern region, were tested for antibodies to Brucella spp. using the milk ring test (MRT) and indirect Enzyme-Linked Immunosorbent Assay (i-ELISA).We found a prevalence of 26.5% (49/185) by the two methods. This is related to previous reports in the region and adds more evidence on the need for further investigations to confirm the source of these antibodies and their relationship with disease in milk producing animals.

Evaluation of the SD Bioline TB Ag MPT64 test for identification of Mycobacterium tuberculosis complex from liquid cultures in Southwestern Uganda.

BACKGROUND: To confirm presence of Mycobacterium tuberculosis complex, some tuberculosis culture laboratories still rely on para-nitrobenzoic acid (PNB), a traditional technique that requires sub-culturing of clinical isolates and two to three weeks to give results. Rapid identification tests have improved turnaround times for mycobacterial culture results. Considering the challenges of the PNB method, we assessed the performance of the SD Bioline TB Ag MPT64 assay by using PNB as gold standard to detect M. tuberculosis complex from acid-fast bacilli (AFB) positive cultures. OBJECTIVES: The aim of this study was to determine the sensitivity, specificity and turnaround time of the SD MPT64 assay for identification of M. tuberculosis complex, in a setting with high prevalence of tuberculosis and HIV. METHODS: A convenience sample of 690 patients, with tuberculosis symptoms, was enrolled at Epicentre Mbarara Research Centre between April 2010 and June 2011. The samples were decontaminated using NALC-NaOH and re-suspended sediments inoculated in Mycobacterium Growth Indicator Tubes (MGIT) media, then incubated at 37 °C for a maximum of eight weeks. A random sample of 50 known negative cultures and 50 non-tuberculous mycobacteria isolates were tested for specificity, while sensitivity was based on AFB positivity. The time required from positive culture to reporting of results was also assessed with PNB used as the gold standard. RESULTS: Of the 138 cultures that were AFB-positive, the sensitivity of the SD MPT64 assay was 100.0% [95% CI: 97.3 - 100] and specificity was 100.0% (95% CI, 96.4 - 100). The median time from a specimen receipt to confirmation of strain was 10 days [IQR: 8-12] with SD MPT64 and 24 days [IQR: 22-26] with PNB. CONCLUSION: The SD MPT64 assay is comparable to PNB for identification of M. tuberculosis complex and reduces the time to detection.

Predictors of delayed culture conversion among Ugandan patients.

BACKGROUND: Estimates of month-2 culture conversion, a proxy indicator of tuberculosis (TB) treatment efficacy in phase-2 trials can vary by culture-type and geographically with lower rates reported among African sites. The sub-study aimed at comparing TB detection rates of different culture media, within and across rifampicin-based regimens (R10, 15 and 20 mg/Kg) over a 6-month treatment follow-up period, and to establish predictors of month-2 culture non-conversion among HIV-negative TB patients enrolled at RIFATOX trial site in Uganda. METHODS: Unlike in other Rifatox Trial sites, it is only in Uganda were Lowenstein-Jensen (LJ) and Mycobacteria growth indicator tube (MGIT) were used throughout 6-months for treatment monitoring. Conversion rates were compared at month-2, 4 and 6 across cultures and treatment-type. Binomial regression analysis performed for predictors of month-2 non-conversion. RESULTS: Of the 100 enrolled patients, 45% had converted based on combined LJ and MGIT by month-2, with no significant differences across treatment arms, p = 0.721. LJ exhibited higher conversion rates than MGIT at month-2 (58.4% vs 56.0%, p = 0.0707) and month-4 (98.9% vs 88.4%, p = 0.0391) respectively, more so within the high-dose rifampicin arms. All patients had converted by month-6. Time-to-TB detection (TTD) on MGIT and social service jobs independently predict month-2 non-conversion. CONCLUSION: The month-2 culture conversion used in phase 2 clinical trials as surrogate marker of treatment efficacy is influenced by the culture method used for monitoring mycobacterial response to TB treatment. Therefore, multi-centric TB therapeutic trials using early efficacy endpoint should use the same culture method across sites. The Time-to-detection of MTB on MGIT prior to treatment and working in Social service jobs bear an increased risk of culture non-conversion at month-2. TRIAL REGISTRATION: ISRCTN ISRCTN55670677 . Registered 09th November 2010. Retrospectively registered.

Assessment of three medical and research laboratories using WHO AFRO_SLIPTA Quality Standards in Southwestern Uganda: a long way to go.

INTRODUCTION: While the laboratory represents more than 70% of clinical diagnosis and patient management, access to reliable and quality laboratory diagnostics in sub-Saharan Africa remains a challenge. To gain knowledge and suggest evidence based interventions towards laboratory improvement in Southwestern Uganda, we assessed the baseline laboratory quality standards in three medical and research laboratories in Southwestern Uganda. METHODS: We conducted a cross sectional survey from October, 2013 to April, 2014. Selected laboratories, including one private research, one private for profit and one public laboratory, were assessed using the WHO AFRO_SLIPTA checklist and baseline scores were determined. RESULTS: The three laboratories assessed met basic facility requirements, had trained personnel, and safety measures in place. Sample reception was properly designed and executed with a well designated chain of custody. All laboratories had sufficient equipment for the nature of work they were involved in. However, we found that standard operating procedures were incomplete in all three laboratories, lack of quality audit schemes by two laboratories and only one laboratory enrolled into external quality assurance schemes. The SLIPTA scores were one star for the research laboratory and no star for both the public and private-for-profit laboratories. CONCLUSION: While most of the laboratory systems were in place, the low scores obtained by the assessed laboratories reflect the need for improvement to reach standards of quality assured diagnostics in the region. Therefore, routine mentorship and regional supportive supervision are necessary to increase the quality of laboratory services.

Screening for Glucose-6-Phosphate Dehydrogenase Deficiency Using Three Detection Methods: A Cross-Sectional Survey in Southwestern Uganda.

Despite the potential benefit of primaquine in reducing Plasmodium falciparum transmission and radical cure of Plasmodium vivax and Plasmodium ovale infections, concerns over risk of hemolytic toxicity in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd) have hampered its deployment. A cross-sectional survey was conducted in 2014 to assess the G6PDd prevalence among 631 children between 6 and 59 months of age in southwestern Uganda, an area where primaquine may be a promising control measure. G6PDd prevalence was determined using three detection methods: a quantitative G6PD enzyme activity assay (Trinity Biotech® G-6-PDH kit), a qualitative point-of-care test (CareStart™ G6PD rapid diagnostic test [RDT]), and molecular detection of the G6PD A- G202A allele. Qualitative tests were compared with the gold standard quantitative assay. G6PDd prevalence was higher by RDT (8.6%) than by quantitative assay (6.8%), using a < 60% activity threshold. The RDT performed optimally at a < 60% threshold and demonstrated high sensitivity (≥ 90%) and negative predictive values (100%) across three activity thresholds (below 60%, 30%, and 40%). G202A allele frequency was 6.4%, 7.9%, and 6.8% among females, males, and overall, respectively. Notably, over half of the G202A homo-/hemizygous children expressed ≥ 60% enzyme activity. Overall, the CareStart™ G6PD RDT appears to be a viable screening test to accurately identify individuals with enzyme activities below 60%. The low prevalence of G6PDd across all three diagnostic modalities and absence of severe deficiency in our study suggests that there is little barrier to the use of single-dose primaquine in this region.