Systematic review of wastewater surveillance of antimicrobial resistance in human populations.

OBJECTIVES: We systematically reviewed studies using wastewater for AMR surveillance in human populations, to determine: (i) evidence of concordance between wastewater-human AMR prevalence estimates, and (ii) methodological approaches which optimised identifying such an association, and which could be recommended as standard. We used Lin's concordance correlation coefficient (CCC) to quantify concordance between AMR prevalence estimates in wastewater and human compartments (where CCC = 1 reflects perfect concordance), and logistic regression to identify study features (e.g. sampling methods) associated with high agreement studies (defined as >70% of within-study wastewater-human AMR prevalence comparisons within ±10%). RESULTS: Of 8,867 records and 441 full-text methods reviewed, 33 studies were included. AMR prevalence data was extractable from 24 studies conducting phenotypic-only (n = 7), genotypic-only (n = 1) or combined (n = 16) AMR detection. Overall concordance of wastewater-human AMR prevalence estimates was reasonably high for both phenotypic (CCC = 0.85 [95% CI 0.8-0.89]) and genotypic approaches (CCC = 0.88 (95% CI 0.84-0.9)) despite diverse study designs, bacterial species investigated and phenotypic/genotypic targets. No significant relationships between methodological approaches and high agreement studies were identified using logistic regression; however, this was limited by inconsistent reporting of study features, significant heterogeneity in approaches and limited sample size. Based on a secondary, descriptive synthesis, studies conducting composite sampling of wastewater influent, longitudinal sampling >12 months, and time-/location-matched sampling of wastewater and human compartments generally had higher agreement. CONCLUSION: Wastewater-based surveillance of AMR appears promising, with high overall concordance between wastewater and human AMR prevalence estimates in studies irrespective of heterogenous approaches. However, our review suggests future work would benefit from: time-/location-matched sampling of wastewater and human populations, composite sampling of influent, and sampling >12 months for longitudinal studies. Further research and clear and consistent reporting of study methods is required to identify optimal practice.

The costs and outcomes of paediatric tuberculosis treatment at primary healthcare clinics in Johannesburg, South Africa.

BACKGROUND: Little up-to-date information is available about the costs of providing drug-susceptible tuberculosis (DS-TB) treatment to paediatric patients in South Africa (SA), nor have actual costs incurred at clinics been compared with costs expected from guidelines. OBJECTIVES: To estimate actual and guideline treatment costs by means of a retrospective cohort analysis. METHODS: We report patient characteristics, outcomes and treatment costs from a retrospective cohort of paediatric and adolescent (<18 years) DS-TB patients registered for treatment from 1 April 2011 to 31 March 2013 at three primary healthcare clinics in Johannesburg, SA. Actual treatment costs in 2015 SA rands and US dollars were estimated from the provider perspective using a standard bottom-up microcosting approach and compared with an estimate of guideline costs. RESULTS: We enrolled 88 DS-TB patients (median age 4 years (interquartile range 1.0 - 9.5), 44.3% female, 22.7% HIV co-infected, 92.0% pulmonary TB). Treatment success was high (89.8%; 13.6% cured, 76.1% completed treatment), and the mean (standard deviation (SD)) cost per patient with treatment success was ZAR1 820/USD143 (ZAR593/USD46), comprising fixed costs (44.0%), outpatient visits (30.7%), medication (19.3%) and laboratory investigations (6.0%). This was 17% more than the mean (SD) cost estimated by applying treatment guidelines (ZAR1 553/USD122 (ZAR1 620/USD127)), with differences due mainly to higher laboratory costs and more outpatient visits taking place than were recommended in national guidelines. CONCLUSIONS: These results are the first reported estimates of paediatric DS-TB treatment costs in SA and show the potential cost savings of closer adherence to national treatment guidelines. The findings were robust in sensitivity analyses and are lower than previous cost estimates in adults.

Outcomes of treatment of drug-susceptible tuberculosis at public sector primary healthcare clinics in Johannesburg, South Africa: A retrospective cohort study.

BACKGROUND: Despite the large number of tuberculosis (TB) patients treated in South Africa (SA), there are few descriptions in the published literature of drug-susceptible TB patient characteristics, mode of diagnosis or treatment outcomes in routine public sector treatment programmes. OBJECTIVE: To enhance the evidence base for public sector TB treatment service delivery, we reported the characteristics of and outcomes for a retrospective cohort of adult TB patients at public sector clinics in the Johannesburg Metropolitan Municipality (JHB), SA. METHODS: We collected medical record data for a retrospective cohort of adult (≥18 years) TB patients registered between 1 April 2011 and 31 March 2012 at three public sector clinics in JHB. Data were abstracted from National TB Programme clinic cards and the TB case registers routinely maintained at study sites. We report patient characteristics, mode of diagnosis, mode of treatment supervision, treatment characteristics, HIV status and treatment outcomes for this cohort. RESULTS: A total of 544 patients were enrolled in the cohort. Most (86%) were new TB cases, 81% had pulmonary TB, 58% were smear-positive at treatment initiation and 71% were HIV co-infected. Among 495 patients with treatment outcomes reported, 80% (n=394) had successful outcomes, 11% (n=55) were lost to follow-up, 8% (n=40) died and 1% (n=6) failed treatment. CONCLUSIONS: Primary healthcare clinics in JHB are achieving relatively high rates of success in treating drug-susceptible TB. Missing laboratory results were common, including follow-up smears, cultures and drug susceptibility tests, making it difficult to assess adherence to guidelines and leaving scope for substantial improvements in record-keeping at the clinics involved.