Dihydroartemisinin-piperaquine (DP) has demonstrated excellent efficacy for the treatment and prevention of malaria in Uganda. However, resistance to both components of this regimen has emerged in Southeast Asia. The efficacy of artemether-lumefantrine, the first-line regimen to treat malaria in Uganda, has also been excellent, but continued pressure may select for parasites with decreased sensitivity to lumefantrine. To gain insight into current drug sensitivity patterns, ex vivo sensitivities were assessed and genotypes previously associated with altered drug sensitivity were characterized for 58 isolates collected in Tororo, Uganda, from subjects presenting in 2016 with malaria from the community or as part of a clinical trial comparing DP chemoprevention regimens. Compared to community isolates, those from trial subjects had lower sensitivities to the aminoquinolines chloroquine, monodesethyl amodiaquine, and piperaquine and greater sensitivities to lumefantrine and mefloquine, an observation consistent with DP selection pressure. Compared to results for isolates from 2010 to 2013, the sensitivities of 2016 community isolates to chloroquine, amodiaquine, and piperaquine improved (geometric mean 50% inhibitory concentrations [IC 50 ] ϭ 248, 76.9, and 19.1 nM in 2010 to 2013 and 33.4, 14.9, and 7.5 nM in 2016, respectively [P Ͻ 0.001 for all comparisons]), the sensitivity to lumefantrine decreased (IC 50 ϭ 3.0 nM in 2010 to 2013 and 5.4 nM in 2016 [P Ͻ 0.001]), and the sensitivity to dihydroartemisinin was unchanged (IC 50 ϭ 1.4 nM). These changes were accompanied by decreased prevalence of transporter mutations associated with aminoquinoline resistance and low prevalence of polymorphisms recently associated with resistance to artemisinins or piperaquine. Antimalarial drug sensitivities are changing in Uganda, but novel genotypes associated with DP treatment failure in Asia are not prevalent.
Background Treatment and control of malaria depends on artemisinin-based combination therapies (ACTs) and is challenged by drug resistance, but thus far resistance to artemisinins and partner drugs has primarily occurred in southeast Asia. The aim of this study was to characterise antimalarial drug susceptibility of Plasmodium falciparum isolates from Tororo and Busia districts in Uganda.Methods In this prospective longitudinal study, P falciparum isolates were collected from patients aged 6 months or older presenting at the Tororo District Hospital (Tororo district, a site with relatively low malaria incidence) or Masafu General Hospital (Busia district, a high-incidence site) in eastern Uganda with clinical symptoms of malaria, a positive Giemsa-stained blood film for P falciparum, and no signs of severe disease. Ex-vivo susceptibilities to ten antimalarial drugs were measured using a 72-h microplate growth inhibition assay with SYBR Green detection. Relevant P falciparum genetic polymorphisms were characterised by molecular methods. We compared results with those from earlier studies in this region and searched for associations between drug susceptibility and parasite genotypes.
Artemisinin partial resistance may facilitate selection of Plasmodium falciparum resistant to combination therapy partner drugs. We evaluated 99 P. falciparum isolates collected in 2021 from northern Uganda, where resistance-associated PfK13 C469Y and A675V mutations have emerged, and eastern Uganda, where these mutations are uncommon. With the ex vivo ring survival assay, isolates with the 469Y mutation (median survival 7.3% for mutant, 2.5% mixed, and 1.4% wild type) and/or mutations in Pfcoronin or falcipain-2a, had significantly greater survival; all isolates with survival >5% had mutations in at least one of these proteins. With ex vivo growth inhibition assays, susceptibility to lumefantrine (median IC50 14.6 vs. 6.9 nM, p < 0.0001) and dihydroartemisinin (2.3 vs. 1.5 nM, p = 0.003) was decreased in northern vs. eastern Uganda; 14/49 northern vs. 0/38 eastern isolates had lumefantrine IC50 > 20 nM (p = 0.0002). Targeted sequencing of 819 isolates from 2015–21 identified multiple polymorphisms associated with altered drug susceptibility, notably PfK13 469Y with decreased susceptibility to lumefantrine (p = 6 × 10−8) and PfCRT mutations with chloroquine resistance (p = 1 × 10−20). Our results raise concern regarding activity of artemether-lumefantrine, the first-line antimalarial in Uganda.
Background Intensive adherence counseling (IAC) is an intervention recommended by the World Health Organization to improve anti-retroviral therapy (ART) adherence among people living with HIV on ART with unsuppressed viral load; and in 2016, the intervention was implemented in Uganda. This study evaluated the effect and experiences of providing IAC in an urban HIV care center in Kampala, Uganda. Methods This was a sequential explanatory mixed-method study that compared viral load suppression during IAC implementation (intervention) to the period before IAC at Kisenyi Health centre IV. Data were abstracted from patient files and viral load register. The effect of IAC on viral load suppression and associated factors were analyzed using modified Poisson regression with robust standard errors. Using in-depth interviews and an inductive analysis approach in Atlas-ti 8. We also explored experiences of providing IAC among healthcare workers. Results A total of 500 records were sampled: 249 (49.8%) in the intervention period and 251 (51.2%) in the pre-intervention period. The mean age was lower during the intervention period 33.1 (± 12.0) than 36.5 (± 13.4) in the pre- intervention period, p = 0.002. More clients were currently on Protease-based regimen in the pre-intervention period 179 (71.3%) than 135 (54.2%) in the intervention period, p ≤ 0.001. In the intervention period, all eligible clients received IAC [249/249 (100.0%)]. Overall, 325 (65.0%) received IAC and of these, 143 (44.1%) achieved viral load suppression compared to 46 (26.3%) who received regular counseling. Receiving IAC significantly increased viral load suppression by 22% (aPR 1.22, 95% CI 1.01–1.47). Clients on Protease-based regimen were less likely to suppress than those on Efavirenz or Nevirapine-based regimens (aPR 0.11, 95% CI 0.08–0.15). All the interviewed healthcare workers lauded IAC for improving ART adherence. However, patient and health care system related factors hindered adherence during IAC. Conclusions The full potential of IAC in achieving viral load suppression in this setting has not been reached due to a combination of the patient and health care system related factors. Provision of adequate IAC necessities and use of patient centered approach should be emphasized to obtain the maximum benefit of the intervention.
Blood culture (BC) processes are critical to the utility of diagnostic testing, bloodstream infection (BSI) management, and antimicrobial resistance (AMR) surveillance. While Uganda has established BC guidelines, often laboratory practice does not meet the desired standards. This compromises pathogen recovery, reliability of antimicrobial susceptibility testing, and diagnostic test utility. This study assessed laboratory BC process outcomes among non-malarial febrile children below five years of age at five AMR surveillance sites in Uganda between 2017 and 2018. Secondary BC testing data was reviewed against established standards. Overall, 959 BC specimens were processed. Of these, 91% were from female patients, neonates, infants, and young children (1–48 months). A total of 37 AMR priority pathogens were identified; Staphylococcus aureus was predominant (54%), followed by Escherichia coli (19%). The diagnostic yield was low (4.9%). Only 6.3% of isolates were identified. AST was performed on 70% (18/26) of identified AMR priority isolates, and only 40% of these tests adhered to recommended standards. Interventions are needed to improve laboratory BC practices for effective patient management through targeted antimicrobial therapy and AMR surveillance in Uganda. Further research on process documentation, diagnostic yield, and a review of patient outcomes for all hospitalized febrile patients is needed.
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