Wilber Sabiiti

Dr. Wilber Sabiiti

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
30 April 2020 in Thorax
Verified
Journal Article
Open access
PDF file
WSWilber Sabiiti
Wilber Sabiiti
KAKhalide Azam
Khalide Azam
EFEoghan Charles William Farmer
Eoghan Charles William Farmer
Davis KuchakaDavis Kuchaka
Davis Kuchaka
BMBariki Mtafya
Bariki Mtafya
SGStephen H Gillespie
Stephen H Gillespie
In this comparative biomarker study, we analysed 1768 serial sputum samples from 178 patients at 4 sites in Southeast Africa. We show that tuberculosis Molecular Bacterial Load Assay (TB-MBLA) reduces time-to-TB-bacillary-load-result from days/weeks by culture to hours and detects early patient treatment response. By day 14 of treatment, 5% of patients had cleared bacillary load to zero, rising to 58% by 12th week of treatment. Fall in bacillary load correlated with mycobacterial growth indicator tube culture time-to-positivity (Spearmans r=−0.51, 95% CI (−0.56 to −0.46), p<0.0001). Patients with high pretreatment bacillary burdens (above the cohort bacillary load average of 5.5log10eCFU/ml) were less likely to convert-to-negative by 8th week of treatment than those with a low burden (below cohort bacillary load average), p=0.0005, HR 3.1, 95% CI (1.6 to 5.6) irrespective of treatment regimen. TB-MBLA distinguished the bactericidal effect of regimens revealing the moxifloxacin—20 mg rifampicin regimen produced a shorter time to bacillary clearance compared with standard-of-care regimen, p=0.008, HR 2.9, 95% CI (1.3 to 6.7). Our data show that the TB-MBLA could inform clinical decision making in real-time and expedite drug TB clinical trials.

23 August 2021 in Antibiotics
Verified
Journal Article
Open access
PDF file
PNPendo M. Ndaki
Pendo M. Ndaki
Martha MushiMartha Mushi
Martha Mushi
JMJoseph R. Mwanga
Joseph R. Mwanga
EKEveline T. Konje
Eveline T. Konje
NNNyanda Elias Ntinginya
Nyanda Elias Ntinginya
HCHATUA Consortium
HATUA Consortium
Worldwide, antimicrobial resistance is increasing rapidly and is associated with misuse of antimicrobials. The HATUA study (a broader 3-country study) investigated the antibiotic dispensing practices of pharmaceutical providers to clients, particularly the propensity to dispense without prescription. A cross-sectional study using a ‘mystery client’ method was conducted in 1148 community pharmacies and accredited drugs dispensing outlets (ADDO) in Mwanza (n = 612), Mbeya (n = 304) and Kilimanjaro (n = 232) in Tanzania. Mystery clients asked directly for amoxicillin, had no prescription to present, did not discuss symptoms unless asked [when asked reported UTI-like symptoms] and attempted to buy a half course. Dispensing of amoxicillin without prescription was common [88.2, 95%CI 86.3–89.9%], across all three regions. Furthermore, the majority of outlets sold a half course of amoxicillin without prescription: Mwanza (98%), Mbeya (99%) and Kilimanjaro (98%). Generally, most providers in all three regions dispensed amoxicillin on demand, without asking the client any questions, with significant variations among regions [p-value = 0.003]. In Mbeya and Kilimanjaro, providers in ADDOs were more likely to do this than those in pharmacies but no difference was observed in Mwanza. While the Tanzanian government has laws, regulations and guidelines that prohibit antibiotic dispensing without prescription, our study suggests non-compliance by drug providers. Enforcement, surveillance, and the provision of continuing education on dispensing practices is recommended, particularly for ADDO providers.

5 March 2024 in The Lancet Microbe
Verified
Journal Article
Open access
EMEmmanuel Musisi
Emmanuel Musisi
SWSamuel Wamutu
Samuel Wamutu
WSWilly Ssengooba
Willy Ssengooba
SKSharifah Kasiinga
Sharifah Kasiinga
ASAbdulwahab Sessolo
Abdulwahab Sessolo
WSWilber Sabiiti
Wilber Sabiiti
In 2018, the tuberculosis molecular bacterial load assay (TB-MBLA), a ribosomal RNA-based test, was acknowledged by WHO as a molecular assay that could replace smear microscopy and culture for monitoring tuberculosis treatment response. In this study, we evaluated the accuracy of TB-MBLA for diagnosis and monitoring of treatment response in comparison with standard-of-care tests. For this longitudinal prospective study, patients aged 18 years or older with presumptive tuberculosis (coughing for at least 2 weeks, night sweats, and weight loss) were enrolled at China-Uganda Friendship Hospital Naguru (Kampala, Uganda). Participants were evaluated for tuberculosis by TB-MBLA in comparison with Xpert MTB/RIF Ultra (Xpert-Ultra) and smear microscopy, with Mycobacteria Growth Indicator Tube (MGIT) culture as a reference test. Participants who were positive on Xpert-Ultra were enrolled on a standard 6-month anti-tuberculosis regimen, and monitored for treatment response at weeks 2, 8, 17, and 26 after initiation of treatment and then 3 months after treatment. Between Nov 15, 2019, and June 15, 2022, 210 participants (median age 35 years [IQR 27-44]) were enrolled. 135 (64%) participants were male and 72 (34%) were HIV positive. The pretreatment diagnostic sensitivities of TB-MBLA and Xpert-Ultra were similar (both 99% [95% CI 95-100]) but the specificity was higher for TB-MBLA (90% [83-96]) than for Xpert-Ultra (78% [68-86]). Ten participants were Xpert-Ultra trace positive, eight (80%) of whom were negative by TB-MBLA and MGIT culture. Smear microscopy had lower diagnostic sensitivity (75% [65-83]) but higher specificity (98% [93-100]) than TB-MBLA and Xpert-Ultra. Among participants who were smear microscopy negative, the sensitivity of TB-MBLA was 96% (95 CI 80-100) and was 100% (95% CI 86-100) in those who were HIV positive. 129 (61%) participants were identified as tuberculosis positive by Xpert-Ultra and these individuals were enrolled in the treatment group and monitored for treatment response. According to TB-MBLA, 19 of these patients cleared bacillary load to zero by week 2 of treatment and remained negative throughout the 6-month treatment follow-up. Positivity for tuberculosis decreased with treatment as measured by all tests, but the rate was slower with Xpert-Ultra. Consequently, 31 (33%) of 95 participants were still Xpert-Ultra positive at the end of treatment but were clinically well and negative on TB-MBLA and culture at 6 months of treatment. Two patients were still Xpert-Ultra positive with a further 3 months of post-treatment follow-up. The rate of conversion to negative of the DNA-based Xpert-Ultra was 3·3-times slower than that of the rRNA-based TB-MBLA. Consequently for the same patient, it would take 13 weeks and 52 weeks to reach complete tuberculosis negativity by TB-MBLA and Xpert-Ultra, respectively. Participants who were positive on smear microscopy at 8 weeks, who received an extra month of intensive treatment, had a similar TB-MBLA-measured bacillary load at 8 weeks to those who were smear microscopy negative. TB-MBLA has a similar performance to Xpert-Ultra for pretreatment diagnosis of tuberculosis, but is more accurate at detecting and characterising the response to treatment than Xpert-Ultra and standard-of-care smear microscopy. European and Developing Countries Clinical Trials Partnership, Makerere University Research and Innovation Fund, US National Institutes of Health.

12 July 2021 in BMJ Open
Verified
Journal Article
Open access
PDF file
EMElizabeth F Msoka
Elizabeth F Msoka
FOFred Orina
Fred Orina
ESErica Samson Sanga
Erica Samson Sanga
BMBarbara Miheso
Barbara Miheso
SMSimeon Mwanyonga
Simeon Mwanyonga
WSWilber Sabiiti
Wilber Sabiiti
Objectives Early diagnosis and timely treatment are key elements of a successful healthcare system. We assessed the role of socioeconomic and cultural norms in accelerating or decelerating uptake and utilisation of health technologies into policy and practice. Setting Secondary and tertiary level healthcare facilities (HCFs) in three East African countries. Level of HCF was selected based on the WHO recommendation for implantation of tuberculosis (TB) molecular diagnostics. Participants Using implementation of TB diagnostics as a model, we purposively selected participants (TB patients, carers, survivors, healthcare practitioners, community members, opinion leaders and policy-makers) based on their role as stakeholders. In-depth interviews, key informant interviews and focus group discussions were held to collect the data between 2016 and 2018. The data were transcribed, translated, coded and analysed by thematic-content analysis. Results A total of 712 individuals participated in the study. Socioeconomic and cultural factors such as poverty, stigma and inadequate knowledge about causes of disease and available remedies, cultural beliefs were associated with low access and utilisation of diagnostic and treatment tools for TB. Poverty made people hesitate to seek formal healthcare resulting in delayed diagnosis and resorting to self-medication and cheap herbal alternatives. Fear of stigma made people hide their sickness and avoid reporting for follow-up treatment visits. Inadequate knowledge and beliefs were fertile ground for aggravated stigma and believing that diseases like TB are caused by spirits and thus cured by spiritual rituals or religious prayers. Cultural norms were also the basis of gender-based imbalance in accessing care, ‘I could not go to hospital without my husband’s permission’, TB survivor. Conclusion Our findings show that socioeconomic and cultural factors are substantial ‘roadblocks’ to accelerating the uptake and utilisation of diagnostic and treatment tools. Resolving these barriers should be given equal attention as is to health system barriers.

24 August 2021 in BMJ Global Health
Verified
Journal Article
Open access
PDF file
NNNyanda Elias Ntinginya
Nyanda Elias Ntinginya
Davis KuchakaDavis Kuchaka
Davis Kuchaka
FOFred Orina
Fred Orina
IMIvan Mwebaza
Ivan Mwebaza
ALAlphonce Liyoyo
Alphonce Liyoyo
WSWilber Sabiiti
Wilber Sabiiti
Background: Early access to diagnosis is crucial for effective management of any disease including tuberculosis (TB). We investigated the barriers and opportunities to maximise uptake and utilisation of molecular diagnostics in routine healthcare settings. Methods: Using the implementation of WHO approved TB diagnostics, Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) and Line Probe Assay (LPA) as a benchmark, we evaluated the barriers and how they could be unlocked to maximise uptake and utilisation of molecular diagnostics. Results: Health officers representing 190 districts/counties participated in the survey across Kenya, Tanzania and Uganda. The survey findings were corroborated by 145 healthcare facility (HCF) audits and 11 policy-maker engagement workshops. Xpert MTB/RIF coverage was 66%, falling behind microscopy and clinical diagnosis by 33% and 1%, respectively. Stratified by HCF type, Xpert MTB/RIF implementation was 56%, 96% and 95% at district, regional and national referral hospital levels. LPA coverage was 4%, 3% below culture across the three countries. Out of 111 HCFs with Xpert MTB/RIF, 37 (33%) used it to full capacity, performing ≥8 tests per day of which 51% of these were level five (zonal consultant and national referral) HCFs. Likewise, 75% of LPA was available at level five HCFs. Underutilisation of Xpert MTB/RIF and LPA was mainly attributed to inadequate—utilities, 26% and human resource, 22%. Underfinancing was the main reason underlying failure to acquire molecular diagnostics. Second to underfinancing was lack of awareness with 33% healthcare administrators and 49% practitioners were unaware of LPA as TB diagnostic. Creation of a national health tax and decentralising its management was proposed by policy-makers as a booster of domestic financing needed to increase access to diagnostics. Conclusion: Our findings suggest higher uptake and utilisation of molecular diagnostics at tertiary level HCFs contrary to the WHO recommendation. Country-led solutions are crucial for unlocking barriers to increase access to diagnostics.

1 April 2019 in Journal of Clinical Microbiology
Verified
Journal Article
Closed access
PDF file
WSWilber Sabiiti
Wilber Sabiiti
KAKhalide Azam
Khalide Azam
EEEzembro Esmeraldo
Ezembro Esmeraldo
NBNilesh Bhatt
Nilesh Bhatt
ARAndrea Rachow
Andrea Rachow
SGStephen H. Gillespie
Stephen H. Gillespie
The World Health Organization End tuberculosis (TB) strategy has called for development of- and increased access to- effective tools for diagnosis and treatment of TB disease. Mycobacterium tuberculosis (Mtb), the causative agent of TB is categorized as highly infectious agent. Consequently, diagnostic tests that involve comprehensive manipulation of specimens from presumed tuberculosis cases must be performed in a category three laboratory. We have evaluated the use of heat-inactivation to render TB samples safe to work with whilst preserving RNA for downstream molecular tests. Using Mycobacterium bovis Bacillus Calmette Guérin (BCG) cultures and TB positive sputa we show that boiling for 20 min at 80-, 85-, and 95- oC inactivates all Mtb bacilli. The efficiency of inactivation was verified by culturing heat-treated and untreated (live) fractions of BCG and TB sputum for 42 days. No growth was observed in the cultures of heat-treated samples. In contrast the optical density of untreated BCG in Middlebrook 7H9 broth rose from 0.04 to 0.85 and the untreated sputa flagged positive at 3 days of incubation in Mycobacterium Growth Indicator Tube. Quantification of reference genes, 16S rRNA, tmRNA, pre-16S rRNA and rpoB by Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) showed minimal loss in estimated bacterial load. The loss was RNA-species dependent, <1log10, 1.1log10, 1.3log10 and 2.4log10 estimated CFU/ml for 16S rRNA, tmRNA, pre-16S and rpoB respectively. The RNA loss was independent of inactivation temperature. These findings show that heat-inactivation could obviate the need for category three laboratory to perform RNA-based testing of TB samples.