National diagnostic reference levels for digital diagnostic and screening mammography in Uganda.

INTRODUCTION: Screening and diagnostic mammography are associated with some risk of radiation-induced breast cancer. This study was conducted to establish the National Diagnostic Reference Levels (NDRLs) for digital diagnostic and screening mammography in Uganda to achieve breast radiation dose optimization. METHODS: A cross-sectional study was conducted among female participants recruited by consecutive sampling from three selected hospitals with digital mammography in Uganda. The study variables extracted from the mammography machines were exposure factors, compressed breast thickness (CBT), and Average Glandular Dose (AGD) of two standard mammogram views. The stratified National DRL was derived by calculating the 75th percentile of the AGD across all the samples at various CBT ranges for both screening and diagnostic mammography in craniocaudal (CC) and mediolateral oblique (MLO) views. RESULTS: We included 300 participants with mean ages of 50.28±9.32 and 47.45±13.45 years for the screening and diagnostic mammography, respectively. There were statistically significant positive correlations between AGD and exposure factors (mAs, kVp) (all p-values<0.0001). For screening mammography, mAs demonstrated a strong positive correlation (r = 0.8369 in CC, 0.8133 in MLO), whereas kVp showed a positive correlation with relatively lower coefficients (r = 0.3700 in CC, 0.3080 in MLO). For diagnostic mammography, mAs exhibited an even stronger positive correlation (r = 0.8987 in CC, 0.8762 in MLO), and kVp maintained a positive correlation with somewhat lower coefficients (r = 0.4954 in CC, 0.3597 in MLO). In screening mammography, for CBT within the range of (7-39) mm, the NDRLs were (1.5mGy, 1.66mGy) in CC) and MLO views. For CBT in the range of (40-59) mm, the NDRLs were (1.78mGy, 1.87mGy), and for CBT in the range of (60-99) mm, the NDRLs were (2.18mGy, 2.22mGy). For diagnostic mammography, the NDRLs were established as (1.7mGy, 1.91mGy), (2.00mGy, 2.09mGy), and (2.63mGy, 2.81mGy) for CBT ranges of (7-39) mm, (40-59) mm, and (60-99) mm, respectively. CONCLUSION: The NDRLs for digital screening and diagnostic mammography in Uganda have been proposed for the first time. The NDRL values in mammography should be specific to CBT ranges and mammographic views for both diagnostic and screening mammography.

Integration of HIV Testing in a Community Intervention for Tuberculosis Screening Among Household Contacts of Patients with Tuberculosis in Cameroon and Uganda.

INTRODUCTION: People living with HIV are considered at higher risk of developing severe forms of tuberculosis (TB) disease. Providing HIV testing to TB-exposed people is therefore critical. We present the results of integrating HIV testing into a community-based intervention for household TB contact management in Cameroon and Uganda. METHODS: Trained community health workers visited the households of index patients with TB identified in 3 urban/semiurban and 6 rural districts or subdistricts as part of a cluster-randomized trial and provided TB screening to all household contacts. Voluntary HIV counseling and testing were offered to contacts aged 5 years or older with unknown HIV status. We describe the cascade of care for HIV testing and the factors associated with the acceptance of HIV testing. RESULTS: Overall, 1983 household contacts aged 5 years or older were screened for TB. Of these contacts, 1652 (83.3%) did not know their HIV status, 1457 (88.2%) accepted HIV testing, and 1439 (98.8%) received testing. HIV testing acceptance was lower among adults than children [adjusted odds ratio (aOR) = 0.35, 95% confidence interval (CI): 0.22 to 0.55], those living in household of an HIV-positive vs HIV-negative index case (aOR = 0.56, 95% CI: 0.38 to 0.83), and contacts requiring a reassessment visit after the initial TB screening visit vs asymptomatic contacts (aOR = 0.20, 95% CI: 0.06 to 0.67) and was higher if living in Uganda vs Cameroon (aOR = 4.54, 95% CI: 1.17 to 17.62) or if another contact of the same index case was tested for HIV (aOR = 9.22, 95% CI: 5.25 to 16.18). CONCLUSION: HIV testing can be integrated into community-based household TB contact screening and is well-accepted.

Cost-effectiveness of community-based household tuberculosis contact management for children in Cameroon and Uganda: a modelling analysis of a cluster-randomised trial.

BACKGROUND: WHO recommends household contact management (HCM) including contact screening and tuberculosis-preventive treatment (TPT) for eligible children. The CONTACT trial found increased TPT initiation and completion rates when community health workers were used for HCM in Cameroon and Uganda. METHODS: We did a cost-utility analysis of the CONTACT trial using a health-system perspective to estimate the health impact, health-system costs, and cost-effectiveness of community-based versus facility-based HCM models of care. A decision-analytical modelling approach was used to evaluate the cost-effectiveness of the intervention compared with the standard of care using trial data on cascade of care, intervention effects, and resource use. Health outcomes were based on modelled progression to tuberculosis, mortality, and discounted disability-adjusted life-years (DALYs) averted. Health-care resource use, outcomes, costs (2021 US$), and cost-effectiveness are presented. FINDINGS: For every 1000 index patients diagnosed with tuberculosis, the intervention increased the number of TPT courses by 1110 (95% uncertainty interval 894 to 1227) in Cameroon and by 1078 (796 to 1220) in Uganda compared with the control model. The intervention prevented 15 (-3 to 49) tuberculosis deaths in Cameroon and 10 (-20 to 33) in Uganda. The incremental cost-effectiveness ratio was $620 per DALY averted in Cameroon and $970 per DALY averted in Uganda. INTERPRETATION: Community-based HCM approaches can substantially reduce child tuberculosis deaths and in our case would be considered cost-effective at willingness-to-pay thresholds of $1000 per DALY averted. Their impact and cost-effectiveness are likely to be greatest where baseline HCM coverage is lowest. FUNDING: Unitaid and UK Medical Research Council.

Effectiveness of a community-based approach for the investigation and management of children with household tuberculosis contact in Cameroon and Uganda: a cluster-randomised trial.

BACKGROUND: Globally, the uptake of tuberculosis-preventive treatment (TPT) among children with household tuberculosis contact remains low, partly due to the necessity of bringing children to health facilities for investigations. This study aimed to evaluate the effect on TPT initiation and completion of community-based approaches to tuberculosis contact investigations in Cameroon and Uganda. METHODS: We did a parallel, cluster-randomised, controlled trial across 20 clusters (consisting of 25 district hospitals and primary health centres) in Cameroon and Uganda, which were randomised (1:1) to receive a community-based approach (intervention group) or standard-of-care facility-based approach to contact screening and management (control group). The community-based approach consisted of symptom-based tuberculosis screening of all household contacts by community health workers at the household, with referral of symptomatic contacts to local facilities for investigations. Initiation of TPT (3-month course of rifampicin-isoniazid) was done by a nurse in the household, and home visits for TPT follow-up were done by community health workers. Index patients were people aged 15 years or older with bacteriologically confirmed, drug-susceptible, pulmonary tuberculosis diagnosed less than 1 month before inclusion and who declared at least one child or young adolescent (aged 0-14 years) household contact. The primary endpoint was the proportion of declared child contacts in the TPT target group (those aged <5 years irrespective of HIV status, and children aged 5-14 years living with HIV) who commenced and completed TPT, assessed in the modified intention-to-treat population (excluding enrolled index patients and their contacts who did not fit the eligibility criteria). Descriptive cascade of care assessment and generalised linear mixed modelling were used for comparison. This study is registered with ClinicalTrials.gov (NCT03832023). FINDINGS: The study included nine clusters in the intervention group (after excluding one cluster that did not enrol any index patients for >2 months) and ten in the control group. Between Oct 14, 2019 and Jan 13, 2022, 2894 child contacts were declared by 899 index patients with bacteriologically confirmed tuberculosis. Among all child contacts declared, 1548 (81·9%) of 1889 in the intervention group and 475 (47·3%) of 1005 in the control group were screened for tuberculosis. 1400 (48·4%) child contacts were considered to be in the TPT target group: 941 (49·8%) of 1889 in the intervention group and 459 (45·7%) of 1005 in the control group. In the TPT target group, TPT was commenced and completed in 752 (79·9%) of 941 child contacts in the intervention group and 283 (61·7%) of 459 in the control group (odds ratio 3·06 [95% CI 1·24-7·53]). INTERPRETATION: A community-based approach using community health workers can significantly increase contact investigation coverage and TPT completion among eligible child contacts in a tuberculosis-endemic setting. FUNDING: Unitaid. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Clinical and radiographic factors do not accurately diagnose smear-negative tuberculosis in HIV-infected inpatients in Uganda: a cross-sectional study.

BACKGROUND: Although World Health Organization guidelines recommend clinical judgment and chest radiography for diagnosing tuberculosis in HIV-infected adults with unexplained cough and negative sputum smears for acid-fast bacilli, the diagnostic performance of this approach is unknown. Therefore, we sought to assess the accuracy of symptoms, physical signs, and radiographic findings for diagnosing tuberculosis in this population in a low-income country with a high incidence of tuberculosis. METHODOLOGY: We performed a cross-sectional study enrolling consecutive HIV-infected inpatients with unexplained cough and negative sputum smears for acid-fast bacilli at Mulago Hospital in Kampala, Uganda. Trained medical officers prospectively collected data on standard symptoms and signs of systemic respiratory illness, and two radiologists interpreted chest radiographs in a standardized fashion. We calculated positive- and negative-likelihood ratios of these factors for diagnosing pulmonary tuberculosis (defined when mycobacterial cultures of sputum or bronchoalveolar lavage fluid were positive). We used both conventional and novel regression techniques to develop multivariable prediction models for pulmonary tuberculosis. PRINCIPAL FINDINGS: Among 202 enrolled HIV-infected adults with negative sputum smears for acid-fast bacilli, 72 (36%) had culture-positive pulmonary tuberculosis. No single factor, including respiratory symptoms, physical findings, CD4+ T-cell count, or chest radiographic abnormalities, substantially increased or decreased the likelihood of pulmonary tuberculosis. After exhaustive testing, we were also unable to identify any combination of factors which reliably predicted bacteriologically confirmed tuberculosis. CONCLUSIONS AND SIGNIFICANCE: Clinical and radiographic criteria did not help diagnose smear-negative pulmonary tuberculosis among HIV-infected patients with unexplained cough in a low-income setting. Enhanced diagnostic methods for smear-negative tuberculosis are urgently needed.