The in vivo pattern of binding of RAG1 and RAG2 to antigen receptor loci.

The critical initial step in V(D)J recombination, binding of RAG1 and RAG2 to recombination signal sequences flanking antigen receptor V, D, and J gene segments, has not previously been characterized in vivo. Here, we demonstrate that RAG protein binding occurs in a highly focal manner to a small region of active chromatin encompassing Ig kappa and Tcr alpha J gene segments and Igh and Tcr beta J and J-proximal D gene segments. Formation of these small RAG-bound regions, which we refer to as recombination centers, occurs in a developmental stage- and lineage-specific manner. Each RAG protein is independently capable of specific binding within recombination centers. While RAG1 binding was detected only at regions containing recombination signal sequences, RAG2 binds at thousands of sites in the genome containing histone 3 trimethylated at lysine 4. We propose that recombination centers coordinate V(D)J recombination by providing discrete sites within which gene segments are captured for recombination.

Enhanced tuberculosis diagnosis with computer-aided chest X-ray and urine LAM in adults with HIV admitted to hospital (CASTLE study): A cluster randomised trial.

BACKGROUND: People with HIV (PHIV) admitted to hospital have high mortality, with tuberculosis (TB) being the major cause of death. Systematic use of new TB diagnostics could improve TB diagnosis and might improve outcomes. METHODS: We conducted a cluster randomised trial among adult PHIV admitted to Zomba Central Hospital, Malawi. Admission-days were randomly assigned to: enhanced TB diagnostics using urine lipoarabinomannan (LAM) antigen tests (SILVAMP-LAM, Fujifilm, Japan and Determine-LAM, Alere/Abbot, USA), digital chest X-ray with computer aided diagnosis (dCXR-CAD, CAD4TBv6, Delft, Netherlands), plus usual care ("enhanced TB diagnostics"); or usual care alone ("usual care"). The primary outcome was TB treatment initiation during admission. Secondary outcomes were 56-day mortality, TB diagnosis within 24-hours, and undiagnosed TB at discharge, ascertained by culture of one admission sputum sample. FINDINGS: Between 2 September 2020 and 15 February 2022, we recruited 419 people. Four people were excluded post-recruitment, leaving 415 adults recruited during 207 randomly assigned admission-days in modified intention-to-treat analysis. At admission, 90.8% (377/415) were taking antiretroviral therapy (ART) with median (IQR) CD4 cell count 240 cells/mm3. In the enhanced diagnostic arm, median CAD4TBv6 score was 60 (IQR: 51-71), 4.4% (9/207) had SILVAMP-LAM-positive and 14.4% (29/201) had Determine-LAM positive urine with three samples positive by both urine tests. TB treatment was initiated in 46/208 (22%) in enhanced TB diagnostics arm and 24/207 (12%) in usual care arm (risk ratio [RR] 1.92, 95% CI 1.20-3.08). There was no difference in mortality by 56 days (enhanced TB diagnosis: 54/208, 26%; usual care: 52/207, 25%; hazard ratio 1.05, 95% CI 0.72-1.53); TB treatment initiation within 24 hours (enhanced TB diagnosis: 8/207, 3.9%; usual care: 5/208, 2.4%; RR 1.61, 95% CI 0.53-4.71); or undiagnosed microbiological-confirmed TB at discharge (enhanced TB diagnosis, 0/207 (0.0%), usual care arm 2/208 (1.0%) (p = 0.50). INTERPRETATION: Urine SILVAMP-LAM/Determine-LAM plus dCXR-CAD diagnostics identified more hospitalised PHIV with TB than usual care. The increase in TB treatment appeared mainly due to greater use of Determine-LAM, rather than SILVAMP-LAM or dCXR-CAD. Poor concordance between Determine-LAM and SILVAMP-LAM urine tests requires further investigation. Inpatient mortality for adults with HIV remains unacceptability high.

Cost-effectiveness of COVID rapid diagnostic tests for patients with severe/critical illness in low- and middle-income countries: A modeling study.

BACKGROUND: Rapid diagnostic tests (RDTs) for coronavirus disease (COVID) are used in low- and middle-income countries (LMICs) to inform treatment decisions. However, to date, it is unclear when this use is cost-effective. Existing analyses are limited to a narrow set of countries and uses. The aim of this study is to assess the cost-effectiveness of COVID RDTs to inform the treatment of patients with severe illness in LMICs, considering real world practice. METHODS AND FINDINGS: We assessed the cost-effectiveness of COVID testing across LMICs using a decision tree model, differentiating results by country income level, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) prevalence, and testing scenario (none, RDTs, polymerase chain reaction tests-PCRs and combinations). LMIC experts defined realistic care pathways and treatment options. Using a healthcare provider perspective and net monetary benefit approach, we assessed both intended (COVID symptom alleviation) and unintended (treatment side effects) health and economic impacts for each testing scenario. We included the side effects of corticosteroids, which are often the only available treatment for COVID. Because side effects depend both on the treatment and the patient's underlying illness (COVID or COVID-like illnesses, such as influenza), we considered the prevalence of COVID-like illnesses in our analyses. We found that SARS-CoV-2 testing of patients with severe COVID-like illness can be cost-effective in all LMICs, though only in some circumstances. High influenza prevalence among suspected COVID cases improves cost-effectiveness, since incorrectly provided corticosteroids may worsen influenza outcomes. In low- and some lower-middle-income countries, only patients with a high index of suspicion for COVID should be tested with RDTs, while other patients should be presumed to not have COVID. In some lower-middle-income and upper-middle-income countries, suspected severe COVID cases should almost always be tested. Further, in these settings, negative test results in patients with a high initial index of suspicion should be confirmed through PCR and, during influenza outbreaks, positive results in patients with a low initial index of suspicion should also be confirmed with a PCR. The use of interleukin-6 receptor blockers, when supported by testing, may also be cost-effective in higher-income LMICs. The cost at which they would be cost-effective in low-income countries ($162 to $406 per treatment course) is below current prices. The primary limitation of our analysis is substantial uncertainty around some of the parameters in our model due to limited data, most notably on current COVID mortality with standard of care, and insufficient evidence on the impact of corticosteroids on patients with severe influenza. CONCLUSIONS: COVID testing can be cost-effective to inform treatment of LMIC patients with severe COVID-like disease. The optimal algorithm is driven by country income level and health budgets, the level of suspicion that the patient may have COVID, and influenza prevalence. Further research to better characterize the unintended effects of corticosteroids, particularly on influenza cases, could improve decision making around the treatment of those with COVID-like symptoms in LMICs.

Structural basis for the activation and suppression of transposition during evolution of the RAG recombinase.

Jawed vertebrate adaptive immunity relies on the RAG1/RAG2 (RAG) recombinase, a domesticated transposase, for assembly of antigen receptor genes. Using an integration-activated form of RAG1 with methionine at residue 848 and cryo-electron microscopy, we determined structures that capture RAG engaged with transposon ends and U-shaped target DNA prior to integration (the target capture complex) and two forms of the RAG strand transfer complex that differ based on whether target site DNA is annealed or dynamic. Target site DNA base unstacking, flipping, and melting by RAG1 methionine 848 explain how this residue activates transposition, how RAG can stabilize sharp bends in target DNA, and why replacement of residue 848 by arginine during RAG domestication led to suppression of transposition activity. RAG2 extends a jawed vertebrate-specific loop to interact with target site DNA, and functional assays demonstrate that this loop represents another evolutionary adaptation acquired during RAG domestication to inhibit transposition. Our findings identify mechanistic principles of the final step in cut-and-paste transposition and the molecular and structural logic underlying the transformation of RAG from transposase to recombinase.

Accuracy of and preferences for blood-based versus oral-fluid-based HIV self-testing in Malawi: a cross-sectional study.

BACKGROUND: HIV self-testing (HIVST) can use either oral-fluid or blood-based tests. Studies have shown strong preferences for self-testing compared to facility-based services. Despite availability of low-cost blood-based HIVST options, to date, HIVST implementation in sub-Saharan Africa has largely been oral-fluid-based. We investigated whether users preferred blood-based (i.e. using blood sample derived from a finger prick) or oral fluid-based HIVST in rural and urban Malawi. METHODS: At clinics providing HIV testing services (n = 2 urban; n = 2 rural), participants completed a semi-structured questionnaire capturing sociodemographic data before choosing to test using oral-fluid-based HVST, blood-based HIVST or provider-delivered testing. They also completed a self-administered questionnaire afterwards, followed by a confirmatory test using the national algorithm then appropriate referral. We used simple and multivariable logistic regression to identify factors associated with preference for oral-fluid or blood-based HIVST. RESULTS: July to October 2018, N = 691 participants enrolled in this study. Given the choice, 98.4% (680/691) selected HIVST over provider-delivered testing. Of 680 opting for HIVST, 416 (61.2%) chose oral-fluid-based HIVST, 264 (38.8%) chose blood-based HIVST and 99.1% (674/680) reported their results appropriately. Self-testers who opted for blood-based HIVST were more likely to be male (50.3% men vs. 29.6% women, p < 0.001), attending an urban facility (43% urban vs. 34.6% rural, p = 0.025) and regular salary-earners (49.5% regular vs. 36.8% non-regular, p = 0.012). After adjustment, only sex was found to be associated with choice of self-test (adjusted OR 0.43 (95%CI: 0.3-0.61); p-value < 0.001). Among 264 reporting blood-based HIVST results, 11 (4.2%) were HIV-positive. Blood-based HIVST had sensitivity of 100% (95% CI: 71.5-100%) and specificity of 99.6% (95% CI: 97.6-100%), with 20 (7.6%) invalid results. Among 416 reporting oral-fluid-based HIVST results 18 (4.3%) were HIV-positive. Oral-fluid-based HIVST had sensitivity of 88.9% (95% CI: 65.3-98.6%) and specificity of 98.7% (95% CI: 97.1-99.6%), with no invalid results. CONCLUSIONS: Offering both blood-based and oral-fluid-based HIVST resulted in high uptake when compared directly with provider-delivered testing. Both types of self-testing achieved high accuracy among users provided with a pre-test demonstration beforehand. Policymakers and donors need to adequately plan and budget for the sensitisation and support needed to optimise the introduction of new quality-assured blood-based HIVST products.

Experience of social harms among female sex workers following HIV self-test distribution in Malawi: results of a cohort study.

BACKGROUND: In Malawi, female sex workers (FSW) have high HIV incidence and regular testing is suggested. HIV self-testing (HIVST) is a safe and acceptable alternative to standard testing services. This study assessed; whether social harms were more likely to be reported after HIVST distribution to FSW by peer distributors than after facility-based HIV testing and whether FSW regretted HIVST use or experienced associated relationship problems. METHODS: Peer HIVST distributors, who were FSW, were recruited in Blantyre district, Malawi between February and July 2017. Among HIVST recipients a prospective cohort was recruited. Interviews were conducted at baseline and at end-line, 3 months later. Participants completed daily sexual activity diaries. End-line data were analysed using logistic regression to assess whether regret or relationship problems were associated with HIVST use. Sexual activity data were analysed using Generalised Estimating Equations to assess whether HIVST use was temporally associated with an increase in social harms. RESULTS: Of 265 FSW recruited and offered HIVST, 131 completed both interviews. Of these, 31/131(23.7%) reported initial regret after HIVST use, this reduced to 23/131(17.6%) at the 3-month follow-up. Relationship problems were reported by 12/131(9.2%). Regret about HIVST use was less commonly reported in those aged 26-35 years compared to those aged 16-25 years (OR immediate regret-0.40 95% CI 0.16-1.01) (OR current regret-0.22 95% CI 0.07 - 0.71) and was not associated with the HIVST result. There was limited evidence that reports of verbal abuse perpetrated by clients in the week following HIVST use were greater than when there was no testing in the preceding week. There was no evidence for increases in any other social harms. There was some evidence of coercion to test, most commonly initiated by the peer distributor. CONCLUSIONS: Little evidence was found that the peer distribution model was associated with increased levels of social harms, however programmes aimed at reaching FSW need to carefully consider possible unintended consequences of their service delivery approaches, including the potential for peer distributors to coerce individuals to test or disclose their test results and alternative distribution models may need to be considered.

Lessons learned from implementation of four HIV self-testing (HIVST) distribution models in Zambia: applying the Consolidated Framework for Implementation Research to understand impact of contextual factors on implementation.

BACKGROUND: Although Zambia has integrated HIV-self-testing (HIVST) into its Human Immunodeficiency Virus (HIV) regulatory frameworks, few best practices to optimize the use of HIV self-testing to increase testing coverage have been documented. We conducted a prospective case study to understand contextual factors guiding implementation of four HIVST distribution models to inform scale-up in Zambia. METHODS: We used the qualitative case study method to explore user and provider experiences with four HIVST distribution models (two secondary distribution models in Antenatal Care (ANC) and Antiretroviral Therapy (ART) clinics, community-led, and workplace) to understand factors influencing HIVST distribution. Participants were purposefully selected based on their participation in HIVST and on their ability to provide rich contextual experience of the distribution models. Data were collected using observations (n = 31), group discussions (n = 10), and in-depth interviews (n = 77). Data were analyzed using the thematic approach and aligned to the four Consolidated Framework for Implementation Research (CFIR) domains. RESULTS: Implementation of the four distribution models was influenced by an interplay of outer and inner setting factors. Inadequate compensation and incentives for distributors may have contributed to distributor attrition in the community-led and workplace HIVST models. Stockouts, experienced at the start of implementation in the secondary-distribution and community-led distribution models often disrupted distribution. The existence of policy and practices aided integration of HIVST in the workplace. External factors complimented internal factors for successful implementation. For instance, despite distributor attrition leading to excessive workload, distributors often multi-tasked to keep up with demand for kits, even though distribution points were geographically widespread in the workplace, and to a less extent in the community-led models. Use of existing communication platforms such as lunchtime and safety meetings to promote and distribute kits, peers to support distributors, reduction in trips by distributors to replenish stocks, increase in monetary incentives and reorganisation of stakeholder roles proved to be good adaptations. CONCLUSION: HIVST distribution was influenced by a combination of contextual factors in variable ways. Understanding how the factors interacted in real world settings informed adaptations to implementation devised to minimize disruptions to distribution.

Impact of Community-Wide Tuberculosis Active Case Finding and Human Immunodeficiency Virus Testing on Tuberculosis Trends in Malawi.

BACKGROUND: Tuberculosis case-finding interventions are critical to meeting World Health Organization End TB strategy goals. We investigated the impact of community-wide tuberculosis active case finding (ACF) alongside scale-up of human immunodeficiency virus (HIV) testing and care on trends in adult tuberculosis case notification rates (CNRs) in Blantyre, Malawi. METHODS: Five rounds of ACF for tuberculosis (1-2 weeks of leafleting, door-to-door enquiry for cough and sputum microscopy) were delivered to neighborhoods ("ACF areas") in North-West Blantyre between April 2011 and August 2014. Many of these neighborhoods also had concurrent HIV testing interventions. The remaining neighborhoods in Blantyre City ("non-ACF areas") provided a non-randomized comparator. We analyzed TB CNRs from January 2009 until December 2018. We used interrupted time series analysis to compare tuberculosis CNRs before ACF and after ACF, and between ACF and non-ACF areas. RESULTS: Tuberculosis CNRs increased in Blantyre concurrently with start of ACF for tuberculosis in both ACF and non-ACF areas, with a larger magnitude in ACF areas. Compared to a counterfactual where pre-ACF CNR trends continued during ACF period, we estimated there were an additional 101 (95% confidence interval [CI] 42 to 160) microbiologically confirmed (Bac+) tuberculosis diagnoses per 100 000 person-years in the ACF areas in 3 and a half years of ACF. Compared to a counterfactual where trends in ACF area were the same as trends in non-ACF areas, we estimated an additional 63 (95% CI 38 to 90) Bac + diagnoses per 100 000 person-years in the same period. CONCLUSIONS: Tuberculosis ACF was associated with a rapid increase in people diagnosed with tuberculosis in Blantyre.

Secondary distribution of HIV self-test kits by HIV index and antenatal care clients: implementation and costing results from the STAR Initiative in South Africa.

BACKGROUND: Partner-delivered HIV self-testing kits has previously been highlighted as a safe, acceptable and effective approach to reach men. However, less is known about its real-world implementation in reaching partners of people living with HIV. We evaluated programmatic implementation of partner-delivered self-testing through antenatal care (ANC) attendees and people newly diagnosed with HIV by assessing use, positivity, linkage and cost per kit distributed. METHODS: Between April 2018 and December 2019, antenatal care (ANC) clinic attendees and people or those newly diagnosed with HIV clients across twelve clinics in three cities in South Africa were given HIVST kits (OraQuick Rapid HIV-1/2 Antibody Test, OraSure Technologies) to distribute to their sexual partners. A follow-up telephonic survey was administered to all prior consenting clients who were successfully reached by telephone to assess primary outcomes. Incremental economic costs of the implementation were estimated from the provider's perspective. RESULTS: Fourteen thousand four hundred seventy-three HIVST kits were distributed - 10,319 (71%) to ANC clients for their male partner and 29% to people newly diagnosed with HIV for their partners. Of the 4,235 ANC clients successfully followed-up, 82.1% (3,475) reportedly offered HIVST kits to their male partner with 98.1% (3,409) accepting and 97.6% (3,328) using the kit. Among ANC partners self-testing, 159 (4.8%) reported reactive HIVST results, of which 127 (79.9%) received further testing; 116 (91.3%) were diagnosed with HIV and 114 (98.3%) initiated antiretroviral therapy (ART). Of the 1,649 people newly diagnosed with HIV successfully followed-up; 1,312 (79.6%) reportedly offered HIVST kits to their partners with 95.8% (1,257) of the partners accepting and 95.9% (1,206) reported that their partners used the kit. Among these index partners, 297 (24.6%) reported reactive HIVST results of which 261 (87.9%) received further testing; 260 (99.6%) were diagnosed with HIV and 258 (99.2%) initiated ART. The average cost per HIVST distributed in the three cities was US$7.90, US$11.98, and US$14.81, respectively. CONCLUSIONS: Partner-delivered HIVST in real world implementation was able to affordably reach many male partners of ANC attendees and index partners of people newly diagnosed with HIV in South Africa. Given recent COVID-19 related restrictions, partner-delivered HIVST provides an important strategy to maintain essential testing services.

High Intrapulmonary Rifampicin and Isoniazid Concentrations Are Associated With Rapid Sputum Bacillary Clearance in Patients With Pulmonary Tuberculosis.

BACKGROUND: Intrapulmonary pharmacokinetics may better explain response to tuberculosis (TB) treatment than plasma pharmacokinetics. We explored these relationships by modeling bacillary clearance in sputum in adult patients on first-line treatment in Malawi. METHODS: Bacillary elimination rates (BER) were estimated using linear mixed-effects modelling of serial time-to-positivity in mycobacterial growth indicator tubes for sputum collected during the intensive phase of treatment (weeks 0-8) for microbiologically confirmed TB. Population pharmacokinetic models used plasma and intrapulmonary drug levels at 8 and 16 weeks. Pharmacokinetic-pharmacodynamic relationships were investigated using individual-level measures of drug exposure (area-under-the-concentration-time-curve [AUC] and Cmax) for rifampicin, isoniazid, pyrazinamide, and ethambutol, in plasma, epithelial lining fluid, and alveolar cells as covariates in the bacillary elimination models. RESULTS: Among 157 participants (58% human immunodeficiency virus [HIV] coinfected), drug exposure in plasma or alveolar cells was not associated with sputum bacillary clearance. Higher peak concentrations (Cmax) or exposure (AUC) to rifampicin or isoniazid in epithelial lining fluid was associated with more rapid bacillary elimination and shorter time to sputum negativity. More extensive disease on baseline chest radiograph was associated with slower bacillary elimination. Clinical outcome was captured in 133 participants, with 15 (11%) unfavorable outcomes recorded (recurrent TB, failed treatment, or death). No relationship between BER and late clinical outcome was identified. CONCLUSIONS: Greater intrapulmonary drug exposure to rifampicin or isoniazid in the epithelial lining fluid was associated with more rapid bacillary clearance. Higher doses of rifampicin and isoniazid may result in sustained high intrapulmonary drug exposure, rapid bacillary clearance, shorter treatment duration and better treatment outcomes.

Did you hear about HIV self-testing? HIV self-testing awareness after community-based HIVST distribution in rural Zimbabwe.

BACKGROUND: Several trials of community-based HIV self-testing (HIVST) provide evidence on the acceptability and feasibility of campaign-style distribution to reach first-time testers, men and adolescents. However, we do not know how many remain unaware of HIVST after distribution campaigns, and who these individuals are. Here we look at factors associated with never having heard of HIVST after community-based campaign-style HIVST distribution in rural Zimbabwe between September 2016 and July 2017. METHODS: Analysis of representative population-based trial survey data collected from 7146 individuals following community-based HIVST distribution to households was conducted. Factors associated with having never heard of HIVST were determined using multivariable mixed-effects logistic regression adjusted for clustered design. RESULTS: Among survey participants, 1308 (18.3%) self-reported having never heard of HIVST. Individuals who were between 20 and 60 years old {20-29 years: [aOR = 0.74, 95% CI (0.58-0.95)], 30-39 years: [aOR = 0.56, 95% CI (0.42-0.74)], 40-49 years: [aOR = 0.50, 95% CI (0.36-0.68)], 50-59 years [aOR = 0.58, 95% CI (0.42-0.82)]}, who had attained at least ordinary level education [aOR = 0.51, 95% CI (0.34-0.76)], and who had an HIV test before [aOR = 0.30, 95% CI (0.25-0.37)] were less likely to have never heard of HIVST compared with individuals who were between 16 and 19 years old, who had a lower educational level and who had never tested for HIV before, respectively. In addition, non-household heads or household head representatives [aOR = 1.21, 95% CI (1.01-1.45)] were more likely to report never having heard of HIVST compared to household head and representatives. CONCLUSIONS: Around one fifth of survey participants remain unaware of HIVST even after an intensive community-based door-to-door HIVST distribution. Of note, those least likely to have heard of self-testing were younger, less educated and less likely to have tested previously. Household heads appear to play an important role in granting or denying access to self-testing to other household members during door-to-door distribution. Differentiated distribution models are needed to ensure access to all. Trial registration PACTR, PACTR201607001701788. Registered 29 June 2016, https://pactr.samrc.ac.za/ PACTR201607001701788.

"You have a self-testing method that preserves privacy so how come you cannot give us treatment that does too?" Exploring the reasoning among young people about linkage to prevention, care and treatment after HIV self-testing in Southern Malawi.

BACKGROUND: Young people, aged 16-24, in southern Malawi have high uptake of HIV self-testing (HIVST) but low rates of linking to services following HIVST, especially in comparison, to older generations. The study aim is to explore the barriers and facilitators to linkage for HIV prevention and care following uptake of HIV self-testing among young Malawians. METHODS: We used qualitative methods. Young people aged 16-24 who had received HIVST; community-based distribution agents (CBDAs) and health care workers from the linked facilities were purposively sampled from two villages in rural southern Malawi. RESULTS: We conducted in-depth interviews with thirteen young people (9 female) and held four focus groups with 28 healthcare workers and CBDAs. Young people strongly felt the social consequences associated with inadvertent disclosure of HIV sero-status were a significant deterrent to linkage at their stage in life. They also felt communication on testing benefits and the referral process after testing was poor. In contrast, they valued encouragement from those they trusted, other's positive treatment experiences and having a "strength of mind". CBDAs were important facilitators for young people as they are able to foster a trusting relationship and had more understanding of the factors which prevented young people from linking following HIVST than the healthcare workers. Young people noted contextual barriers to linkage, for example, being seen on the road to the healthcare centre, but also societal gendered barriers. For example, young females and younger adolescents were less likely to have the financial independence to link to services whilst young males (aged 19-24) had the finances but lacked a supportive network to encourage linkage following testing. Overall, it was felt that the primary "responsibility" for linking to formal healthcare following self-testing is shouldered by the young person and not the healthcare system. CONCLUSIONS: Young people are happy to self-test for HIV but faced barriers to link to services following a self-test. Potential interventions for improving linkage suggested by this analysis include the establishment of youth-friendly linkage services, enhanced lines of communication between young people and healthcare providers and prioritising linkage for future interventions when targeting young people following HIVST.

Sensitivity and specificity of OraQuick® HIV self-test compared to a 4th generation laboratory reference standard algorithm in urban and rural Zambia.

BACKGROUND: HIV self-testing (HIVST) has the potential to increase coverage of HIV testing, but concerns exist about intended users' ability to correctly perform and interpret tests, especially in poor communities with low literacy rates. We assessed the clinical performance of the 2016 prototype OraQuick® HIV Self-Test in rural and urban communities in Zambia to assess the sensitivity and specificity of the test compared to the national HIV rapid diagnostic test (RDT) algorithm and a laboratory reference standard using 4th generation enzyme immunoassays and HIV RNA detection. METHODS: Participants were recruited from randomly selected rural and urban households and one urban health facility between May 2016 and June 2017. Participants received a brief demonstration of the self-test, and then self-tested without further assistance. The research team re-read the self-test, repeated the self-test, drew blood for the laboratory reference, and conducted RDTs following the national HIV testing algorithm (Determine™ HIV1/2 (Alere) confirmed using Unigold™ HIV1/2 (Trinity Biotech)). Selected participants (N = 85) were videotaped whilst conducting the testing to observe common errors. RESULTS: Initial piloting showed that written instructions alone were inadequate, and a demonstration of self-test use was required. Of 2,566 self-test users, 2,557 (99.6%) were able to interpret their result. Of participants who were videoed 75/84 (89.3%) completed all steps of the procedure correctly. Agreement between the user-read result and the researcher-read result was 99.1%. Compared to the RDT algorithm, user-conducted HIVST was 94.1% sensitive (95%CI: 90.2-96.7) and 99.7% specific (95%CI: 99.3-99.9). Compared to the laboratory reference, both user-conducted HIVST (sensitivity 87.5%, 95%CI: 82.70-91.3; specificity 99.7%, 95%CI: 99.4-99.9) and the national RDT algorithm (sensitivity 93.4%, 95%CI: 89.7-96.1%; specificity 100% (95%CI: 99.8-100%) had considerably lower sensitivity. CONCLUSIONS: Self-testers in Zambia who used OraQuick® HIV Self-Test achieved reasonable clinical performance compared to the national RDT algorithm. However, sensitivity of the self-test was reduced compared to a laboratory reference standard, as was the national RDT algorithm. In-person demonstration, along with the written manufacturer instructions, was needed to obtain accurate results. Programmes introducing self-care diagnostics should pilot and optimise support materials to ensure they are appropriately adapted to context.

Risk factors for sustained virological non-suppression among children and adolescents living with HIV in Zimbabwe and Malawi: a secondary data analysis.

BACKGROUND: We investigated risk factors for sustained virological non-suppression (viral load ≥ 1000 copies/ml on two tests 48 weeks apart) among children and adolescents accessing HIV care in public sector clinics in Harare, Zimbabwe and Blantyre, Malawi. METHODS: Participants were enrolled between 2016 and 2019, were aged 6-19 years, living with HIV, had chronic lung disease (FEV z-score < -1) and had taken antiretroviral therapy (ART) for at least six months. We used multivariate logistic regression to identify risk factors for virological non-suppression after 48 weeks, among participants who were non-suppressed at enrolment. RESULTS: At enrolment 258 participants (64.6%) were on first-line ART and 152/347 (43.8%) had virological non-suppression. After 48 weeks 114/313 (36.4%) were non-suppressed. Participants non-suppressed at baseline had almost ten times higher odds of non-suppression at follow-up (OR = 9.9, 95%CI 5.3-18.4, p < 0.001). Of those who were non-suppressed at enrolment, 87/136 (64.0%) were still non-suppressed at 48 weeks. Among this group non-suppression at 48 weeks was associated with not switching ART regimen (adjusted OR = 5.55; 95%CI 1.41-21.83); p = 0.014) and with older age. Twelve participants switched regimen in Zimbabwe and none in Malawi. CONCLUSIONS: Viral non-suppression was high among this group and many with high viral load were not switched to a new regimen, resulting in continued non-suppression after 48 weeks. Further research could determine whether improved adherence counselling and training clinicians on regimen switches can improve viral suppression rates in this population. TRIAL REGISTRATION: Secondary cohort analysis of data from BREATHE trial (Clinicaltrials.gov NCT02426112 ).

Effects of Coronavirus Disease Pandemic on Tuberculosis Notifications, Malawi.

The coronavirus disease (COVID-19) pandemic might affect tuberculosis (TB) diagnosis and patient care. We analyzed a citywide electronic TB register in Blantyre, Malawi and interviewed TB officers. Malawi did not have an official COVID-19 lockdown but closed schools and borders on March 23, 2020. In an interrupted time series analysis, we noted an immediate 35.9% reduction in TB notifications in April 2020; notifications recovered to near prepandemic numbers by December 2020. However, 333 fewer cumulative TB notifications were received than anticipated. Women and girls were affected more (30.7% fewer cases) than men and boys (20.9% fewer cases). Fear of COVID-19 infection, temporary facility closures, inadequate personal protective equipment, and COVID-19 stigma because of similar symptoms to TB were mentioned as reasons for fewer people being diagnosed with TB. Public health measures could benefit control of both TB and COVID-19, but only if TB diagnostic services remain accessible and are considered safe to attend.

Effect of community-led delivery of HIV self-testing on HIV testing and antiretroviral therapy initiation in Malawi: A cluster-randomised trial.

BACKGROUND: Undiagnosed HIV infection remains substantial in key population subgroups including adolescents, older adults, and men, driving ongoing transmission in sub-Saharan Africa. We evaluated the impact, safety, and costs of community-led delivery of HIV self-testing (HIVST), aiming to increase HIV testing in underserved subgroups and stimulate demand for antiretroviral therapy (ART). METHODS AND FINDINGS: This cluster-randomised trial, conducted between October 2018 and July 2019, used restricted randomisation (1:1) to allocate 30 group village head clusters in Mangochi district, Malawi to the community-led HIVST intervention in addition to the standard of care (SOC) or the SOC alone. The intervention involved mobilising community health groups to lead the design and implementation of 7-day HIVST campaigns, with cluster residents (≥15 years) eligible for HIVST. The primary outcome compared lifetime HIV testing among adolescents (15 to 19 years) between arms. Secondary outcomes compared: recent HIV testing (in the last 3 months) among older adults (≥40 years) and men; cumulative 6-month incidence of ART initiation per 100,000 population; knowledge of the preventive benefits of HIV treatment; and HIV testing stigma. Outcomes were measured through a post-intervention survey and at neighboring health facilities. Analysis used intention-to-treat for cluster-level outcomes. Community health groups delivered 24,316 oral fluid-based HIVST kits. The survey included 90.2% (3,960/4,388) of listed participants in the 15 community-led HIVST clusters and 89.2% (3,920/4,394) of listed participants in the 15 SOC clusters. Overall, the proportion of men was 39.0% (3,072/7,880). Most participants obtained primary-level education or below, were married, and reported a sexual partner. Lifetime HIV testing among adolescents was higher in the community-led HIVST arm (84.6%, 770/910) than the SOC arm (67.1%, 582/867; adjusted risk difference [RD] 15.2%, 95% CI 7.5% to 22.9%; p < 0.001), especially among 15 to 17 year olds and boys. Recent testing among older adults was also higher in the community-led HIVST arm (74.5%, 869/1,166) than the SOC arm (31.5%, 350/1,111; adjusted RD 42.1%, 95% CI 34.9% to 49.4%; p < 0.001). Similarly, the proportions of recently tested men were 74.6% (1,177/1,577) and 33.9% (507/1,495) in the community-led HIVST and SOC arms, respectively (adjusted RD 40.2%, 95% CI 32.9% to 47.4%; p < 0.001). Knowledge of HIV treatment benefits and HIV testing stigma showed no differences between arms. Cumulative incidence of ART initiation was respectively 305.3 and 226.1 per 100,000 population in the community-led HIVST and SOC arms (RD 72.3, 95% CI -36.2 to 180.8; p = 0.18). In post hoc analysis, ART initiations in the 3-month post-intervention period were higher in the community-led HIVST arm than the SOC arm (RD 97.7, 95% CI 33.4 to 162.1; p = 0.004). HIVST uptake was 74.7% (2,956/3,960), with few adverse events (0.6%, 18/2,955) and at US$5.70 per HIVST kit distributed. The main limitations include the use of self-reported HIV testing outcomes and lack of baseline measurement for the primary outcome. CONCLUSIONS: In this study, we found that community-led HIVST was effective, safe, and affordable, with population impact and coverage rapidly realised at low cost. This approach could enable community HIV testing in high HIV prevalence settings and demonstrates potential for economies of scale and scope. TRIAL REGISTRATION: Clinicaltrials.gov NCT03541382.

Computer-aided X-ray screening for tuberculosis and HIV testing among adults with cough in Malawi (the PROSPECT study): A randomised trial and cost-effectiveness analysis.

BACKGROUND: Suboptimal tuberculosis (TB) diagnostics and HIV contribute to the high global burden of TB. We investigated costs and yield from systematic HIV-TB screening, including computer-aided digital chest X-ray (DCXR-CAD). METHODS AND FINDINGS: In this open, three-arm randomised trial, adults (≥18 years) with cough attending acute primary services in Malawi were randomised (1:1:1) to standard of care (SOC); oral HIV testing (HIV screening) and linkage to care; or HIV testing and linkage to care plus DCXR-CAD with sputum Xpert for high CAD4TBv5 scores (HIV-TB screening). Participants and study staff were not blinded to intervention allocation, but investigator blinding was maintained until final analysis. The primary outcome was time to TB treatment. Secondary outcomes included proportion with same-day TB treatment; prevalence of undiagnosed/untreated bacteriologically confirmed TB on day 56; and undiagnosed/untreated HIV. Analysis was done on an intention-to-treat basis. Cost-effectiveness analysis used a health-provider perspective. Between 15 November 2018 and 27 November 2019, 8,236 were screened for eligibility, with 473, 492, and 497 randomly allocated to SOC, HIV, and HIV-TB screening arms; 53 (11%), 52 (9%), and 47 (9%) were lost to follow-up, respectively. At 56 days, TB treatment had been started in 5 (1.1%) SOC, 8 (1.6%) HIV screening, and 15 (3.0%) HIV-TB screening participants. Median (IQR) time to TB treatment was 11 (6.5 to 38), 6 (1 to 22), and 1 (0 to 3) days (hazard ratio for HIV-TB versus SOC: 2.86, 1.04 to 7.87), with same-day treatment of 0/5 (0%) SOC, 1/8 (12.5%) HIV, and 6/15 (40.0%) HIV-TB screening arm TB patients (p = 0.03). At day 56, 2 SOC (0.5%), 4 HIV (1.0%), and 2 HIV-TB (0.5%) participants had undiagnosed microbiologically confirmed TB. HIV screening reduced the proportion with undiagnosed or untreated HIV from 10 (2.7%) in the SOC arm to 2 (0.5%) in the HIV screening arm (risk ratio [RR]: 0.18, 0.04 to 0.83), and 1 (0.2%) in the HIV-TB screening arm (RR: 0.09, 0.01 to 0.71). Incremental costs were US$3.58 and US$19.92 per participant screened for HIV and HIV-TB; the probability of cost-effectiveness at a US$1,200/quality-adjusted life year (QALY) threshold was 83.9% and 0%. Main limitations were the lower than anticipated prevalence of TB and short participant follow-up period; cost and quality of life benefits of this screening approach may accrue over a longer time horizon. CONCLUSIONS: DCXR-CAD with universal HIV screening significantly increased the timeliness and completeness of HIV and TB diagnosis. If implemented at scale, this has potential to rapidly and efficiently improve TB and HIV diagnosis and treatment. TRIAL REGISTRATION: clinicaltrials.gov NCT03519425.

The long term effect of pulmonary tuberculosis on income and employment in a low income, urban setting.

BACKGROUND: Mitigating the socioeconomic impact of tuberculosis (TB) is key to the WHO End TB Strategy. However, little known about socioeconomic well-being beyond TB-treatment completion. In this mixed-methods study, we describe socioeconomic outcomes after TB-disease in urban Blantyre, Malawi, and explore pathways and barriers to financial recovery. METHODS: Adults ≥15 years successfully completing treatment for a first episode of pulmonary TB under the National TB Control Programme were prospectively followed up for 12 months. Socioeconomic, income, occupation, health seeking and cost data were collected. Determinants and impacts of ongoing financial hardship were explored through illness narrative interviews with purposively selected participants. RESULTS: 405 participants were recruited from February 2016 to April 2017. Median age was 35 years (IQR: 28-41), 67.9% (275/405) were male, and 60.6% (244/405) were HIV-positive. Employment and incomes were lowest at TB-treatment completion, with limited recovery in the following year: fewer people were in paid work (63.0% (232/368) vs 72.4% (293/405), p=0.006), median incomes were lower (US$44.13 (IQR: US$0-US$106.15) vs US$72.20 (IQR: US$26.71-US$173.29), p<0.001), and more patients were living in poverty (earning

Durations of asymptomatic, symptomatic, and care-seeking phases of tuberculosis disease with a Bayesian analysis of prevalence survey and notification data.

BACKGROUND: Ratios of bacteriologically positive tuberculosis (TB) prevalence to notification rates are used to characterise typical durations of TB disease. However, this ignores the clinical spectrum of tuberculosis disease and potentially long infectious periods with minimal or no symptoms prior to care-seeking. METHODS: We developed novel statistical models to estimate progression from initial bacteriological positivity including smear conversion, symptom onset and initial care-seeking. Case-detection ratios, TB incidence, durations, and other parameters were estimated by fitting the model to tuberculosis prevalence survey and notification data (one subnational and 11 national datasets) within a Bayesian framework using Markov chain Monte Carlo methods. RESULTS: Analysis across 11 national datasets found asymptomatic tuberculosis durations in the range 4-8 months for African countries; three countries in Asia (Cambodia, Lao PDR, and Philippines) showed longer durations of > 1 year. For the six countries with relevant data, care-seeking typically began half-way between symptom onset and notification. For Kenya and Blantyre, Malawi, individual-level data were available. The sex-specific durations of asymptomatic bacteriologically-positive tuberculosis were 9.0 months (95% credible interval [CrI]: 7.2-11.2) for men and 8.1 months (95% CrI: 6.2-10.3) for women in Kenya, and 4.9 months (95% CrI: 2.6-7.9) for men and 3.5 months (95% CrI: 1.3-6.2) for women in Blantyre. Age-stratified analysis of data for Kenya showed no strong age-dependence in durations. For Blantyre, HIV-stratified analysis estimated an asymptomatic duration of 1.3 months (95% CrI: 0.3-3.0) for HIV-positive people, shorter than the 8.5 months (95% CrI: 5.0-12.7) for HIV-negative people. Additionally, case-detection ratios were higher for people living with HIV than HIV-negative people (93% vs 71%). CONCLUSION: Asymptomatic TB disease typically lasts around 6 months. We found no evidence of age-dependence, but much shorter durations among people living with HIV, and longer durations in some Asian settings. To eradicate TB transmission, greater gains may be achieved by proactively screening people without symptoms through active case finding interventions.

Pattern of abnormalities amongst chest X-rays of adults undergoing computer-assisted digital chest X-ray screening for tuberculosis in Peri-Urban Blantyre, Malawi: A cross-sectional study.

BACKGROUND: The prevalence of diseases other than tuberculosis (TB) detected during chest X-ray screening is poorly described in sub-Saharan Africa. Computer-assisted digital chest X-ray technology is available for TB screening and has the potential to be a screening tool for non-communicable diseases as well. Low- and middle-income countries are in a transition period where the burden of non-communicable diseases is increasing, but health systems are mainly focused on addressing infectious diseases. METHODS: Participants were adults undergoing computer-assisted chest X-ray screening for tuberculosis in a community-wide tuberculosis prevalence survey in Blantyre, Malawi. Adults with abnormal radiographs by field radiographer interpretation were evaluated by a physician in a community-based clinic. X-ray classifications were compared to classifications of a random sample of normal chest X-rays by radiographer interpretation. Radiographic features were classified using WHO Integrated Management for Adult Illnesses (IMAI) guidelines. All radiographs taken at the screening tent were analysed by the Qure.ai qXR v2.0 software. RESULTS: 5% (648/13,490) of adults who underwent chest radiography were identified to have an abnormal chest X-ray by the radiographer. 387 (59.7%) of the participants attended the X-ray clinic, and another 387 randomly sampled normal X-rays were available for comparison. Participants who were referred to the community clinic had a significantly higher HIV prevalence than those who had been identified to have a normal CXR by the field radiographer (90 [23.3%] vs. 43 [11.1%] p-value < 0.001). The commonest radiographic finding was cardiomegaly (20.7%, 95% CI 18.0-23.7). One in five (81/387) chest X-rays were misclassified by the radiographer. The overall mean Qure.ai qXR v2.0 score for all reviewed X-rays was 0.23 (SD 0.20). There was a high concordance of cardiomegaly classification between the physician and the computer-assisted software (109/118, 92.4%). CONCLUSION: There is a high burden of cardiomegaly on a chest X-ray at a community level, much of which is in patients with diabetes, heart disease and high blood pressure. Cardiomegaly on chest X-ray may be a potential tool for screening for cardiovascular NCDs at the primary care level as well as in the community.