Community tuberculosis screening, testing and care, Uganda.

Objective: To assess the effectiveness of a community-based tuberculosis and leprosy intervention in which village health teams and health workers conduct door-to-door tuberculosis screening, targeted screenings and contact tracing. Methods: We conducted a before-and-after implementation study in Uganda to assess the effectiveness of the community tuberculosis intervention by looking at reach, outputs, adoption and effectiveness of the intervention. Campaign 1 was conducted in March 2022 and campaign 2 in September 2022. We calculated percentages of targets achieved and compared case notification rates during the intervention with corresponding quarters in the previous year. We also assessed the leprosy screening. Findings: Over 5 days, campaign 1 screened 1 289 213 people (2.9% of the general population), of whom 179 144 (13.9%) fulfilled the presumptive tuberculosis criteria, and 4043 (2.3%) were diagnosed with bacteriologically-confirmed tuberculosis; 3710 (91.8%) individuals were linked to care. In campaign 2, 5 134 056 people (11.6% of the general population) were screened, detecting 428 444 (8.3%) presumptive tuberculosis patients and 8121 (1.9%) bacteriologically-confirmed tuberculosis patients; 5942 individuals (87.1%) were linked to care. The case notification rate increased from 48.1 to 59.5 per 100 000 population in campaign 1, with a case notification rate ratio of 1.24 (95% confidence interval, CI: 1.22-1.26). In campaign 2, the case notification rate increased from 45.0 to 71.6 per 100 000 population, with a case notification rate ratio of 1.59 (95% CI: 1.56-1.62). Of the 176 patients identified with leprosy, 137 (77.8%) initiated treatment. Conclusion: This community tuberculosis screening initiative is effective. However, continuous monitoring and adaptations are needed to overcome context-specific implementation challenges.

Chest Radiograph Screening for Detecting Subclinical Tuberculosis in Asymptomatic Household Contacts, Peru.

The World Health Organization's end TB strategy promotes the use of symptom and chest radiograph screening for tuberculosis (TB) disease. However, asymptomatic early states of TB beyond latent TB infection and active disease can go unrecognized using current screening criteria. We conducted a longitudinal cohort study enrolling household contacts initially free of TB disease and followed them for the occurrence of incident TB over 1 year. Among 1,747 screened contacts, 27 (52%) of the 52 persons in whom TB subsequently developed during follow-up had a baseline abnormal radiograph. Of contacts without TB symptoms, persons with an abnormal radiograph were at higher risk for subsequent TB than persons with an unremarkable radiograph (adjusted hazard ratio 15.62 [95% CI 7.74-31.54]). In young adults, we found a strong linear relationship between radiograph severity and time to TB diagnosis. Our findings suggest chest radiograph screening can extend to detecting early TB states, thereby enabling timely intervention.

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.

Assisted Partner Notification Services in Namibia: Comparison of Case-Finding in Persons With New and Previously Diagnosed Human Immunodeficiency Virus, and Success as a Platform for PrEP Referral.

BACKGROUND: Assisted partner notification services (APS) are widely implemented throughout sub-Saharan Africa. The effectiveness of APS among persons with previously diagnosed human immunodeficiency virus (HIV) infection is uncertain, and there are few published data on the success of integrating referrals for HIV preexposure prophylaxis (PrEP) into APS. METHODS: Staff in 22 Namibian Ministry of Health and Social Service clinics offered APS to patients newly and previously diagnosed with HIV (index cases [ICs]) between October 2019 and June 2021. Counselors used a structured interview guide to elicit ICs' sex partners and biological children and assisted ICs to arrange testing of contacts. Contacts testing HIV-positive were linked to HIV services and those 14 years or older testing negative were offered PrEP. The primary outcome was the case-finding index (contacts testing HIV-positive ÷ ICs receiving APS). RESULTS: Staff provided APS to 1222 (78%) of 1557 newly diagnosed ICs eliciting 1155 sex partners and 649 biological children. Among 280 previously diagnosed ICs, 279 sex partners and 158 biological children were elicited. The case-finding index was higher among ICs with newly diagnosed HIV compared with previously diagnosed HIV (0.14 vs 0.09, P = 0.46), though this difference was not statistically significant. Most sex partners testing HIV-negative were initiated on PrEP (67% in sex partners from newly diagnosed ICs; 74% in sex partners from previously diagnosed ICs). CONCLUSIONS: Assisted partner notification services successfully identified sex partners and biological children with undiagnosed HIV infection when provided to both newly and previously diagnosed ICs. Integration of referral to PrEP resulted in many HIV-negative partners initiating PrEP.

"The targets are driving the agenda and that probably needs to change": stakeholder perspectives on HIV partner notification in sub-Saharan Africa.

BACKGROUND: Voluntary assisted partner notification (VAPN) in HIV contact tracing is a globally recommended strategy to identify persons who have been exposed to HIV and link them to HIV testing and follow-up. However, there is little understanding about how VAPN is experienced by stakeholders in sub-Saharan African (SSA) contexts. We conducted a multi-level and multi-national qualitative analysis evaluating stakeholder perspectives surrounding VAPN implementation to inform the development of future VAPN policies. METHOD: We conducted in-depth interviews (IDIs) with VAPN stakeholders at global (n = 5), national (n = 6), and community level (n = 4) across a total of seven SSA countries. Eligible participants were ≥ 18 years old and had experience developing, implementing, or overseeing VAPN policies in SSA. We sought to understand stakeholder's perspectives on policy development, implementation, and perceived outcomes (barriers and facilitators). Interviews were audio recorded, transcribed, and analyzed thematically using a combination of inductive and deductive approaches. RESULTS: Between December 2019 and October 2020 we conducted 15 IDIs. While participants agreed that VAPN resulted in a high yield of people newly diagnosed with HIV; they noted numerous barriers surrounding VAPN implementation across global, national, and community levels, the majority of which were identified at community level. Barriers at global and national level included high target setting, contradictory laws, and limited independent research disenfranchising the experiences of implementing partners. The barriers identified at community level included client-level challenges (e.g., access to healthcare facilities and fear of adverse events); healthcare worker challenges (e.g., high workloads); limited data infrastructure; and cultural/gender norms that hindered women from engaging in HIV testing and VAPN services. In response to these barriers, participants shared implementation facilitators to sustain ethical implementation of VAPN services (e.g., contact tracing methods) and increase its yield (e.g., HIV self-testing integrated with VAPN services). CONCLUSION: Overall, stakeholders perceived VAPN implementation to encounter barriers across all implementation levels (global to community). Future VAPN policies should be designed around the barriers and facilitators identified by SSA stakeholders to maximize the implementation of (ethical) HIV VAPN services and increase its impact in sub-Saharan African settings.

Cost-effectiveness analysis of adding tuberculosis household contact investigation on passive case-finding strategy in Southwestern Uganda.

INTRODUCTION: The standard passive case-finding strategy implemented by most developing countries is inadequate to detect new cases of Tuberculosis. A household contact investigation is an alternative approach. However, there is limited cost-effectiveness data to support planning and implementation in low and middle-income countries. The study aimed to evaluate the cost-effectiveness of adding household contact investigation (HCI) to the passive case-finding (PCF) strategy in the Tuberculosis control program in Southwestern Uganda. METHODS: We conducted an economic evaluation using a retrospective study approach and bottom-up costing (ingredients) techniques. It was a synthesis-based evaluation of existing data extracted from the District Health Information System (DHIS 2), TB registers, and a primary cost survey. The study compared two methods of Tuberculosis (TB) case finding (PCF and HCI) strategies. Regarding PCF, patients either self-reported their signs and symptoms or were prompted by healthcare workers. At the same time, HCI was done by home visiting and screening contacts of TB patients. Patients and household contacts presumed to have Tuberculosis were requested to produce samples for analysis. We applied a static decision-analytic modeling framework to examine both strategies' costs and effectiveness. The study relied on cost and probability estimates from National Tuberculosis (TB) program data, activity costs, and published literature. It was performed from the societal and provider perspectives over 1.5 years across 12 facilities in Ntungamo, Sheema, and Rwampara Districts. The primary effectiveness measure was the number of TB cases detected (yield) and the number needed to screen (NNS). The TB yield was calculated from the number of patients screened during the period under study. The incremental cost-effectiveness ratio (ICER) was expressed as cost in 2021 US$ per additional TB case detected. We did not apply a discount rate because of the short analytic time horizon. RESULTS: The unit costs of detecting a Tuberculosis case were US$ (United States dollar) 204.22 for PCF and US$ 315.07 for HCI. Patient and caregiver costs are five times more in PCF than in HCI [US$26.37 Vs. US$ 5.42]. The ICER was US$ 3,596.94 per additional TB case detected. The TB screening yields were 0.52% (1496/289140) for passive case finding and 5.8% (197/3414) for household contact investigation. Household contact investigation yield among children 0-14 Vs. 15+ years [6.2% Vs.5.4%] P = 0.04. The Yield among People living with HIV (PLHIV) Vs. HIV-negative [15.8% Vs.5.3%] P = 0.03 in HHCI. The PCF yield in men Vs. Women [1.12% Vs.0.28%] P<0.01. The NNS in PCF was 193 [95% CI: 186-294] and 17 [95% CI: 14-22] in HCI. CONCLUSION: Our baseline assumptions and the specific implementations of adding HCI to existing PCF programs in the context of rural African settings prove to be not cost-effective, rather than HCI as a strategy. HCI effectively identifies children and PLHIV with TB and should be prioritized. Meanwhile, the Passive case-finding strategy effectively finds men with TB and costs lower than household contact investigation.

Improving Tuberculosis Case Detection in Children: Summary of Innovations and Findings From 18 Countries.

Despite a growing focus on the plight of tuberculosis (TB) among children, 56% of the 1.2 million children who develop TB annually are not detected and notified. TB REACH is a platform of the Stop TB Partnership that supports innovative interventions to improve TB case detection and preventative treatment. We present summary findings from 27 TB REACH-supported projects in 18 countries. Interventions were designed around intensified case-finding approaches (facility-based systematic screening and contact investigation), capacity building (including decentralized care delivery and supported decision-making), and improving diagnostic methods (ie, introduction of alternative respiratory specimens and new tools to aid the diagnosis). These interventions were evaluated on how they worked to identify children with TB, prevent further transmission of TB among children, and strengthen the health system involved with childhood TB care. Overall, 13 715 children were detected with TB, improving case notifications by 34%. In addition, nearly 5000 eligible contacts were enrolled on TB preventive treatment through these interventions. Focusing efforts and funding on childhood TB can produce marked improvements in case detection.

¿Cuál es el efecto de añadir estrategias de trazabilidad digitales a trazabilidad manual en contexto de brotes de enfermedades infecciosas como COVID-19?: síntesis rápida de evidencia / What is the effect of adding digital traceability strategies to manual traceability in the context of infectious disease outbreaks such as COVID-19?: rapid evidence of synthesis

ANTECEDENTES Y OBJETIVO La trazabilidad de contactos rápida y oportuna ha sido considerada clave para controlar la transmisión del SARS-CoV-2. Sin embargo, la efectividad de los métodos manuales o tradicionales de trazabilidad han sido cuestionados, y en su lugar o a modo complementario, distintas soluciones digitales se han desarrollado con el fin de facilitar la gestión, notificación y seguimiento de contactos y casos. En este contexto la Coordinación Nacional de Testeo Trazabilidad y Aislamiento solicita una síntesis de evidencia con el objetivo de evaluar la efectividad del uso complementario de sistemas digitales a los métodos manuales de trazabilidad. METODOLOGÍA Se buscaron revisiones sistemáticas en las bases de datos Embase y Medline a través de Ovid, y Epistemonikos, con fecha 25 de agosto de 2021. Además, se construyó una matriz de evidencia con el objetivo de encontrar literatura adicional. Se utiliza la metodología GRADE. Criterios de inclusión: sistemas de trazabilidad digital como softwares, plataformas o apps móviles; artículos que evaluaron trazabilidad manual complementada con sistemas digitales. Criterios de exclusión: dispositivos portátiles, enfermedades que no se enmarcaron en contexto de brote, artículos sobre "vigilancia epidemiológica" que no especifican sobre trazabilidad de contactos y que no evalúan la intervención. RESULTADOS Se recuperaron 5 revisiones sistemáticas, de las cuales se obtuvieron los siguientes resultados: -La evidencia de efecto disponible tiene certeza baja a muy baja, por lo que es muy probable que los resultados observados varíen con la publicación de nuevos y mejores estudios, a saber: • La inclusión de aplicaciones móviles automatizadas de trazabilidad podría reducir la transmisión de la enfermedad y aumentar el número de contactos en cuarentena por cada caso COVID-19. • El uso de sistemas digitales semi-automatizados podría aumentar el número de contactos identificados, y disminuir el tiempo hasta notificación o cuarentena, el tiempo laboral asociado y el número de personas encargadas de esta tarea. -La implementación de estas tecnologías requiere de una evaluación sobre impactos en equidad, costos, nivel de implementación (conectividad local y capacitación) y percepción de los usuarios.

Tuberculosis infection screening in children with close contact: a hospital-based study.

BACKGROUND: Identifying and prioritizing at-risk populations is critical for pediatric tuberculosis control. We aimed to identify a latent tuberculosis infection (LTBI) screening strategy that is appropriate for the Chinese context among children with different TB exposure levels and to explore its clinical importance. METHODS: During 2013-2015, we enrolled hospitalized children with suspected respiratory infectious disease (RID) for LTBI screening using the tuberculin skin test (TST) and interferon-γ release assay (IGRA) T-SPOT.TB as part of a work up for their RID. Participants with confirmed diagnosis were classified into three subgroups according to level of exposure to TB: no reported contact risk, with household contact risk, and with non-household contact risk. RESULTS: A total 6202 children (median age: 4.76 years; interquartile range: 1.0-8.0 years) were enrolled. Children with no reported contact risk had the lowest proportions of positive results for the IGRA (0.7%) and TST (3.3%). The proportion of positive results for each test was higher for household contacts than non-household contacts. The TST positive proportion was much higher than that for the IGRA in all three groups. Children with IGRA+/TST+ results had larger indurations than those with IGRA- /TST+ results (15 mm vs. 13 mm, P = 0.02). For IGRA, older age (> 5 years) and non-household or household contact risk were associated with a positive result. CONCLUSIONS: Positive IGRA results in children with a contact risk can serve as a critical reference for LTBI management. IGRA can be used, in preference to TST, for Chinese children with a TB exposure risk.

Mitigation of in-hospital risk of coronavirus disease 2019: Experience from a haematology-oncology and stem cell transplant setting.

Background: . Coronavirus disease 2019 (Covid-19) was first described in December 2019 and has evolved into an ongoing global pandemic. Cancer patients on chemotherapy are immunocompromised and are at the highest risk of Covid-19-related complications. We describe our experience with the management of haematology-oncology and stem cell transplant (SCT) patients receiving curative chemotherapy in a hospital with a high influx of Covid-19 patients. Methods: . We did a prospective observational study at a 99-bedded cancer centre of a tertiary care teaching hospital from April 2020 to September 2020. Preventive measures taken were categorized as follows: (i) staff: screening, mandatory use of personal protective equipment (PPE), risk stratification of potential exposure and testing and isolation as needed; (ii) patients: mandatory viral polymerase chain reaction testing, segregation of positive and untested patients and testing of family members; and (iii) environment: mandatory regular cleaning, visitor restriction, telemedicine services and reassignment of priority to clinic visits. Treatment of the underlying conditions was continued with added precautions. Results: . A total of 54 patients were included in the analysis, including 48 with haematological malignancies and 6 for stem cell therapy. Preventive measures were universally applied, and chemotherapy with a curative intent was initiated as per protocol. Three patients were detected to have Covid-19 infection before admission and one after the institution of chemotherapy. Nine patients died after the first cycle of chemotherapy, 2 due to severe Covid-19-related illness and 7 due to complications of chemotherapy or disease progression. Conclusions: . In the wake of the Covid-19 pandemic, treatment for haematological malignancies must continue while balancing the risk of Covid-19 infections. Our report emphasizes the effectiveness of measures such as hand hygiene, social isolation, patient segregation, use of masks and PPE and universal pre-treatment testing for Covid-19 in reducing the risk of infection in a high-risk clinical setting.

Improving child tuberculosis contact identification and screening in Lesotho: Results from a mixed-methods cluster-randomized implementation science study.

BACKGROUND: Child tuberculosis (TB) contact management is recommended for preventing TB in children but its implementation is suboptimal in high TB/HIV-burden settings. The PREVENT Study was a mixed-methods, clustered-randomized implementation study that evaluated the effectiveness and acceptability of a community-based intervention (CBI) to improve child TB contact management in Lesotho, a high TB burden country. METHODS: Ten health facilities were randomized to CBI or standard of care (SOC). CBI holistically addressed the complex provider-, patient-, and caregiver-related barriers to prevention of childhood TB. Routine TB program data were abstracted from TB registers and cards for all adult TB patients aged >18 years registered during the study period, and their child contacts. Primary outcome was yield (number) of child contacts identified and screened per adult TB patient. Generalized linear mixed models tested for differences between study arms. CBI acceptability was assessed via semi-structured in-depth interviews with a purposively selected sample of 20 healthcare providers and 28 caregivers. Qualitative data were used to explain and confirm quantitative results. We used thematic analysis to analyze the data. RESULTS: From 01/2017-06/2018, 973 adult TB patients were recorded, 490 at CBI and 483 at SOC health facilities; 64% male, 68% HIV-positive. At CBI and SOC health facilities, 216 and 164 child contacts were identified, respectively (p = 0.16). Screening proportions (94% vs. 62%, p = 0.13) were similar; contact yield per TB case (0.40 vs. 0.20, p = 0.08) was higher at CBI than SOC health facilities, respectively. CBI was acceptable to caregivers and healthcare providers. CONCLUSION: Identification and screening for TB child contacts were similar across study arms but yield was marginally higher at CBI compared with SOC health facilities. CBI scale-up may enhance the ability to reach and engage child TB contacts, contributing to efforts to improve TB prevention among children.

An Evolutionary Portrait of the Progenitor SARS-CoV-2 and Its Dominant Offshoots in COVID-19 Pandemic.

Global sequencing of genomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to reveal new genetic variants that are the key to unraveling its early evolutionary history and tracking its global spread over time. Here we present the heretofore cryptic mutational history and spatiotemporal dynamics of SARS-CoV-2 from an analysis of thousands of high-quality genomes. We report the likely most recent common ancestor of SARS-CoV-2, reconstructed through a novel application and advancement of computational methods initially developed to infer the mutational history of tumor cells in a patient. This progenitor genome differs from genomes of the first coronaviruses sampled in China by three variants, implying that none of the earliest patients represent the index case or gave rise to all the human infections. However, multiple coronavirus infections in China and the United States harbored the progenitor genetic fingerprint in January 2020 and later, suggesting that the progenitor was spreading worldwide months before and after the first reported cases of COVID-19 in China. Mutations of the progenitor and its offshoots have produced many dominant coronavirus strains that have spread episodically over time. Fingerprinting based on common mutations reveals that the same coronavirus lineage has dominated North America for most of the pandemic in 2020. There have been multiple replacements of predominant coronavirus strains in Europe and Asia as well as continued presence of multiple high-frequency strains in Asia and North America. We have developed a continually updating dashboard of global evolution and spatiotemporal trends of SARS-CoV-2 spread (http://sars2evo.datamonkey.org/).

Ethical issues in managing the COVID-19 pandemic.

The COVID-19 pandemic has had an immense and worldwide impact. In light of future pandemics or subsequent waves of COVID-19 it is crucial to focus on the ethical issues that were and still are raised in this COVID-19 crisis. In this paper, we look at issues that are raised in the testing and tracing of patients with COVID-19. We do this by highlighting and expanding on an approach suggested by Fineberg that could serve as a public health approach. In this way, we highlight several ethical issues. As regards testing, questions are raised such as whether it is ethical to use less reliable tests in order to increase testing capacity or minimize harm for patients. Another issue is how wide testing should be and whether selective testing is in accordance with principles of social justice. Patients who have recovered from COVID-19 might have some degree of immunity but attributing certain 'immunopriviliges' raises ethical questions. The use of various tracing methodologies (mobile apps or databases and trained tracers) raised evident questions of social justice and privacy. We argue why it is key to always uphold a test of proportionality where a fair balance must be sought.

The epidemiological impact of the NHS COVID-19 app.

The COVID-19 pandemic has seen the emergence of digital contact tracing to help to prevent the spread of the disease. A mobile phone app records proximity events between app users, and when a user tests positive for COVID-19, their recent contacts can be notified instantly. Theoretical evidence has supported this new public health intervention1-6, but its epidemiological impact has remained uncertain7. Here we investigate the impact of the National Health Service (NHS) COVID-19 app for England and Wales, from its launch on 24 September 2020 to the end of December 2020. It was used regularly by approximately 16.5 million users (28% of the total population), and sent approximately 1.7 million exposure notifications: 4.2 per index case consenting to contact tracing. We estimated that the fraction of individuals notified by the app who subsequently showed symptoms and tested positive (the secondary attack rate (SAR)) was 6%, similar to the SAR for manually traced close contacts. We estimated the number of cases averted by the app using two complementary approaches: modelling based on the notifications and SAR gave an estimate of 284,000 (central 95% range of sensitivity analyses 108,000-450,000), and statistical comparison of matched neighbouring local authorities gave an estimate of 594,000 (95% confidence interval 317,000-914,000). Approximately one case was averted for each case consenting to notification of their contacts. We estimated that for every percentage point increase in app uptake, the number of cases could be reduced by 0.8% (using modelling) or 2.3% (using statistical analysis). These findings support the continued development and deployment of such apps in populations that are awaiting full protection from vaccines.

Quantified TB Exposure Can Predict Prevalent TB Disease in Child Contacts.

In a matched case-control study in Pakistan, we found that quantified tuberculosis (TB) exposure using a 10-point score is associated with prevalent TB disease in pediatric household contacts. A 1 unit increase in TB exposure score increased the odds of TB disease by 44% (conditional odds ratio: 1.44, 95% confidence interval: 1.33-1.56). Collecting well-documented exposure history can help TB diagnosis in resource-limited settings.

Assessing the feasibility and effectiveness of household-pooled universal testing to control COVID-19 epidemics.

Outbreaks of SARS-CoV-2 are threatening the health care systems of several countries around the world. The initial control of SARS-CoV-2 epidemics relied on non-pharmaceutical interventions, such as social distancing, teleworking, mouth masks and contact tracing. However, as pre-symptomatic transmission remains an important driver of the epidemic, contact tracing efforts struggle to fully control SARS-CoV-2 epidemics. Therefore, in this work, we investigate to what extent the use of universal testing, i.e., an approach in which we screen the entire population, can be utilized to mitigate this epidemic. To this end, we rely on PCR test pooling of individuals that belong to the same households, to allow for a universal testing procedure that is feasible with the limited testing capacity. We evaluate two isolation strategies: on the one hand pool isolation, where we isolate all individuals that belong to a positive PCR test pool, and on the other hand individual isolation, where we determine which of the individuals that belong to the positive PCR pool are positive, through an additional testing step. We evaluate this universal testing approach in the STRIDE individual-based epidemiological model in the context of the Belgian COVID-19 epidemic. As the organisation of universal testing will be challenging, we discuss the different aspects related to sample extraction and PCR testing, to demonstrate the feasibility of universal testing when a decentralized testing approach is used. We show through simulation, that weekly universal testing is able to control the epidemic, even when many of the contact reductions are relieved. Finally, our model shows that the use of universal testing in combination with stringent contact reductions could be considered as a strategy to eradicate the virus.

The long-term impact of the Leprosy Post-Exposure Prophylaxis (LPEP) program on leprosy incidence: A modelling study.

BACKGROUND: The Leprosy Post-Exposure Prophylaxis (LPEP) program explored the feasibility and impact of contact tracing and the provision of single dose rifampicin (SDR) to eligible contacts of newly diagnosed leprosy patients in Brazil, India, Indonesia, Myanmar, Nepal, Sri Lanka and Tanzania. As the impact of the programme is difficult to establish in the short term, we apply mathematical modelling to predict its long-term impact on the leprosy incidence. METHODOLOGY: The individual-based model SIMCOLEP was calibrated and validated to the historic leprosy incidence data in the study areas. For each area, we assessed two scenarios: 1) continuation of existing routine activities as in 2014; and 2) routine activities combined with LPEP starting in 2015. The number of contacts per index patient screened varied from 1 to 36 between areas. Projections were made until 2040. PRINCIPAL FINDINGS: In all areas, the LPEP program increased the number of detected cases in the first year(s) of the programme as compared to the routine programme, followed by a faster reduction afterwards with increasing benefit over time. LPEP could accelerate the reduction of the leprosy incidence by up to six years as compared to the routine programme. The impact of LPEP varied by area due to differences in the number of contacts per index patient included and differences in leprosy epidemiology and routine control programme. CONCLUSIONS: The LPEP program contributes significantly to the reduction of the leprosy incidence and could potentially accelerate the interruption of transmission. It would be advisable to include contact tracing/screening and SDR in routine leprosy programmes.

Epidemiological analysis of a COVID-19 outbreak associated with an infected surgeon.

Control of the novel COronaVIrus Disease-2019 (COVID-19) in a hospital setting is a priority. A COVID-19-infected surgeon performed surgical activities before being tested. An exposure risk classification was applied to the identified exposed subjects and high- and medium-risk contacts underwent active symptom monitoring for 14 days at home. All healthcare professionals (HCPs) were tested for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) at the end of the quarantine and serological tests were performed. Three household contacts and 20 HCPs were identified as high- or medium-risk contacts and underwent a 14-day quarantine. Fourteen HCPs and 19 patients were instead classified as low risk. All the contacts remained asymptomatic and all HCPs tested negative for SARS-CoV-2. About 25-28 days after their last exposure, HCPs underwent serological testing and two of them had positive IgM but negative confirmatory swabs. In a low COVID-19 burden area, the in-hospital transmission of SARS-CoV-2 from an infectious doctor did not occur and, despite multiple and frequent contacts, a hospital outbreak was avoided. This may be linked to the adoption of specific recommendations and to the use of standard personal protective equipment by HCPs.

SARS-CoV-2 outbreak in a tri-national urban area is dominated by a B.1 lineage variant linked to a mass gathering event.

The first case of SARS-CoV-2 in Basel, Switzerland was detected on February 26th 2020. We present a phylogenetic study to explore viral introduction and evolution during the exponential early phase of the local COVID-19 outbreak from February 26th until March 23rd. We sequenced SARS-CoV-2 naso-oropharyngeal swabs from 746 positive tests that were performed at the University Hospital Basel during the study period. We successfully generated 468 high quality genomes from unique patients and called variants with our COVID-19 Pipeline (COVGAP), and analysed viral genetic diversity using PANGOLIN taxonomic lineages. To identify introduction and dissemination events we incorporated global SARS-CoV-2 genomes and inferred a time-calibrated phylogeny. Epidemiological data from patient questionnaires was used to facilitate the interpretation of phylogenetic observations. The early outbreak in Basel was dominated by lineage B.1 (83·6%), detected first on March 2nd, although the first sample identified belonged to B.1.1. Within B.1, 68·2% of our samples fall within a clade defined by the SNP C15324T ('Basel cluster'), including 157 identical sequences at the root of the 'Basel cluster', some of which we can specifically trace to regional spreading events. We infer the origin of B.1-C15324T to mid-February in our tri-national region. The other genomes map broadly over the global phylogenetic tree, showing several introduction events from and/or dissemination to other regions of the world via travellers. Family transmissions can also be traced in our data. A single lineage variant dominated the outbreak in the Basel area while other lineages, such as the first (B.1.1), did not propagate. A mass gathering event was the predominant initial source of cases, with travel returners and family transmissions to a lesser extent. We highlight the importance of adding specific questions to epidemiological questionnaires, to obtain data on attendance of large gatherings and their locations, as well as travel history, to effectively identify routes of transmissions in up-coming outbreaks. This phylogenetic analysis in concert with epidemiological and contact tracing data, allows connection and interpretation of events, and can inform public health interventions. Trial Registration: ClinicalTrials.gov NCT04351503.