Phylodynamic analysis reveals disparate transmission dynamics of -complex lineages in Botswana.

Tuberculosis epidemics have traditionally been conceptualized as arising from a single uniform pathogen. However, -complex (Mtbc), the pathogen causing tuberculosis in humans, encompasses multiple lineages exhibiting genetic and phenotypic diversity that may be responsible for heterogeneity in TB transmission. We analysed a population-based dataset of 1,354 Mtbc whole-genome sequences collected over four years in Botswana, a country with high HIV and tuberculosis burden.

Using genomic epidemiology and geographic activity spaces to investigate tuberculosis outbreaks in Botswana.

Background: The integration of genomic and geospatial data into infectious disease transmission analyses typically includes residential locations and excludes other activity spaces where transmission may occur ( work, school, or social venues). The objective of this analysis was to explore residential as well as other activity spaces of tuberculosis (TB) outbreaks to identify potential geospatial 'hotspots' of transmission.

Methods: We analyzed data that included geospatial coordinates for residence and other activity spaces collected during 2012-2016 for the Kopanyo Study, a population-based study of TB transmission in Botswana.

Experience of Public Health Departments in Implementation of COVID-19 Case Investigation and Contact Tracing Programs.

Objective: Case investigation and contact tracing (CI/CT) are fundamental public health efforts widely used during the COVID-19 pandemic to mitigate transmission. This study investigated how state, local, and tribal public health departments used CI/CT during the COVID-19 pandemic, including CI/CT methodology, staffing models, training and support, and efforts to identify or prioritize populations disproportionately affected by COVID-19.

Methods: During March and April 2022, we conducted key informant interviews with up to 3 public health officials from 43 state, local, and tribal public health departments.

Representativeness of a national, probability-based panel survey of COVID-19 isolation practices-United States, 2020-2022.

The U.S. Centers for Disease Control and Prevention (CDC) received surveillance data on how many people tested positive for SARS-CoV-2, but there was little information about what individuals did to mitigate transmission.

Design and Modification of COVID-19 Case Investigation and Contact Tracing Interview Scripts Used by Health Departments Throughout the COVID-19 Pandemic.

Objectives: We sought to (1) document how health departments (HDs) developed COVID-19 case investigation and contact tracing (CI/CT) interview scripts and the topics covered, and (2) understand how and why HDs modified those scripts.

Design: Qualitative analysis of CI/CT interview scripts and in-depth key informant interviews with public health officials in 14 HDs. Collected scripts represent 3 distinct points (initial, the majority of which were time stamped May 2020; interim, spanning from September 2020 to August 2021; and current, as of April 2022).

Home-Based Testing and COVID-19 Isolation Recommendations, United States.

Using a nationally representative panel survey, we examined isolation behaviors among persons in the United States who had positive SARS-CoV-2 test results during January 2021-March 2022. Compared with persons who received provider-administered results, persons with home-based results had 29% (95% CI 5%-47%) lower odds of following isolation recommendations.

Use of High-Resolution Geospatial and Genomic Data to Characterize Recent Tuberculosis Transmission, Botswana.

Combining genomic and geospatial data can be useful for understanding Mycobacterium tuberculosis transmission in high-burden tuberculosis (TB) settings. We performed whole-genome sequencing on M. tuberculosis DNA extracted from sputum cultures from a population-based TB study conducted in Gaborone, Botswana, during 2012-2016.

Isolation and Quarantine for Coronavirus Disease 2019 in the United States, 2020-2022.

Background: Public health programs varied in ability to reach people with coronavirus disease 2019 (COVID-19) and their contacts to encourage separation from others. For both adult case patients with COVID-19 and their contacts, we estimated the impact of contact tracing activities on separation behaviors from January 2020 until March 2022.

Methods: We used a probability-based panel survey of a nationally representative sample to gather data for estimates and comparisons.

Experiences with COVID-19 case investigation and contact tracing: A qualitative analysis.

Case investigation and contact tracing (CI/CT) is a critical part of the public health response to COVID-19. Individuals' experiences with CI/CT for COVID-19 varied based on geographic location, changes in knowledge and guidelines, access to testing and vaccination, as well as demographic characteristics including age, race, ethnicity, income, and political ideology. In this paper, we explore the experiences and behaviors of adults with positive SARS-CoV-2 test results, or who were exposed to a person with COVID-19, to understand their knowledge, motivations, and facilitators and barriers to their actions.

Estimated Cases Averted by COVID-19 Digital Exposure Notification, Pennsylvania, USA, November 8, 2020-January 2, 2021.

We combined field-based data with mathematical modeling to estimate the effectiveness of smartphone-enabled COVID-19 exposure notification in Pennsylvania, USA. We estimated that digital notifications potentially averted 7-69 cases/1,000 notifications during November 8, 2020-January 2, 2021. Greater use and increased compliance could increase the effectiveness of digital notifications.

Influence of COVID-19 for delaying the diagnosis and treatment of pulmonary tuberculosis-Tianjin, China.

Background: The COVID-19 pandemic has disrupted the diagnosis, treatment, and care for tuberculosis (TB). Delays in seeking TB care may result in increased community transmission and unfavorable treatment outcomes. We sought to understand the influence of the COVID-19 pandemic on the proportion of patients with TB who delayed seeking the diagnosis and care for TB and explore the reasons for their postponement.

High Community Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Associated With Decreased Contact Tracing Effectiveness for Identifying Persons at Elevated Risk of Infection-Vermont.

Vermont contact tracing consistently identified people at risk for coronavirus disease 2019 (COVID-19). However, the prevalence ratio (PR) of COVID-19 among contacts compared with noncontacts when viral transmission was high (PR, 13.5 [95% confidence interval {CI}, 13.

Characterizing tuberculosis transmission dynamics in high-burden urban and rural settings.

Mycobacterium tuberculosis transmission dynamics in high-burden settings are poorly understood. Growing evidence suggests transmission may be characterized by extensive individual heterogeneity in secondary cases (i.e.

Isoniazid-associated pellagra during mass scale-up of tuberculosis preventive therapy: a case-control study.

Background: Pellagra is caused by niacin (vitamin B3) deficiency and patients with pellagra present with a characteristic rash. Isoniazid disrupts intracellular niacin synthesis and might induce niacin deficiency. In 2017, Malawi scaled up continuous isoniazid preventive treatment (IPT) for tuberculosis prevention among people living with HIV.

Tuberculosis attributed to transmission within healthcare facilities, Botswana-The Kopanyo Study.

Objective: Healthcare facilities are a well-known high-risk environment for transmission of , the etiologic agent of tuberculosis (TB) disease. However, the link between transmission in healthcare facilities and its role in the general TB epidemic is unknown. We estimated the proportion of overall TB transmission in the general population attributable to healthcare facilities.

Estimated COVID-19 Cases and Hospitalizations Averted by Case Investigation and Contact Tracing in the US.

Importance: Evidence of the impact of COVID-19 case investigation and contact tracing (CICT) programs is lacking, but policy makers need this evidence to assess the value of such programs.

Objective: To estimate COVID-19 cases and hospitalizations averted nationwide by US states' CICT programs.

Design, Setting, And Participants: This decision analytical model study used combined data from US CICT programs (eg, proportion of cases interviewed, contacts notified or monitored, and days to case and contact notification) with incidence data to model outcomes of CICT over a 60-day period (November 25, 2020, to January 23, 2021).

Overseas Treatment of Latent Tuberculosis Infection in US-Bound Immigrants.

Seventy percent of tuberculosis (TB) cases in the United States occur among non-US-born persons; cases usually result from reactivation of latent TB infection (LTBI) likely acquired before the person's US arrival. We conducted a prospective study among US immigrant visa applicants undergoing the required overseas medical examination in Vietnam. Consenting applicants >15 years of age were offered an interferon-γ release assay (IGRA); those 12-14 years of age received an IGRA as part of the required examination.

COVID-19 Contact Tracing Outcomes in Washington State, August and October 2020.

Case investigation and contact tracing are important tools to limit the spread of SARS-CoV-2, particularly when implemented efficiently. Our objective was to evaluate participation in and timeliness of COVID-19 contact tracing and whether these measures changed over time. We retrospectively assessed COVID-19 case investigation and contact tracing surveillance data from the Washington State centralized program for August 1-31, 2020 and October 1-31, 2020.

Estimates of Cases and Hospitalizations Averted by COVID-19 Case Investigation and Contact Tracing in 14 Health Jurisdictions in the United States.

Context: The implementation of case investigation and contact tracing (CICT) for controlling COVID-19 (caused by SARS-CoV-2 virus) has proven challenging due to varying levels of public acceptance and initially constrained resources, especially enough trained staff. Evaluating the impacts of CICT will aid efforts to improve such programs.

Objectives: Estimate the number of COVID-19 cases and hospitalizations averted by CICT and identify CICT processes that could improve overall effectiveness.

Use of SMS-linked electronic surveys for COVID-19 case investigation and contact tracing - Marin County, CA, USA.

Objectives: We sought to quantify the proportion of contacts reported by persons with COVID-19 through a short message service (SMS)-linked survey in comparison to the proportion of contacts reported during a follow-up phone-interview. We also sought to assess improvement in contact tracing timeliness associated with sending SMS-linked surveys.

Study Design: During December 4-15, 2020, persons identified as COVID-19 cases whose data was entered into Marin County's contact tracing database on even days received a SMS-linked survey and persons whose data was entered on odd days did not; all were called for case investigation and contact tracing.

COVID-19 Case Investigation and Contact Tracing in the US, 2020.

Importance: Contact tracing is a multistep process to limit SARS-CoV-2 transmission. Gaps in the process result in missed opportunities to prevent COVID-19.

Objective: To quantify proportions of cases and their contacts reached by public health authorities and the amount of time needed to reach them and to compare the risk of a positive COVID-19 test result between contacts and the general public during 4-week assessment periods.

Early-phase scale-up of isoniazid preventive therapy for people living with HIV in two districts in Malawi (2017).

Background: Isoniazid preventive therapy (IPT) against tuberculosis (TB) is a life-saving intervention for people living with HIV (PLHIV). In September 2017, Malawi began programmatic scale-up of IPT to eligible PLHIV in five districts with high HIV and TB burden. We measured the frequency and timeliness of early-phase IPT implementation to inform quality-improvement processes.

COVID-19 Case Investigation and Contact Tracing in Central Washington State, June-July 2020.

Objective: To evaluate participation in COVID-19 case investigation and contact tracing in central Washington State between June 15 and July 12, 2020.

Methods: In this retrospective observational evaluation we combined SARS-CoV-2 RT-PCR and antigen test reports from the Washington Disease Reporting System with community case investigation and contact tracing data for 3 health districts (comprising 5 counties) in central Washington State. All 3 health districts have large Hispanic communities disproportionately affected by COVID-19.