Investigation of contacts of patients with tuberculosis (TB) is a priority for TB control in high-income countries, and is increasingly being considered in resource-limited settings. This review was commissioned for a World Health Organization Expert Panel to develop global contact investigation guidelines.We performed a systematic review and meta-analysis of all studies reporting the prevalence of TB and latent TB infection, and the annual incidence of TB among contacts of patients with TB.After screening 9,555 titles, we included 203 published studies. In 95 studies from low- and middle-income settings, the prevalence of active TB in all contacts was 3.1% (95% CI 2.2–4.4%, I²=99.4%), microbiologically proven TB was 1.2% (95% CI 0.9–1.8%, I²=95.9%), and latent TB infection was 51.5% (95% CI 47.1–55.8%, I²=98.9%). The prevalence of TB among household contacts was 3.1% (95% CI 2.1–4.5%, I²=98.8%) and among contacts of patients with multidrug-resistant or extensively drug-resistant TB was 3.4% (95% CI 0.8–12.6%, I²=95.7%). Incidence was greatest in the first year after exposure. In 108 studies from high-income settings, the prevalence of TB among contacts was 1.4% (95% CI 1.1–1.8%, I²=98.7%), and the prevalence of latent infection was 28.1% (95% CI 24.2–32.4%, I²=99.5%). There was substantial heterogeneity among published studies.Contacts of TB patients are a high-risk group for developing TB, particularly within the first year. Children <5 yrs of age and people living with HIV are particularly at risk. Policy recommendations must consider evidence of the cost-effectiveness of various contact tracing strategies, and also incorporate complementary strategies to enhance case finding.

Active case finding is a top priority for the global control of tuberculosis, but robust evidence for its effectiveness in high-prevalence settings is lacking. We sought to evaluate the effectiveness of household-contact investigation, as compared with standard, passive measures alone, in Vietnam.

Around one third of the world's population may harbour latent tuberculosis infection (LTBI), an asymptomatic immunological state that confers a heightened risk of subsequently developing tuberculosis (TB). Effectively treating LTBI will be essential if the End TB Strategy is to be realized. This review evaluates the evidence in relation to the effectiveness of preventive antibiotic therapy to treat LTBI due to both drug-susceptible and drug-resistant bacteria. Current national and international preventive therapy guidelines are summarized, as well as ongoing randomized trials evaluating regimens to prevent drug-resistant TB. Populations that may benefit most from screening and treatment for LTBI include close contacts of patients with TB (particularly children under 5 years of age) and individuals with substantial immunological impairment. The risks and benefits of treatment must be carefully balanced for each individual. Electronic decision support tools offer one way in which clinicians can help patients to make informed decisions. Modelling studies indicate that the expanded use of preventive therapy will be essential to achieving substantial reductions in the global TB burden. However, the widespread scale-up of screening and treatment will require careful consideration of cost-effectiveness, while ensuring the drivers of ongoing disease transmission are also addressed.

The global drive to vaccinate against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) began in December 2020 with countries in Europe, Middle East, and North America leading the roll out of a mass-vaccination program. This systematic review synthesised all available English-language guidelines and research regarding mass-vaccination for COVID-19 until 1 March 2021—the first three months of the global mass-vaccination effort. Data were extracted from national websites, PubMed, Embase, Medline and medRxiv, including peer and non-peer review research findings. A total of 15 national policy documents were included. Policies were summarised according to the World Health Organisation (WHO) framework for mass vaccination. All included policies prioritised front-line health care workers and the elderly. Limited information was available regarding staffing, cold chain, communication strategies and infrastructure requirements for effective vaccine delivery. A total of 26 research studies were identified, reporting roll-out strategies, vaccine uptake and reasons for refusal, adverse effects, and real-life estimates of efficacy. Early data showed a reduction in SARS-CoV-2 cases, hospitalisation and deaths in settings with good coverage. Very low rates of vaccine-related serious adverse events were observed. These findings provide an overview of current practice and early outcomes of COVID-19 mass-vaccination, guiding countries where roll-out is yet to commence.

Ensuring patients fully adhere to their treatment is a major challenge for TB control programmes in resource-limited settings. This study was conducted three outpatient tuberculosis clinics in Hanoi, Vietnam. We aimed to evaluate the feasibility of using asynchronous Video Directly Observed Therapy (VDOT) to support treatment adherence among patients with bacteriologically confirmed pulmonary tuberculosis. In this cohort study, consecutive adult patients with bacteriologically confirmed pulmonary TB were invited to enroll in a programme of VDOT. Patients were trained to use a smartphone to record themselves taking treatment for TB. Videos were uploaded to an online server and reviewed daily by study staff for at least two months. Adherence was evaluated based upon monthly pill count. Between November 2016 and January 2017, 40 of 78 eligible participants (51.3%) agreed to commence VDOT. Among participating patients, 27 (71.1%) of patients took all required doses. A median of 88.4% (interquartile range 75.8%-93.7%) of doses were correctly recorded and uploaded. Participants rated the VDOT interface highly, despite facing some initial technical difficulties. VDOT was feasible and resulted in high rates of treatment adherence in a resource-limited setting.