Progress towards the elimination of hepatitis B in children in Colombia: A novel two-phase study approach.

The World Health Organization (WHO) has established a target to eliminate mother-to-child-transmission (EMTCT) of hepatitis B virus (HBV), defined as a prevalence of hepatitis B surface antigen (HBsAg) of ≤0.1% among children, by 2030. Using nationally representative serosurveys to verify achievement of this target requires large sample sizes and significant resources. We assessed the feasibility of a potentially more efficient two-phase method to verify EMTCT of HBV in Colombia. In the first phase, we conducted a risk assessment to identify municipalities at the highest risk of ongoing HBV transmission. We ranked the 1122 municipalities of Colombia based on the reports of HBV infection in pregnant women per 1000 population. Municipalities with ≥0.3 reports per 1000 persons (equating to the top quartile) were further assessed based on health facility birth rates, coverage with three doses of hepatitis B vaccine (HepB3) and seroprevalence data. Hepatitis B risk was considered to be further increased for municipalities with HepB3 coverage or health facility birth rate <90%. In the second phase, we conducted a multistage household serosurvey of children aged 5-10 years in 36 municipalities with the highest assessed HBV risk. HBsAg was not detected in any of 3203 children tested, yielding a 90% upper confidence bound of <0.1% prevalence. Coverage with HepB3 and hepatitis B birth dose was high at 97.5% and 95.6%, respectively. These results support the conclusion that Colombia has likely achieved EMTCT of HBV.

Is tuberculosis elimination a feasible goal in Colombia by 2050?

Colombia has an underreporting of 30% of the total cases, according to World Health Organization (WHO) estimations. In 2016, successful tuberculosis (TB) treatment rate was 70%, and the mortality rate ranged between 3.5% and 10%. In 2015, Colombia adopted and adapted the End TB strategy and set a target of 50% reduction in incidence and mortality by 2035 compared with 2015. The aims of this study were: To evaluate whether Colombia will be able to achieve the goals of TB incidence and mortality by 2050, using the current strategies; and whether the implementation of new screening, diagnosis and TB treatment strategies will allow to achieve those WHO targets. An ecological study was conducted using TB case-notification, successful treatment and mortality rates from the last 8 years (2009-17). System dynamics analysis was performed using simulated scenarios: (1) continuation with the same trends following the trajectory of the last 8 years (Status quo) and (2) modification of the targets between 2017 through 2050, assuming the implementation of multimodal strategies to increase the screening, to improve the early diagnosis and to improve the treatment adherence. Following the current strategies, it is projected that Colombia will not achieve the End TB strategy targets. Achieving the goal of TB incidence of 10/100 000 by 2050 will only be possible by implementing combined strategies for increasing screening of people with respiratory symptoms, improving access to rapid diagnostic tests and improving treatment adherence. Therefore, it is necessary to design and implement simultaneous strategies according to the population needs and resources, in order to stride towards the End TB targets.