ABSTRACT
Heteroresistance in MTB refers to the presence of distinct subpopulations of bacteria with varying levels of antibiotic susceptibility within a population. Multidrug-resistant and rifampicin-resistant TB are serious global health concerns. In this study, we aimed to determine the prevalence of heteroresistance in MTB from sputum samples of new TB cases using Droplet Digital PCR mutation detection assays for katG and rpoB genes, which are commonly associated with resistance to isoniazid and rifampicin, respectively. We found that out of 79 samples, 9 (11.4%) exhibited mutations in katG and rpoB genes. INH mono-resistant TB, RIF mono-resistant TB, and MDR-TB samples constituted 1.3%, 6.3%, and 3.8% of new TB cases, respectively. Heteroresistance in katG, rpoB, and both genes were found in 2.5%, 5%, and 2.5% of total cases, respectively. Our results suggest that these mutations may have arisen spontaneously, as the patients had not yet received anti-TB drugs. ddPCR is a valuable tool for the early detection and management of DR-TB, as it can detect both mutant and wild-type strains in a population, enabling the detection of heteroresistance and MDR-TB. Overall, our findings highlight the importance of early detection and management of DR-TB for effective TB control (in katG, rpoB, and katG/rpoB).
ABSTRACT
Tuberculosis (TB) is one of the top 10 causes of death worldwide. It is challenging to find methods of diagnosis of active pulmonary TB that are sensitive enough to detect cases for proper treatment before unintentional transmission. Droplet digital PCR (ddPCR) is a highly sensitive method to detect genetic material of pathogens, but it has rarely been used for diagnosis of TB. This study compared the sensitivity of ddPCR with that of GeneXpert and AFB smear microscopy in 180 leftover sputum samples from patients suspected of having TB on the basis of clinical symptoms and radiography. Absolute quantification of copy numbers of MTB-specific genes was possible using ddPCR targeting the mpt64 gene. Among the 180 samples, 41.1% were diagnosed as having TB using ddPCR. The sensitivities of AFB smear microscopy, GeneXpert and ddPCR were 41.9%, 82.4% and 100%, respectively. AFB smear microscopy and GeneXpert both had a specificity of 100%, and the specificity of ddPCR was 95.3%. The accuracy of ddPCR (97.2%) is higher than that of GeneXpert (92.7%). This robust ddPCR system could potentially be used as a method for early diagnosis of TB.
ABSTRACT
Background: Myanmar is a country undergoing rapid transitions in health. Its national strategic policy for young people's health is being revised but there is a paucity of population data to inform local priorities and needs. Objective: In this paper we describe a comprehensive profile of adolescent health in Myanmar to focus policy and health actions. Methods: We used available primary data, and modelled estimates from the GBD 2017, to describe health outcomes (mortality and morbidity), health risks and determinants for adolescents in Myanmar between 1990-2017. A governance group of key stakeholders guided the framing of the study, interpretation of findings, and recommendations. Results: Overall health has improved for adolescents in Myanmar since 1990, however adolescent mortality remains high, particularly so for older adolescent males; all-cause mortality rate for 10-24 years was 70 per 100,000 for females and 149 per 100,000 for males (16,095 adolescent deaths in 2017). Overall, the dominant health problems were injuries for males and non-communicable disease for females in a context of ongoing burden of communicable and nutritional diseases for both sexes, and reproductive health needs for females. Health risks relating to undernutrition (thinness and anaemia) remain prevalent, with other health risks (overweight, binge alcohol use, and substance use) relatively low by global and regional standards but increasing. Gains have been made in social determinants such as adolescent fertility and modern contraception use; however, advances have been more limited in secondary education completion and engagement in employment and post education training. Conclusions: These results highlight the need to focus current efforts on addressing disease and mortality experienced by adolescents in Myanmar, with a specific focus on injury, mental health and non-communicable disease.
