Pyrosequencing for diagnosis of multidrug and extensively drug-resistant tuberculosis: A systemic review and meta-analysis

Patterns of childhood tuberculosis diagnosis in Ethiopia: A multicenter cross-sectional study

Background

Children share 12% of the global 10 million people infected with tuberculosis (TB) each year. Closing case detection gap in children remains difficult, with 56% of all children and 65% under-five with TB missed each year. We aimed to assess the patterns of childhood TB diagnosis and underlying determinants in Ethiopia when different TB diagnostic platforms are applied.

Methods

A multi-site, cross-sectional study was carried out in Ethiopia as part of the larger EXIT-TB study - evidence-based multiple focused integrated intensified TB screening package. Outpatient children aged ≤ 15 with cough of any duration seeking care at four healthcare facilities in Ethiopia were enrolled consecutively. Participants underwent sputum Xpert MTB/RIF and/or smear microscopy and posteroanterior chest X-ray (CXR), and their clinical and sociodemographic data were captured using a structured questionnaire. Data were analyzed using Stata version 23. Multiple regression model was computed to determine the factors that influence TB case detection, with a 95% confidence interval (CI) and p < 0.05 taken as statistically significant.

Results

A total of 438 children were enrolled. Of these, 399 had CXR examination of which 55 (13.8%) were suggestive of TB, 270 had Xpert MTB/RIF testing of which 32 (11.9%) were positive, and AFB smear microscopy was done for 51 children of which 2 (3.9%) were positive. Febrile children were more likely to be diagnosed with pulmonary TB than those without fever [aPR = 1.3, 95% CI (1.1-1.4)], and those with a TB contact history were more likely to be diagnosed with pulmonary TB than those with no such contacts [aPR = 1.2, 95% CI (1.1-1.3)]. Children from rural residences were more likely to be diagnosed with TB than those from urban residences [aPR = 1.3, 95% CI (1.1-1.5)].

Conclusion

The findings showed that clinical diagnosis remains an important method of TB diagnosis in children and the preferred choice to avert underdiagnosis. A more sensitive TB diagnostic method for children was symptom screening, followed by CXR and Xpert MTB/RIF assay or smear microscopy. Hence, an algorithm that combines clinical, CXR, and microbiological confirmatory tests can improve the rate of pulmonary TB diagnosis in children till more accurate and cost-effective diagnostic tools are accessible. Fever, weight loss, and TB contact history are highly associated with TB positivity rates in children.

Direct detection of drug-resistant Mycobacterium tuberculosis using targeted next generation sequencing

Mycobacterium tuberculosis complex (MTBC) infections are treated with combinations of antibiotics; however, these regimens are not as efficacious against multidrug and extensively drug resistant MTBC. Phenotypic (growth-based) drug susceptibility testing on slow growing bacteria like MTBC requires many weeks to months to complete, whereas sequencing-based approaches can predict drug resistance (DR) with reduced turnaround time. We sought to develop a multiplexed, targeted next generation sequencing (tNGS) assay that can predict DR and can be performed directly on clinical respiratory specimens. A multiplex PCR was designed to amplify a group of thirteen full-length genes and promoter regions with mutations known to be involved in resistance to first- and second-line MTBC drugs. Long-read amplicon libraries were sequenced with Oxford Nanopore Technologies platforms and high-confidence resistance mutations were identified in real-time using an in-house developed bioinformatics pipeline. Sensitivity, specificity, reproducibility, and accuracy of the tNGS assay was assessed as part of a clinical validation study. In total, tNGS was performed on 72 primary specimens and 55 MTBC-positive cultures and results were compared to clinical whole genome sequencing (WGS) performed on paired patient cultures. Complete or partial susceptibility profiles were generated from 82% of smear positive primary specimens and the resistance mutations identified by tNGS were 100% concordant with WGS. In addition to performing tNGS on primary clinical samples, this assay can be used to sequence MTBC cultures mixed with other mycobacterial species that would not yield WGS results. The assay can be effectively implemented in a clinical/diagnostic laboratory with a two to three day turnaround time and, even if batched weekly, tNGS results are available on average 15 days earlier than culture-derived WGS results. This study demonstrates that tNGS can reliably predict MTBC drug resistance directly from clinical specimens or cultures and provide critical information in a timely manner for the appropriate treatment of patients with DR tuberculosis.

Capacity and Readiness Assessment of Healthcare Facilities for Digital Health Interventions Against Tuberculosis and HIV in Addis Ababa, Ethiopia

Background

There is a high level of concern that low-income countries lack the capacity and readiness to effectively adopt, implement, and scale up digital health interventions (DHIs). We aimed to assess the infrastructure and human resource capacity and readiness of healthcare facilities to adopt and implement any new DHI for tuberculosis (TB) and HIV care and treatment in Addis Ababa, Ethiopia.

Method

We carried out a cross-sectional, mixed-methods study in 14 public healthcare facilities that provide TB and HIV care and treatment services. Providers' perceived readiness to adopt and implement digital health was assessed using a self-administered questionnaire designed based on an adapted eHealth readiness assessment model that covers six domains: core readiness, organizational cultural readiness, value proposition readiness, technological readiness, regulatory policy readiness, and operational resource readiness. The infrastructure and human resource capacity were assessed on-site using a tool adapted from the Technology Infrastructure Checklist. Internal consistency was assessed using Cronbach's alpha, and the significant relationship between the composite variables was assessed using Pearson's correlation coefficients (r).

Result

We assessed 14 facilities on-site and surveyed 60 TB and HIV healthcare providers. According to Cronbach's alpha test, all the six technology acceptance domains had a value of >0.8, suggesting a strong interrelatedness between the measuring items. The correlation between technological readiness and operational resource readiness was significant (r = 0.8). The providers perceived their work environment as good enough in electronic data protection, while more efforts are needed in planning, training, adapting, and implementing digital health. Of the 14 facilities, 64.3% lack the plan to establish a functional local area network, and 43% lack skilled staff on payroll to provide maintenance of computers and other digital technologies.

Conclusion

Like many developing countries, there was a modest infrastructure and human resource capacity and readiness of public healthcare facilities in Addis Ababa, Ethiopia, to nurture and strengthen DHIs across the TB and HIV cascades of care. Technological and operational resource readiness, including funding and a Well-trained workforce, are essential for successful implementation and use of digital health against the two infectious diseases of global importance in such settings.

Five-year trend analysis of tuberculosis in Bahir Dar, Northwest Ethiopia, 2015-2019

Background

Tuberculosis (TB) remains a major cause of morbidity and mortality in Ethiopia despite the increased availability of effective treatments. Trend analysis of issues and priorities affecting TB programs across different regions of the country is critical to ensure equitable and sustainable TB outcomes. We aimed to analyze the trends of TB in Bahir Dar, Northwest Ethiopia, over 5 years from 2015 to 2019.

Methods

An institution-based, retrospective cross-sectional study was conducted in Bahir Dar, the capital city of the Amhara Region in Ethiopia. Five-year data and records of individual TB cases were reviewed from all public and private health-care facilities and health bureaus in Bahir Dar. Using a standard checklist adapted from the World Health Organization, data were abstracted relevant to sociodemographic characteristics of the patients, year and type of TB infection, and HIV status. SPSS version 20 software was used for data analysis.

Results

Data of 4275 patients with TB were identified, of which 929 (21.7%) were smear-positive pulmonary TB, 1195 (28%) were smear-negative pulmonary TB, and 2151 (50.3%) were extrapulmonary TB patients. TB was more prevalent in the age group 15-34 years (51.2%), and females (55.5%). In the years from 2015 to 2019, the prevalence of all forms of TB was 922 (21.6%), 812 (19.0%), 843 (19.7%), 876 (20.5%), and 822 (19.2%), respectively, demonstrating a decreasing trend though inconsistent. The variables sex (adjusted odds ratio [AOR]: 1.734, 95% confidence interval [CI] [1.390-2.187]), HIV co-infection (AOR: 1.875, 95% CI [1.553-2.265]), and age <15 years (AOR: 1.372, 95% CI [1.121-1.680]) showed a significant association with TB infection.

Conclusions

The prevalence of TB in Bahir Dar, Northwest Ethiopia, demonstrated a decreasing trend over the years from 2015 to 2019 but with inconsistencies. HIV co-infection significantly increased the risk of developing TB, and productive age groups and females were at the greater prevalence of TB, highlighting the importance of strengthening sustainable TB care and prevention interventions toward these groups of people.