Background: Despite the fact that the number of CT exams is small among all radiography investigations, a high amount of medical radiation exposure comes from CT application. Most developed nations have adopted regular audits to ensure optimization of ionizing radiations in the CT examinations, but on the contrary, it has infrequently been performed in developing countries like Nigeria. Objectives: This study was designed to carry out an audit of CT examinations at two selected diagnostic centers in the South-South region of Nigeria. Materials and methods: This study was a retrospective cross-sectional study conducted in two radiological facilities, which involved 210 tomographs of the chest, head, and abdomen, selected using a convenient method. The CT examinations were done using the departmental protocols and the generated data were analyzed statistically using descriptive statistics. Results: Head examination was the most commonly performed CT examination (56.7%), followed by abdominal 28.6 % and the least 14.8% was chest. The most common indication was a road traffic accident (RTA) 11.4%. The distribution of the type of CT machine that was used for the study showed that the Toshiba machine was used for most of the subjects 132 (62.9%) followed by Optima CT660 78 (37.1%). It was seen that 48.6% of the study used 0.75s, 40.5% used 0.5s, 10.5% used 0.35s and only 0.5% used 1s scan time. The effective doses were adult head (2.31±0.14), chest (4.65±0.21), abdominal (7.70±0.17), pediatric head (2.81±0.21), and pediatric chest (9.96±0.12). Conclusion: The carrying out of clinical audits is imperative to ensure both safeties of patients and diagnostic accuracy.

Rifampicin-resistant tuberculosis (RR-TB) has become a major threat globally. This study aims to develop a new assay, RIF-RDp, to enhance the detection of RR-TB based on combined locked nucleic acid (LNA) probes with high-resolution melting curve analysis (HRM). Two new LNA probes were designed to target the class-III and IV mutations of rpoB, H526D, and D516V. LNA probes showed 100% specificity in the detection of mutant targets among characterized and blinded Mycobacterium tuberculosis (Mtb) isolates. The performance of RIF-RDp was evaluated using 110 blinded clinical Mtb isolates in northern Thailand against drug-susceptibility testing (DST), DNA sequencing, and a commercial real-time PCR kit. This assay showed sensitivity and specificity of 94.55% and 98.18% compared to DST, and 96.36% and 100% compared to DNA sequencing. The efficacy of RIF-RDp was comparable to the commercial kit and DNA sequencing. The Cohen’s Kappa statistic showed almost perfect agreement between RIF-RDp and the commercial kit (κ = 0.95), and RIF-RDp and DNA sequencing (κ = 0.96). Furthermore, this is the first report of the rare mutation profiles, S531W, and a triple codon deletion (510–512) in northern Thailand. According to high accuracy, the RIF-RDp assay may render an easy-to-use, low-cost, and promising diagnostics of RR-TB in the future.

The epidemiology and genotypes of multidrug-resistant tuberculosis (MDR-TB), a global public health threat, remain limited. The genotypic distribution and factors associated with MDR-TB in upper northern Thailand between 2015 and 2019 were investigated. The DNA sequencing of rpoB, katG, and inhA promoter of 51 multidrug-resistant Mycobacterium tuberculosis isolates revealed nine patterns of the rpoB gene mutation distributed in seven provinces. The S531L mutation was the most common mutation in all provinces. The rpoB mutation in Chiang Rai, Chiang Mai, and Lampang was highly diverse compared to other areas. Here, the mutation profiles that have yet to be reported in northern Thailand (H526P, Q513P, and H526C) were detected in Chiang Rai province. The S315T katG mutation was the most common genotype associated with INH resistance, especially in Chiang Mai and Lampang. Further analysis of data from 110 TB patients (42 MDR-TB and 68 drug-susceptible TB) revealed that <60 years of age was a significant factor associated with MDR-TB (OR = 0.316, 95% CI 0.128–0.784, p = 0.011) and ≥60 years of age was a significant factor associated with the S315T katG-mutation (OR = 8.867, 95% CI 0.981–80.177, p = 0.047). This study highlighted the necessity for continuous surveillance and risk factor monitoring for effective control of MDR-TB.