Publications by authors named "Vibol Iem"
Background: In 2022, fewer than half of persons with tuberculosis (TB) had access to molecular diagnostic tests for TB due to their high costs. Studies have found that the use of artificial intelligence (AI) software for chest X-ray (CXR) interpretation and sputum specimen pooling can each reduce the cost of testing. We modeled the combination of both strategies to estimate potential savings in consumables that could be used to expand access to molecular diagnostics.
View Article and Find Full Text PDFBackground: The World Health Organization (WHO) recommends the diagnosis of tuberculosis (TB) using molecular tests, such as Xpert MTB/RIF (MTB/RIF) or Xpert Ultra (Ultra). These tests are expensive and resource-consuming, and cost-effective approaches are needed for greater coverage.
Methods: We evaluated the cost-effectiveness of pooling sputum samples for TB testing by using a fixed amount of 1,000 MTB/RIF or Ultra cartridges.
The global Covid-19 pandemic has limited access to molecular TB diagnostics and National Programmes are struggling to maintain essential services. The pooling method (testing several samples together) could reduce the number of cartridges and staff time needed for TB diagnosis but has not been tested within the pandemic. We conducted two independent cross-sectional surveys.
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- The COVID-19 pandemic necessitated mass testing, leading to a study in Lao PDR exploring pooled testing to enhance laboratory capacity.
- In this study, 1,568 patients were tested in groups of four, resulting in a significant percentage of negative pools and a high confirmation rate of positive pools through individual testing.
- The findings indicated that pooling not only saved 67% on testing materials but also improved testing capacity, suggesting that countries could benefit from implementing pooled testing strategies for effective COVID-19 screening.
Introduction: Active case finding (ACF) of individuals with tuberculosis (TB) is a key intervention to find the 30% of people missed every year. However, ACF requires screening large numbers of individuals who have a low probability of positive results, typically <5%, which makes using the recommended molecular tests expensive.
Methods: We conducted two ACF surveys (in 2020 and 2021) in high TB burden areas of Lao PDR.
GeneXpert-based testing with Xpert MTB/RIF or Ultra assays is essential for tuberculosis diagnosis. However, testing may be affected by cartridge and staff shortages. More efficient testing strategies could help, especially during the coronavirus disease pandemic.
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- A study in Lao PDR aimed to understand the genetic features and drug resistance of the tuberculosis (TB) bacteria, M. tuberculosis, during the first National TB Prevalence Survey (2010-2011).
- Out of 222 analyzed TB isolates, 11 showed resistance to isoniazid and 2 were classified as multidrug-resistant (MDR-TB), predominantly from the Beijing family.
- The majority of isolates belonged to the East African-Indian family (76.7%), with a notable clustering rate of 11% and mini-outbreaks linked to drug-resistant Beijing genotypes, highlighting differences in strain prevalence compared to neighboring countries.
Objective: To present results of the first national anti-tuberculosis (TB) drug resistance survey conducted in Lao PDR between May 2016 and August 2017 to determine the prevalence of resistance to first-line anti-TB drugs among new and previously treated pulmonary TB cases in the country.
Methods: Patients with sputum smear-positive pulmonary TB were enrolled from 42 TB laboratories distributed in 40 clusters throughout the country. Survey sites were selected using probability-proportional-to-size sampling among all diagnostic centres in the country.
Objective: The objective of the study was to measure the prevalence of bacteriologically confirmed pulmonary tuberculosis (TB) in Lao PDR in 2010-2011.
Method: A nationwide, multistage cluster-sampled cross-sectional survey was undertaken in 2010-2011. All consenting participants ≥15 years were screened for pulmonary TB with chest X-ray and symptom questionnaire.
Article Synopsis
- Lao PDR is among the top seven countries in the WHO Western Pacific Region affected by tuberculosis (TB), but no prior studies had assessed drug resistance due to late implementation of testing methods.
- A cross-sectional study conducted in three hospitals from April to November 2010 investigated drug resistance by testing patients suspected of having pulmonary TB, utilizing various culture and assay methods.
- The results showed that out of 104 tuberculosis-positive cultures, 6.8% of new cases and 14.3% of previously treated cases exhibited resistance to isoniazid (INH), including the first identification of a strain resistant to multiple drugs (XDR), highlighting the need for improved drug resistance surveillance in Lao PDR.