1.Tuberculosis case-finding in Cambodia: analysis of case notification data, 2000 to 2013
Fukushi Morishita ; Valérie Burrus Furphy ; Miwako Kobayashi ; Nobuyuki Nishikiori ; Mao Tan Eang ; Rajendra-Prasad Yadav
Western Pacific Surveillance and Response 2015;6(1):15-24
The routine tuberculosis (TB) surveillance system in Cambodia has been strengthened under the National TB Programme (NTP). This paper provides an overview of the TB surveillance data for Cambodia at the national level for the period 2000 to 2013 and at the subnational level for 2013.
The proportion of the total population that were screened for TB rose from 0.4% in 2001 to 1.1% in 2013, while the smear-positivity rate decreased from 28.9% to 8.1% in the same period. The total number of notified TB cases increased steadily from 2000; this has stabilized in recent years with 39 055 cases notified in 2013. The proportion of all TB cases that were smear-positive decreased from 78% in 2000 to 36% in 2013. Case notification rates (CNRs) for all forms of TB and new smear-positive TB in 2013 were 261 and 94 per 100 000 population, respectively. Higher CNRs were found in the north-west and south-east parts of the country and were higher for males especially in older age groups.
The increase in TB screening, decline in the smear-positive rate and decline in notified smear-positive TB cases likely reflect a long-term positive impact of the NTP. A negative correlation between the proportion of the population screened and the smear-positivity rate at the subnational level helped identify where to find undiagnosed cases. Subnational differences in case notification of the elderly and in children provide more specific targets for case-finding and further encourage strategic resource allocation.
2.The association between household poverty rates and tuberculosis case notification rates in Cambodia, 2010
Wong Man Kai ; Yadav Rajendra-Prasad ; Nishikiori Nobuyuku ; Eang Mao Tan
Western Pacific Surveillance and Response 2013;4(1):25-33
Introduction: Poverty is a risk factor for tuberculosis (TB); it increases the risk of infection and active disease but limits diagnostic opportunities. The role of poverty in the stagnant case detection in Cambodia is unclear. This study aims to assess the relationship between district household poverty rates and sputum-positive TB case notification rates (CNRs) in Cambodia in 2010.
Methods: Poisson regression models were used to calculate the relative risk of new sputum-positive TB CNR for Operational Districts (ODs) with different poverty rates using data from the National Centre for Tuberculosis and Leprosy Control and the National Committee for SubNational Democratic Development. Models were adjusted for other major covariates and a geographical information system was used to examine the spatial distribution of these covariates in the country.
Results: The univariate model showed a positive association between household poverty rates and sputum-positive TB CNRs. However, in multivariate models, after adjusting for major covariates, household poverty rates showed a significantly negative association with sputum-positive TB CNRs (relative risk [RR] = 0.95 per 5% increase in poverty rate). The negative association was stronger among males than females (RR = 0.93 versus 0.96 per 5% increase in poverty rate). Similar spatial patterns were observed between household poverty rates and other covariates, particularly OD population density.
Conclusion: Household poverty rate is associated with a decrease in sputum-positive TB CNR in Cambodia, particularly in men. The potential of combining surveillance data and socioeconomic variables should be explored further to provide more insights for TB control programme planning.
3.Comparative Evaluation of Several Gene Targets for Designing a Multiplex-PCR for an Early Diagnosis of Extrapulmonary Tuberculosis.
Ankush RAJ ; Netrapal SINGH ; Krishna B GUPTA ; Dhruva CHAUDHARY ; Aparna YADAV ; Anil CHAUDHARY ; Kshitij AGARWAL ; Mandira VARMA-BASIL ; Rajendra PRASAD ; Gopal K KHULLER ; Promod K MEHTA
Yonsei Medical Journal 2016;57(1):88-96
PURPOSE: Diagnosis of extrapulmonary tuberculosis (EPTB) poses serious challenges. A careful selection of appropriate gene targets is essential for designing a multiplex-polymerase chain reaction (M-PCR) assay. MATERIALS AND METHODS: We compared several gene targets of Mycobacterium tuberculosis, including IS6110, devR, and genes encoding MPB-64 (mpb64), 38kDa (pstS1), 65kDa (hsp65), 30kDa (fbpB), ESAT-6 (esat6), and CFP-10 (cfp10) proteins, using PCR assays on 105 EPTB specimens. From these data, we chose the two best gene targets to design an M-PCR. RESULTS: Among all gene targets tested, mpb64 showed the highest sensitivity (84% in confirmed cases and 77.5% in clinically suspected cases), followed by IS6110, hsp65, 38kDa, 30kDa, esat6, cfp10, and devR. We used mpb64+IS6110 for designing an M-PCR assay. Our M-PCR assay demonstrated a high sensitivity of 96% in confirmed EPTB cases and 88.75% in clinically suspected EPTB cases with a high specificity of 100%, taking clinical diagnosis as the gold standard. CONCLUSION: These M-PCR results along with the clinical findings may facilitate an early diagnosis of EPTB patients and clinical management of disease.
Bacteriological Techniques/methods
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DNA Transposable Elements/genetics
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DNA, Bacterial/analysis/genetics
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Early Diagnosis
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Female
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Gene Amplification
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Humans
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Male
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Multiplex Polymerase Chain Reaction/*methods
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Mycobacterium tuberculosis/genetics/*isolation & purification
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Polymerase Chain Reaction/*methods/standards
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Sensitivity and Specificity
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Tuberculosis/*diagnosis