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Durations of asymptomatic, symptomatic, and care-seeking phases of tuberculosis disease with a Bayesian analysis of prevalence survey and notification data
- Source :
- BMC Medicine, Vol 19, Iss 1, Pp 1-13 (2021), BMC Med, BMC Medicine
- Publication Year :
- 2021
- Publisher :
- BMC, 2021.
-
Abstract
- Background Ratios of bacteriologically positive tuberculosis (TB) prevalence to notification rates are used to characterise typical durations of TB disease. However, this ignores the clinical spectrum of tuberculosis disease and potentially long infectious periods with minimal or no symptoms prior to care-seeking. Methods We developed novel statistical models to estimate progression from initial bacteriological positivity including smear conversion, symptom onset and initial care-seeking. Case-detection ratios, TB incidence, durations, and other parameters were estimated by fitting the model to tuberculosis prevalence survey and notification data (one subnational and 11 national datasets) within a Bayesian framework using Markov chain Monte Carlo methods. Results Analysis across 11 national datasets found asymptomatic tuberculosis durations in the range 4–8 months for African countries; three countries in Asia (Cambodia, Lao PDR, and Philippines) showed longer durations of > 1 year. For the six countries with relevant data, care-seeking typically began half-way between symptom onset and notification. For Kenya and Blantyre, Malawi, individual-level data were available. The sex-specific durations of asymptomatic bacteriologically-positive tuberculosis were 9.0 months (95% credible interval [CrI]: 7.2–11.2) for men and 8.1 months (95% CrI: 6.2–10.3) for women in Kenya, and 4.9 months (95% CrI: 2.6–7.9) for men and 3.5 months (95% CrI: 1.3–6.2) for women in Blantyre. Age-stratified analysis of data for Kenya showed no strong age-dependence in durations. For Blantyre, HIV-stratified analysis estimated an asymptomatic duration of 1.3 months (95% CrI: 0.3–3.0) for HIV-positive people, shorter than the 8.5 months (95% CrI: 5.0–12.7) for HIV-negative people. Additionally, case-detection ratios were higher for people living with HIV than HIV-negative people (93% vs 71%). Conclusion Asymptomatic TB disease typically lasts around 6 months. We found no evidence of age-dependence, but much shorter durations among people living with HIV, and longer durations in some Asian settings. To eradicate TB transmission, greater gains may be achieved by proactively screening people without symptoms through active case finding interventions
- Subjects :
- Male
Malawi
Epidemiology
Psychological intervention
Disease
wa_20_5
0302 clinical medicine
Prevalence
Credible interval
030212 general & internal medicine
POPULATION
11 Medical and Health Sciences
Transmission (medicine)
Incidence
Incidence (epidemiology)
1. No poverty
General Medicine
3. Good health
TANZANIA
Medicine
Female
wf_200
medicine.symptom
BURDEN
Life Sciences & Biomedicine
Research Article
medicine.medical_specialty
wa_950
Tuberculosis
030231 tropical medicine
wa_395
Bayesian statistics
Asymptomatic
03 medical and health sciences
Medicine, General & Internal
General & Internal Medicine
medicine
Humans
Care-seeking
Science & Technology
business.industry
Bayes Theorem
medicine.disease
NATIONAL-SURVEY
Sub-clinical tuberculosis
business
Demography
Subjects
Details
- Language :
- English
- ISSN :
- 17417015
- Volume :
- 19
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- BMC Medicine
- Accession number :
- edsair.doi.dedup.....ea957fae26c8aa0f2f31c13702d96aaf