Modeling tuberculosis dynamics with the presence of hyper-susceptible individuals for Ho Chi Minh City from 1996 to 2015 11 Medical and Health Sciences 1117 Public Health and Health Services

Dao Nguyen Vinh, Dang Thi Minh Ha, Nguyen Thi Hanh, Guy Thwaites, Maciej F. Boni, Hannah E. Clapham, Nguyen Thuy Thuong Thuong

Research output: Contribution to journalArticle

Abstract

Background: The depletion of CD4 cell is the underlying reason for TB hyper-susceptibility among people with HIV. Consequently, the trend of TB dynamics is usually hidden by the HIV outbreak. Methods: Here, we aim to evaluate the trend of TB dynamics quantitatively by a simple mathematical model using the known prevalence of hyper-susceptible individuals in the population. In order to estimate the parameters governing transmission we fit this model in a maximum likelihood framework to both reported TB cases and data from samples tested with Interferon Gamma Assay from Ho Chi Minh City - a city with high TB transmission and strong synchronization between HIV/AIDS and TB dynamics. Results: Our results show that TB transmission in HCMC has been declining among people without HIV; we estimate a 18% (95% CI: 9-25%) decline in the transmission parameter between 1996 and 2015. Furthermore, we show that co-infected patients have limited contribution to the transmission process. For hyper-susceptible individuals, our model suggests that the risk of a new active TB infection occurring is significantly higher than the risk of relapsed active TB, while this is not the case for people without hyper-susceptibility. Conclusions: The increase of TB notifications in Ho Chi Minh City from 1996 to 2008 is evitable when, as occurred, the number of hyper-susceptible individuals increased faster than the decrease of TB transmission rate. The sharp decrease in TB notifications observed in this city from 2008 to 2015 is the combined result of the decrease of TB transmission rate and the decrease of hyper-susceptible individuals in the population. For hyper-susceptible individuals, we propose that the reason for the reduced relapsed active TB risk is HIV treatment delay. According to HIV treatment guidelines issued by Vietnam's Ministry of Health, hyper-susceptible individuals usually have to wait until their CD4 cell count falls under 350 cells/μl to start ART. Once patients begin ART, they will remain on ART for the rest of their life and thus have greater protection against relapses of TB. We therefore hypothesize that the delay in using ART imposes considerable TB burden on HCMC despite the declining transmission process.

Original languageEnglish (US)
Article number494
JournalBMC Infectious Diseases
Volume18
Issue number1
DOIs
StatePublished - Oct 1 2018

Fingerprint

Health Services
Tuberculosis
Public Health
HIV
Health
Vietnam
CD4 Lymphocyte Count
Population
Interferon-gamma
Disease Outbreaks
Acquired Immunodeficiency Syndrome
Theoretical Models
Guidelines
Recurrence
Therapeutics
Infection

All Science Journal Classification (ASJC) codes

  • Infectious Diseases

Cite this

Vinh, Dao Nguyen ; Ha, Dang Thi Minh ; Hanh, Nguyen Thi ; Thwaites, Guy ; Boni, Maciej F. ; Clapham, Hannah E. ; Thuong, Nguyen Thuy Thuong. / Modeling tuberculosis dynamics with the presence of hyper-susceptible individuals for Ho Chi Minh City from 1996 to 2015 11 Medical and Health Sciences 1117 Public Health and Health Services. In: BMC Infectious Diseases. 2018 ; Vol. 18, No. 1.
@article{ca3732a262c741d2b07dc88aca6901f0,
title = "Modeling tuberculosis dynamics with the presence of hyper-susceptible individuals for Ho Chi Minh City from 1996 to 2015 11 Medical and Health Sciences 1117 Public Health and Health Services",
abstract = "Background: The depletion of CD4 cell is the underlying reason for TB hyper-susceptibility among people with HIV. Consequently, the trend of TB dynamics is usually hidden by the HIV outbreak. Methods: Here, we aim to evaluate the trend of TB dynamics quantitatively by a simple mathematical model using the known prevalence of hyper-susceptible individuals in the population. In order to estimate the parameters governing transmission we fit this model in a maximum likelihood framework to both reported TB cases and data from samples tested with Interferon Gamma Assay from Ho Chi Minh City - a city with high TB transmission and strong synchronization between HIV/AIDS and TB dynamics. Results: Our results show that TB transmission in HCMC has been declining among people without HIV; we estimate a 18{\%} (95{\%} CI: 9-25{\%}) decline in the transmission parameter between 1996 and 2015. Furthermore, we show that co-infected patients have limited contribution to the transmission process. For hyper-susceptible individuals, our model suggests that the risk of a new active TB infection occurring is significantly higher than the risk of relapsed active TB, while this is not the case for people without hyper-susceptibility. Conclusions: The increase of TB notifications in Ho Chi Minh City from 1996 to 2008 is evitable when, as occurred, the number of hyper-susceptible individuals increased faster than the decrease of TB transmission rate. The sharp decrease in TB notifications observed in this city from 2008 to 2015 is the combined result of the decrease of TB transmission rate and the decrease of hyper-susceptible individuals in the population. For hyper-susceptible individuals, we propose that the reason for the reduced relapsed active TB risk is HIV treatment delay. According to HIV treatment guidelines issued by Vietnam's Ministry of Health, hyper-susceptible individuals usually have to wait until their CD4 cell count falls under 350 cells/μl to start ART. Once patients begin ART, they will remain on ART for the rest of their life and thus have greater protection against relapses of TB. We therefore hypothesize that the delay in using ART imposes considerable TB burden on HCMC despite the declining transmission process.",
author = "Vinh, {Dao Nguyen} and Ha, {Dang Thi Minh} and Hanh, {Nguyen Thi} and Guy Thwaites and Boni, {Maciej F.} and Clapham, {Hannah E.} and Thuong, {Nguyen Thuy Thuong}",
year = "2018",
month = "10",
day = "1",
doi = "10.1186/s12879-018-3383-3",
language = "English (US)",
volume = "18",
journal = "BMC Infectious Diseases",
issn = "1471-2334",
publisher = "BioMed Central",
number = "1",

}

Modeling tuberculosis dynamics with the presence of hyper-susceptible individuals for Ho Chi Minh City from 1996 to 2015 11 Medical and Health Sciences 1117 Public Health and Health Services. / Vinh, Dao Nguyen; Ha, Dang Thi Minh; Hanh, Nguyen Thi; Thwaites, Guy; Boni, Maciej F.; Clapham, Hannah E.; Thuong, Nguyen Thuy Thuong.

In: BMC Infectious Diseases, Vol. 18, No. 1, 494, 01.10.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Modeling tuberculosis dynamics with the presence of hyper-susceptible individuals for Ho Chi Minh City from 1996 to 2015 11 Medical and Health Sciences 1117 Public Health and Health Services

AU - Vinh, Dao Nguyen

AU - Ha, Dang Thi Minh

AU - Hanh, Nguyen Thi

AU - Thwaites, Guy

AU - Boni, Maciej F.

AU - Clapham, Hannah E.

AU - Thuong, Nguyen Thuy Thuong

PY - 2018/10/1

Y1 - 2018/10/1

N2 - Background: The depletion of CD4 cell is the underlying reason for TB hyper-susceptibility among people with HIV. Consequently, the trend of TB dynamics is usually hidden by the HIV outbreak. Methods: Here, we aim to evaluate the trend of TB dynamics quantitatively by a simple mathematical model using the known prevalence of hyper-susceptible individuals in the population. In order to estimate the parameters governing transmission we fit this model in a maximum likelihood framework to both reported TB cases and data from samples tested with Interferon Gamma Assay from Ho Chi Minh City - a city with high TB transmission and strong synchronization between HIV/AIDS and TB dynamics. Results: Our results show that TB transmission in HCMC has been declining among people without HIV; we estimate a 18% (95% CI: 9-25%) decline in the transmission parameter between 1996 and 2015. Furthermore, we show that co-infected patients have limited contribution to the transmission process. For hyper-susceptible individuals, our model suggests that the risk of a new active TB infection occurring is significantly higher than the risk of relapsed active TB, while this is not the case for people without hyper-susceptibility. Conclusions: The increase of TB notifications in Ho Chi Minh City from 1996 to 2008 is evitable when, as occurred, the number of hyper-susceptible individuals increased faster than the decrease of TB transmission rate. The sharp decrease in TB notifications observed in this city from 2008 to 2015 is the combined result of the decrease of TB transmission rate and the decrease of hyper-susceptible individuals in the population. For hyper-susceptible individuals, we propose that the reason for the reduced relapsed active TB risk is HIV treatment delay. According to HIV treatment guidelines issued by Vietnam's Ministry of Health, hyper-susceptible individuals usually have to wait until their CD4 cell count falls under 350 cells/μl to start ART. Once patients begin ART, they will remain on ART for the rest of their life and thus have greater protection against relapses of TB. We therefore hypothesize that the delay in using ART imposes considerable TB burden on HCMC despite the declining transmission process.

AB - Background: The depletion of CD4 cell is the underlying reason for TB hyper-susceptibility among people with HIV. Consequently, the trend of TB dynamics is usually hidden by the HIV outbreak. Methods: Here, we aim to evaluate the trend of TB dynamics quantitatively by a simple mathematical model using the known prevalence of hyper-susceptible individuals in the population. In order to estimate the parameters governing transmission we fit this model in a maximum likelihood framework to both reported TB cases and data from samples tested with Interferon Gamma Assay from Ho Chi Minh City - a city with high TB transmission and strong synchronization between HIV/AIDS and TB dynamics. Results: Our results show that TB transmission in HCMC has been declining among people without HIV; we estimate a 18% (95% CI: 9-25%) decline in the transmission parameter between 1996 and 2015. Furthermore, we show that co-infected patients have limited contribution to the transmission process. For hyper-susceptible individuals, our model suggests that the risk of a new active TB infection occurring is significantly higher than the risk of relapsed active TB, while this is not the case for people without hyper-susceptibility. Conclusions: The increase of TB notifications in Ho Chi Minh City from 1996 to 2008 is evitable when, as occurred, the number of hyper-susceptible individuals increased faster than the decrease of TB transmission rate. The sharp decrease in TB notifications observed in this city from 2008 to 2015 is the combined result of the decrease of TB transmission rate and the decrease of hyper-susceptible individuals in the population. For hyper-susceptible individuals, we propose that the reason for the reduced relapsed active TB risk is HIV treatment delay. According to HIV treatment guidelines issued by Vietnam's Ministry of Health, hyper-susceptible individuals usually have to wait until their CD4 cell count falls under 350 cells/μl to start ART. Once patients begin ART, they will remain on ART for the rest of their life and thus have greater protection against relapses of TB. We therefore hypothesize that the delay in using ART imposes considerable TB burden on HCMC despite the declining transmission process.

UR - http://www.scopus.com/inward/record.url?scp=85054254337&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85054254337&partnerID=8YFLogxK

U2 - 10.1186/s12879-018-3383-3

DO - 10.1186/s12879-018-3383-3

M3 - Article

C2 - 30285633

AN - SCOPUS:85054254337

VL - 18

JO - BMC Infectious Diseases

JF - BMC Infectious Diseases

SN - 1471-2334

IS - 1

M1 - 494

ER -