The potential impact of enhanced diagnostic techniques for tuberculosis driven by HIV: a mathematical model.
OBJECTIVE
To explore the potential impact of enhanced tuberculosis (TB) diagnostic techniques as a TB control strategy in an adult population with high HIV prevalence.


METHODS
A compartmental difference-equation model of TB/HIV was developed using parameter estimates from the literature.


METHODS
The impact of five TB control interventions (rapid molecular testing, mycobacterial culture, community-wide and HIV-targeted active case finding, and highly active antiretroviral therapy) on TB incidence, prevalence, and mortality was modeled in a steady-state population with an HIV prevalence of 17% and annual TB incidence of 409 per 100 000. Sensitivity analyses assessed the influence of each model parameter on the interventions' mortality impact.


RESULTS
Enhanced diagnostic techniques (rapid molecular testing or culture) are each projected to reduce TB prevalence and mortality by 20% or more, an impact similar to that of active case-finding in 33% of the general community and greater than the effect achievable by case-finding or antiretroviral treatment efforts in HIV-positive patients alone. The projected impact of enhanced diagnostics on TB incidence (< 10% reduction) is smaller. The impact of TB diagnostics is sensitive to the quality of existing diagnostic standards and the level of access to diagnostic services, but is robust across a wide range of population parameters including HIV and TB incidence.


CONCLUSIONS
Enhanced TB diagnostic techniques may have substantial impact on TB morbidity and mortality in HIV-endemic regions. As TB rates continue to increase in these areas, enhanced diagnostic techniques merit further consideration as TB control strategies.
Dowdy
David W
DW
Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland 21231, USA.
Chaisson
Richard E
RE
Moulton
Lawrence H
LH
Dorman
Susan E
SE
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis*; D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D015373:Bacterial Typing Techniques; D003140:Communicable Disease Control; D004269:DNA, Bacterial / Q000032:analysis; D003906:Developing Countries; D004196:Disease Outbreaks; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy; D006297:Health Services Accessibility; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015233:Models, Statistical; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification; D015995:Prevalence; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology
D019380:Anti-HIV Agents; D004269:DNA, Bacterial