| Abstract |
Tuberculosis (TB) remains the leading
cause of death in people living with HIV/AIDS (PLWA) globally.
Recently, WHO recommended the intertwining of Tuberculosis
and HIV program services in resource poor settings where the
incidence of both diseases is high. Household settings represent
a centrally important as well as high risk site for transmission
for both diseases, yet at the present time there is no formal
policy recommendation to evaluate household members for TB.
HIV is transmitted sexually or thorough vertical transmission
in families. TB is transmitted through shared infected airspace
over time, making household contacts at particularly high
risk of infection. Although HIV positive individuals generally
develop TB with higher organism burdens (suggesting a higher
grade of contagion) than HIV negative individuals, they experience
an accelerated time course from infection to activity to death
(if untreated) from TB (a shorter time course during which
to transmit). Whether HIV positive pulmonary TB cases are
more or less contagious than HIV negative source cases is
unclear; studies have demonstrated conflicting results. No
studies have been performed to evaluate transmission in areas
where both HIV and TB incidences are high. Studies at various
time points in the evolution of these epidemics may demonstrate
that different strategies regarding contact tracing is warranted
in areas of varying incidence of the two diseases. A single
recommendation may no longer be appropriate for global recommendations.
We hypothesize that under the conditions found in Eldoret,
Kenya (high TB prevalence, crowded urban living space), that
there will be an increased prevalence of active cases of TB
in households in which the index case is HIV positive versus
HIV negative. Active cases will be evaluated as the primary
endpoint rather than TB infection due to the ability to perform
molecular fingerprinting on mTb isolates to clearly link transmitted
cases. Latent TB infection will be measured as a secondary
aim, but could be explained either by household transmission
or by community transmission in a high prevalence TB area.
This study will be a cross sectional study, designed to obtain
baseline data for a larger, longitudinal cohort study. The
study will be carried out through the HIV/TB Clinics of the
Moi University Faculty of Health Sciences in Eldoret, Kenya.
TB culture will be performed at the reference laboratory of
the Kenya National TB Control Program. Fingerprinting will
be performed at the Miriam Hospital TB Molecular Epidemiology
Lab.
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