The Risk of Tuberculosis Reinfection Soon after Cure of a First Disease Episode Is Extremely High in a Hyperendemic Community

Abstract

Elevated rates of reinfection tuberculosis in various hyperendemic regions have been reported and, in particular, it has been shown that in a high-incidence setting near Cape Town, South Africa, the rate of reinfection tuberculosis (TB) disease after cure of a previous TB disease episode is about four times greater than the rate of first-time TB disease. It is not known whether this elevated rate is caused by a high reinfection rate due, for instance, to living circumstances, or a high rate of progress to disease specific to the patients, or both. In order to address that question we analysed an extensive data set from clinics attended by TB patients in the high-incidence setting near Cape Town, South Africa and found that, in fact, the (average) rate of reinfection (as opposed to the rate of reinfection disease) after cure of a previous TB disease episode is initially about 0.85 per annum. This rate diminishes rapidly over time and after about ten years this rate is similar to the rate of infection in the general population. Also, the rate of progress to disease after reinfection is initially high but declines in subsequent years down to the figure typical for the general population. These findings suggest that the first few months after cure of a TB disease episode form a critical period for controlling reinfection disease in a hyperendemic setting and that monitoring such cured patients could pre-empt a reinfection progressing to active disease.

Risk factors for recurrent tuberculosis after successful treatment in a high burden setting: a cohort study

“…After following a cohort of largely HIV-coinfected ambulatory individuals successfully treated for pulmonary tuberculosis disease in a high burden setting for a median of 6 years, we found that 11% (95% CI 7.2 to 13.8%) had bacteriologically proven recurrent tuberculosis and an additional 3% (95% CI 1.2 to 4.8%) had empirically-diagnosed recurrent tuberculosis. This is consistent with other studies performed in high burden settings [ 2 , 27 ].…”

“…Patients who have recently completed treatment for tuberculosis (TB) are at elevated risk of recurrent TB disease, either as a result of relapse or reinfection [ 1 , 2 ]. When individuals are diagnosed with recurrent TB, they are less likely to complete treatment and suffer higher mortality than those with first episodes of TB [ 3 ].…”

“…Studies of recurrent TB are challenging to conduct because the risk of recurrent TB can remain elevated for up to ten years [ 2 ]. In this analysis, we combined a research database with electronic notification records to study the long term risk of recurrent tuberculosis among a cohort of ambulatory pulmonary TB patients with a high prevalence of HIV co-infection after successful completion of anti-tubercular therapy.…”

T Cells Primed by Live Mycobacteria Versus a Tuberculosis Subunit Vaccine Exhibit Distinct Functional Properties

“…A significant proportion of TB patients successfully cured after chemotherapy exhibit recurrent disease. Similar to recrudescence of a latent infection, many of these cases can be ascribed to reactivation of residual bacilli after treatment failure but, especially in high-incidence areas, exogenous re-infections seem to account for a significant proportion of TB recurrence ( De Boer and Van Soolingen, 2000 , Guerra-Assuncao et al, 2015 , Sonnenberg et al, 2001 , Uys et al, 2015 , Verver et al, 2005 ). Such TB patients could simply just be inherently more susceptible, thus exhibiting recurrent infections.…”

The Origin and Maintenance of Tuberculosis is Explained by Its Subclinical Course, the Neolithic Revolution Being the Trigger for Its Devastating Deadly Drift

“…The drainage of the infection on exposed individuals is given by 75,76 , which is assumed to be reduced by the possibility of endogenous or exogenous reactivation of the infection, defined as and , respectively. Thus, bacillary drainage is defined as: = 0.1 -a -r. Uys et al 77 determined that recovered subjects have a sevenfold higher chance of developing disease, which is given by w in our model. The birth rate ( ) is determined from the mean number of births per fertile woman/year ( ).…”