Detection Rats Technology for Diagnosis of Tuberculosis in High-Risk Populations

Abstract

Prevalence of tuberculosis (TB) in prisoners in Tanzania and other sub-Saharan African countries is considered to be higher than in other populations thus prisons are important source of TB transmission. Control of TB in prisons through appropriate screening and diagnosis is challenging in most low-income countries such as Tanzania that is among world’s 22 countries with high burden of TB. Commonly used TB diagnostic test (smear microscopy) have low sensitivity, and most advanced GeneXpert method is rather expensive for developing countries. SUA-APOPO TB detection rats’ technology is most promising and increases TB case detection by over 40% in hospitals in Dar es Salaam Tanzania and Maputo Mozambique. This paper reports on improved TB detection in a selected prison in Tanzania using TB detection rats. Sputum samples (n = 11,424) were collected from 5,840 patients whom 3,491 were men, 2,349 were women. Of these, 386 patients were children altogether seeking diagnosis of TB at Ukonga prison dispensary from January 2013 to October 2015) and Keko prison dispensary from February to October 2015). Samples were routinely examined by Ziehl Neelsen (ZN) staining and later tested by rats APOPO TB laboratory, Sokoine University of Agriculture, Morogoro. Rats’ positive samples were concentrated and confirmed by fluorescent microscopy (LED-FM) or ZN microscopy. A total of 709 individuals (12%) were diagnosed as smearpositive TB by the prison hospital, whereas rats detected an additional 302 TB patients. This increased the case detection in the prison population by 43%. The use of rats’ technology increased the prevalence of smear-positive TB in prisons from 12% to 17.3% (n = 1,011) that is higher than prevalence reported in prisons elsewhere using microscopy. This finding shows that detection rats’ technology can help reduce the burden of TB in developing countries. There is need to expand application of this technology to other risk populations including miners.This technology can improve workforce, livelihood and socio-economy by reducing TB related expenses.