A number of east African countries, including Tanzania and Mozambique, have started training giant pouched rats, which are known for their highly developed sense of smell, to detect tuberculosis (TB). According to Reuters, Belgian NGO APOPO, which already uses trained rats to sniff out landmines, will soon be using the giant rodents to carry out a mass screening for TB among inmates in crowded prisons.
Inaccurate detection methods make TB one of the world’s deadliest infectious diseases. According to the World Health Organization (WHO), about nine million new cases of TB are contracted every year, and of that number, around three million cases go undiagnosed, resulting in around two million deaths.
In a conventional medical laboratory setting, TB is detected by carrying out a sputum smear microscopy, a slow and costly process that has not changed much in the years since it was developed. The process also carries a significant chance of an inaccurate diagnosis. The WHO insists that lab technicians should not carry out more than 20 procedures per day, as the chances of misdiagnosis increase when that number is exceeded.
Photo Credit: Livemint
Tanzanian heath officials claim that each of the APOPO trained rats can make a near perfect diagnosis within 20 minutes by simply sniffing the saliva of infected patients. Other methods typically take about two weeks to get a final result.
Scientists with APOPO say the trained rats have an almost 100 percent accuracy at detecting strains of tuberculosis, maintaining that the system is fast, cheap, and has the potential to greatly lower screening costs in poor countries.
“We believe our unique TB detection rat technology will prove itself as an effective mass-screening tool,” said APOPO’s U.S. Director Charlie Richter.
“We then aim to expand the program to all prisons, shantytowns, factories, and other settings in Tanzania, Mozambique, and other high TB-burden countries, as well as in high-risk groups such as those individuals living with HIV/AIDS. This will improve and save lives all over the globe at a low cost,” Richter explained.
Funding from the United States Agency for International Development has allowed APOPO to screen more than 340,000 TB samples, prevented the spread of another 36,000 new infections, and increased detection rates by over 40 percent.
A pilot phase will soon be implemented focusing on crowded communities with poor sanitary facilities like slums and jails, where studies show the rates of infection to be nearly 10 times higher than in the general population.
