Study experiments with more convenient disease testing schedule
An international team of researchers has found that revised protocols for diagnosing tuberculosis may be more user-friendly for patients and help bring more people into treatment, especially in poorer countries.
In many places around the world where tuberculosis is a major threat, suspected cases are diagnosed by looking through a microscope for the TB bacteria in sputum - the mixture of saliva and mucus that the patient coughs up.
Under current protocol, three specimens are collected on two consecutive days - one "on-the-spot" in the clinic, one the next morning at home, and then a third "spot" sample when the patient returns to the clinic.
But many patients don't live near a diagnosis facility, so often they come once, but don't return for the next day's tests.
Luis Cuevas of the World Health Organization and the University of Liverpool in England and colleagues tested a variation of the protocol, taking two "spot" samples in the clinic an hour apart, and a third one the next day.
"And if you use the new scheme, you end up with exactly the same result. Whether you do it one way or another, you end up with the same number of cases."
Not only that, the results from examining just the first two specimens identified most TB-positive patients. So if both specimens are collected on day one, there is a greater likelihood of an accurate diagnosis.
The studies were done in Ethiopia, Nepal, Nigeria, and Yemen.
Researcher Cuevas says it's important to improve the process of diagnosing tuberculosis. "What we see very frequently is that accessing the diagnosis for TB is often a barrier to access treatment for TB. So, facilitating a rapid diagnosis is very key to improve access to treatment."
There are more high-tech diagnostic tests for tuberculosis, but they are as much as 15 times more expensive than microscopic examination of the sputum, so in resource-poor countries the less costly diagnosis procedure is likely to remain dominant.