Indonesia: No progress in TB diagnosis
Technological development in the diagnosis of tuberculosis has been stagnant during the past 10 years, leading to the disease becoming a serious threat, an official says.
The Health Ministry’s tuberculosis directorate head, Dyah Erti Mustikawati, said technological developments used to diagnose tuberculosis (TB) had not progressed, making Bioterrain analysis (BTA) and culture breeding the only TB detection methods.
“If we have new technology which is more cost efficient, then it would be helpful because tuberculosis cases in Indonesia remain high,” she said on Friday.
According to the World Health Organization (WHO), TB is already one of the world’s worst killers along with malaria and HIV/AIDS. It accounted for 9.4 million cases and 1.7 million deaths in 2009 globally.
Indonesia had 450,000 TB cases in 2010, the fourth-highest TB rate in the world in that year. Overall, Indonesia ranked 9th in terms of countries with the highest prevalence of TB in 2011.
Meanwhile, recent molecular epidemiology research shows that molecular diagnostics in TB can reduce the threat of the infectious disease, as it offers simpler but more effective detection methods that may prevent delays in diagnosing the bacterial infection.
Vivi Lisdawati, a researcher from the Health Research and Development Agency (Balitbangkes) at the Health Ministry, said on Friday that molecular diagnostics in TB was now the most cost-efficient and highly accurate diagnosing tool for the infection when compared to conventional diagnostic methods, as it could amplify bacteria without using a thermo cycler or a Polymerase chain reaction (PCR).
Molecular diagnostics could also become an alternative to the limits of conventional diagnostic tools, she said.
“We have been able to develop a detection tool for TB bacteria through characterizing Indonesian-origin bacteria by using molecular diagnostics,” said Vivi of the latest TB research conducted by the agency’s Biomedical and Health Basic Technology Center.
The research shows that the molecular diagnostics method, called “Loop-mediated isothermal amplification” (LAMP) had the potential to become an alternative method of TB detection as it could work in constant temperatures and did not need a thermo cycler.
“PCR is quite expensive. Thus, it would be better for us to use this simple diagnostic tool if using PCR is not a necessity in the diagnostic process,” said Vivi.
Currently, two conventional diagnostic methods, namely BTA and culture breeding, remain the gold standards for diagnosing TB in Indonesia.
The sensitivity of BTA, for example, ranges from 67 percent to 87 percent, although its specificity can reach 90-100 percent. The success of the diagnosis depends on the skills of clinical laboratory workers.
They need to receive routine training and close monitoring. Moreover, bacteria taken from suspected patients should first grow
to large numbers before the lab workers could consider them to have TB. Therefore, “fake negative” cases could often occur in lab tests using BTA.
“In detecting TB cases, we’ve often found ‘fake negatives’, especially with the growing number of TB-HIV cases,” said Vivi.
Specific skills required by lab workers in conducting the bacteria identification also posed a challenge to another conventional diagnostic method, namely culture breeding. “To accurately identify the bacteria, we have to first breed it, which may last between 8 to 10 weeks. It’s not time-efficient,” said Vivi.
The three-year long research took place during 2008-2010 and involved scientists from several institutions, including the Eijkman Institute in Jakarta, Balai Besar Laboratorium Kesehatan (BBLK) in Surabaya, East Java, and Hasanuddin University’s School of Medicine in Makassar, South Sulawesi. During the research, scientists identified bacteria in sputum specimens taken from TB patients in 16 cities.
After identifying 149 genotypes from 404 Mycobacterium tuberculosis-spoligotype patterns found in cities, scientists revealed that TB cases in each region were caused by different genotypes of TB bacteria.
The Mycobacterium TB Beijing genotype is responsible for most TB cases in the western provinces of Indonesia, while Mycobacterium tuberculosis EAI and Mycobacterium tuberculosis lipoarabinomannan (LAM) dominate most TB cases in eastern parts of the country.
“We also found that 77 percent of a total of 404 samples were still drug-sensitive. So, we can still give them the first-line of anti-TB medication,” said Vivi. However, about 20 percent of bacteria species were resistant to either isonicotinylhydrazine (INH) or rifampicin. About three percent were multidrug-resistant (MDR) to the Mycobacterium TB type.
“If we can detect early such multidrug-resistant TB cases, then we can give infected people proper medication as early as possible, preventing the further spread of the disease,” said Vivi, adding that molecular diagnostics could identify 40 samples all at once in three hours.