New testing device to improve management of drug-resistant TB

Mellen Kimaiga, a TB testing specialist,  explains how the GeneXpert machine works. Right:  Sister Veronicah Wanjiru of Mbungoni Catholic Clinic in Mombasa displays a poster on tuberculosis prevention. PHOTO | SARAH OOKO
Mellen Kimaiga, a TB testing specialist, explains how the GeneXpert machine works. Right: Sister Veronicah Wanjiru of Mbungoni Catholic Clinic in Mombasa displays a poster on tuberculosis prevention. PHOTO | SARAH OOKO 

Mary Akinyi was diagnosed with Tuberculosis (TB) five years ago. She was immediately put on a six month treatment programme requiring her to take first line anti-TB drugs each day for that period.

Despite adhering to the medication, Ms Akinyi noticed that her condition was not improving.

“I was stressed because I was taking the drugs religiously but I was not getting well.”

It is only after the six months were over without any remarkable progress that the doctor finally recommended further tests to determine the cause of her ordeal.

Akinyi eventually tested positive for drug resistant TB but she only found out three months later. During the waiting period, she had been freely mingling with family members and other villagers who unknowingly contracted the disease from her.

Such stories are replicated countless times in the country. Most Kenyans with drug resistant TB never know where they got it from.

People may get the disease while travelling to work in a crowded bus, having lunch in a quiet restaurant or idling around in town. If someone with untreated drug resistant TB coughs next to them, the person releases germs which others unknowingly inhale and become sick too.

“So the only way to stop transmission is to ensure that we diagnose the disease promptly and ensure that all those suffering from it begin treatment immediately,” said Dr Enock Masini, Head of the National Tuberculosis, Leprosy and Lung Disease (NTLD) programme at the Ministry of Health (MOH).


To address the diagnosis challenge, MOH is now rolling out a new TB testing device known as the GeneXpert. This technology makes it possible for health facilities to accurately detect drug resistant TB in just about two hours.

Previously, this type of test could only be conducted in two public laboratories in the country — one in Nairobi and another in Kisumu.

Therefore, sputum samples (mixture of saliva and mucus coughed up from the lungs) from those suspected to have the disease had to be transported from all over the country to just these two locations.

Due to transportation logistics and complexity of the previous testing method (known as culture testing), patients like Akinyi were subject to long waiting periods.

Worse still, logistical challenges sometimes led to samples being misplaced before reaching the laboratories. And if they made it safely, the results could get lost along the way.

In some instances, poor handling of the sputum samples during transportation compromised their quality thus rendering them useless for tests.

“So you can imagine a patient waiting for three months only to be told that due to one problem or another, they have to wait for another three months,” said Dr Masini.

He added: “Some patients would give up and refuse to give another sample. Then they would show up later at the hospital when in critical condition. And remember that all this time the sick patient will be transmitting the disease to unknowing people due to lack of treatment.”

Severe symptoms

These challenges have greatly contributed to the drug resistant TB burden in the country. Patients with this strain of the disease have more severe symptoms compared to those with normal TB.

Their treatment course is also much more intensive and costlier. The patients are also likely to have many adverse effects from the strong drugs that they are required to take.

Dr Masini stated that the more than 120 GeneXpert machines, currently present in selected health facilities across counties are providing solutions to this challenge.

Because the machines are closer to Kenyans at the grassroots, the MOH has been able to diagnose more drug resistant TB cases than it previously did.

In 2015 for instance, over 400 cases were diagnosed compared to an average of about 200 in yester years. The latter figure was the highest number ever recorded in just a year.

As more hospitals continue to adopt the digital technology, he said the number of patients with drug resistant TB will keep increasing since it is estimated that there are about 1,000 cases of the disease that are never “caught” each year due to limitations of the previously used diagnosis method.

“So it’s not like people are becoming sicker. It just that we are now getting previously missed cases,” explained Dr Masini.

Because the GeneXpert machines are closer to people at the counties, health workers no longer need to wait for six months for TB patients to complete their first course of treatment before finding out if the patients are suffering from a drug resistant strain of the disease.

“We review our TB patients regularly now and if we notice that their condition is not improving then a decision is promptly made to test for drug resistant TB,” said Ms Mellen Kimaiga, Laboratory Manager at the Rhodes Chest and TB clinic in Nairobi.

She added that since the test takes only two hours, the patients do not need to leave the hospital and come back at a later date.

“They just sit at the waiting area and if the results turn out to be positive for drug resistant TB, we then put them on treatment immediately to prevent the spread of the disease.”

The easy to use technology has also made it possible for lower level facilities such as health centres and clinics — frequented by most Kenyans — to conduct drug resistant TB tests.

Final stages

Previous tests required high level laboratories and sophisticated medical equipment that were unavailable in most counties.

Researchers are now in the final stages of developing portable GeneXpert machines that community health volunteers can easily carry around and use for testing drug resistant TB at the community level.

Since the testing process of this new technology is automated, Ms Kimaiga states that hospitals are now able to analyse numerous samples and thus diagnose many patients.

“You just mix the sputum with some reagents then you put the mixture in the machine. And within a short time you will have your results.”

She added: “Due to the automated process, our contact with the sputum samples is greatly minimised. This protects health workers from unnecessary exposure to the TB bacteria which can make them sick.”

As the GeneXpert machines can be linked to mobile phones, once test results are out, doctors and patients are automatically alerted via their phone of the outcomes.

“So, patients don’t need to travel back to the hospital for the results when they are unwell. They also save on bus fare,” stated Kimaiga.

Dr Masini said that aside from “catching” drug resistant TB, the machine is also effective at detecting mild TB cases which previous technologies had a challenge with.

People living with HIV/Aids are most vulnerable to Tuberculosis yet initially it was difficult to detect the disease early enough in this group. “But we are glad that the new technology has solved that problem.”

But the GeneXpert alone is not enough, to effectively control and eliminate TB, patients are required to adhere to treatment and finish the prescribed doses until they get a clean bill of health from their doctors.

Drug resistant TB can be transmitted directly from one person to another. But people with normal TB can also progress to drug resistant TB if they do not complete their treatment.

The new technology is also helping the Ministry of Health to conduct the ongoing TB prevalence survey that will provide Kenyans with accurate statistics on the burden of drug resistant TB in the country.