Angelique Batamuriza, who lives with HIV, is more susceptible to tuberculosis, whose germs are spread through the air from one person to another.

This makes early diagnosis extremely crucial.

The 34-year-old mother of two, who is also a widow, says at one point, she started experiencing a severe cough.

"In January this year, I visited Rwamagana District Hospital and was diagnosed with TB within two hours after providing sputum. I started on treatment immediately,” she says.

Her children, too, were tested and found to be negative, she reveals.

Every two weeks, the resident of Isibagire village, Kigabiro Sector, treks to the hospital for routine checkups and medicine. She reports that her health has been steadily improving.

If she had contracted the bacteria several months earlier, Angelique, like many patients, may not have survived, according to Edouard Nkubito Mirimo, her physician and AIDS Healthcare Foundation’s Regional Medical Officer in charge of East.

TB tests, he further shares, took three to five weeks to give results. That is because laboratories in Rwanda used the tedious sputum smear microscopy. For the smear, the lab staff puts some of a patient’s sputum into a particular container to grow, which can take up to five weeks to obtain results. However, if the bacteria grow, the culture result is positive.

Some patients, as a result, died before diagnosis was made, while others progressed to chronic disease.

TB, as Mirimo defines it, is caused by the bacteria Mycobacterium Tuberculosis and mainly affects the lungs. However, it can also affect other organs, such as the spine, brain, or kidneys.

It is easily cured with antibiotics when diagnosed early but can be severe if not treated, he adds.

In 2010, the World Health Organization (WHO) recommended that rapid molecular assays, such as the GeneXpert machine, be used as the initial test to diagnose TB instead of microscopy in high-risk groups.

The GeneXpert TB test is revolutionizing the response to TB by drastically reducing the time of diagnosis. "GeneXpert gives you the test result in less than two hours,” says Mirimo.

"This ensures patients, especially those with co-morbidities such as HIV, are treated promptly. This also prevents them from spreading the bacteria.”

How it works

This is how it works. A medic takes sputum from a patient, mixes it with the necessary reagents, loads it into a disposable test cartridge, and inserts it into the GeneXpert machine.

The machine provides real-time analysis of the results, which are typically displayed on the system’s interface.

As such, GeneXpert is more accurate and time-effective than conventional sputum smear microscopy or culture when detecting TB. By testing additional sample types, the TB diagnostic gap can be reduced.

"GeneXpert is a fully automated system that doesn’t require technical expertise and multiple manual steps, thus reducing the chances of manual errors. It can also be done in rural areas as it’s portable and decentralized. This test reduces the turnaround time associated with TB PCR testing,” Mirimo says.

The Medical Director AHF, Julius Kamwesiga, explains that the test&039;s high sensitivity helps correctly identify patients with TB bacteria. In contrast, it specificity correctly identifies people without the disease, ensuring more accurate results.

"GeneXpert machines are more accurate because one can detect wherever TB is because it doesn’t just affect the lungs. Their sensitivity and specificity depend on the source of the microbe. For example, if it comes from a lymph node, the sensitivity will be over 83 percent, and the specificity will be 94 percent. If it comes from cerebrospinal fluid, you have a sensitivity of 81 percent and specificity of 98 percent,” Kamwesiga says.

"When it (tuberculosis) is coming from the sputum, with the GeneXpert, you have a sensitivity of 94 percent and specificity of 99 percent, and if it is coming from peripheral fluid, say the person is not able to breathe, the GeneXpert machine will show that he or she has 46 percent sensitivity and 99 percent specificity.”

According to Byiringiro Rusiro, Head of the TB infection control unit at Rwanda Biomedical Center, 81 GeneXpert machines are already used for TB diagnosis in all 48 hospitals and some health centers with high TB rates in Rwanda.

Increased tests reducing mortality

Rusiro says that 150,320 people with TB symptoms were tested through microscopy and GeneXpert during the financial year 2023-2024.

However, the number of TB tests using GeneXpert machines has increased, with 55,672, 76,682, and 118,677 done in 2021, 2022, and 2023, respectively.

He explained that GeneXpert's low performance in 2021 was due to the COVID-19 pandemic when health services were not optimal. In 2022, the national TB Program faced the challenge of maintaining GeneXpert machines, as some modules were not functional.

Nonetheless, the quick diagnosis and treatment led to a significant drop in the mortality rate caused by TB between 2021 and 2023, from 9.2 deaths per population of 100,000 to 4.3 deaths per population of 100,000.

Numbers in reduction of TB deaths in Rwanda from 2001 to 2003. Source: RBC

Kamwesiga shares that one factor contributing to this decline is that GeneXpert can also tell if the first-line drug will work in positive cases.

GeneXpert efficiently detects whether the TB infection resists countering drugs like rifampicin. If it’s resistant to the drug, it implies the presence of multi-drug-resistant TB. Identifying this is crucial as it informs doctors of direct treatment decisions and guides patients toward the right management path, he says.

A point-of-care lateral-flow test performed on urine is also recommended by WHO; its primary use is to assist with the diagnosis of TB in people with advanced HIV disease, in combination with rapid molecular tests.

Additional rapid molecular tests are designed to detect resistance to various first—and second-line anti-TB drugs. At the same time, sequencing technologies can provide a comprehensive individual drug resistance profile.

Delayed diagnosis results

In April this year, Emmanuel Habimana, a 50-year-old motorcyclist, felt excruciating chest pain and a severe cough that he blamed on the cold weather that he braves when working.

After several tests, including an x-ray, at Kacyiru Health Center, he was diagnosed with TB a week later and started treatment immediately.

The focal point nurse at the health center, Jeanne Uzayisenga, says diagnosis results are often delayed because the health center relies on one GeneXpert machine from the district hospital. In addition, the national TB Program faces the challenge of maintaining GeneXpert machines with malfunctioning modules.

With three tests done monthly, on average, she believes that if the health center owned at least one rapid test machine, tests for TB at Kacyiru Health Center would increase.

Kamwesiga also says that the challenge with not having these machines in all diagnostic and treatment centers is that it would risk patients spreading the disease since a person with high immunity may not know they have it.

"Anytime we suspect they have TB and results come in time, they immediately start their medication, and you don't need a long time. Even seven days are enough to stop you from spreading the disease.”

To improve the RDTs shortage, presumptive patients not in the high-risk groups are tested using microscopy. Presumptive patients that are part of the high-risk groups include people living with HIV, people above 55 years of age, and children below 15 years.

"On average, about 150,000 presumptive TB patients need TB testing, but the GeneXpert machine can't cover all of them. So, we put in place some indications for this rapid testing tool for some groups and areas where we think they are eligible for the expert test,” Rusiro says.

Kigali City, he adds, accounts for 30 percent of all TB cases in Rwanda, making it a high-risk zone for TB, which qualifies it for installation of these RDTs.

"In other provinces, we diagnose most patients with TB symptoms, if they are not in high-risk groups, using microscopy, which, although not very sensitive, serves the purpose.

Despite the challenges, Batamuriza and many others who have benefited from the tech-mediated TB rapid test are happy to be alive and on their way to recovery, thanks to the device's timely diagnosis.