APOPO RATS RECORDING MILESTONES IN MOROGORO, TANZANIA !!!

TB detection rat named Vidic sniffs one hole after another at Apopo’s laboratory in Morogoro Region. PHOTOS | SONGA WA SONGA      

By Songa wa Songa, The Citizen Reporter

Posted  Monday, May 11  2015 at  14:12

IN SUMMARY

The 41-year-old had been coughing up a mixture of blood and sputum for two months. She was weak and had lost weight and her appetite. All tests for Tuberculosis, taken at public hospitals, including Mbagala Rangi Tatu, were negative.

Dar es Salaam. Sylvia Komba said her last prayer on an afternoon in December 2013 as she lay helplessly in her bed at Mbagala in Dar es Salaam.

The 41-year-old had been coughing up a mixture of blood and sputum for two months. She was weak and had lost weight and her appetite. All tests for Tuberculosis, taken at public hospitals, including Mbagala Rangi Tatu, were negative.

“I used all cough syrups and pills available in drug stores but the symptoms not only persisted but worsened,” she says.

All she could do now was wait to breathe her last and return to her maker. And then a miracle happened. Her phone rang. She gathered the little strength still left in her and picked it. The caller was a volunteer from Mkuta, a non-governmental organisation that keeps track of tuberculosis and Aids patients and encourages them to take their medicine. And then she got a message that changed her life.

“I was told that a sample from Mbagala Rangi Tatu hospital had been taken to Apopo laboratory in Morogoro that uses rat detection technology and had turned out positive,” she recalls. “The next day, I was taken to hospital and began taking medicines immediately. I completed the medication and I am now fit, as you can see.”

Asked why she believed her death was certain, Ms Komba suddenly lost her smile. It turned out that, back in 2002, her husband succumbed to the same symptoms she now had. He went to a number of public hospitals, including Mbagala Rangi Tatu. TB tests were done using smear microscopy but all turned out negative. Even X-ray did not detect it.

She added: “A day before he died, a specialist in a private hospital diagnosed him with TB. He took the medicine only once and died the same day as he was too weak. I wish the rat technology was there back then. My husband would be alive today.”

Another Mbagala resident, Mr Nicolaus Shomari, was about to breathe his last but was miraculously saved by rat diagnosis. In December this year, the 34-year-old and sole bread winner in his family, was in such a desperate state that he believed the end was near.

He had a permanent cough, pain in the chest, fatigue, weight loss and fever. The hawker was confined in bed and this meant the rest of the family were also in bed most of the time, but for a different reason—hunger.

“Doctors suspected TB but tests in several hospitals, including Mbagala Rangi Tatu, were negative,” he said: “I was weak to the point of supporting myself with a walking stick.”

In February, when he thought he had reached the point of no return, Mr Shomari received what he now calls a “miracle phone call” from Mkuta volunteer. The sample that was sent to Apopo laboratory in Morogoro was positive. That same day, he went to hospital and began taking anti-TB medicines. He continues using them.

“Look at me now,” he said proud Mapambano ya Kifua Kikuu na Ukimwi Tanzania (Mkuta), whose team of volunteers work in partnership with Apopo, is mostly composed of former TB patients.

“We visit partner hospitals and convince each and every TB suspect to provide us with their phone number and physical address, which makes it easier to track them,” said Mkuta Programme Supervisor Scholastica Myemba.

From loathed pests to Hero Rats

In Tanzania, and indeed the rest of Africa, rats are pests hated for their destructive behaviour. They destroy crops in the fields and food stocks in homes, so humans have always been out to thwart the enemy—rats—that, if left free to roam, can potentially lead to hunger. Aware of the danger facing them, rats do one thing whenever they encounter humans: They run as fast as possible.

But this relationship is now changing as the two former enemies now live and work together as comrades determined to defeat a completely different foe. In the town of Morogoro, African giant pouched rats and humans work together in a laboratory to detect Tuberculosis pathogens.

Since several tests are misdiagnosed through the widely used standard technology— smear microscopy—this new approach appears to be the new front in the war against TB in Tanzania and the rest of the developing world.

Apopo, the Dutch acronym for Anti-Personnel Landmines Detection Product Development, initially began training rats to detect landmines but later diversified and included TB in a project hosted by the Morogoro-based Sokoine University of Agriculture (SUA).

Though pioneer rats were captured in the bushes, Apopo initiated a breeding programme to ensure no shortage of supply at any given time.

The magic trick

The trick lies in two things: Smell and the click sound, which means reward. At four weeks old, when they open their eyes, rats are given stage one training called socialisation or habituation. They are introduced to contact with humans but the units (of the course) smell recognition, click sound and reward for the identification of the right smell, begin in the fifth week.

They are taught that a click means food. Click training takes about two weeks, after which they start scent discrimination training when they are about seven weeks old.

TB detection rats are rewarded for identifying Volatile Organic Compound (VOC) found in Mycobacterium tuberculosis. Mine detection rats are introduced to the smell of TNT that is found in landmines.

A rat is introduced to the VOC repetitively and gets used to it. So when different smells are placed in closed containers in a row, the rat is made to smell each container. Whenever it detects the VOC odour, it scratches the container and, with that, a click sound is made. The rat is given a pat on the back in the form of a banana or mashed avocado.

At Apopo’s TB detection rats training and research centre, three men sit in the laboratory’s evaluation room—the trainer, who knows the behaviour of the rat—the handler and the observer. A steel bar with 10 holes is inserted in a glass cage with the rat inside. Small containers with sputum samples are put in the holes and the rat begins sniffing them one by one. When it senses VOC in one of the holes, it stays longer there as it scratches the surface of the hole, which largely stays closed but with a tiny space to allow it to sense the odour. Once the team is satisfied, a click sound is made and the rat runs to an opening in the far right of the cage for a reward.

“But the indication has to be very strong,” says Mr Fidelis John, the training supervisor at the centre. “The scratching has to go on for between three to five seconds.”

In a negative result, the rat sniffs for a second or two and moves to the next one until it has worked all the 10 holes. The bar is removed and another one is inserted and the evaluation continues.

Mr John said the invention is fast and efficient since one rat can clear 70 samples within 10 minutes in what they believe to be fool-proof accuracy.

But extra care is taken to ensure that the rats and the staff are not exposed to the pathogens. Once the samples have been received from partner hospitals, they are treated and nothing is left to chance.

“We don’t dare touch live samples because TB is a contagious airborne disease. We use autoclave to inactivate the bacteria,” he said.

The centre, which is the second line of testing, receives an average of 170 samples per day from 24 hospitals—21 in Dar es Salaam and three in Morogoro.

In another evaluation room, the glass cage is connected to a laptop computer and is called an autocage. The process is the same but it is the computer programme that detects the three to 10 minutes time range and the scratching. Once that is achieved, the computer releases a click sound, which means the sample is positive.

At the end of the session when the detection rat named Vidic is let out of the cage, it jumps onto the shoulder of its trainer, Mr Sama Ulanga, and the two congratulate each other for a job well done.

According to Quality Control Supervisor Haruni Ramadhani, the invention is far more cost effective than other testing technologies such as gene, expert, culture and microscopy. “No money is spent on expensive equipment, chemicals and maintenance,” he said.

When it comes to accuracy, while the standard technology in“Mycobacterium tuberculosis can hide from the microscope lenses but cannot disguise the odour it produces from our rats,” Mr Ramadhani said. And the heat inactivation treatment does not diminish or remove the smell. Another advantage is the fact that the rats can work effectively for seven years, which is a long life in captivity for a wild animal.

According to Apopo Communications Assistant Ragna Frans, the total number of samples screened by rats in 2014 alone was 40,062 with additional positive cases that were missed by hospitals at

1, 412.

“We have achieved additional case detection rate of 39 per cent,” she said, adding that in Morogoro there are 31 operational TB detection rats while another one is in training. In Mozambique there are nine operational rats.

As for the expansion to other African countries, Ms Frans said negotiations with the South African government were at an advanced stage with that country expressing an interest in using the technology, especially in highly populated areas with rampant TB cases such as mines and prisons.

“We are in the middle of accuracy test,” she said. “We are comparing ours with other technologies in a bid to convince WHO to approve this invention.” Things look good so far.

Because Apopo works directly with patients, they have been given ethical clearance by the ministry of health’s TB and leprosy control programmes in both Tanzania and Mozambique, according to Ms Frans.

In Mozambique, where they are partnering with 13 hospitals, the total number of samples screened by rats in 2014 was 18,096 with an additional 645 TB patients detected by rats in Maputo, Mozambique. There, they achieved additional case detection rate of 52 per cent.

Ms Frans on How the Idea Came About

“Bart Weetjens, APOPO’s founder, kept pet rats as a child and got to know the little animals as intelligent, trainable and with a very accurate sense of smell. Years later, while analysing the landmine problem in Sub-Saharan Africa, it struck him how expensive and dangerous the process of landmine clearance is. When he came across an article about gerbils detecting explosives in airports relying on their keen sense of smell, he remembered his own pet rats, put two and two together and got the idea to start training rats as a cheaper, more efficient and readily available means to detect landmines in war-torn countries. The explosive used in most landmines, TNT, has a strong odour—and this is what the rats are trained on. Later on, Bart and a research team wanted to see if there were other odour-related humanitarian issues where the rats could be used and they came across Tuberculosis. In the very late stages of the disease, even people can smell Tuberculosis so they decided to give it a try and started training rats—with success.”

Demining training

An expansive track of land belonging to SUA, where the demining training takes place, looks like a real landmine-littered field.

Safety lines are drawn where trainers and any other visitors are allowed to walk through. Real landmines are planted underneath. The 1,000 mines are provided by the Tanzania Peoples’ Defence Force (TPDF).

Tanzania—smear microscopy—struggles to see the bacteria with high chances of misdiagnosis, the rats go for the odour.