Malawi: Mercy Banda looks away as a blood sample is taken from her arm. Banda, 33, is HIV positive and is having her viral load tested at the Namitambo health clinic in Chiradzulu, southern Malawi. She should know the results in a couple of hours.
In the past, when blood samples were sent away to the district hospital, about 40km away or even to Blantyre, Malawi’s commercial centre, it would have taken more than a month. That’s if the sample wasn’t lost on the way to the hospital, or in the health facility, which would conduct hundreds of tests every week.
But that was before the arrival of a simple amplification-based assay (Samba) machine. Developed by the University of Cambridge to offer viral load testing, CD4 counts and early infant diagnosis, the device should improve HIV services for the population in this poor, rural community.
The Samba machine was developed by Dr Helen Lee, research director of the diagnostics development unit at Cambridge’s department of haematology. It is manufactured by Diagnostics for the Real World, a spinout company based in California, set up by Lee. Field trials took place in Malawi and Uganda last year in collaboration with the NGO Medecins Sans Frontieres (MSF), which is implementing a three-year project to test new ways of treating HIV in remote settings, funded by the global health initiative Unitaid.
Namitambo received its machine in August. “The Samba machine makes the job easier,” says Jeffrey Golozeria, a nurse at the centre, which has more than 5,000 patients living with HIV on its books. “Previously we were sending viral loads to Blantyre, which could take a minimum of a month, but sometimes three months before we got the results.”
The World Health Organisation (WHO) says viral load testing, which detects the level of the HIV virus in the blood, is the best way to monitor the affects of antiretroviral treatment. Regular tests, which are recommended by the WHO, allow health workers to check people are taking their tablets and, crucially, to see if they are working. High viral load levels suggest they may not be, and an assessment can be made as to whether the patient needs to switch drugs. But viral load testing is expensive, and its use in remote areas is limited and time-consuming since tests have traditionally been conducted in hospital laboratories.
Staff at Namitambo believe the Samba machine, which they say is quick and simple to use, could change that. Preparation of the blood sample is conducted in one part of the machine, while amplification and detection is performed in another, using a closed disposable cartridge that avoids contamination and contains all the necessary reagents. The cartridges do not need to be stored in a fridge, which are rare in rural centres, and stay fresh for about a year. Up to four samples can run simultaneously in the Samba, and an average of 12 samples are tested each day at a cost of about $17 (Dh62.43) each (compared with upwards of $25 in other settings).
The machine uses electricity, but batteries lasting up to eight hours are set to switch on automatically if the power goes off.
Chiradzulu is the first district in Malawi to receive Samba machines. There are two in the district, but plans are in place to install a machine in seven other health centres in the region. Unitaid has given an $8 million grant to Diagnostics for the Real World to speed up manufacturing and get the machines out on the market.
A Samba 2 machine is now being developed and could be rolled out next year. It should be even simpler to use. “It’s good to have Samba machines in rural areas like this,” says Golozeria. “It’s better for patients.”
— Guardian News and Media Ltd