Samba II technology: could it be an answer to Covid-19 testing in Zimbabwe?

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Tinomuda Chakanyuka

That African countries should scale up Covid-19 testing is not debatable. In fact, it’s a no brainer.  What has however been causing sleepless nights for most Governments on the continent is how to scale up testing. 

It’s a conundrum. One they need answers to very quickly.  Yet, more often than not, answers to the most complex of puzzles are right under our noses.  We don’t need to search high and low.

Until a Covid-19 vaccine is ready, African Governments need to employ effective and extensive testing as a way of flattening the curve.

But what does “flattening the curve” mean?

This is the process of slowing the spread of a virus in order to reduce the peak number of infected people requiring care at a given period. The higher the peak, the more the number of people infected.

Flattening the curve is critical. But many Governments in Africa may not afford to carry out mass testing to achieve this. Yet, these Governments cannot afford losing citizens to the disease either.

The predicament begs solutions.

Europe, the US and Asia have been hit hard by Covid-19. Africa has had a window of opportunity, after the virus visited its shores pretty late. Therefore, the continent has a window of opportunity to react to the epidemic. But if that window is not fully utilized, as the World Health Organisation warned, Africa could soon be an epicenter of this global pandemic.

Intervention must be immediate and has to be scaled up.

Since recording its first Covid-19 case in March, Zimbabwe has tested less than 30 000 people — a negligible percentage of the country’s total population of about 14 million.

Dr Agnes Mahomva, previously Health and Child Care permanent secretary and now Chief Coordinator of National Response to the Covid-19 pandemic in the Office of the President and Cabinet, explained the challenges the country has been facing in combating Covid-19. “While we have decentralized testing across the country, we continue to face an acute shortage of Personal Protective Equipment (PPE). The challenge is a global one.”

In addition to sufficient PPEs, consistent and large scale testing for Covid-19 is critical to the control of this virus. Neighbouring South Africa is now conducting more than 10,000 tests a day. The country has achieved this by drawing heavily from their experience in dealing with TB and HIV.

Zimbabwe has set a target to test 1,000 people a day, but this target has been met only a handful of times since testing started. The country has vast experience in combating TB and HIV. In fact, Zimbabwe is one of the countries in Africa that is leading in fighting HIV.  Lessons drawn from the experience in combating HIV can surely be employed in fighting Covid-19.

“One key lesson is multisectoral collaboration and coordination,” Head of Epidemiology and Disease Control in the Ministry of Health and Child Care Dr Portia Manangazira told ZTN.

She added, “Players from both the public and private sector have collaborated in fighting HIV. We are basically using the same approach in responding to the Covid-19 pandemic”.

Zimbabwe is one of the first countries on the continent to roll out Point-of-Care (POC) HIV testing using SAMBA II, a technology developed at the University of Cambridge. This technology is being used in Early Infant Diagnosis (EID) of HIV as well as viral load testing for therapy monitoring in adults.

The country has 125 SAMBA II machines at 25 health centres in all the country’s 10 provinces. This is according to data from the Ministry of Health and Child Care. Interestingly, the same technology can also be used for Covid-19, with a turnaround time of 75-90 minutes.  Other tests take about 5 hours to 24 hours or even longer.

The United Kingdom, one of the countries that have been hit hard by Covid-19 has already started using SAMBA II technology to test for the virus. Validation in 172 patient samples were carried out by the Public Health England laboratory in Cambridge. The SAMBA test proved to have 98.9 percent sensitivity and 100 percent specificity.

Sensitivity refers to the ability to correctly identify positive cases while specificity is the ability to correctly identify negative cases.

SAMBA II technology was developed by Diagnostics for the Real World, a spin-off company from Cambridge University. While it was originally designed to test for HIV in hard to reach areas in Africa, work to adapt the technology to test for Covid-19 started in early February this year.

On Saturday April 4, the Medicines and Healthcare Products Regulatory Agency approved Samba II for use in the UK and countries in Europe.

As Zimbabwe grapples with expanding testing and case identification, to get a true picture of the pandemic, answers to this challenge could well be found in the Samba II technology.

Each SAMBA II machine has the capacity to carry out around 16 Covid-19 tests a day. With 125 machines, Zimbabwe could conduct an additional 2,000 tests a day.

“It’s not easy because of the cost factor. But we are considering all available options that could help us test as many people as we can,” Health and Child Care Minister Dr Obadiah Moyo said.

The SAMBA technology was designed for hard-to-reach areas. Zimbabwe has distributed the machines to clinics and hospitals in remote areas.

With the country working to decentralize Covid-19 testing, health facilities with the Samba II machines could be a solution. 

CEO of Diagnostics for the Real World, Dr Helen Lee described the SAMBA II machine as, “cutting-edge technology so simple and robust, it can be placed literally anywhere and operated by anyone with minimum training.”

But just how does the SAMBA II work in the diagnosis of Covid-19?

The technology looks for tiny traces of genetic material belonging to the virus, amplifies it billions of times chemically and is therefore extremely sensitive in the detection of active infections.

A nasal and throat swab is collected from a patient and once uploaded to the machine, it looks for tiny traces of genetic material belonging to the coronavirus, and amplifies it billions of time chemically in fully automated fashion.

This technology could change the face of Covid-19 in Zimbabwe by helping authorities expand testing and case identification to get a true picture of the pandemic.

Early identification of Covid-19 infection is beneficial to treatment of infected individuals but will also lead to well-informed interventions to curb the spread of the epidemic.