Leviathan Viral Testing Africa has added the Biotime range of Covid-19 antibody tests to its portfolio.

The company is also the exclusive African distributor of the LifeCase PCR testing solution manufactured by Evotech-Mirai Genomics (EMG). The Biotime range will be sold by LVT Medical, a wholly-owned subsidiary of Leviathan Viral Testing Africa, which has the exclusive rights for Africa.

Established in 2008, Biotime specialises in R&D and the production of diagnostic devices and reagents. Biotime has successfully established a mature worldwide medical distribution channel, with Leviathan Viral Testing Africa being its exclusive representative on the continent.

Biotime’s Covid-19 IgM/IgG antibody test is a rapid lateral flow, qualitative, and convenient way to detect IgM and IgG antibodies to the Covid-19 virus in human serum, plasma, or whole blood samples.

Bearing the European CE Mark and laboratory tested by the UK’s National Health Services (NHS), Biotime offers one of the most accurate and reliable antibody tests on the market. It has been approved for use in several countries, including Brazil and the US, where it had FDA approval under the brand name Healgen.

“We have performed tests using the Biotime Covid-19 serology test on 50 PCR confirmed patients,: the UK Medicines and Healthcare products Regulatory Authority (MHRA) states. “The test picked up every single infected patient. To further elaborate, the test picked up IgM positives in early-stage disease, IgG positives in later-stage disease, and IgM/IgG positive in mid-stage.

“In addition, a few patients who tested negative with PCR techniques and had obvious clinical radiological picture consistent with Covid-19 tested positive with Biotime, suggesting a role for antibody testing over and above PCR. We are very pleased with these findings and are recommending the service approve these tests.”

A recent study (Pollán et al, 2020) suggests that PCR and serology could be complementary for testing regimes as the tests target different viral proteins. Serology testing for SARS-CoV-2 can better quantify the number of cases of Covid-19, including those that may present with mild symptoms, be asymptomatic or have recovered.

Serology tests are blood-based tests that can be used to identify whether people have been exposed to a particular pathogen by looking at their immune response.

In contrast, the RT-PCR tests currently being used globally to diagnose cases of Covid-19 can only indicate the presence of viral material during infection and will not indicate if a person was infected and subsequently recovered.

Serology is considered the best tool to determine the spread of an infectious disease, particularly with regards to those patients who are asymptomatic or have incomplete or partial symptoms.

These tests can give greater detail into the prevalence of a disease in a population by identifying individuals who have seroconverted and developed antibodies, a protective immune response in possible future re-infections.

Gerald Naidoo, CEO of Leviathan Viral Testing Africa, explains that both types are vital in the fight against Covid-19, providing authorities and individuals with vital information about rates of infection.

“As South Africa continues to fight the surge in infections, knowing how many people have recovered – even the asymptomatic cases – will be extremely important to helping government identify focus areas. Adding an antibody test to our suite of solutions, we have ensured we can remain a trusted supplier that provides complete Covid-19 track, trace, and test capabilities, further assisting in helping South Africa gain insight into the progress of the pandemic,” he says.

The largest prevalence study (ENE-COVID) of SARS-CoV-2, performed in Spain, concluded that seroprevalence was close to 90% after 14 days after a positive PCR test. This was consistent with other studies that had a more than 90% prevalence of infected people displaying an IgG response 14 days since the onset of symptoms (Health Information and Quality Authority) and another study demonstrating a 99% prevalence antibody repose among confirmed Covid-19 cases (Wajnberg et al., 2020).

“This is why we have developed a three-tier testing strategy that is proving extremely effective in combatting the spread of Covid-19 in high density critical infrastructure workplaces, such as those in the energy and minerals sectors. Combining screening, serology testing and PCR testing, this approach is based on the US Centres for Disease Control (CDC) guidelines and avoids workplace shutdowns, revenue loss, and most importantly, ensures a safe and healthy environment for employees and their families,” Naidoo says.

The Biotime IgM Rapid Test provides results within 15 minutes. Immunoglobulin M (IgM), which is found mainly in the blood and lymph fluid, is the first antibody to appear in the response to initial exposure to a new infection. IgM offers high specificity and high sensitivity to SARS-CoV-2, which offers significant value in the early detection of Covid-19.

Immunoglobulin G (IgG), the most abundant type of antibody, is found in blood and protects against re-infections. IgG appears later than IgM in patients when they have been infected with SARS-CoV-2, and is indicative of viral neutralising activity, but it can persist in the blood for several months, so a positive IgG result may indicate patients were infected with the virus in the past. The extent of immunity provided by IgG specific for Covid-19 is unknown, and further research needs to be done to establish how long IgG will remain in circulation before degradation.

“As the world continues to battle Covid-19 spikes, it is just as important to understand who may have been infected – and recovered – in the past as those that are currently struggling with the disease. We are proud to be able to bring another weapon into the fight against Covid-19 in South Africa with the Biotime test range,” Naidoo concludes.