Two Guinea Labs Tested 4,683 Fever Samples and Found Lassa Cases

Two laboratories in Forest Guinea tested 4,683 samples from suspected viral hemorrhagic fever cases between 2017 and 2024, returning results in one day on average. A study in npj Viruses, based on nearly a decade of surveillance, also documents the burden of Lassa fever in the region.

The 2014-2016 Ebola epidemic in West Africa showed the need for decentralized local laboratory capacity. Work began in late 2016 on the Laboratory for Viral Haemorrhagic Fevers in Guéckédou, which has operated since 2017. The laboratory at the regional hospital in N'Zérékoré, first set up during the Ebola outbreak, was strengthened in 2021.

Both belong to the national surveillance system for these diseases and work under a mandate from the Guinean Ministry of Health, with support from the National Reference Laboratory in Conakry. They offer free molecular tests for Ebola, Marburg and Lassa viruses, plus yellow fever and dengue.

Faster detection, and the first Lassa data

The teams found Ebola, Marburg and Lassa infections, among others. In 2021 they quickly identified the return of Ebola and the emergence of Marburg virus disease, which helped confirm the cases and start countermeasures.

Testing also produced reliable numbers on Lassa fever, yellow fever and dengue in a region where a lack of testing had long limited surveillance. Between 2020 and 2024 the laboratories confirmed 30 Lassa fever cases, mainly in the prefectures of Guéckédou and N'Zérékoré.

Lassa fever is endemic in West Africa, but in Guinea it had rarely been documented. Before the two laboratories existed there were only a few individual case reports, although earlier studies of antibodies in the population had suggested the virus is widespread in some regions. These are the first systematically confirmed acute cases from the area.

About two-thirds of patients with known outcomes died, or 67.9%. The authors conclude that Lassa fever has long been underestimated in Forest Guinea. The small number of cases in the literature was probably due to underdiagnosis and underreporting, since reliable diagnosis was not possible without local laboratories.

"Our work demonstrates that Lassa virus is circulating in Forest Guinea," said Youssouf Sidibe, head of the N'Zérékoré laboratory and a lead author. He added that active surveillance should continue, ideally through a One Health approach.

Funding after the donors

International funders, above all the Global Health Protection Programme of the German Federal Ministry of Health, have contributed significantly to setting up and running the laboratories. Keeping them going beyond time-limited, donor-funded programs remains a major challenge.

"The open question is sustainability," said Dr. Sophie Duraffour, who heads the Outbreak Preparedness and Response laboratory group at the Bernhard Nocht Institute for Tropical Medicine. She said funding for this kind of work is still mostly tied to specific programs.

The teams see room to broaden the range of tests, bring in peripheral health centers and develop the laboratories into regional training centers. Such centers could train specialists from other prefectures and neighboring countries and help build a cross-border network for outbreak diagnostics.

The authors note that parts of Africa are again facing Ebola outbreaks, currently caused by Bundibugyo virus.

Source: Medical Xpress