DNA tests of Lassa virus mid-outbreak helped Nigeria target its response
Analysis of genetic data in the field eased worries that a more transmissible strain had arisen
When an outbreak of a viral hemorrhagic fever hit Nigeria in 2018, scientists were ready: They were already in the country testing new disease-tracking technology, and within weeks managed to steer health workers toward the most appropriate response.
Lassa fever, which is transmitted from rodents to humans, pops up every year in West Africa. But 2018 was the worst season on record for Nigeria. By mid-March, there were 376 confirmed cases — more than three times as many as by that point in 2017 — and another 1,495 suspected. Health officials weren’t sure if the bad year was being caused by the strains that usually circulate, or by a new strain that might be more transmissible between humans and warrant a stronger response.