The agency revealed in its published Week 9 report that both health care workers were infected in Ondo State between March 1 and March 7, 2021.

The viral haemorrhagic illness killed another health care worker weeks ago in Taraba State.

A total of 25 new cases were reported in six states, according to the latest situation report.

Edo recorded the highest number of cases with 13, followed by Ondo with six. Taraba and Ebonyi recorded two cases each, while Benue and Kaduna recorded one case each.

Edo recorded the only fatality of the week under review, raising the death toll for the year to 32.

Nigeria has now recorded 161 Lassa fever cases this year, with cases detected in 45 local government areas across 12 states.

Edo has recorded the highest number of cases with 73, followed by Ondo with 38, and Taraba with 16.

The three states have also recorded the highest number of deaths with 11, nine, and eight, respectively.

Lassa fever infection can happen through contact with excreta or urine of rodents; contact with a probable or confirmed Lassa fever case within a period of 21 days of onset of symptoms; or any person with inexplicable bleeding/hemorrhagia.

Symptoms of Lassa fever include malaise, fever, headache, sore throat, cough, nausea, vomiting, diarrhoea, myalgia, chest pain, and hearing loss.

The NCDC said last year a large epidemiological study being implemented in Nigeria and other West African countries is expected to contribute to Lassa fever vaccine development.