<<Print>>

At least 43 people have died and 450 people are ill in a Lassa fever outbreak in Nigeria, according to the World Health Organization.

Lassa fever, an acute viral hemorrhagic illness, is endemic in most of West Africa, especially Nigeria, where it was discovered in 1969. Symptoms can be mild or severe, including hemorrhaging in the gums, eyes or nose.

Many of its symptoms mimic Ebola, but Lassa fever is caused by the Lassa virus and transmitted by multimammate rats.

The disease is transmitted to humans through contact with food or items contaminated by infected rats or through contact with bodily fluids from an infected person.

Person-to-person transmission is low but has been seen in Nigerian hospital settings, where four health workers died within five weeks during this outbreak.

The WHO said Tuesday that from January 1 through February 4, there have been 450 suspected cases reported, and 132 of those have been laboratory-confirmed. However, a report released Sunday by the Nigeria Centre For Disease Control said that as of February 11, there were 615 reported cases, with 193 of those confirmed, and it put the number of deaths at 57. The discrepancy could be due to a delay in reporting data to the WHO.

A surge in infection

More than 100 people died and 501 suspected cases were reported in Nigeria between December 2016 and June 2017, according to the WHO. Lassa fever has been spreading at an unprecedented rate in southern Nigeria.

The WHO says the high number of reported cases in the new outbreak is "concerning," and it is investigating and scaling up responses in southern Nigeria.

"We are observing an unusually high number of cases for this time of year," said Dr. Wondimagegnehu Alemu, the WHO representative in Nigeria.

"Among those infected are 11 health workers, four of whom have died," the WHO said in a statement. "WHO is advising national authorities on strengthening infection, prevention and control practices in healthcare settings."

Dr. Chikwe Ihekweazu, director of the Nigeria Centre for Disease Control, says three things may be driving the recent outbreaks: First, Nigeria's growing population and its dwindling land have brought individuals closer to the disease host, the multimmamate rat. In addition, there is improved detection of cases.

"Nigeria's growing population density worsened, which is worsened by lack of hygiene in its cities, are some factors driving this present outbreak," Ihekweazu said.

"Rats are not attracted to clean environments, and our cities are not the cleanest of places."