The peak season for Lassa
fever in West Africa is about to begin. The viral haemorrhagic fever
has been largely forgotten in the Ebola crisis, and health workers are
warning that they may not have the resources to deal with the disease if
cases increase.
At first sight the symptoms of Lassa are identical to Ebola.
There can be bleeding, vomiting and fever. But whereas Ebola is a new
outbreak, Lassa is a constant presence. Every year it infects from
300,000 to 500,000 people, killing up to 20,000.
All of the countries worst hit by Ebola are home to Lassa
fever. On Friday, Dr Geraldine O'Hara from Doctors Without Borders (MSF)
told the BBC that one of her colleagues had died of Lassa despite all efforts to save her.
Nigeria may also be seeing its first outbreak of the season. Only weeks after successfully containing Ebola, Nigerian media have reported an outbreak of Lassa in Oyo State.
There is one main difference between an outbreak of Ebola and Lassa. A
Lassa outbreak is caused by rats. The rodents carry the disease into
homes and food stores, especially in the dry season running from
November to April.
"We have had literally dozens of cases of Lassa fever already
in the eastern part of Sierra Leone," said Prof Robert Garry of Tulane
University which has researched Lassa in West Africa for a decade.
Once infected, Lassa can spread from person-to-person. Not
everyone who catches it becomes seriously ill, but fatality rates have
been known to be as high as 70%. It is less easily transmitted than
Ebola, but nonetheless patients must still be treated in complete
isolation.
The containment of Lassa fever was a major focus in West Africa until
Ebola arrived. It was in a Lassa laboratory that Sierra Leone's first
Ebola case was identified.
Dr Sheik Umar Khan,
head of the Lassa fever programme at Kenema Government Hospital, had
spent a decade building a specialised treatment centre. He died of Ebola
in September.
"We lost our head physician and six of our nurses and a lab
technician," said Dr John Schieffelin from Tulane University, who worked
at the hospital.
Kenema's Lassa ward had been overwhelmed with Ebola patients.
"It is essentially abandoned except for the Ebola treatment area," said
Dr Schieffelin.
The remaining health workers in West Africa are already overstretched
with Ebola. As cases of a second haemorrhagic fever begin to rise, some
are worried that Lassa may go undiagnosed and untreated.
"Attention has completely shifted now from Lassa to Ebola.
There are cases of Lassa fever being actually considered to be Ebola
cases in many places," said Prof Christian Happi of Redeemer's
University in Nigeria. "In that regard it is a very complicated
situation for us, especially in Liberia and in Sierra Leone."
"This is a hidden disaster," said Dr Matthias Borchert in
Liberia from the Charite University of Medicine in Berlin and the London
School of Hygiene and Tropical Medicine. "The health system in Liberia
has virtually come to a halt for anything but Ebola. Whether it is
Lassa, malaria or complicated deliveries - it is difficult to find any
treatment."
