Lassa fever, an acute viral disease that occurs in West Africa was first discovered in 1969 when two missionary nurses died in Lassa village in Borno.
It is an animal-borne or zoonotic illness caused by the Lassa virus, hence, it was named after the town where the first cases originated.
It is carried by a type of rat that is common in West Africa and can be life-threatening and hemorrhagic, which means it can cause bleeding.
The virus is transferred to humans via contact with food or household items that are contaminated with rat urine or faeces, commonly by the infected Mastomys rodent.
The virus can spread from person-to-person via bodily fluids and causes a range of symptoms including vomiting, swelling of the face, bleeding and pain in the chest, back and abdomen.
In Nigeria, Lassa fever usually occurs during the dry season between January and April, claiming many lives, as other people get quarantined while undergoing treatment.
Cases of deaths arising from the fresh outbreak of Lassa fever this year have risen to no fewer than 41across the country as at Jan. 28, 2020 and has continued to rise by the day.
The Minister of Health, Dr Osagie Ehanire, said on Tuesday while providing an update at a news conference in Abuja that 258 confirmed cases have also been recorded in 19 out of the 36 states of the federation since the beginning of the year, with majority of the cases in the southern states of Ebonyi, Edo and Ondo.
He said that with the tropical climate in Nigeria, there is a risk of infectious diseases like Lassa fever because of the vector – rats and other rodents — which is also the case in other West African countries with a similar environment.
The minister, however, adds that health authorities are working toward providing response activities, surveillance and contact tracing in affected states.
He explained that “Nigeria is contributing to research for the development of Lassa Fever vaccine to proffer lasting solution to the disease.’’
The Nigeria Centre for Disease Control (NCDC), a government agency with the mandate to lead the prevention, detection and control of communicable diseases of national and international public health importance, says it has five functional molecular laboratories for diagnosing and detecting the disease in the country.
Its Director-General, Dr Chikwe Ihekweazu, told News Agency of Nigeria (NAN) in Abuja that the laboratories are located at NCDC’s National Reference Laboratory in Abuja, Irrua Specialist Teaching Hospital in Edo, Federal Medical Centre Owo in Ondo State, Alex Ekwueme Federal University Teaching Hospital Abakaliki and Lagos University Teaching Hospital.
Ihekweazu said “presently, samples from suspected Lassa fever patients from South-South states and some states in the South-West are tested at the Irrua Specialist Teaching Hospital; while samples from South-East states are tested at the Alex Ekwueme Federal University Teaching Hospital, Abakaliki.
“Samples from states in the North are tested at the NCDC National Reference Laboratory in Abuja and samples from South-West states are tested at Lagos State University Teaching Hospital, while Federal Medical Centre, Owo in Ondo State, the newest laboratory, collects samples from Ondo State only.”
The NCDC boss noted that the five laboratories have the capacity to diagnose Lassa fever in the country.
He added that each laboratory costs about N100 million to equip initially, and millions of Naira to maintain functionality.
He explained that NCDC had established a sample transportation mechanism to ensure that samples were sent from state capitals to designated laboratories.
The director-general, who said that laboratories were critical to reducing turnaround time between identifying a suspected case and confirmation, noted that each laboratory provided diagnostic support for a number of states in the country.
“This is to ensure prompt case management and other response activities, thereby reducing the number of deaths.”
According to him, Nigeria is contributing to research and other activities for the development of a Lassa fever vaccine.
He said that the NCDC headquarters, laboratories in the three main treatment centres in the country — Irrua Specialist Teaching Hospital, Federal Medical Centre Owo and Alex Ekwueme Federal University Teaching Hospital Abakaliki, as well as the Virology Laboratory of Lagos University Teaching Hospital, Lagos, are contributing to the research.
Ihekweazu added that the laboratories would also play key roles in the Lassa fever epidemiological study that would provide data to guide research and response activities.
He said that the study would begin before the end of March 2020.
However, some experts lament that with the predictable cycle of the destructive disease, Nigeria should have learnt and developed a more lasting solution and approach by now that can save people from the grip of the fever.
Although money is being spent on interventions to curtail the spread of the disease every year it occurs, casualties are always recorded, including medical doctors who are supposed to take care of patients.
Just like the case in Taraba where the disease claimed four lives, Dr Ahmed Jatau, the acting Head, Clinical Services at Federal Medical Centre, Jalingo, said: “a medical doctor tested positive.”
He explained that the doctor, a house officer, was currently undergoing treatment at Irrua Specialist Hospital in Edo.
The state’s Commissioner for Health, Dr Innocent Vakkai, who said that the state government had activated surveillance system for more case detection and proper treatment, noted that efforts were ongoing to create awareness about the symptoms of the disease among residents.
He regretted that challenges such as a late report of cases to hospitals and difficult terrain remained major problems to the management of the disease.
He explained that “we sent 10 suspected cases for test and six tested positive and out of the six confirmed cases, four died even before their results came in.
“Out of the remaining two, one has been discharged, while the other, who is our own staff, has been transferred to Irrua Specialist Hospital in Edo for further treatment.
“We have, however, fumigated the house officers quarters against rodents.”
Consequently, diagnosis and prompt treatment should be the major areas of concern as there is currently no vaccine for Lassa fever, while symptoms vary.
Clinically, the disease can resemble other viral hemorrhagic fevers, including Ebola, malaria and typhoid.
The only definitive tests for Lassa fever are laboratory-based, and the handling of specimens can be hazardous as only specialised institutions can conduct it.
Lassa fever is generally diagnosed by using enzyme-linked Immunosorbent Serologic Essays (ELISA) to detect IgM and IgG antibodies and Lassa antigens.
Reverse Transcription-Polymerase Chain Reaction (RT-PCR) can also be used in the early stages of the disease.
In terms of treatment, rehydration and treatment of symptoms can improve the chances of survival if diagnosed early.
If prescribed early, the antiviral drug — Ribavirin — has proven useful in fighting the Lassa virus, but how it works remains unclear.
Therefore, there is the need to increase the number of laboratories for testing the disease in the country so that medication can commence promptly, as the five molecular labs may not be adequate to cover the whole nation.
Samples of suspected cases from places like Lassa town of Borno State where the disease originated, or Bama or Biu, all in Borno, may take time to reach any of the five molecular laboratories for confirmation due to distance, which may delay the commencement of treatment.
More laboratories should, therefore, be established across the country for easy access, while sensitisation continues on the dangers of the disease, its symptoms and how to keep safe, as work is on to get a vaccine that will protect people even before the commencement of the Lassa season.