Almost half a century after the discovery of Lassa fever in Nigeria, the virus has continued to be a recurrent challenge with hundreds of lives lost every year in the country. The recent confirmed cases in some states have again brought to the fore the need for scale up surveillance system and research on vaccines. Martins Ifijeh writes
Early this year when the country experienced yet another round of Lassa fever outbreak, not less than 80 Nigerians lost their lives across five states of the federation, prompting the federal government to say it was putting all measures in place to prevent more deaths, while also reiterating that all existing Lassa fever centres in the country will be well equipped to further tackle cases of the virus.
Fast forward seven months after, another round of Lassa fever outbreak is finding its way into the country, with two already recorded casualties; a 54-year-old man, who died in Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Anambra, about two week ago, and one from Gombe State, who died August 22, 2016. Other cases have been confirmed already in Bauchi, Gombe, Plateau and Rivers States.
Like a familiar scenario, the spread of the present outbreak can almost be predicted, especially by keen observers who had monitored previous outbreaks of the viral disease and how they played out. First, an outbreak will be recorded in a state, then it spreads to neighboring states, with many confirmed cases accompanied by casualty figures, and then suddenly, there will be interventions by the relevant bodies in tackling it, and then the outbreak picks up again after few months, while the government uses same interventions on it.
But with a new government in place, from the Presidency, the Federal Ministry of Health, up to the Nigerian Institute for Medical Research (NIMR) and the Nigeria Centre for Disease Control, (NCDC), stakeholders are of the opinion that old approaches against Lassa fever outbreaks must be suspended, as it has obviously not yielded lasting solution to the menace, while also calling for solutions geared towards vaccines and establishment of Lassa fever centres for prompt tackling of the scourge.
They said government must look beyond providing fire brigade approach to ending disease outbreaks in the country, adding that, that had been the approach since the very first outbreak of the virus, which was why at 47 years after, people were still dying from the disease.
For example, a Virologist, Dr. Olaolu Akinjide, believes since the disease originated from Lassa community in Borno State, it behoves on the country to find a lasting solution to the reoccurring bouts of the outbreak, which he said was becoming a national embarrassment.
“It’s almost 50 years since the first case of the disease was noticed here. We should not wait for another country to find a vaccine for us. Researches in this regard should be given priority by the government. We have a medical research institute that should be funded to come up with solutions in this regard,” he said.
This again brings to fore the level of priority placed on medical research in the country. While the United States National Institute of Health will spend about 32.3 billion dollars this year alone on medical research for the American people, the entire health budget for Nigeria cannot be said to be close to that figure.
According to the World Health Organisation, between 300,000 and 500,000 cases are recorded annually, with about 5,000 deaths recorded yearly, especially in sub-Sahara West African region.
Apart from Nigeria, which has one of the highest burdens of the disease, other countries that have recorded the outbreak are Liberia, Sierra Leone, Guinea and the Central African Republic.
Akinjide also wondered why the country only had two active Lassa fever centres to cater for the several Nigerians who are infected yearly by the virus. “The government should scale up the establishment of Lassa fever centres across the country. The present two centres, which are the ones in Irrua Specialist Teaching Hospital (ISTH) and that in Lagos University Teaching Hospital (LUTH) cannot be said to be enough for prompt diagnosis and treatment of cases,” he explained.
Though the federal government had consistently said the country has 13 Lassa fever centres, Akinjide insists that there were only two centres serving the over 180 million persons living in the country.
Also on his part, the President of the Nigerian Academy of Science (NAS), Prof. OyewaleTomori, during the last outbreak of the virus, wondered why Nigeria was not taking surveillance system seriously, adding that, the country has a weak surveillance system, poor funding of epidemiology studies, inadequate diagnostic centres and poor awareness of the disease.
Tomori, a one-time Regional Virologist for the WHO, Africa Region, said the current Lassa fever outbreak (the outbreak in January) confirms that the country was unable to sustain or repeat the Ebola success because success with one disease can only be repeated if the disease surveillance was resilient, sustainable and consistent.
He said the country was paying for years of neglect of the national disease surveillance and laboratory support systems.
But what is the government doing to curb the renewed outbreak? The Director General of NCDC, Dr. Chikwe Ihekweazu, said resources have been immediately mobilised from its centre and the Nigerian Field Epidemiology and Laboratory Training Programme (NFELTP), to support the investigation and management of cases in the affected states, adding that this public health response has commenced immediately in all affected states under the leadership of the respective state Ministries of Health.
He said the five confirmed cases were reported from four states of Nigeria within the week 24th August to 2nd September: “Two cases were reported from Plateau State, one from Rivers, and one each from Bauchi and Gombe. The case reported from Gombe died on 22nd August 2016, all other cases are alive,” adding that, the early detection of the reported cases will go a long way to significantly improve the likelihood of survival of the cases and also reduce the risk of transmission.
Earlier in the year, the Minister of Health, Prof. Isaac Adewole, said the government would stamp out Lassa fever outbreaks from the country before the end of the year.
He said: “We are also concerned. We want to find out why we are still having this Lassa fever in spite of human and material resources that we have in this country. We inaugurated a Lassa fever eradication committee chaired by one of the foremost virologists in this country and we are committed to signing the obituary of Lassa fever this year,” he noted.
According to the WHO, it is a known fact that humans become infected with Lassa fever virus from exposure to urine or faeces of infected Mastomys rats. The virus may be spread among humans through direct contact with the blood, urine, faeces, or other bodily secretions of an infected person.
It could also be transmitted from person to person through exchange of body fluid and blood, contaminated medical equipments or through sexual intercourse.
Those at risk
Available information suggests that everyone is at risk, as it may occur in all age groups, both sexes, and in all classes of people. However, it has been observed that people with poor hygiene or those in rural areas where Mastomys are usually found are more susceptible to it.
Adewole during one of the outbreaks advised Nigerians to properly cover their foods in order not to get exposed to the virus-causing vector, as people who refuse to do so were at a high risk of being infected by the virus.
Tomori says symptoms may start to appear between six to 21 days, and may start with gradual symptoms like fever, general weakness and malaise.
Other symptoms include headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough and abdominal pain may follow. Experts believed in severe cases symptoms may include bleeding from the mouth, nose, ear, vagina, as well as seizures, tremor, coma or even death.
Deafness may occur in 25 per cent of patients who survive the disease. In half of these cases, hearing returns partially after one to three months. Transient hair loss and gait disturbance may occur during recovery as well.
Experts believe general diagnosis is often difficult because the symptoms are non-specific, since it is difficult to distinguish from other viral hemorrhagic fevers such as Ebola virus and many other diseases causing fever, including malaria and typhoid.
But, it is advised that definitive diagnosis be done in specialised laboratories like the ones in ISTH and LUTH.
Treatment and prophylaxis
The antiviral drug ribavirin seems to be an effective treatment for Lassa fever if given early
in the course of clinical illness. There is no evidence to support the role of ribavirin as post-
exposure prophylactic treatment for Lassa fever. There is currently no vaccine that protects against Lassa fever.