From Ebola to Lassa fever: When the rat succeeds the bat


Just like a nightmare, Lassa fever has taken over from where Ebola stopped in West Africa, especially in Nigeria which, according to the World Health Organisation (WHO), reportedly recorded 159 suspected cases of Lassa fever, including 82 deaths, across 19 states between August 2015 and January 2016.

For most West African countries, especially Nigeria, that had devastating experiences with the Ebola outbreak, it isn’t yet time to heave a sigh of relief as the sub-region battles the onslaught of Lassa fever. The last Ebola outbreak, which was the worst of its kind, tormented the West African countries between December 2013 and November 2015, and infected about 29,000 people, claiming over 11,315 lives.

Like the Ebola virus, the Lassa virus is transmitted through close contact with the virus host or the sweat, vomit, blood or other bodily fluids of an infected person, or the recently deceased. Both cause severe fever and muscle pain, weakness, vomiting and diarrhoea. In many cases, they shut down organs and cause unstoppable internal bleeding. Patients often succumb within 3 to 21 days.

However, unlike Ebola, Lassa is treatable with Ribavirin – an antiviral drug that is only effective if administered within the first six days after the disease onset.  Also, Lassa fever patients benefit from careful monitoring of fluid, electrolyte and oxygen levels.

Infection with Lassa virus often arises from exposure to infected rodents. Person-to-person transmission occurs through direct contact with sick patients in both community and health care settings. Those at greatest risk are persons living in rural areas where the carriers are found. Health care workers are also at risk if adequate infection control practices are not maintained.

According to the Wikipedia, Lassa fever or Lassa haemorrhagic fever (LHF) is an acute viral haemorrhagic fever caused by the Lassa virus and first described in 1969 in the town of Lassa, in Borno State, Nigeria. Lassa fever is a member of the Arenaviridae virus family. Similar to ebola, clinical cases of the disease had been known for over a decade, but had not been connected with a viral pathogen.

Lassa frequently infects people in West Africa. It results in 300,000 to 500,000 cases annually and causes about 5,000 deaths each year. Outbreaks of the disease have been observed in Nigeria, Liberia, Sierra Leone, Guinea, and the Central African Republic. The primary animal host of the Lassa virus is the Natal multimammate mouse (Mastomys natalensis), an animal found in most of sub-Saharan Africa. The virus is probably transmitted by contact with the faeces or urine of animals accessing grain stores in residences.

Given its high rate of incidence, Lassa fever is a major problem in affected countries because in 80 per cent of cases, the disease is asymptomatic, but in the remaining 20 per cent, it takes a complicated course. The virus is estimated to be responsible for about 5,000 deaths annually and it accounts for up to one-third of deaths in hospitals within the affected regions and 10 to 16 per cent of total cases.

The Wiki report states further that after an incubation period of six to 21 days, an acute illness with multiorgan involvement will develop. s nonspecific symptoms include fever, facial swelling, and muscle fatigue, as well as conjunctivitis and mucosal bleeding.

An acute viral illness, Lassa fever, according to the Federal Ministry of Health, has so far claimed over 70 lives across over 17 states of the country and the FCT.

In order to curtail the spread of the disease, the federal government has created the Lassa Fever Rapid Response Committee, which goal is to control and prevent the spread of the malady. Public health officials have also asked Nigerians to stop burning bushes as this drives rats out of the bush and into nearby houses. Government has also placed a ban on consumption of rats that are a delicacy common to some states in the Middle Belt region of the country, so as to curtail the spread of the disease.

The garri connection

The Medical and Health Workers Union, Lagos State Council, has discouraged the consumption of soaked garri as a preventive measure against Lassa fever. Chairman of the Union, Mr Razak Adeofalade, was quoted to have said: “We are going to encourage members of the public to depart from the process of drinking garri. At this period, it is better that the cassava flour is utilised for eba, because of the use of hot water. We are waging total war and that is: ‘War against Rats,’ and that is what we are going to do to ensure we do not have more victim of Lassa fever in the state.”

Continuing, he said: “Garri is often fried half-dry and subsequently dried on polythene sheets on tarred roads or compounds in villages, where rats feed on them, and in the process defecate and urinate on the garri, which dries up with it. If used for eba, the virus may die because of the hot water used. But if soaked in normal water and consumed, the virus is directly ushered in.”

However, in a swift reaction, the association of cassava processors, through their chairman, Pastor Tayo Adewumi, reportedly debunked the warning on garri, stressing that the virus can hardly survive the production process. He explained that the cyanide content in cassava makes it difficult for rats to feed on it during production process.

He however drew attention to the need for better hygienic practices at home, saying that if not properly stored after production, rats could feed, urinate and defecate on it and by so doing people could come down with Lassa fever.

Remedial measures

At a meeting of the National Council of Health in Abuja to adopt strategies for combating Lassa fever and other viral diseases in the country, the minister of health, Prof. Isaac Adewole, warned health managers not to deceive executives by keeping silence on the spread of the disease.

During the emergency meeting, Adewole was quoted as saying, “We currently have testing capability in 14 testing centres, some of which are in Maiduguri, Kano, Iddo, Irrua, Lagos, Port Harcourt and the FCT. We have treatment centres all over the country. We have enough personnel for managing Lassa fever. Unlike Ebola Virus Disease that is untreatable, Lassa fever is treatable. But we must start treatment on time to enable us to save the patients.”

The minister while assuring the public that the federal government would maintain high level of alert to eliminate the disease soon, added that the ministry had deployed rapid response teams to all affected states to assist in investigating and verifying fresh cases of the disease.

He further added that government had raised a four-man expert committee, led by Prof. Michael Asuzu, to visit Kano, Niger and Bauchi States, saying the committee would embark on a fact finding mission, assess the current situation, document response experiences, identify gaps and proffer recommendations on how to prevent future occurrences.

According to him, the task of the committee was to document lessons learnt for better planning of an affective responsive. He also said the federal government had also given the Committee on the Eradication of Lassa fever in Nigeria, headed by Prof. Oyewale Tomori, president of the Nigeria Academy of Science, a mandate to provide a one-health approach to the complete elimination of the disease in the country.

Issues for consideration

However, beyond the promises by the state and federal governments, there are fundamental issues that need to be addressed, if the country must conquer the scourge of Lassa fever. A nation as diverse as Nigeria should have a national response strategy for disease outbreak which should be automatically activated once there is an outbreak of a highly infectious disease like Lassa fever. It is imperative to strengthen the nation’s National Centre for Disease Control to ensure this important agency is able to deliver on its mandate of helping to prevent disease outbreaks and needless deaths of Nigerians from conditions like Lassa fever that are preventable and treatable.

Lassa fever has been with us since 1969; therefore, we must come out of the box and design a new and sincere approach to dealing with a disease that is quite endemic in our region, rather than continue with the fire brigade methods of raising alarm, waiting for ministerial updates on deaths tolls on television, setting up committee, and begging for international donations.

It is also important that Nigerians themselves are orientated to pay more attention to disease prevention. The health ministry must leave no stone unturned in ensuring that Nigerians are enlightened about strategies to adopt to prevent diseases because prevention is better than cure.

Importantly, elimination of rats is key to controlling the Lassa fever virus. Also, proper sanitization of the environment is advisable, while people should make sure that their house is not conducive for rodents by getting rid of old newspapers and books that can be food to them. Beyond this, they should store their food items in containers to avoid being contaminated by rodents. Also, they should endeavour to wash every plate before using them and immediately after usage, and they should dispose of all dirt in air-tight plastic containers that cannot be accessible to rats.