By Demola Akinyemi,      Ilorin

Professor Uade Sam Ugbomoiko is a parasitologist and former Head of Department of Zoology, University of Ilorin. His research focus covers parasites of small mammals, epidemiology and control of zoonotic parasites. Ugbomoiko gives a fresh insight into the treatment of diseases in Nigeria and how to stem the tide.   He speaks against the backdrop of the Lassa fever outbreak in Nigeria.

Basically,what do you think is the main cause of Lassa fever?

Lassa fever is caused by Lassa virus,anarena virus of about 110nm in diameter. It belongs to the group of viruses that causes haemorrhagic fever in Argentina and Bolivia. The disease is transmissible between human and animal, and the only known animal host is the multimammate peri-domestic rat called  mastomys natalensis.

In other words, it is a wild rat that naturally lives in the bush during the raining season but frequently visit human habitations in search of harvested food during the dry season.   So far, Lassa virus occurs only in the West Africa sub-region, mainly Nigeria, Liberia, Sierra Leone, Senegal and Guinea. It has also been isolated in Mozambique.

What are the diseases likely to be transmitted through rats, apart from Lassa fever?

A bewildering number of other viral, bacterial and parasitic diseases are transmissible by rats. The most prevalent and cosmopolitan rat-borne disease in Nigeria is the toxoplasmosis, a protozoan parasite that frequently causes spontaneous abortion and still-birth in pregnant women. Let us not also forget the role of rat in the transmission of leishmaniasis, bubonic plague, tick-borne encephalitis and leptospirosis. Unfortunately, many other zoonotic diseases, hitherto unknown in our   environment, may emerge due to global warming (climate change). Tapeworms and roundworms known in rats are also transmissible to human.

Do you think Lassa fever is preventable?

As a zoologist with interest in parasite control, I believe Lassa fever, like other infectious pathogens, is preventable if careful epidemiological details of the disease are known. After all, Nigeria was able to control and eliminate Guinea worm (dracontiasis), thanks to international health agencies that collaborated with our experts drawn from the health and university communities. The question you asked on in the lips of many well-meaning Nigerians who know that this preventable disease was first reported in Nigeria over 40 years ago, precisely 1969.Prevention would not only be by treating all infected cases and by rapid dissemination of information on how to avoid the disease agents .I think the Minister of Health has, rightly and urgently, ordered the commencement of rapid control measures i.e. locate infected cases, isolate and treat promptly. Individual and community mobilization have also commenced.

The truth is that they are short term measures to rid our society of Lassa fever. I am sure the Minister of Health would want to do the unexpected by setting up research team(s) that will provide reliable epidemiological data fora long term control plan. We have seen that Ebola virus, a more virulent virus, was controlled though no lesson was learnt from it. Till date, I am not aware of any research team(s) in place to identify the species/type of bat and/or ‘bush meat’ that transmits Ebola virus. Meanwhile a number of research institutes and competent researchers in universities are available in Nigeria to undertake such challenges. We should tap the knowledge of our experts to control Lassa fever and other related diseases.

What proactive steps do you think can be taken by stakeholders to prevent such occurrence in the future?

Government should learn to avoid a knee-jerk approach to disease control. The current style of disease control has made Nigeria an endemic country for  many preventable diseases.

Recent WHO reports show that Nigeria has the highest number of schistosomiasis, ascariasis and other preventable parasitic diseases in sub-Saharan Africa.

We should learn to adopt the principle of laying siege on infectious agents. The re-emergence of Lassa fever, after the first few reported cases in Lassa and Jos villages in 1969, started in early 1990s. From my observation, no detailed research information on the ecology, biology and distribution of  mastomys  nor the virus is known to government. All we hear and read from the  media about this virus and the animal host are probably textbook information collated from other endemic areas. Our research data should reveal the average proportion of rat infected in a rat population, the sex and age that commonly carries infection.     Effective control strategic plans are based on highly reliable research data on disease epidemiology.

The current knowledge about the animal host (M. natalensis) is also grossly inadequate for any effective control strategic plan.   For instance, there are about three siblings of  mastomys  in Nigeria i.e.  M. natalensis, M. hubertiand  M. kollmanngerus.

All these species are morphologically indistinguishable (looking alike) and do not interbreed but can maintain a sympatric population at any given location. Besides, their occurrence vary from one geographical location to another. It is not impossible, therefore, that a different species of  mastomysand/or other type of peri-domestic rat (like luphorumis  species) may be transmitting this virus in the savanna region of Nigeria (Kano, Taraba and Nassarawa).Government should urgently constitute a research team consisting of experts in virology, zoology and public health from universities and research institutions with a view to obtaining up-to-date research information upon which control plans will be anchored. In many developed countries, well-funded disease control centers are established in states for data gathering.

Federal institutions like the National Arbovirus Research Centre in Enugu and Medical Research Centre in Lagos have suddenly become moribund because of insufficient funding; they rely majorly on the generosity of international agencies. Unfortunately, many international researchers find Nigeria unsafe for research collaboration because of the problems of Boko Haram and kidnappings. This has grave consequences on our up-coming academics in the universities.

For majority of Nigerians   not infected with Lassa fever, what are the  steps to be taken to avoid contacting the dreaded disease?

As mentioned earlier, the short term measures read out in media, both electronic and print, require the following steps.

—Block rat access routes into the house.Mastomys and, indeed, other wild rats, would not stray beyond 250 m from their habitat. Therefore, houses located close to the bush must clear the surrounding bushes at least about 250 m away from the house,

*avoid stocking freshly harvested grains (rice, beans, maize, ground nuts and fruits including palm nuts) close to the house.

*  keep away your cooked food and utensils from rats,

*  wash hands and cooking utensils properly and regularly with soap,

*  avoid rat meat, otherwise cook rat meat improperly (not roasting meat in the open fire like ‘suya’) before eating, and

*  report infected cases immediately to the specialized hospital for prompt medical treatment,

Don’t you think there is the need for a national summit to enlighten the public on the danger inherent in the disease?

I think the issue of disease control should be the concern of the experts in the related areas if they are well motivated. To enlighten the public on a disease is a compulsory responsibility of the experts and government. government should adequately fund research and the existing disease control centers if she’s unable to establish such center in all the states of the federation.   To me, hospital-based disease control unit like the Lassa Fever Centre in Irrua, Edo State is inappropriate in all ramifications.   National summit may only be an option if all other steps fail.