…Says nation yet to learn from Ebola outbreak

RECENTLY, the Lagos University Teaching Hospital, LUTH, witnessed an outbreak of Lassa fever that claimed two lives and infected five doctors while hundreds were kept under surveillance.

Ever since, there have been posers as to the incident particularly the infection of five doctors.  Prior to the outbreak since December 2016, series of Lassa fever outbreaks have been reported across the country. Renowned Virologist and former President, Nigerian Academy of Science, Professor Oyewale Tomori, in this encounter with Chioma Obinna, bares his mind as to why Lassa fever has been a threat in Nigeria and why the country must respond appropriately.  Excerpts:

Prof Oyewale Tomori

According to available records, Lassa Fever was only reported in 6 or 7 states between 1969 and 2008. Between 2009 and 2015, reports of Lassa fever outbreaks have come from between 10 and 14 states. Last year no less than 26 states reported cases of Lassa fever, and up to July 2017, at least 18 states have reported outbreaks of the disease. Moreover, we used to consider Lassa fever a dry season disease, now we know better that the disease occurs throughout the year with peaks during the dry season.

Evironmental

filth

The continuing spread in, and invasion of Nigeria by Lassa fever may not be unconnected with the increase and spread of rodents through the country. With increasing movement of people into unplanned cities, coupled with our inability to keep clean environments, sanitation has gone to the dogs and we are getting filthier and filthier by the day as our cities are turned to refuse dumps and garbage heaps.

Rodents love such environment, and now bold to even invade the office of our President. Some of these rodents will include members of the Mastomys species, which are well known for their prodigious fecundity. These rodents with hairless tails, large ears,  small eyes, pointed snout and 7 to 12 pairs of teats, mature sexually early in life.

With a gestation period of 23 days, they can have 12 litters per year, that is, every month, with 9-13 baby mastomys per litter.  In real time figures, one mother Mastomys can produce between 98 and 156 babies in one year, So in the friendly environment of filth created in our cities, these rodents can easily overrun our cities invading our kitchens, restaurants, offices and contaminating every space with their Lassa virus laden excreta.

Nation off track

I can say with confidence that Nigerian governments between 1969 and 2015 have cared little or not at all about controlling Lassa Fever. As earlier mentioned, Lassa fever cases and deaths were restricted to a few states reporting no more than 50 cases and smaller number of deaths. We all know that until hundreds of people get sick and scores die, no Nigerian government worth its name and salt will bother itself with such small numbers of cases and deaths.

So the tragedy of Lassa Fever over the past years has continued to traumatise our nation. Well, we seem to be making efforts to be “on top” of the Lassa fever situation, as the current government has set up various committees to control the disease and the National Center for Disease Control (NCDC) is making efforts to improve surveillance and laboratory diagnosis of the disease.

What to do

However, if we must beat Lassa or at least bring it under control, we need to do more. We need to review past recommendations of the numerous Committees we set up to control the disease and promptly provide funds to implement the recommendations.

We have had enough of Committees, what we need is Commitment to the recommendations of the past. During the NCDC meeting held from 20-21 August 2016, in Abuja, I remember telling participants that I have in my archives, recommendations arising from Lassa Fever workshops held in 1989, 1999, 2005, 2007and 2009, none of which has been implemented. I also said that the recommendation that will arise from the current meeting will differ only in minor details from those made 30 years previous.

So it is not that we do not know what to do with Lassa Fever, it is just that we are unprepared and unwilling to do what is right and proper.

Until Lassa Fever attains the status of Ebola virus and we have cases occurring among dwellers of Aso Rock or those in any of the 36 State Houses, absolutely nothing will be done about Lassa Fever!

LUTH outbreak

The situation has been well described. It only shows that we have not yet learnt our lesson. Was it not Nigeria that was praised globally for dealing with Ebola? So how come Lassa Fever is now thrashing us all over the country and all we can do is provide an incomplete line list of cases and deaths?

How come we still cannot agree on the exact numbers of Lassa Fever cases and deaths? And how come States and the Federal governments are at each other’s throats disputing the occurrence of cases? How come nearly all states have to send their samples to one laboratory which depends to a large extent for its resources of reagents and consumables on foreign donors? How come we are still so dependent on foreign donors to even conduct the diagnostic test for Lassa Fever? How come????? We must continue to ask.

Hospitals & high index of suspicion

They already know what to do. There are enough guidelines pasted on walls of hospital wards and clinics. Providing guidelines is not enough, guide funds to the lines of implementation. Provide gloves and personal protective equipment to health workers in the battle field of the war against viral hemorrhagic fevers, and do not send health workers on a suicide mission to confront nasty diseases unequipped and unprotected.

Increase our awareness of the disease and mode of transmission of Lassa fever and keep our environment clean to prevent invasion by rats and rodents.

Nigeria must regard Lassa fever as a public health event of national concern and a health security issue. Just as each of our state and federal governments never fail to budget for and allocate funds for the security votes, so also must we provide the funds needed for the health security of our citizens. Only that when such fund is provided, we spend the funds with transparency and accountability.

This should not be another security vote disbursed under the cloak and hood. It must be fund disbursed and allocated for intended purposes and of which we are also informed of who spent what on which item

Nearly 50 years after the discovery of Lassa fever, there is no vaccine against it. The disease continues to cause significant morbidity and mortality in the endemic countries of West Africa, claiming a considerable number of health workers in health facilities especially where infection control is weak and inadequate.

Way forward

Consequently, we need to seriously institute and maintain other control strategies for the prevention of Lassa fever, if the menace – deaths, misery, pain and sorrow – associated with the disease must be minimised and checked. This demands a proper understanding of the mode of transmission and risk factors of the disease. We must focus on rodent control, as it is nearly impossible to eradicate the rodents. This requires that we limit as much as possible, the access of the Mastomys rodents to our food of human residence and place of work.

A regular surveillance for the multimammate rats has to be part of our strategy. Rodents can be kept under control by keeping a clean and sanitary environment and using rodenticides, different types of traps (snap and glue traps) and natural enemies of the rodent, such as cats.

There is a special need to stress the importance of community and environmental hygiene as effective measure to prevent contact between the rat and humans. We must desist from the ineffectual and pointless monthly environmental sanitation exercises and ensure that at all times, we keep the house and the surroundings clean. We must dispose our garbage far away from residential areas.

We need to avoid bush burning which results in driving the Mastomys natalensis rodents indoors. We must block all potential rat hideouts and entry points to dwelling houses.

Our food must be properly stored in well covered rodent-proof containers to avoid undue exposure of rodents to our food source. Our food must be properly cooked, Should we suspect possible rodent contamination with our food, it must be promptly disposed. As for fruits, vegetables and other food items that must be eaten raw, proper washing and hand washing and care in handling, must be strictly followed. As earlier indicated, hospitals must strictly follow standard infection control practices to avoid spreading the disease among healthcare workers and patients. Corpses of people dying of Lassa Fever must be treated with utmost care to avoid the transmission of infection to health workers as well as family and community members. Precautionary measures must be taken with the burial of the bodies, especially avoiding traditional washing of the body. As much as possible, such bodies should be buried privately

Causes & transmission: The rodent, Mastomys natalensis or multimammate rat, found in most of tropical and Subtropical Africa, is the natural host of Lassa fever virus. Infected rats shed the virus in urine and droppings throughout their lifetime. The excreta contaminate all surfaces they come in contact with. The transmission of the virus can therefore occur in a number of ways including: i). direct from rat or its excrements from eating of food contaminated by the rodent excreta or served with contaminated plates as well as drinking contaminated water, exposure of cuts, wounds and sores to rat excrements and hunting, preparing and use of the rats as food. ii). through aerosol – when a Lassa Fever case coughs or sneezes and the contaminated aerosol is inhaled by an unsuspecting uninfected individual.

This route of transmission explains the disease in persons who visit Lassa wards without touching infected persons or objects and stress the need for regular use of face masks as part of Personal Protective Equipment (PPE). Although aerosol transmission is established, the direct exposure to blood or body secretions/excretions is more common in the transmission of Lassa virus between humans. iii). person-to-person transmission (PTP) can occur when a healthy individual comes in contact with virus in the blood, tissue, secretions, or excretions of an individual infected person with the Lassa virus, as with transmission within the hospital environment through the use of previously used needles, use of unsterile medical equipment and needle prick injury often due to recapping of needles or unsafe disposal of sharps. Even eminent health workers and scientists have suffered fatally from needle prick injuries.

Previous incidents: We remember the episodes of reported Lassa outbreaks in two hospitals in Aboh Mbaise (Imo State) and Aba (Abia State) in 1989 ignited by crude and unacceptable medical practices.

There were 34 cases with 22 deaths (CFR 65 per cent). The fatalities included six nurses, two physicians and a surgeon. Right from the first reported outbreak of Lassa fever in Nigeria in 1969, virtually every reported outbreak had resulted in hospital acquired infection of doctors, nurses And other hospital staff. Indeed, we only become aware of an ongoing outbreak, when nurses and doctors are infected and the hospital is closed.  These hospital associated outbreaks result from poor standard of infection control practices in our health care system.

For example in 2012, in Ebonyi State, 20 cases (10 confirmed and 10 suspected) were recorded during the outbreak. Nosocomial transmission to six health workers occurred through the index case. In the same year in Taraba State, of 35 cases reported, eight (22 per cent) occurred in health workers- 2 doctors, 5 nurses, and 1 other hospital staff.

These are the high prices our society and the health care system pays for entrusting health care services to careless professionals and poorly trained auxiliary nurses amongst others. Lassa fever can also be sexually transmitted because the virus survives in semen for up to three months after recovery from the disease. Infants can be infected with Lassa virus through the breast milk, although this is not common as there is high foetal wastage with Lassa fever disease. We must however bear in mind that neonates are at risk of with the Lassa virus congenitally or during birth.

In summary, Lassa fever cannot be spread through casual contact (including skin-to-skin contact without exchange of body fluids) but through contact with the virus in tissue, blood, body fluids, secretions or excretions. This includes coughing, sneezing, kissing, sexual intercourse and breastfeeding.

In health care settings transmission may be through pharyngeal secretions, urine, faeces, and vomitus or from Mastomys contaminated needles. On the average, it takes three to nine weeks before the virus can be detected in the urine.

In nature, rodent-to-rodent transmission occurs both vertically and horizontally. Vertical transmission occurs between an infected rodent mother and the child, through the transplacenta or soon after birth. This ensures the continued maintenance of the infection in the natural host. Infected rodents develop chronic carrier state as is characteristic of viruses of the arenavirus family.