The Rising Tide of Lassa fever in Nigeria: Any Role for Libraries?
Introduction
Lassa fever is caused by the Lassa virus. It is a zoonotic disease, meaning that humans become
infected from contact with infected animals. The animal reservoir, or host, of the virus is a rodent
of the genus Mastomys,(M.natalensis), ( Plate 1) ) It is a small soft-furred and naked tailed
rodent, 25 to 27 centimeters long and weighing roughly 60 grammes. It is commonly known as
the “multimammate rat because females have eight to fourteen pairs of tits, instead of the five or
six that is typical of other rodents. Mastomy is a highly prolific breeder, producing a liter of eight
to ten pups monthly, year round (Plate2).. Other rodents of the Mastomys genus had been found
to carry the virus. (Princewill, 2012).
Lassa fever is associated with sporadic infections, during which time the fatality rate can reach
50%.The rats do not become ill but they can shed the virus in their excreta (urine and faeces). (
Ogbuet al, 2007). Lassa fever occurs more in the dry season than in the raining season.
The onset of the disease is usually gradual, starting with fever and general weakness. After a few
days, headache, sore throat, muscle pain, chest pain, nausea, vomiting,diarrhoea, cough, and
abdominal pains may follow. Severe cases may progress to show facial swelling (plate 3) fluid in
the lung cavity, bleeding from mouth, nose, vagina or gastrointestinal tract, and low blood
pressure. Protein may be noted in the urine. Shock, seizures, tremor, disorientation, and coma
may be seen in the late stages. Deafness occurs in 25% of patients of who half recover some
function after 1-3 months. The overall case-fatality rate is 1%, up to 15% among hospitalized
patients (WHO, 2012) Death usually occurs within 14 days of onset in fatal cases. The disease is
especially severe late in pregnancy, with maternal death and/or foetal loss occurring in greater
than 80% of cases during the third trimester. (WHO, 2012)
Persons at greatest risk are those living in rural areas where Mastomys are usually found,
especially in areas of poor sanitation or crowded living conditions. Health care workers are at
risk if proper barrier nursing and infection control practices are not maintained.
Humans usually become infected with Lassa virus from exposure to excreta of infected
Mastomys. Both direct exposure, (touching the excreta) and Lassa virus may also be spread
between humans through direct contact with the blood, urine, faeces, or other bodily secretions
of a person with Lassa fever.
2
Plate1.Animal Host: Mastomynatalensis
Source (Centre for Diseases Control (CDC), 2002)
Plate2Mastyomyswith Litters .Source This Day Newspaper (This Day Live)
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Plate 3: A Lassa fever patient showing swollen of the eyes
Source: Lassa fever picture (www.picsearh.com )
The onset of Lassa fever is initially difficult to diagnose and has nonspecific clinical symptoms
which have been confused with yellow fever and typhoid. There is evidence of persistent
infection, it is tremendously contagious, and has a high mortality ( Tomoriet al 1988).. Lassa
fever is one of the endemic zoonosis in Nigeria with a high probability for nosocomial
transmissions due to several health care sector challenges. Although treatment is available for
Lassa fever, early diagnosis is still difficult in almost all Nigerian health institutions. (Fabiyiet al.
1988)
Nigeria is currently being ravaged by Lassa fever. Federal Ministry of Health Weekly
Epidemiology Report that indicates Lassa fever has been reported from 21 out 36 States of
Nigeria as at 20th April 2012.
Statement of Objective
The sole aim of this paper is:
To present a state of knowledge report on the following:
the symptoms and diagnosis of the Lassa fever,
transmission of the fever,
reported cases of Lassa fever in Nigeria,
mortality of Lassa fever
preservation and control of Lassa fever,
treatment of Lassa fever
roles of libraries in reducing the menace of the disease.
.
Information gathering tools
The information gathering tools used for this research are:
Literature search
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Newspaper reports
Discussion with colleagues and neighbours
Symptoms and Diagnosis
The onset of Lassa fever is insidious, with gradual feeling of fever and shivering accompanied
by malaise, headache, generalized aching frequently with pain behind the sternum and a sore
throat. This may be accompanied by nausea, vomiting, diarrhoea or cough. There may be
patches of white or yellowish exudates and occasionally small vesicles or shallow ulcers on the
tonsils and pharynx and this is an important diagnostic feature. As the illness progresses the
body temperature may rise to 41ºC with daily fluctuations of 2-3ºC. Fever is very variable,
occurring constantly or in peaks, and lasting on average for 16 days; extremes of 6-30 days
have been reported.
Additional common symptoms include; abdominal pain, diarrhoea, or constipation,
conjunctivitis, Skin rashes and jaundice occur in rare cases. (WHO. 2012)
Some patients may experience bleeding from the gums. In addition, capillary lesions cause
haemorrhaging in the stomach, small intestine, kidneys, lungs, and brain. Less than 30% of
patients present with bleeding; this is a predictor of a significantly higher risk of death (Tomoriet
al 1988). In severe cases of Lassa fever, shock and vascular collapse occur, followed by
death. Patients who will survive begin to recover 2-3 weeks after onset of the
disease. Temporary or permanent deafness in one or both ears occurs in 29% of Lassa fever
patients. (WHO , 2002)
Complications of the disease after recovery include hair loss, loss of coordination, psychiatric
syndromes (such as mania, depression, dementia, psychosis and sleep disorders) and the most
common, deafness, which occurs in about 30 % of the patients. (Solbrig 1993).
Because the symptoms of Lassa fever are so varied and non-specific, clinical diagnosis is often
difficult, especially early in the course of the disease. The fever is difficult to distinguish from
many other diseases which cause fever, including malaria, shigellosis, typhoid fever, yellow
fever and other viral haemorrhagic fevers.
Transmission of the fever
There are a number of ways in which the virus may be transmitted, or spread, to humans. The
Mastomysrodents shed the virus in urine and droppings freely throughout their lifespan and their
saliva. The virus can be transmitted through direct contact with these materials, through touching
objects or eating food contaminated with these materials, or through cuts or sores. (Adewuyiet
al, 2009). Because Mastomysrodents often live in and around homes and scavenge on human
food remains or poorly stored food, transmission of this sort is common. Contact with the virus
may also occur when a person inhales tiny particles in the air contaminated with rodent
excretions. This is called aerosol or airborne transmission. Finally, because Mastomys rodents
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are sometimes consumed as food, infection may occur via direct contact when they are caught
and prepared for food.
Lassa fever may also spread through person-to-person contact. This occurs when a person comes
into contact with virus in the blood, tissue, secretions, or excretions of an individual infected
with the Lassa virus..
Humans can contract the disease from other humans via aerosol transmission (coughing), or from
direct contact with infected human blood, urine, or semen.
Risk to Health care workers
Human to human transmission is common in both village and health care settings, where, along
with the above-mentioned modes of transmission, the virus also may be spread in contaminated
medical equipment, such as re-used needles (This is called nosocomial transmission.)
Health workers are not spared in the recorded infection and consequent death by this disease;
From the first reported case 43 years ago to this year’s outbreak, doctors and nurses have not
been spared from the devastating effects of the disease (Ruby,2012) .So far from available
records not less than ten hospital workers including the Chief Medical Director of Igboji
General Hospital Ikwo in Ikwo Local Council of Ebonyi State have died from the disease.
Prevention and control of Lassa fever in Nigeria
Prevention of Lassa fever in Nigeria communities can be based on promoting personal and
community hygiene to prevent people from coming into contact with rodents which are common
in dirty environments, clean environments will reduce the rat population.
Effective measures include storing grains and other foodstuffs in rodent-proof containers,
disposing of garbage far from the home, proper covering of food, discarding food eaten by rats
maintaining clean households and keeping cats.
Family members and health care workers should always be careful to avoid contact with blood
and body fluids while caring for sick persons. Routine barrier nursing precautions probably
protect against transmission of Lassa virus in most circumstances. However, for added safety,
patients suspected to have Lassa fever should be cared for under specific isolation precautions,
which include the wearing of protective clothing such as masks, gloves, gowns, and face shields,
and the systematic sterilization of contaminated equipment
However, the wide distribution of Mastomys in Africa could make complete control of this
rodent reservoir a great challenge
Reported cases of Lassa fever in Nigeria
A summary of the reported cases of Lassa fever in Nigeria is shown in Table1
This table shows alarming numbers for 2012. The report from the Federal Ministry of health
weekly update up to 20th April 2012 shows that there were altogether 136 confirmed
cases from 21 States of the country.
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Mortality
From the data in table 1, the mortality rate of Lassa fever is very high. Between 1969 and
2012 a total of 1088 cases of Lassa fever were reported out of which 357 were clinically
confirmed with 230 deaths representing 64.4 %.The highest outbreak is 2012 where 136
people were infected with 87 deaths representing 63.9 %. Efforts must be geared towards
reducing the menace of the disease in the next dry season.
Table 1: Reported cases of Lassa fever
S\N Date/Year State Cases
Reported
Clinically
confirmed
Mortality
1 1969 Lassa (Borno State) 2 2 1
2 1970 Plateau State 28 28 13
3 1989 Edo State 34 22 20
4 1995 Imo State, Edo State 34 34 20
5 2005 Ebonyi State 4 4 2
6 2007 Edo, Taraba and
BornoStates
55 55 40
7 2008 Federal Capital
Territory(Abuja) and
Plateau State
4 4 4
8 2009 Edo State 7 7 5
9 2010 Kebbi State 22 22 17
10 2011 Edo, Taraba, Ebonyi,
Ondo, Plateau and
Rivers, Borno States
50 50 26
11 2012 Ebonyi, Borno,
Gombe,RiversPlateau,An
ambraYobe, Edo,
Lagos,Kogi,Kebbi,
Taraba
,Ondo,DeltaKano,Nassar
awa, Plateau and
Imo,Oyo, Adamawa
States and FCT (Abuja)
855 136 87
Total 1088 357 230
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Treatment of Lassa fever
No vaccine for Lassa fever is currently available for use by humans, and the only available drug,
ribavirin, is only effective if administered early in infection (within the first 6 days after disease
onset).
Discussion
The analysis of reported cases of Lassa fever is presented in Tables 2 and 3. It will be observed
that between 1969 (when the first case was reported) to this year 2012, five States were affected
only once, but eight states had been affected more than once (Table2). Of greatest concern is the
increase in number of cases from 2011 to 2012.
This calls for concern and prompt intervention from the stakeholders to prevent the spread of this
disease to other parts of the country not yet affected and to stop re-occurrence in the affected
States.
Table 2: Recurrence of reported cases of Lassa fever in Nigeria
No of years
diseases are
reported
Number of State(s)
concerned
1 year only 5
2 different
years
2
3 different
years
3
4 different
years
2
6 different
years
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Table 3: Number of states of reported cases of Lassa fever in Nigeria
Date/years Number of States
1969 1 State
1970 1 State
1989 1 State
1995 2 States
2005 1 State
2007 3 States
2008 2 States
2009 1 State
2010 1 State
2011 7 States
2012 21 States
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From only one State (Borno State) where this disease was first discovered in 1969, the tide gradually increased
to 3 states by 2010. In 2011, there was a sharp increase to 7 seven states. This year the number jumped to 21
states. The time for action is now, especially in the two states where cases had been in four different years and
particularly Edo State where cases have been reported in six different years. (Table 3)The high mortality rate for
Lassa fever infection is shown in Figure 2. The lowest reported mortality was46.4% in 1970 and it can be 100%
as in 2008.
The following reasons account for the rising tide of Lassa fever in Nigeria:
Many Nigerians especially in the rural areas are oblivious of the diseases
There is the problem of self-medication .Many Nigerians prefer to self-medicate.
Hospitals are usually the last resort and in the case of Lassa fever it might be too late
Culturally in the rural areas, farm produce are sun dried on the road sides where they are
exposed to infection with rat urine and faeces. Rats are consumed in many rural areas.
Lack of Government policy on the control and eradication of Lassa fever especially at the
state and local government levels. At present, only two laboratories in the country ( Irrua
Specialist Hospital ( ISH) in Irrua, Edo State and the Central Medical Laboratory at the
Lagos University Teaching Hospital (LUTH) )have the capacity to screen blood for Lassa
virus. A high percentage of cases of Lassa fever referred to ISH end up in death because
they are referred late and have to travel long distance to Irrua.
The level of campaign against this disease is still low especially in rural areas.
0
20
40
60
80
100
120
Mo
rtali
ty p
erc
en
tag
e
Year
Fig 2 :Percentage mortality for each year of reported cases of Lassa fever
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The Role of Medical Libraries and Medical Librarians
The activities of Medical Librarians should be oriented towards the goal of producing a healthy
society as well as assisting the individual in making informed health decisions. Librarians should
help physicians, allied health professionals and researchers to stay abreast of new developments
in their speciality areas. (King, 1987)
Medical librarians provide access to resources in a variety of formats, ranging from traditional
prints to electronic sources and data (Nail, 2006). Librarians are expected to work towards the
social and community goals of producing a healthy society as well as assisting the individual to
make more informed health decisions.
The roles of Medical libraries in curbing the rising tide of Lassa fever in Nigeria include
but not limited to the following:
Providing quality information on Lassa fever as an emerging disease.
Creating awareness on the causes, symptoms and prevention of Lassa fever.
Providing educational programs for the general public on locating and evaluating
information on Lassa fever.
Providing a current awareness service about Lassa fever for health professionals
Initiating and participating in research that can curb and eventually lead to the
eradication of the disease.
Sending information to hospitalized patients and community members about the disease.
Collaborating with government and non-governmental organizations in packaging,
repackaging and promoting health information
Collaborating with community health workers and other agencies to mobilize and
educate community members on this dangerous emerging diseases
Conclusion and Recommendations
It is imperative that an intensive and comprehensive awareness be carried out to curb the rising
tide of Lassa fever in Nigeria and the roles of libraries in accomplishing this task cannot be
emphasised.
Intensive awareness campaign for the eradication of Lassa fever
Campaign for the control of Lassa fever must be intensified more than ever before. The war
against the disease must be fought collectively to achieve the desired result of preventing a
deadly, emerging epidemic. All the members of the community must be sensitized of the
possibility of eradication through prevention. To achieve this, the following must be done
without further delay:
There must be nationwide media publicity on the spread of the disease across the country.
All categories of libraries must be stocked with materials on symptoms, prevention and
control of Lassa fever.
In collaboration with radio and television stations, the ministries of information should
feature drama and playlets that inform people about the disease.
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The literate members of the community should be reached through the billboards,
newspaper and magazines, posters, pamphlets and handbills.
Traditional rulers and chiefs should be enlightened about the disease and they in turn will
enlighten their subjects.
Mothers should also be made aware of the epidemic of Lassa fever and that they should
desist from self-medication but refer all cases of fever in the hospital because it could be
Lassa fever.
Health officials especially in endemic areas must go round the villages and outlets to
ensure proper maintenance of deep well and water reservoirs.
Farmers should be enlightened on danger of spreading farm products on the road side and
open places.
The rural dwellers should be discouraged from eating any type of rat.
It is expected that if all these measures are taken, there is the possibility of complete eradication
of Lassa fever in Nigeria. The case of Jigawa State where the outbreak of Lassa fever was
prevented through public awareness is a pointer to the possibility of eradication of Lassa fever in
the states of Nigeria
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