THE INCREASING INCIDENCE OF LASSA FEVER IN NIGERIA

[Image credit](By Kelly, et al - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3562201/, CC BY 3.0, Link)

After reading the Nigerian Centre for Disease Control weekly report for March 2018, as a concerned Nigerian, I began worried and restless. I asked myself repeatedly, is Lassa fever now an endemic disease in Nigeria? If yes, can the endemicity be compared to that of malaria?

According to this report, Nigeria has recorded 1121 suspected cases in 2018 (from January to March 4th March 2018). Of these, 353 has been confirmed positive, 8 probable and the others are either awaiting laboratory results or negative, the case fataility for this period was reported to be 23.8%. This is alarming, comparing this data with the statistics of Lassa fever outbreak from December 2016 to Dec 24, 2017, made me worried. Within this year (2016-2017) 1022 suspected cases were reported, 322 confirmed, 308 probable, 92 deaths recorded while case fatality was 12.4%.

Does this report not call for serious concern? The health of the population should be of concern and the activities of the government should lay more emphasis on primary health care.

How Can this Increase in Incidence Be Reduced Drastically?

The activities of health institutions should be geared towards prevention of Lassa fever outbreak rather than treatment. Public health education will also play an important role in reducing the incidence of Lassa fever outbreak. Before I continue writing on reducing the incidence of Lassa fever in Nigeria, a brief explanation of the Lassa virus will help us understand why there is an urgent need to reduce the incidence drastically.

Lassa fever was first identified in1969 in a village called Lassa in Borno state, Nigeria. The viral particle was isolated from three missionary nurses who died in Lassa although it was first described in the 1950s.

Lassa virus is an enveloped, round or pleomorphic, single-stranded, bi - segmented RNA, hemorrhagic fever virus (family Arenaviridae). It causes acute viral illness for about one to four weeks. Lassa virus is assumed to be endemic in Sierra Leone, Liberia, Benin, Guinea, and some parts of Nigeria although it has also been identified in some other countries e.g Ivory Coast, Mali, Senegal, Gambia, Ghana, Burkina Faso, and the Central African Republic.

Lassa virus is mainly transmitted from animals(Rodents) to persons (zoonosis).

• Through contact with food contaminated with the rodent droppings or urine of infected multimammate rats (Mastomys natalensis) or contaminated house items.
• Inhaling aerosols in air contaminated with rodent excretions,
• Ingestion of the virus in food or contaminated utensils.

Apart from animals to human transmission, it could also be transmitted from human to human. Each infected person provides a new source of infection for others. This could be through:

• Direct contact with bodily fluids of an infected person.
• Reuse of needle, sharp object. Cut or open wound.

The period between the entry of Lassa virus and the exhibition of signs and symptoms of the disease ranges from about 6–21 days. When the onset of the disease is symptomatic, it usually shows a slow but gradual progressive raise, starting flu-like symptoms e.g. Fever, general body weakness, and malaise.

After a few days, headache, vomiting, diarrhoea, cough, abdominal pain, sore throat, muscle pain, and chest may follow.
Low blood pressure, swelling in the face, Presence of fluid in the lung cavity, and bleeding from the nose, mouth, vagina or gastrointestinal tract may develop in severe cases.

In the later stage of the disease, tremor, shock and coma results while protein may also be noticed in the urine of the victims.

In about 20% of the individuals who survive this disease, deafness occurs although hearing may return partially in 50% of the cases after 2- 3 months.

About 75% of people who are infected with the Lassa virus do not manifest symptoms and in some cases, infections may result in severe disease that affects some organs such as the kidneys, liver and spleen.

Back to the question, can the incidence be reduced? Yes, it can be reduced. Although there is no available vaccine yet for the prevention of Lassa fever, it is important to note a decrease in the number of people affected can be achieved through the following:

• Village based programs or round table discussion for communities should be organized to educate the populace on the need to control and eradicate rodent in the environment with proper and safe disposal.

• The media can also help in educating the public by creating more awareness about the Lassa virus.

• Promoting good “community hygiene” that will discourage rodents from entering homes.

• Proper storage of grains and other foodstuffs in containers that can't be tampered with by rodents

• The general public should be educated to avoid contact with blood and body fluids when caring for sick persons in their communities.

• Several cases of Lassa fever has been reported among health care workers in Nigeria, it is therefore important that, staffs in health-care settings should always apply and maintain standard infection prevention and control precautions when caring for patients.

• Immediate contact to local and national authorities and the arrangement for fast laboratory testing by health-care workers when attending to suspected cases of Lassa fever.

Treatment of Lassa virus deisease

The antiviral drug Ribavirin (Copegus, Ribasphere, Rebetol), a broad spectrum antiviral agents are given intravenously, is an effective treatment for Lassa fever if given early in the course of clinical illness.

Thank you for reading, I hope this will be helpful.

References

WHO 1
WHO 2
CDC.
NCDC
Vanguard Nigeria
Reliefweb 1

Image Credit
[Image 2](By UN - [1], Public Domain, Link)
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