With over 200 deaths to Lassa Fever in 2023 and 108 deaths so far in 2024, PAUL ADUWOKE writes on the causes and symptoms of the disease and the efforts of the Nigeria Centre for Disease Control and Prevention (NCDC) and other stakeholders to contain the current outbreak.
Again, Lassa fever is on the prowl in Nigeria and the Nigeria Centre for Disease Control and Prevention (NCDC) is battling to bring it under control and ensure less infections and deaths.
In its latest situation report published on its website for week eight of 2024, the Nigeria Centre for Disease Control (NCDC), confirmed 96 new Lass fever infections and 23 deaths across 12 states in one week, spanning 19 to 25 February.
The report reveals that the number of new confirmed cases increased from 66 in week seven to 96 cases, adding that six new health workers were affected in the reporting week.
The report said: “In week eight, the number of new confirmed cases increased from 66 in epi week seven, 2024, to 96 in epi week eight, 2024. These were reported in Edo, Ondo, Taraba, Bauchi, Kaduna, Benue, Ebonyi, Kogi, Nasarawa, Enugu, Gombe, and Rivers states.
“Cumulatively, from week one to eight, 2024, 108 deaths have been reported with a Case Fatality
“Sixty-four per cent of all confirmed Lassa fever cases were reported from these three states – Ondo, Edo and Bauchi – while 36 per cent were reported from 21 states with confirmed Lassa fever cases. Of the 64 per cent confirmed cases, Edo reported 26 per cent, Ondo 23 per cent, and Bauchi 15 per cent. The predominant age group affected is 31-40 years. The male-to-female ratio for confirmed cases is 1:0.9. The number of suspected cases decreased compared to that reported for the same period in 2023. Six new healthcare workers were affected in the reporting week eight.”
On its website, the NCDC explains that the Lassa virus is transmitted to man by infected multi-mammate rats, the mastomys natalensis species complex which is the reservoir host.
“Humans become infected from direct contact with the urine and faeces of the rat which contains the virus, through touching soiled objects, eating contaminated food or exposure to open cuts or sores. Secondary transmission from person to person can occur following exposure to the virus in the blood, tissue, urine, faeces or other bodily secretions of an infected individual. Hospital-acquired (nosocomial) transmission from person to person are not uncommon, and importantly can occur if appropriate Personal Protective Equipment (PPE) is not worn when managing suspected cases,” it explained on its website.
In week 52 of 2023 (December 25-31), the disease caused 227 deaths across 124 local councils in 28 states of the federation.
So, as the number of cases continues to rise in 2024, health experts have cautioned Nigerians to avoid contact with rats by ensuring good environmental hygiene through proper disposal of wastes, storing food in rat tight containers, placing garbage dump far away from homes as well as engaging in the reduction of the rat population.
The experts stated that infected patients should be isolated while health workers should ensure standard infection prevention and control protocols.
Explaining how this year’s outbreak was identified, the NCDC DG, Dr. Jide Idris, said the centre was notified by the Kaduna State Ministry of Health of the report of deaths from suspected viral hemorrhagic fever at the 44 Nigerian Army Reference Hospital in Kaduna.
Idris, who is a former Commissioner for Health, Lagos State, said that following the notification, the NCDC has been working with both institutions to conduct a comprehensive investigation of the suspected cases as well as ramp up response activities.
He noted that four of the six blood samples from suspected cases sent to the Bayero University Teaching Hospital in Kano were confirmed for Lassa fever, adding that 25 close contacts of all these cases were under follow up and placed on prophylactic medicine.
Idris explained that the Kaduna State Ministry of Health has also activated their Incident Management System with all the response pillars including intensified risk communication and community engagement for the prevention and control of Lassa fever in the affected communities.
The DG explained that the centre, through the recently activated multi-sectoral multi-disciplinary Incident Management System, has taken some actions which include distribution of medical supplies for case management, infection prevention and control, laboratory diagnosis, among others, in all Lassa fever treatment centres in the country.
He added that the centre has also embarked on capacity building exercises of some healthcare workers across all the geopolitical zones on Lassa fever preparedness, readiness and response through the pilot Lassa fever clinical management fellowship; and also the distribution of Lassa fever social and behaviour change communication (SBC) materials to all the 36 states and the Federal Capital Territory (FCT), Abuja.
Idris explained that the disease would initially appear like any other common illnesses accompanied by a fever, such as malaria.
“Other symptoms include headache, general body weakness, cough, nausea, vomiting, diarrhoea, muscle pains, chest pain, sore throat, and, in severe cases, bleeding from ears, eyes, nose, mouth and other body openings, hence the name hemorrhagic.
“The time between infection and the appearance of symptoms of the disease, incubation period is three to 21 days,” he added.
He disclosed that people of all age groups who come in contact with the urine, faeces, saliva or blood of infected rats are at risk of contracting the disease, adding that people living in rat-infested environments are mostly at risk.
Also at risk are: “People who consume potentially contaminated foodstuff, especially those left open overnight or dried outside in the open; people who handle or process rodents for consumption; people who do not perform hand and environmental hygiene at appropriate times; caregivers of infected persons with poor infection prevention and control measures; healthcare workers, which including doctors, nurses and other health workers who provide direct patient care in the absence of standard precautions; hospital staff who clean and disinfect contaminated surfaces, materials and supplies without adequate protective gear; laboratory staff who handle blood samples of suspected Lassa fever patients without appropriate precautions and persons who prepare and/or handle bodies of deceased Lassa fever cases without appropriate precautions.”
On how to prevent Lassa fever, Idris advised Nigerians to always keep their environment clean and block all holes in their houses to prevent the entry of rats and other rodents.
He stressed: “Cover your dust or waste bins and dispose your refuse properly. Communities should set up dump sites far from their homes to reduce the chances of the entry of rodents into their homes.”
He added that it is safer to store food items such as rice, garri, beans, corn/maize, among others, in tightly sealed or well-covered containers.
“Avoid drying food stuff outside on the ground or roadside, where it is at risk of contamination. Discourage bush burning, because this destroys the homes and food sources of rodents and drives them to migrate from the bushes to human residences to find food,” he said.
He noted that people can eliminate rats in their homes and communities by using rat traps and other appropriate and safe means.
“At all times, practice good personal and hand hygiene by frequently washing hands with soap under running water or using hand sanitisers when necessary,” he advised.
He urged people to visit the nearest health facility if they notice any of the signs and symptoms associated with Lassa fever mentioned earlier or call their state’s Ministry of Health hotline and 6232 (NCDC).
“This is essential because early identification and treatment of cases appear to be more effective and can save lives. People should avoid self-medication to ensure proper diagnosis and early treatment.
“Healthcare workers are advised to always practice standard infection prevention and control practices, i.e., using gloves, face masks, and other appropriate personal protective equipment while handling patients or providing care for an ill patient.
“Healthcare workers should maintain a high index of suspicion for Lassa fever such as being vigilant and consider a diagnosis of Lassa fever when seeing patients presenting with febrile illness,” he noted.
Idris urged healthcare providers to report all suspected cases of Lassa fever to their local council Disease Surveillance and Notification Officer to ensure prompt diagnosis, referral and early commencement of public health actions.
He stated that the country was, at this period, also responding to other disease outbreaks including meningitis, 507 cases and 63 deaths in 19 states; measles, 915 suspected, 516 confirmed cases with two deaths in 29 states; diphtheria, 16,248 cases and 646 deaths in 22 states, and cholera.”
According to him, these statistics are high and totally unacceptable to the government.
“So, safeguarding our health is our collective responsibility. We sincerely acknowledge and commend the efforts of all the affected state governments including the FCT, the various State Ministries of Health, the numerous health workers and other stakeholders who have taken charge of these situations in their various states. In the spirit of collaboration, we will continue to support them,” he pledged.
A Public Health expert, Dr. Obinna Ebirim, told The Guardian that Lassa fever is an acute viral hemorrhagic illness caused by Lassa virus, which belongs to the arenaviridae family.
His words: “The virus is found in rats. The multimammate rat of the genus Mastomys is the reservoir of Lassa virus. Lassa fever is therefore called a zoonosis because the disease results from human to animal contact. Specifically, human beings are infected through contact with items contaminated by the faeces or urine of infected rats among others. The symptomatology, include fever, weakness and malaise, muscle pain, which mimics other infections like malaria and typhoid fever in the mild form of the disease. However, in the serious form of the infection (which occurs in only 20 per cent of patients), bleeding from the gums, anus and vagina occurs in addition to diarrhea, vomiting, deafness, among others”.
A Senior Lecturer and Consultant Public Health Physician at Department of Community Health and Primary Health Care, Lagos State University College of Medicine (LASUCOM), Dr. Modupe Akinyinka, said that symptoms of Lassa fever include fever and general weakness.
“After a few days, headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough and abdominal pain may follow. In severe cases, facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract may occur.”
She said Lassa fever occurs in all age groups and both sexes, stressing that persons at greatest risk are those living in rural areas or anywhere with rats.
“Treatment is available with an anti-viral drug and other supportive treatments,” she said.
She said that Lassa virus infections can only be diagnosed definitively in a Virology laboratory using the following tests: The reverse transcriptase polymerase chain reaction (RT-PCR) assay, testing for IgM, antigen detection tests and virus isolation by cell culture.
She explained that these tests could be done at the Virology Reference Laboratory at the Lagos University Teaching Hospital (LUTH), Idi-Araba, among other hospitals.
In terms of management of the virus, Akinyinka said the only known specific treatment is ribavirin, which may be effective if given within the first six days of illness.
“It should be given intravenously for 10 days. Supportive treatment should include paracetamol, vitamin k, phytamenadione, heamacel, ringers lactate, anti-malaria and antibiotics- start by I.V. If the patient is severely anaemic, consider transfusion,” she noted.
She explained that currently, there is no vaccine that protects against Lassa fever.
“Prevention of Lassa fever relies on promoting good community hygiene to discourage rodents from entering homes. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the home and maintaining clean households.”
“In healthcare settings, prevention is by standard precautions where all blood and body fluids are considered potentially infectious. Standard precautions are applied to all patients at all times and in all health care settings. These include hand hygiene, use of appropriate personal protective equipment (PPE), waste disposal, cleaning and disinfection of medical equipment and environment, safe injection practices,” she said.
