Resurgence of Lassa fever in Nigeria
The current upsurge in the cases of lassa fever demands urgent attention of governments at all levels. Lassa fever is an acute febrile illness, with bleeding and death in severe cases. According to the World Health Organisation (WHO), it is an acute viral haemorrhagic illness of two to 21 days duration that occurs largely in West Africa. The disease dates from to 1950s, but the virus was first described in 1969 from a case in the town of Lassa, in Borno State, Nigeria. The virus is zoonotic, or animal-borne. Again, WHO states that the reservoir or host of the Lassa virus is the “multimammate rat” called mastomys natalensis, which has many breasts and lives in the bush and around residential areas. So, it is spread by rats!
The virus is shed in the urine and faeces of the rats, hence can be transmitted to humans via direct contact, touching objects or eating food contaminated with these materials or through cuts or sores. Person-to-person infections and laboratory transmission can also occur, particularly in hospitals lacking adequate infection prevention and control measures. Persons at greatest risk are those living in rural areas where mastomys are usually found and especially in communities in cities with poor sanitation as well as crowded living conditions.
About 80 per cent of human infections are without symptoms; the remaining cases have severe multiple organ disease, where the virus affects several organs in the body, such as the liver, spleen and kidneys. According to the WHO, the onset of the disease, when it is symptomatic, is usually gradual, starting with fever, general weakness, muscle and joint pains, prostration and malaise. 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 and low blood pressure may develop. Shock, seizures, tremor, disorientation, and coma may be seen in the later stages.
Lassa fever is known to be endemic in Benin Republic, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria, but probably exists in other West African countries as well. In 2017, Benin, Burkina Faso, Sierra Leone, and Togo experienced outbreaks that have since been controlled. Although, Nigeria is one of several West African countries in which Lassa fever is endemic, with seasonal outbreaks occurring annually between December and June, the current outbreak of the disease in Nigeria, however, is continuing beyond the normal season and killing people almost annually. In 2016, the country reported 273 suspected cases and 149 deaths (case fatality rate 55 per cent) from 23 states. According to Nigeria Centre for Disease Control (NCDC), during the 2017 outbreak, nineteen (19) States (Ogun, Bauchi, Plateau, Ebonyi, Ondo, Edo, Taraba, Nasarawa, Rivers, Kaduna, Gombe, Cross-River, Borno, Kano, Kogi, Enugu, Anambra, Lagos and Kwara) reported at least one confirmed case each. As at November 2017, the outbreak was active in 5 states – Ondo, Edo, Plateau Bauchi and Kaduna.
On January 14, this year, four cases of Lassa fever among health care workers in Ebonyi State were reported at the Nigeria Centre for Disease Control (NCDC). Three of the four cases – two medical doctors and a nurse have subsequently passed away, despite efforts to save their lives. According to the University Graduates of Nursing Science Association (UGONSA), at the latest count, more than 40 health workers have died as a result of Lassa fever in Ebonyi alone in the past 13 years.
In other states of the federation, there have been reports of more cases. Again, a medical doctor with the Federal Medical Centre (FMC), Lokoja, Kogi State who tested positive to Lassa fever, died of the disease earlier this week, while Lassa fever has hit Ondo State.
However, this situation does not call for panic as early supportive care with rehydration and symptomatic treatment improves survival chances. As such, the affected State Ministries of Health and the Federal Ministry of Health should respond to contain the current Lassa fever outbreak by mobilising human and material resources to trace the sources and extent of the disease, follow up on potential contacts, identify early and test suspected cases.
Notwithstanding, the resurgence of Lassa fever in the country should be a major source of worry as reports from some parts of the country are scary, especially because health workers are dying of the disease they are to cure.
As such, all hands must be on deck to redress this situation. Strategically, since there is currently no vaccine that protects against Lassa fever prevention is the key. Its prevention relies on scientific interventions, societal and individual behavioural changes hinged on good hygiene. Individuals should learn to store grains and other foodstuff in rodent-proof containers, dispose of garbage far from the home and maintain clean households. Health workers should maintain a high level of alert in the wake of this new outbreak and observe universal precautions in handling all suspected cases of this viral haemorrhagic fever. The scientific intervention requires a connect between town and gown. The Federal Ministry of Health, Centre for Disease Control (CDC) in Nigeria, Nigerian Institute of Medical Research, Institute of Human Virology, Nigerian research and development units of health-related organisations such as pharmaceutical companies and universities should collaborate and engage in a well-coordinated manner to search for solutions through research on the specie of rat that hosts the Lassa virus and how to make them de-zoonotic in order to render them impotent as carriers. They should also lead a vaccine and treatment research, particularly now that the federal government recently said that Nigeria is set to resume local production of vaccines after 27 years.. In addition, any institution or individual who has done any useful research should make it public. Also, the relevant ministries, departments and agencies of government at all levels should map the pattern of the outbreak with a view to preventing or dealing with future occurrences.
Finally, the virology centre built by the Ebonyi State government two years ago should be made fully functional, to reduce the unnecessary and arduous ferrying of victims of Lassa fever from the east, by road to Irrua in Edo, a process that often leads to death from exhaustion of some victims.