COMBATING LASSA FEVER’S RESURGENCE
The new wave of fresh outbreak of Lassa fever in the country should give everyone something to worry about. A latest report has it that the Federal Capital Territory (FCT), Abuja has recorded a fresh case of Lassa fever, bringing the number of confirmed cases to three within three months. One of the two victims of the confirmed cases earlier recorded at Bwari Area Council of the FCT died in January. Similarly, in Ekiti State, three persons have been reportedly killed in a fresh outbreak of Lassa fever in the state. The Commissioner for Health, Dr. Olurotimi Ojo, who disclosed this revealed that five out of the eight suspected cases in the state tested negative while one was uncertain and the last one pending.
Lassa fever, a haemorrhagic viral infection is named after Lassa, a village in Borno State on the South of Lake Chad where the disease was first discovered in 1969 after two missionary nurses lost their lives. Lassa fever manifests like other so-called common ailments such as malaria and typhoid fever. The onset is gradual which makes early diagnosis difficult leading to fatal consequences. It is estimated that 10 per cent of almost 500, 000 people infected with Lassa fever lose their lives and approximately 15 per cent of hospitalised patients die. The disease is more severe in pregnancy particularly in the third trimester, and foetal loss occurs in greater than 80 per cent of cases.
It is caused by a species of rodents called the Natal multimammate rat, the common African rat, or the African soft-furred rat. The Lassa virus is transmitted when the droppings, that is the urine or faeces of the rat- the natural reservoir for the virus- comes in contact with foodstuffs or in the process of the rat accessing grain stores, either in silos or in residences. The rodents live in houses with humans and deposit excreta on floors, tables, beds and food. Consequently the virus is transmitted to humans through cuts and scratches, or inhaled via dust particles in the air. In some regions these rodents are also consumed as food. Secondary transmission of the virus between humans occurs through direct contact with infected blood or bodily secretions. This occurs mainly between individuals caring for sick patients although anyone who comes into close contact with a person carrying the virus is at risk of infection. Nosocomial transmission, that is the transmission that occurs as a result of treatment in a hospital and outbreaks in healthcare facilities in endemic areas represent a significant burden on the healthcare system.
In the early stages, Lassa fever is often misdiagnosed as common cold, typhoid or malaria, and as a result many patients fail to receive appropriate medical treatment. Making a correct diagnosis of Lassa fever is made difficult by the wide spectrum of clinical effects that manifest, ranging from asymptomatic to multi-organ system failure and death. The onset of the illness is typically mild, with no specific symptoms that would distinguish it from other febrile illnesses. In 80% of cases, the disease is without symptoms but in the remaining 20%, it takes a complicated course. It has an incubation period of six to 21 days after which an acute illness develops.
Early signs include fever, headache and general body weakness, followed by a sore throat, nausea, vomiting, abdominal pain and diarrhea in some cases. After four to seven days, many patients will start to feel better, but a small minority will present with multi-organ involvement. It can affect the gastro intestinal tract causing nausea, vomiting and stooling of blood as well as difficulty in swallowing; cardiovascular system symptoms include hypertension or hypotension as well as abnormal high heart rate and shock. In the respiratory tract, the victim experiences chest pains, cough and difficulty in breathing. The virus also causes difficulty in hearing, meningitis and seizures. Death from Lassa fever most commonly occurs 10 to 14 days after symptom onset. Non-specific symptoms are facial swelling, and muscle fatigue, as well as conjunctivitis and mucosal bleeding. And one of the hallmarks of Lassa virus infection is the absence of functional antibodies during acute infection.
So far, there is no specific treatment for Lassa fever, being a viral infection, but sufferers must constantly have access to balanced diet, antibiotics and vitamin supplements to boost their immune systems to prevent secondary infections. Calista Ozele, Lagos State Ministry of Information and Strategy, Alausa, Ikeja