Over one year after Nigeria suffered from the deadly Ebola virus disease which claimed some lives, including those of car-givers (medical doctors and nurses), an outbreak of a disease of near same symptoms, though not as deadly, Lassa Fever, has been reported in some parts of the country.
At least 150 infections and forty deaths have recorded in the affected states of Taraba, Kano, Rivers, Bauchi, Oyo, Niger and Nasarawa. Lassa Fever is one of the lethal viral haemorrhagic fevers, apart from Ebola, Dengue and some others.
It has mainly affected West Africa and was first discovered in 1969 in a Nigerian town called Lassa, where two missionary nurses died of the disease.
Since then, it has been recurring, especially during the dry season, particularly between December and March, in different parts of the country and the West African sub-region. Poor hygiene and inadequate awareness and public enlightenment have been identified as major causes of its spread.
Lassa Fever is a viral illness
IT is an acute viral illness caused by Lassa virus, a single-stranded RNA virus that belongs to a family called Arenaviridae. The natural host or reservoir of this virus is a rodent known as the ‘multimammate’ rat that belongs to the mastomys genus.
It has been observed that mastomys rats breed very frequently and readily colonise homes; hence the easy spread of this zoonotic virus from infected rodents to unsuspecting humans.
Lassa Fever is common in West Africa
LASSA virus infections are common in West Africa to warrant public health concern.
An average of about 300,000 cases are recorded every year, with 5,000 deaths.
How it is spread to humans
HUMANS can contract the virus when they come in contact, directly or indirectly, with the urine and droppings from infected rats or by breathing in tiny particles from air that has been contaminated with rodent excretions. Some humans who eat infected rodents can equally contract the virus.
If adequate precautions are not taken, care givers, especially doctors and nurses, who handle or treat infected persons can contract the virus from contaminated blood, tissues, secretions or excretions of such patients.
However, it cannot be spread through casual skin-to-skin contacts (including handshakes), provided there are no cuts or bruises.
Lassa Fever usually produces symptoms
LASSA virus has an incubation period of one to three weeks, following which signs and symptoms of the infection emerge. Initially, non-specific symptoms, such as fever, sore throat, cough, back pain, abdominal pain or pain behind the chest wall may be felt, as well as vomiting, diarrhoea and facial swelling. As the disease progresses, mucosal bleeding and bleeding from body orifices may follow.
Lassa Fever can be treated
PROVIDED the affected person presents early enough and prompt diagnosis of Lassa Fever is made, an anti-viral agent called Ribavirin has been shown to be quite effective in reducing morbidity and mortality from the disease.
In addition to Ribavirin administration, supportive treatment may also be given to maintain fluid and electrolyte balance, as well as the blood pressure.
Untreated Lassa Fever often results in death
IT was estimated that 15 to 30 per cent of patients admitted for Lassa Fever end up dying of the illness. Death rates are higher for pregnant women, especially those in the third trimester, and their unborn babies.
Mortality rates in the latter group (unborn babies) sometimes reach 95 per cent. Up to one-third of Lassa Fever survivors may suffer from varying degrees of hearing loss, which may be permanent.
Lassa Fever is better prevented
LIKE is commonly said, prevention is better than cure. Since no vaccine has been developed yet for Lassa virus infection, people are advised to employ every possible means to avoid contact with rodents and infected people.
Homes must be kept clean and rodent-free and foods stored in rodent-proof containers. Health care givers must practise barrier-nursing methods, such as isolation of infected patients and consistent use of face masks, gloves, gowns and goggles when attending to such patients.
