LASSA fever or Lassa hemorrhagic fever, LHF, is an acute viral hemorrhagic fever caused by the Lassa virus and first discovered in 1969 in the town of Lassa, in Borno State, Nigeria. Lassa fever is a member of the Arenaviridae virus family. Similar to ebola, clinical cases of the disease had been known for decades but not connected with a viral pathogen.
Preventing Lassa fever is first about knowing the source.
The reservoir, or host, of Lassa virus is a rodent known as the multimammate rat of the genus Mastomys. It is not certain which species of Mastomys are associated with Lassa. However, at least two species carry the virus in some countries. It is also spread by direct contact with the blood, urine, faeces or other bodily secretions of a person with Lassa fever. In short, those who contract this virus must have touched or eaten something that had been touched by an infected rat.
Humans usually become infected with Lassa virus from exposure to urine or faeces of infected Mastomys rats. Lassa virus may also be spread between humans through direct contact with the blood, urine, faeces, or other bodily secretions of a person infected with Lassa fever.
There is no scientific evidence supporting airborne spread between humans. Person-to-person transmission occurs in both community and health-care settings, where the virus may be spread by contaminated medical equipment, such as re-used needles.
Sexual transmission of Lassa virus has been reported. Lassa fever occurs in all age groups and both sexes. Persons at greatest risk are those living in rural areas where Mastomys are usually found, especially in communities with poor sanitation or crowded living conditions. In addition, educating people who live in high-risk areas about ways to lower the rat populations in their homes will help to control and prevent Lassa fever.
The disease is spread by exposure to and eating of food contaminated with rat dropping or urine. Hence, it is not advisable to sun food items on places where they can be easily infested by rats.
- It is a big risk to soak up garri and drink at this period.
- Keep your houses and surroundings clean as well ensure that all holes through which rats can gain access are blocked. It is also advisable to clear all surrounding bushes and disposing refuse in covered dustbins.
- Discard all foods partly eaten by rats and cover all food and water properly.
Signs and Symptoms of Lassa Fever
The signs and symptoms of Lassa fever usually manifest between one to three weeks after a person has come into contact with the virus. For most of those with a Lassa fever virus infection; around 80 percent symptoms are mild and under-diagnosed. Mild symptoms include weakness, headaches, slight fever and general malaise.
In around 20 percent of infected people, the disease might progress to more serious symptoms that include hemorrhaging of the person’s eyes, gums, or nose; repeated vomiting; respiratory distress, pain in the back, chest and abdomen; facial swelling and shock. Neurological issues have also been described in relation to Lassa fever, to include tremors, hearing loss and encephalitis. An infected person may die within two weeks the symptoms start to surface because of multi-organ failures.
The most common complication of Lassa fever is deafness. Different degrees of deafness happen in around one-third of those who become infected. In many cases, the hearing loss is permanent. The severity of the disease does not affect this particular complication; deafness might develop in mild as well as severe cases.
Between 15 and 20 percent of people who are hospitalised for Lassa fever die from the illness. The death rates for women in the third trimester of pregnancy are exceptionally high. Spontaneous abortion is a very serious complication of the infection; an estimated 95 percent mortality rate in fetuses of infected mothers is an alarm sounding off. Due to the fact that the symptoms of Lassa fever are so nonspecific and varied, clinical diagnosis is often times difficult. Lassa fever is also associated with occasional epidemics. During these epidemics, the fatality rate may reach as high as 50 percent in people who become hospitalised.
Diagnosing Lassa Fever
Lassa fever is most often diagnosed through the use of, ‘enzyme-linked immunosorbent serologic assays, ELISA, which detect IgM and IgG antibodies as well as Lassa antigen. Reverse transcription-polymerase chain reaction, RT-PCR, may be used in diagnosing people who are in the early stage of the disease. The Lassa virus itself may be cultured in seven to 10 days, yet the procedure could only be effective if performed in a high containment laboratory with good laboratory practices. Immunohistochemistry, performed on formalin-fixed tissue specimens, might be used to make a post-mortem diagnosis.
Treating Lassa Fever
‘Ribavirin,’ is an antiviral drug that has been used with success in people affected by Lassa fever. It has shown to be most effective when it is administered early in the course of the illness.
Besides, infected persons are also supposed to receive supportive care that consists of maintenance of oxygenation, blood pressure, treatment of complicating infections and appropriate fluid and electrolyte balance.
According to Wikipedia, Lassa fever is an acute viral illness that occurs in West Africa. The illness was discovered in 1969 when two missionary nurses died from it in Nigeria. The virus is named after the town in Nigeria where the illness first occurred. The virus is a member of the virus family, ‘Arenaviridae,’ and is a single-stranded RNA virus; it is, ‘zoonotic,’ or animal-borne. Lassa fever is endemic in some parts of West Africa like, Liberia, Guinea, Nigeria and Sierra Leone.
Neighbouring countries are also at risk due to the animal vector for Lassa virus. The animal is the, ‘multimammate rat,’ or, ‘Mastomys natalensis,’ which is distributed throughout the region as a whole. In 2009, the first case from Mali was reported in a traveller who was living in southern Mali. Ghana reported its first cases in the year 2011. Isolated cases have been reported in Cote d’Ivoire and Burkina Faso. There is also seismologic evidence of Lassa virus infection in Benin and Tongo.
The number of people who experience Lassa fever each year in West Africa is estimated to be between 100,000 and 300,000, with around 5,000 people dying from the virus. The estimates are crude because surveillance for cases of the disease is not performed uniformly. In some areas of Liberia and Sierra Leone, approximately 10 to 16 percent of those admitted to hospitals each year have Lassa fever, which indicates the serious impact of the virus on the population of these areas.
— Jan 18, 2016 @ 16:50 GMT