Lassa fever has become one of the endemic viral sicknesses in parts of West African countries such as Sierra Leone, Liberia, Guinea and Nigeria.
It is zoonotic meaning it is an animal-borne illness or can spread from animals to humans. Its risk has further extended to Neighboring nations as the organism that transmit Lassa virus, the “multimammate rodent” (Mastomys natalensis) is widely dispersed through-out the region.
Lassa fever was first described in 1950’s and Lassa virus (LASV) was identified in 1969 and is named after Lassa town in northeastern Nigeria where the principal cases happened.
Statistics has shown that an approximately 100,000 to 300,000 infections due to Lassa fever happen yearly, with around 5,000 deaths. There is no standardized survey that has been carried out on Lassa fever; in this way, these evaluations are unrefined.
What causes Lassa Fever and how is it Transmitted?
The host of Lassa virus is a rat known as the “multimammate rodent” (Mastomys natalensis). When rats become infected with the virus it can discharge virus in pee for an all-inclusive timespan, perhaps till it dies. Rats breed as often as possible, and give birth to a large number of its young and are widely distributed in the savannas and woodlands of west, central, and east Africa.
What’s more, Mastomys promptly live in human homes and territories where food is stored. These are some of the major factors that add to the moderately productive spread of Lassa infection from infected rodents to people.
Transmission of Lassa infection to people happens most usually through ingestion of contaminated foods or inward breath. They shed the infection in pee and droppings and direct contact with these materials, touching soiled objects, eating contaminated foods, or introduction to open cuts or injuries, can prompt disease.
Since Mastomys rodents regularly live in and around homes and feed on left over human food items or foods not properly stored, direct contact transmission is normal. Mastomys rodents are now and again are consumed as bush meat and contamination may happen when rodents are gotten and arranged “prepared”.
Contact with the infection may likewise happen when an individual breathes in minor particles in the air contaminated with infected rat discharges. This vaporized or airborne transmission may happen during cleaning exercises, for example, sweeping.
Direct contact with contaminated rodents isn’t the main manner by which individuals are infected; individual to-individual transmission may happen after presentation to infection in the blood, tissue, emissions, or discharges of a Lassa infection contaminated person. Easygoing contact (skin-to-skin contact without exchange of body fluids) doesn’t spread Lassa infection. Individual to-individual transmission is regular in human services settings (called nosocomial transmission) where proper personal protective equipment (PPE) isn’t accessible or not utilized. Lassa infection might be spread in contaminated medicinal equipment, for example, reused needles.
Signs and Symptoms
Signs and Symptoms of Lassa fever ordinarily happen 1-3 weeks after the patient comes into contact with the infection. For most of Lassa fever virus contamination (around 80%), Symptoms are mild and are undiscovered.
Mild Symptoms include slight fever, general discomfort and weakness, and headache. In 20% of contaminated people, nonetheless, illness may advance to increasingly serious manifestations including hemorrhaging (in gums, eyes, or nose, as examples), respiratory distress, repeated vomiting, facial swelling, pain in the chest, back, and abdomen, and shock. Others such as hearing loss, tremors, and encephalitis have also been described. Death may happen within a period of fourteen days after symptoms began due to failure of multiple organs.
The most widely recognized complexity of Lassa fever is deafness. Different degrees of deafness happen in around 33% of contamination, and much of the time hearing loss is changeless. As far as is known, seriousness of the malady doesn’t influence this complexity: deafness may occur mild as well as in extreme cases.
Around 15%-20% of patients hospitalized for Lassa fever pass on from the ailment. Nonetheless, just 1% of all Lassa infection contamination bring about death.
Since the symptoms of Lassa fever are variable and vague or nonspecific, clinical analysis is regularly troublesome. Lassa fever is additionally connected with infrequent epidemics, during which the case-casualty rate can reach 50% in hospitalized patients.
Risk of Exposure
People at most serious danger of Lassa infection contamination are the individuals who live in or visit endemic districts, including Sierra Leone, Liberia, Guinea, and Nigeria and have exposure to the multimammate rodent. Danger of exposure may likewise exist in other west African nations where Mastomys rodents exist. Hospital staff are not at great risk for contamination as long as defensive measures and appropriate cleansing strategies are utilized.
How is Lassa Fever Diagnosed?
Lassa fever is regularly analyzed by utilizing enzyme-linked immunosorbent serologic assays (ELISA), which detect IgM and IgG antibodies as well as Lassa antigen. Reverse transcription-polymerase chain reaction (RT-PCR) can be used in the early stage of disease. The virus itself may be cultured in 7 to 10 days, but this method should just be done in a high regulation research center with great laboratory practices. Immunohistochemistry, performed on formalin-fixed tissue samples, can be utilized to make a posthumous conclusion.
Can Lassa Fever be Cured?
Ribavirin, an antiviral medication, has shown to be successful when used in Lassa fever patients. It has been demonstrated to be best when given from the get-go in the course of the disease.
Patients should likewise get steady supportive care comprising of maintenance of appropriate fluid and electrolyte balance, oxygenation and blood pressure, just as treatment of any other complicating infections.
How can Lassa Fever Be Prevented?
Below are 9 ways to prevent Lassa virus infection:
- Avoid contact with Mastomysrodents, especially in regions where outbreaks occur.
- Put food away in rodent-proof containers
- Keep the home clean, this helps to discourage rodents from entering homes.
- Using these rodents as a food source is not recommended.
- Set Traps in and around homes to help reduce rodent populations.
- Cook all foods thoroughly
- Always wash hands thoroughly after contact with any sick person
- Use hand sanitizers regularly
- When handling infected person, wear protective clothing, such as masks, gloves, gowns, and goggles; use infection control measures, such as complete equipment sterilization; and isolate infected patients from contact with unprotected persons until the disease has run its course.