Pharmacotherapy/Treatment Of Lassa Fever

Lassa fever is a disease caused by a virus. The virus is a single stranded ribonucleic acid (RNA). It belongs to the family arenaviridae. It was first described in the 1950s. It was not until 1969 that it was confirmed.

Mode Of Transmission

Pharmacotherapy of Lassa fever

The mastomys rat is the vector of the virus. Though asymptomatic, they spread it to humans through urine and/or faeces when they come in contact with humans. Human-to-human transmission is also possible through direct contact with body fluids of infected persons. There is no evidence it is contracted through air borne.

Read Also: Drugs for treating Zika virus

Confirmed body fluid that can cause infection include urine, faeces, blood and semen. And these can get into the body through mucous membranes like eye, nose and eyes. Lassa fever can affect people of all ages and sexes.

There is still confusion as to when people become contagious or for how long. Infection from semen of a healthy male that has recovered after three months have been reported. But the virus peaks in blood from four to nine from the day symptoms begin.

Signs And Symptoms

Majority of infected persons are asymptomatic. Only one in five progress to severe situation. It takes about six days to three weeks for symptoms to manifest. For symptomatic patients, it begins with fever, general weakness and malaise. Worse symptoms include headache, sore throat, muscle pain, nausea, vomiting, diarrhea, cough and abdominal pain may follow. In severe cases, fluid from blood vessels enter tissues which causes facial swelling, reddened whites of the eyes and fluid around the lungs and heart. The fluid in the lungs causes dry cough and respiratory distress. Faint rash of the upper body may disturb fair-skinned individuals which is not so with dark skinned.

Worst situations involve bleeding from the mouth, nose, vagina or gastrointestinal tract and low blood pressure. Protein may be noted in the urine. Shock, seizures, tremor, disorientation and coma may be seen in the later stages. Deafness occurs in 25% of patients who survive the disease. In half of these cases, hearing returns partially after one to three months. Transient hair loss and fair disturbance may occur during recovery.

Complications

Death usually occurs within 14 days of the onset of fatal cases. The disease is severe in the late trimester of pregnancy. Maternal death, stillbirth or fetal loss occur in more than 80%. The virus attacks several organs such as liver, spleen and kidney.

Diagnosis/Test

Diagnosis is difficult because it's symptoms are varied. It is hard to differentiate it from other hemorrhagic diseases like ebola and other disease like malaria, typhoid, etc. Laboratory diagnosis is based on:

1.  Reverse transcriptase polymerase chain reaction (RT-PCR)

2. Antibody enzyme-linked immunosorbent assay (ELISA)

3. Antigen detection test

4. Virus isolation by cell culture

Prevention And Control

Community and personal hygiene is the best way to keep rats away from residential areas. Avoid contacts with body fluids of infected people including their properties. Use of personal protective equipment (PPE) when close to infected persons especially in hospital is ideal. Practice safety during administration of injection to patients including burial procedure.

Pharmacotherapy/Treatment

There is no vaccine currently approved by the world health organisation (WHO). Although some countries are currently trying out some new vaccines of which Nigeria is one. Only antiviral ribavirin is approved for treatment which is only effective if given in the early stage of the disease.

Read Also: Drugs for treating ebola

Ribavirin is a drug used for hepatitis. It's mechanism of action in Lassa fever is not known. There is no evidence that it can be used as a prophylaxis. And the injection is preferred to the tablet.

Evidence suggests that it was able to reduce complications of Lassa fever from 50% down to 5% if used early. That is impressive. But so many people still don't follow the regimen due to its adverse effects such as hemolytic anaemia if infused too quickly. Others are weakness, dizziness, headache and nausea.

Loss of fluid can be treated with replacement therapy. Blood pressure level must be maintained using available drugs. Oxygen should be monitored and if need be use a ventilator.

Share On Social Media With Family And Friends To Show You Care!