Lassa fever
Lassa fever
Last update: 2023-06-20
Key facts
Transmission: Animal-borne, direct or indirect contact (reservoir is rats)
- Contact with food or household items contaminated with rodent urine or faeces
- Contact with the blood, faeces, vomit, spit, sweat, tears, breastmilk or semen from a person sick with Lassa
- Contact can be with objects that have been contaminated with the body fluids from a person who is sick with Lassa (for example, bedding, clothes or needles)
- Coming into contact with semen (for example, through sex) from someone who has recovered from Lassa (Lassa can be spread through semen for up to three months after recovery)
Most vulnerable to severe consequences
- Pregnant women and their unborn babies are at high risk of serious disease and bad outcomes
Most vulnerable to contracting the disease
- People living in places where they come into contact with rodents and their waste
- Family and relatives of people who are sick (or who have died) from Lassa
- Health workers who work with people sick with Lassa (especially if the proper precautions are not in place)
General symptoms (** most people infected with Lassa fever show no symptoms **)
- Fever (sometimes)
- Weakness and fatigue (sometimes)
- Headache (sometimes)
- Sore throat (sometimes)
- Muscle pain (sometimes)
- Chest pain (sometimes)
- Nausea, vomiting (sometimes)
- Diarrhoea (sometimes)
- Cough (sometimes)
- Abdominal pain (sometimes)
Symptoms of severe Lassa
- Facial swelling
- Bleeding from the mouth, nose, vagina or anus
- Seizures
- Shaking
- Confusion
- Unconsciousness
- Deafness
What can you do to prevent and control an epidemic?
Reservoir control and prevention
- Promote the use of rodent traps inside and outside homes
- Promote the use of other rodent control measures such as keeping cats
Monitoring the community and identifying sick people
- Identify and immediately isolate sick people
Treatment and management
- Immediately refer suspected cases to treatment centres
- Support contact tracing and follow-up of contacts
- Provide psychosocial support to the sick person, their families and communities
- Support safe and dignified funeral and burial practices for Lassa fever
Safe shelters and spaces
- Promote secured spaces and prevent rodents from entering houses or accessing stored food and water (including pet or animal food)
- Follow recommended environmental hygiene practices
- Dispose of rubbish in rodent-proof containers to minimize possible nesting sites
- Clean and disinfect areas where there is evidence of rodents
- Follow kitchen hygiene practices (for example, clean floors and wash dishes and utensils immediately)
Sanitation and waste management
- Encourage disinfection of homes and other spaces with evidence of rodents
- Encourage disinfection of homes and other spaces where people have been sick or died from Lassa
- Promote disinfection of reusable supplies
- Solid waste management
- Encourage the community to clear away rubbish and garbage
- Encourage safe disposal of contaminated waste (by burning or burying)
- Promote proper and safe disposal of dead rodents
Personal protection and hygiene
- Promote handwashing in communities and in health centres with soap, chlorine solution or hand sanitizer
- Practise and promote social distancing
- Promote the use of personal protective equipment (PPE) and disinfectants when cleaning up rodent droppings and nesting materials
Food hygiene and safety
- Discourage rodents as a food source
Social mobilization and behaviour change
- Find out the specific advice being given by health and other relevant authorities
- Involve the community in managing rumours and misinformation
- Promote the use of condoms for at least three months after a diagnosis of Lassa
- Promote the safe disposal (burning or burying) of contaminated materials
- Promote safe and dignified burials (discuss with your manager to follow national protocols and guidance)
- Model following this advice and inform community members of current health practice advice
- Offer support and encouragement to follow the advice
- Try to gain understanding about if and why health practice advice is not being followed
- With the guidance of your supervisor and health authorities, work with communities to overcome barriers to following health advice and recommended practices
Mapping and community assessment
- Make a map of the community.
- Mark the following information on the map:
- How many people have fallen sick with Lassa? Where?
- How many people have died? Where? When?
- Where are the local health facilities and services? (include traditional healers)
- Where do people obtain their drinking water?
- Record the following information on the back of the map:
- When did people start to fall sick with Lassa?
- How many people live in the affected community?
- How many pregnant women live in the affected areas?
- How do people in the community store their food?
- Are rats or other rodents able to eat it or contaminate it?
- How do people in the community dispose of rubbish and solid waste? (put communal rubbish disposal sites on the map)
- Have the authorities established a reservoir control programme?
- Do community members have any risky habits or practices when they come into contact with live or dead rodents?
- How do people dispose of dead rodents? (for example, are they buried, thrown in the river, burned?)
- What handwashing facilities are available? (put communal handwashing stations on map)
- Do they have soap?
- What are the community’s habits, practices and beliefs about caring for sick people? Consider any differences in roles and responsibilities between men and women.
- What are the community’s burial traditions, funeral procedures and practices?
- Do people in the community know about Lassa?
- Do people know the main signs of Lassa fever?
- Do they know what to do if someone becomes sick (for example phone number to call, actions to take)?
- Do people know how to protect themselves from Lassa?
- Is a social mobilization or health promotion programme in place?
- Are people in the community socially distancing? Why? Why not?
- Which sources do people use/trust the most for information?
- Are there rumours or misinformation about Lassa fever? What are the rumours?
- Are health workers, volunteers or people who have survived Lassa fever stigmatized, left out, threatened or harassed?
Volunteer actions
01. Community-based surveillance
02. Community mapping
03. Communicating with the community
04. Community referral to health facilities
05. Volunteer protection and safety
06. Personal protection equipment (PPE) for highly infectious diseases
09. Preparing oral rehydration solution (ORS)
19. Psychosocial support
20. Isolating sick people
28. Physical distancing
29. Hygiene promotion
31. Good food hygiene
34. Handwashing with soap
35. Handwashing in a highly infectious epidemic
36. Vector and reservoir control
38. Waste disposal and clean-up campaigns
41. Handling and slaughtering animals
42. Promoting safe sex
43. Social mobilization and behaviour change