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🦠microbiology review

Lassa virus

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Lassa virus is a member of the Arenaviridae family and is the causative agent of Lassa fever, a severe and potentially life-threatening viral hemorrhagic fever. It is primarily transmitted to humans through contact with infected rodents or their excreta, making it an important public health concern in endemic areas.

5 Must Know Facts For Your Next Test

  1. Lassa virus is primarily transmitted to humans through contact with infected rodents, such as the multimammate mouse, or their excreta.
  2. Lassa fever has a high mortality rate, ranging from 0.1% to 2% in hospitalized patients, but can reach up to 50% in some outbreaks.
  3. The virus can also be transmitted through person-to-person contact, particularly in healthcare settings, making proper infection control measures crucial.
  4. Early symptoms of Lassa fever include fever, headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhea, cough, and abdominal pain.
  5. Ribavirin, an antiviral medication, is the primary treatment for Lassa fever and has been shown to reduce mortality if administered early in the course of the disease.

Review Questions

  • Describe the primary mode of transmission for the Lassa virus and explain its significance in controlling microbial growth.
    • The Lassa virus is primarily transmitted to humans through contact with infected rodents, such as the multimammate mouse, or their excreta. This mode of transmission is significant in the context of controlling microbial growth because it highlights the importance of proper sanitation, hygiene, and rodent control measures in endemic areas. Implementing effective strategies to limit human exposure to the animal reservoir can help reduce the risk of Lassa virus transmission and the subsequent development of Lassa fever.
  • Discuss the role of ribavirin in the treatment of Lassa fever and analyze its effectiveness in controlling the growth and spread of the Lassa virus.
    • Ribavirin, an antiviral medication, is the primary treatment for Lassa fever. It has been shown to reduce the mortality rate if administered early in the course of the disease. By inhibiting viral replication, ribavirin can help control the growth and spread of the Lassa virus within the infected individual, potentially limiting the severity of the illness and reducing the risk of further transmission. The effectiveness of ribavirin in controlling the Lassa virus is crucial, as it can provide a therapeutic option to manage Lassa fever outbreaks and mitigate the public health impact of this viral hemorrhagic fever.
  • Evaluate the significance of proper infection control measures in healthcare settings in the context of Lassa virus transmission and discuss the potential consequences of inadequate infection control practices.
    • The Lassa virus can also be transmitted through person-to-person contact, particularly in healthcare settings. This highlights the critical importance of implementing proper infection control measures to prevent the spread of the virus within healthcare facilities. Inadequate infection control practices, such as the lack of personal protective equipment (PPE), improper disinfection procedures, or poor hand hygiene, can lead to the nosocomial (hospital-acquired) transmission of the Lassa virus. This can result in the amplification of outbreaks, increased morbidity and mortality among healthcare workers and patients, and the potential for the virus to spread beyond the initial healthcare setting, posing a significant public health threat. Evaluating and ensuring the effectiveness of infection control protocols is essential in controlling the growth and spread of the Lassa virus, particularly in high-risk healthcare environments.