Mpox Outbreak in Sierra Leone: Causes, Risks, and Preventive Measures

As of June 17, 2025, Sierra Leone has reported over 4,000 confirmed mpox cases and 25 fatalities, highlighting an alarming rise in infections across the country. This surge raises concerns about potential regional implications, especially given Sierra Leone's proximity to neighboring West African nations and its status as a key transit point at Lungi International Airport. The virus, which is causing this recent outbreak, appears to be spreading predominantly through person-to-person contact, mainly affecting young men and women engaged in high-risk behaviors such as commercial sex work and multiple partnerships.

Mpox, also known as monkeypox, is caused by the mpox virus, a member of the Orthopoxvirus genus that includes smallpox and chickenpox. Historically, transmission occurred mainly through close physical contact with infected individuals. However, recent studies have documented sexual transmission, indicating evolving patterns of contagion.

The current outbreak in Sierra Leone traces back to a young man with a compromised immune system who traveled to Lungi, a bustling town with significant international traffic, to spend Christmas in December 2024. After engaging in unprotected sex with a hotel worker, he developed symptoms such as fever, muscle pain, and swollen lymph nodes. Confirmed positive for mpox at Freetown’s Connaught Hospital, he received treatment and recovered. The case suggests the possibility that the virus was either imported or has been circulating cryptically within the population at low levels.

To identify the source, health authorities are conducting genomic sequencing on collected specimens, a laboratory technique that deciphers the entire genetic makeup of the virus. This helps scientists understand its origin and monitor mutations, aiding in diagnosis, treatment, and containment strategies.

Sierra Leone’s increased cases and fatalities have led to heightened public concern, particularly among populations involved in high-risk behaviors. The government has implemented emergency measures, including targeted vaccination, active surveillance, contact tracing, quarantine, and risk communication efforts. Nevertheless, resource limitations pose challenges, such as a limited number of testing sites and delays in processing samples, which hamper swift containment.

The expanding mpox outbreak poses a significant threat of regional spillover. West African nations share cultural, trade, and travel ties, facilitating the virus's cross-border spread. Liberia has reported 69 cases, while Ghana has seen 98. Countries can enhance their preparedness through increased border surveillance, testing, active case detection, and contact monitoring.

This situation underscores the importance of regional cooperation and strengthened health infrastructure to prevent broader outbreaks. Vigilant monitoring, public education, and resource allocation are crucial to curbing the spread of mpox in Sierra Leone and neighboring countries.

Source: https://medicalxpress.com/news/2025-06-mpox-sierra-leone-surge-west.html