Freetown (The Conversation)- On June 17, 2025, more than 4000 confirmed MPOX and 25 deaths in Sierra Leone were identified, which increases the risk that the virus spread to neighboring countries and triggers a larger epidemic in all this densely populated region of West Africa. In Sierra Leone, the disease spreading from one person to another, mainly in young men and women.
The Conversation Africa questioned Jia Kangbai, an epidemiologist specializing in infectious diseases at Njala University of Freetown on the causes of this resurgence and how it can be stopped.
MPOX (formerly called “monkey variole”) is a disease caused by the monkey’s smallpox virus. It belongs to the Orthopoxvirus family, which also includes smallpox and chickenpox. Initially, the recognized transmission mode was close physical contact with an infected person. With the emergence of various subclades (Clades 1A and 1b, Clades 2a and 2b) of the MPXV, the sexual transmission of MPOX has been documented in several studies.
What is behind the recent epidemic in Sierra Leone?
The first identified case of the current MPOX epidemic in Sierra Leone is a young man with documented immunodeficiency who had gone to the city of Lungi, in the north of the country, in December 2024 to spend the Christmas holidays with his wife. Two days after his arrival in Lungi, he had unprotected sex with a hotel employee, then developed a high fever, muscle and bodily pain, as well as swelling of the lymph nodes. He was then transferred to the capital, Freetown, where he was diagnosed positive with MPOX. He was then admitted to the Connaught Hospital in Freetown, where he was successfully treated.
Sierra Leone International Airport is located in Lungi. The city is also very busy by international tourists. The current epidemic may have been imported from another country in West Africa. It is also possible that cryptic transmission of the MPXV is in progress in Sierra Leone. Cryptic transmission is a situation in which the virus circulates at such a low level within a population that it is difficult to identify the source when an epidemic declares itself.
As part of our current study in Sierra Leone, we carry out the genomic sequencing of samples taken from this index case in order to determine the source of the MPOX epidemic.
It is a laboratory method used to determine the complete genetic composition of an organism or a specific cell type.
This method can be used to detect changes in certain areas of the genome. These changes can help scientists understand how certain diseases are developing. The results of the genomic sequencing can also be used to diagnose and treat disease.
Should Sierra-Léonais worry about MPOX?
The Sierra-Léonais are visibly worried about the increase in the number of cases and deaths linked to the MPOX recorded during the four months of active surveillance of the disease. What worries most Sierra-Léonais more today is the growing number of sex workers and people with multiple sexual partners who declare that they have contracted MPOX.
Most cases of MPOX in Sierra Leone belong to these groups. This means that to effectively stem the MPOX epidemic in Sierra Leone, special attention must be paid to these groups.
What emergency measures should be put in place to stem the spread?
The emergency measures implemented by the National Public Health Agency include:
- targeted vaccination of populations at risk
- Active surveillance
- Searching for contacts
- quarantine, and
- Effective communication on risks, in particular the sharing of essential health information in order to allow individuals to make informed and positive decisions concerning their safety and personal health.
The effectiveness of these measures is questioned due to the lack of resources. As of June 17, more than 4,000 confirmed cases and 25 deaths were identified, most of the patients being healing. But the number of MPOX screening sites is very limited throughout the country. But in a situation of an epidemic also evolving, the speed is essential. The small number of laboratories lengthen the deadlines between the sampling of samples and the obtaining of the results. This poses a big problem in a country of more than 8 million inhabitants, many of which live in distant areas.
What is the risk of regional spread?
The sub-region of West Africa should be concerned with a spread. The countries of West Africa share very close cultures, which indicates that they have the same origin. In addition, there is significant trade and trafficking in human beings and goods throughout the sub-region, which facilitates the export of MPOX cases.
Liberia, Guinea and Sierra Leone are so interconnected in various fields that everything related to a country affects others. We saw it, in December 2013, when the Ebola epidemic began in Guinea, it quickly spread to Sierra Leone, Liberia and other non -African countries.
At the beginning of June 2025, Liberia had recorded 69 cases of MPOX, while no case had been reported in Guinea. Ghana had reported 98 to 16 June.
Among the strategies that neighboring countries can implement, include strengthening cross -border surveillance at their different borders and carrying out tests for suspicious and probable mpox cases. In addition, they can embark on active surveillance of cases and the search for contacts within their country.
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