Mpox was declared a global public health emergency by the WHO on 14 August 2024.1
This decision was based on the rapid spread of the mpox virus (MPXV) across many African countries, especially in the Democratic Republic of Congo (DRC) and its neighbouring countries.
This public health emergency of international concern (PHEIC) under the International Health Regulations (2005) (IHR) is the second in two years relating to mpox. The first declaration was in July 2022 and was triggered by a multi-country outbreak of mpox, which spread rapidly via sexual contact across a range of countries where the virus had not been seen before. That PHEIC was declared over in May 2023 after there had been a sustained decline in global cases.
This second PHEIC declaration was triggered by an increase in the number of cases in the past month when over 100 laboratory-confirmed cases of clade 1b have been reported in four countries neighbouring the DRC that have not reported mpox before: Burundi, Kenya, Rwanda and Uganda. Experts believe the true number of cases to be higher as a large proportion of clinically compatible cases have not been tested.
Mpox is caused by Orthopoxvirus, which belongs to the Poxviridae family. Other members of the family include viruses that cause smallpox (variola), cowpox, vaccinia and other viruses. The virus was originally discovered in 1958 in monkeys used for research in Denmark. Mpox can spread from person to person or occasionally from animals to humans (zoonotic transmission). The first reported human case occurred in a 9-month-old boy in the DRC in 1970. The disease is characterised by a painful rash, enlarged lymph nodes and fever. 2 3 4
The mpox virus, MPXV, is divided into two genetic clades – I and II. Clade I have been circulating for years in the DRC and several Central African countries. Clade II MPXV was confined in West Africa until the 2022-2023 global epidemic caused by the clade IIb-B.1 MPXV. As it waned, clade I MPXV infections began to rise, initially from zoonotic spillover and subsequently from human-to-human transmission. 2 3 5
Clade I MPXV is deadlier than clade II MPXV, and is associated with severe clinical symptoms and substantial mortality (4–11%). Clade Ib MPXV is responsible for the current epidemic in DRC. Children in DRC have borne the brunt, with 70% of cases and 87% of deaths occurring in those < 15 years old. While transmission occurs via close contact in children, among adults, it is via sexual transmission. Clade II causes less severe illness and lower mortality of <4%.
In humans, the virus is spread via physical contact with someone who is infectious, with contaminated materials, or with infected animals. Person-to-person transmission can occur through direct contact with infectious skin or other lesions as well as from respiratory droplets or aerosols from prolonged close contact. 2
As mpox is similar to chickenpox, measles, bacterial skin infections or other sexually transmissible infections, testing is the key to getting diagnosed and treated. Early detection prevents complications and the spread of the disease.
The WHO has recommended vaccination against the MPXV for individuals at high-risk exposure to the virus; currently, there are two WHO-recommended vaccines. Mass vaccination is not required.6 The infection can be treated with antivirals. Infected persons should isolate themselves as advised by the medical practitioner. Close contacts should monitor themselves for signs and symptoms of the disease for 21 days, and practise good hand hygiene and respiratory etiquette, such as when sneezing and coughing. It is best to avoid contact with immunocompromised people, children and pregnant women.
Generally, poxviruses, including MPXV, are very persistent. They show extraordinary resistance to drying and a higher temperature and pH tolerance. They have long-lasting stability in the environment and can be detected on household surfaces at least 15 days after exposure. However, they are sensitive to common disinfectants, though less sensitive to organic disinfectants.
MPXV continues to spread globally. Overall, 116 countries, including Malaysia, have reported cases.7 8 Malaysia has reported a total of 9 cases, including one in Sarawak in 2023.9 The WHO continues to urge countries to monitor the spread of the disease. The agency also advocates for equitable access to mpox diagnostics, vaccines, supplies for clinical care and other related tools.
Image credit: Featured imaged is created by Gerd Altmann and downloaded from Pixabay.
Reference:
- WHO declares mpox virus a public health emergency of international concern. UN News https://news.un.org/en/story/2024/08/1153176 (2024).
- Mpox (monkeypox). World Health Organization (WHO) https://www.who.int/news-room/fact-sheets/detail/monkeypox (2023).
- Vakaniaki, E. H. et al. Sustained human outbreak of a new MPXV clade I lineage in eastern Democratic Republic of the Congo. Nat. Med. (2024) doi:10.1038/s41591-024-03130-3.
- Mpox Caused by Human-to-Human Transmission of Monkeypox Virus in the Democratic Republic of the Congo with Spread to Neighboring Countries. Aug 7, 2024. at https://emergency.cdc.gov/han/2024/han00513.asp (2024).
- Factsheet for health professionals on mpox (monkeypox). European Centre for Disease Prevention and Control (ECDC) https://www.ecdc.europa.eu/en/all-topics-z/monkeypox/factsheet-health-professionals (2023).
- Vaccines and immunization for monkeypox: Interim guidance, 16 November 2022; 24 August 2022. at https://www.who.int/publications/i/item/WHO-MPX-Immunization (2022).
- Johnson, D. Mpox is still being transmitted across the world, says UN health agency. United Nations https://news.un.org/en/story/2024/08/1153141 (2024).
- 2022-24 Mpox (Monkeypox) Outbreak: Global Trends World Health Organization. Produced on 02 August 2024. World Health Organization (WHO) https://worldhealthorg.shinyapps.io/mpx_global/ (2024).
- Yusry, M. Deputy health minister: Nine monkeypox cases detected in Malaysia since July this year. Malay Mail https://www.malaymail.com/news/malaysia/2023/11/29/deputy-health-minister-nine-monkeypox-cases-detected-in-malaysia-since-july-this-year/104818 (2024).