journal article
LitStream Collection
Monkeypox is an outbreak of international concern
doi: 10.1093/trstmh/trac082pmid: 36088279
On 6 May 2022, a case of monkeypox was reported in the UK. Within 2 weeks further cases had been reported in numerous European countries and subsequently around the world. An international case series1 reported that >98% of cases were in men who identified as gay, bisexual or other men having sex with men (GBMSM). Many patients reported classic symptoms of fever and lethargy, myalgia and headache, lymphadenopathy and the characteristic vesiculopustular rash. However, some cases reported little or no systemic features and unusual rash presentations, often limited to the oral or genital region, with prominent severe pain. Public health authorities moved swiftly to institute case detection, isolation and treatment and contact tracing, together with extensive community engagement. Most cases can be managed in the community, only 10–15% require outpatient support or admission to hospital2 and most cases recover fully within a few weeks. Vaccination with MVA-BN (Imvanex/Jynneos), a live replication-defective modified vaccinia Ankara vaccine,3 has been offered to contacts of confirmed cases, ideally within 4 d of exposure, and to high-risk individuals, including those living with HIV.4 However, even with these measures the epidemic has continued to spread and by 29 July there had been >22 000 cases globally in 79 countries.5 The overwhelming predominance of cases in men has persisted, with few confirmed cases in women and children. The mortality rate has been low with 10 deaths reported in 2022 (five of which have been outside Africa). Monkeypox naturally occurs in west and central Africa, mostly in humans reporting close contact with small rodents or squirrels in forested areas. It is caused by infection with the monkeypox virus, an orthopox virus related to variola (smallpox). Reported cases have been increasing in range and numbers since the 1970s, especially in the Democratic Republic of Congo (DRC) and Nigeria, with at least a 10-fold rise, which is thought to be partly related to waning of the immunity provided by routine smallpox vaccination that ceased in the 1980s.6 Cases outside Africa in the past have been reported rarely and have been related to international travel or the importation of infected animals from endemic countries. Human-to-human transmission outside Africa has been minimal, probably due to prompt recognition of cases and stringent isolation measures. The current epidemic is therefore unprecedented. The most likely reason for this is that the virus has exploited a niche where it can flourish. Transmission occurs through close contact: skin-to-skin, fomites or respiratory droplets, and anyone in close contact with a case is susceptible. Enhanced surveillance in England shows that the infection has predominantly been transmitted in extensive sexual networks of GBMSM.7 A large proportion of cases report attendance at festivals and sex-on-premises venues in the UK, mainly London, Spain, Belgium and Israel. Close contact associated with sex with multiple partners would be sufficient to drive the epidemic, although it is possible that some transmission is sexual as live productive virus was found in the semen of one case on day 6 after onset of symptoms.8 There is also some evidence that the virus may have mutated. Cases in the 2022 epidemic are in a distinct clade, with suggestions that there may have been unrecognised human-to-human transmission before May, but it is unclear whether the virus has adapted to become more transmissible.7,9 Analysis of samples from cases in the DRC indicate a possible correlation between genetic changes and human-to-human transmission.6,10 The WHO convened an Emergency Expert Committee on 23 June that concluded the monkeypox outbreak did not constitute a Public Health Emergency of International Concern (PHEIC), the highest level of alert. The committee urged intense public health response efforts and a review of the situation in a few weeks. The committee met again on 21 July and did not reach consensus. Two days later, Dr Tedros Ghebreyesus, Director General of the WHO, declared the outbreak a PHEIC, stating ‘We have an outbreak that has spread around the world rapidly, through new modes of transmission, about which we understand too little and which meets the criteria in the International Health Regulations’.11 Some of the considerations of the expert committee against declaring a PHEIC were that the necessary tools for control were known and available, and that case numbers appeared to be levelling off in the countries with the most advanced outbreaks. The severity of the disease was perceived to be relatively low, and there was concern that increasing the profile of the epidemic might exacerbate stigma and discrimination against the communities most at risk. There is also an underlying concern about the message that declaring a PHEIC would send about global health priorities if a disease that has been steadily increasing in Africa for decades is only declared an emergency when it affects rich countries in Europe and the Americas. It is anticipated that the declaration of a PHEIC will increase international coordination, galvanise the response and raise awareness among health workers and the communities at risk. Work is needed to reduce stigma and discrimination, as in many countries GBMSM are marginalised and even criminalised, and this may drive cases and transmission underground if patients are too scared to present themselves. Research is needed urgently to better understand how the infection is transmitted from person to person, and also whether humans might infect animals, leading to a reservoir of infection in animals outside Africa. We need to work to improve access to rapid diagnostic tests and measure the effectiveness of antiviral drugs and vaccine regimens. An important benefit will be if this increases capacity in west and central Africa for surveillance and response for monkeypox and other diseases with epidemic potential. Supplies of monkeypox vaccines need to be expanded and distributed in an equitable fashion. We need to learn the lessons of the importance of global solidarity from the recent COVID-19 pandemic. Author's contributions: JW has undertaken all the duties of authorship and is guarantor of the paper. Funding: None. Competing interests: The author declares there are no competing interests. Ethical approval: None. Data availability: None. References 1 Thornhill JP , Barkai S, Walmsely S et al. Monkeypox virus infection in humans across 16 countries—April–June 2022 . New Engl J Med . 2022 ; doi: 10.1056/NEJMoa2207323. Google Scholar OpenURL Placeholder Text WorldCat 2 United Kingdom Health Security Agency (UKHSA) . Investigation into monkeypox outbreak in England: technical briefing 3 . 2022 . Available at https://www.gov.uk/government/publications/monkeypox-outbreak-technical-briefings/investigation-into-monkeypox-outbreak-in-england-technical-briefing-3 [accessed 29 July 2022] . OpenURL Placeholder Text WorldCat 3 Pittman PR , Hahn M, Lee HS et al. Phase 3 efficacy trial of modified vaccinia Ankara as a vaccine against smallpox . New Engl J Med . 2019 ; 381 ( 20 ): 1897 – 908 . Google Scholar Crossref Search ADS PubMed WorldCat 4 UKHSA . Monkeypox contact tracing classification and vaccination matrix. V11.1 (25 July 2022) Monkeypox contact tracing guidance: classification of contacts and advice for vaccination and follow-up . Available at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1093527/monkeypox-contact-tracing-classification-and-vaccination-matrix-version-11.1-25-July-2022.pdf [accessed 29 July 2022] . OpenURL Placeholder Text WorldCat 5 US Centers for Disease Control and Surveillance 2022. Monkeypox Outbreak Global Map. Available at https://www.cdc.gov/poxvirus/monkeypox/response/2022/world-map.html [accessed July 29, 2022] . 6 Bunge EM , Hoet B, Chen L et al. The changing epidemiology of human monkeypox—A potential threat? A systematic review . PLoS Negl Trop Dis . 2022 ; 16 ( 2 ): e0010141 . Google Scholar Crossref Search ADS PubMed WorldCat 7 UKHSA. Investigation into monkeypox outbreak in England: technical briefing 4. 2022. Available at https://www.gov.uk/government/publications/monkeypox-outbreak-technical-briefings/investigation-into-monkeypox-outbreak-in-england-technical-briefing-4 [accessed 29 July 2022] . OpenURL Placeholder Text WorldCat 8 Lapa D , Carletti F, Mazzotta V et al. Monkeypox virus isolation from a semen sample collected in the early phase of infection in a patient with prolonged seminal viral shedding . Lancet Infect Dis . 2022 ; https://doi.org/10.1016/S1473-3099(22)00513-8. Google Scholar OpenURL Placeholder Text WorldCat 9 UKHSA. Investigation into monkeypox outbreak in England: technical briefing 1. 2022 . Available at https://www.gov.uk/government/publications/monkeypox-outbreak-technical-briefings/investigation-into-monkeypox-outbreak-in-england-technical-briefing-1 [accessed 29 July 2022] . OpenURL Placeholder Text WorldCat 10 Kugelman JR , Johnston SC, Mulembakani PM et al. Genomic variability of monkeypox virus among humans, Democratic Republic of the Congo . Emerg Infect Dis . 2014 ; 20 ( 2 ): 232 – 9 . Google Scholar Crossref Search ADS PubMed WorldCat 11 World Health Organisation . Second meeting of the International Health Regulations. 2005 . IHR Emergency Committee regarding the multi-country outbreak of monkeypox. Available at https://www.who.int/news/item/23-07-2022-second-meeting-of-the-international-health-regulations-(2005)-(ihr)-emergency-committee-regarding-the-multi-country-outbreak-of-monkeypox [accessed 2 July 2022] . OpenURL Placeholder Text WorldCat © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.