Monkeypox virus outbreaks in the African continent: A new zoonotic alert – Correspondence

Dear Editor,

A new outbreak of monkeypox has emerged globally as the health system is recuperating from the devastating effects of the corona pandemic and as we all fear the probable emergence of another wave of COVID-19 in such a pandemic-weary world. The monkeypox virus, which causes the disease, is a zoonotic, double-strand enveloped DNA virus, and is a member of Poxviridae family under the genus of Orthopoxvirus. Its symptoms, which include rash, headache and fever, are comparable to but less severe than those of smallpox, a related disease that was eradicated through vaccination campaigns by May 1980 [1]. Director-General of the World Health Organization (WHO) declared the multi-country monkeypox outbreak as a public health emergency of international concern on July 23, 2022 [2].

The monkeypox virus spreads primarily through close and intimate contact with someone who has the disease, particularly through contact with bodily fluids, lesions on the skin or internal mucosal surfaces, such as in the mouth or throat, as well as respiratory droplets and contaminated objects. According to current data, the majority of cases in the current monkeypox outbreak are believed to be among gay, bisexual, and other men who have sex with men. However, anyone who has had close, personal contact with a person who has monkeypox, regardless of sexual orientation or gender identity is at risk [3].

The current monkeypox outbreak has been reported by more than 87 countries where monkeypox is not endemic, and globally as of 19 August 2022, confirmed cases surpassed 41,358 with almost 99% of which are in countries that have never historically reported the disease, and in non-endemic countries reported their first related deaths [3]. Monkeypox does not have a drug or vaccine. It is commonly treated by managing symptoms and preventing or improving complications. However, currently in some countries, such as USA, a smallpox vaccine called JYNNEOS has been recommended for preexposure vaccination of occupationally exposed individuals to monkeypox virus [4]. Besides, other types of vaccines are also under assessment for current use. Studies reported that a vaccine prepared against smallpox is more than 85% protective against monkeypox. In addition, the European Medical Association has recently approved tecovirimat, a drug for smallpox to be used for the treatment of monkeypox in 2022 [5,6].

Monkeypox is endemic in Central and West Africa, though the true burden of the disease is not well known. The first documented monkeypox case was in the Democratic Republic of Congo in 1970 [7]. Phylogenetically monkeypox virus has two clades (subtypes) which are geographically, epidemiologically and clinically diverse: the central African (Congo Basin) clade and the west African clade. Of these two clades, the Congo basin, which remains endemic in the Democratic Republic of Congo, is more transmissible, causes more severe disease, and has a higher case fatality rate (CFR) up to 11% with documented human-to-human transmission [8,9]. In comparison, the West African clade shows a CFR <1%, and no human-to-human transmission was ever documented [10].

The West African clade isolates came from outbreaks in Liberia, Nigeria, Sierra Leone, Ivory Coast, and United States of America (primarily imported from Ghana), whereas the Central African clade isolates originated from Central African Republic, Cameroon, Gabon, Sudan, and the Democratic Republic of Congo [11]. The Congo Basin clade is more prevalent than the West African clade, according to data currently available, since it is endemic in the Democratic Republic of Congo, where more than 2000 cases are reported every year [12].

Monkeypox virus outbreaks have historically increased since 1970, but have principally been contained within Africa. A significant number of monkeypox confirmed cases have been reported from the equatorial Central and West African countries including Cameroon, Democratic Republic of Congo, Liberia, Côte d'Ivoire, Ghana, Nigeria, and Sierra Leone from 1970 to 2018, with peak mortality rates approaching 10% [13,14], This is probably an undercount because of limited testing and surveillance capacity in the African health system. In an African setting, the monkeypox virus can be misdiagnosed with other illnesses involving a rash, as evidenced by 50% of suspected monkeypox cases in the Democratic Republic of Congo being misdiagnosed as chickenpox, which is caused by Varicella-zoster virus [15].

Monkeypox in its current form pertains to characteristic symptoms (skin rash) and rarely spreads asymptomatically, unlike COVID-19. Nonetheless, the current abrupt worldwide outbreak raises concerns that the virus may undergo potential genotypic mutations, which could result in high virus transmissibility or increased severity of the disease [16]. These issues raise concerns about the additional burden on the already hampered health system worldwide, particularly in the developing nations of Africa. Before this year, only a few monkeypox cases had been reported outside Africa; all of them were related to animal imports from the African continent or to travelers who had visited the endemic areas. Principally, these outbreaks in non-endemic countries were short-lived [17]. However, the current spread seeks special attention despite the mild clinical course and low contagion rate, and thus monkeypox should be considered as a potential threat, especially to the already drained health care system in the African continent.

The fact that some African nations have been dealing with monkeypox outbreaks ever since the first detection of the human case in the Democratic Republic of the Congo in 1970 is overlooked. The world seems to divert its eyes to the monkeypox outbreak by the time it starts spreading to the Western nation. Although African clinicians are frustrated by monkeypox having been largely ignored by Western nations until now, it is worrisome that the current global outbreaks still will not improve the situation for Africa [18]. This assumption is mainly due to the limited vaccine and treatment resources. It is clear that there is high hope of using approved drugs and vaccines for the smallpox virus to deal with the current monkeypox outbreak; however, it will not be an easy task to control or treat newly emerging monkeypox cases. This is largely due to the unavailability of large stocks of the vaccine or drug given the stoppage of smallpox vaccination and treatment programs during the past 5 decades. The vaccines are only available at the CDC national stockpile. Therefore, such countermeasures are not readily available in the meantime; even if they do, their immediate access to the African nations will be a big question. Furthermore, the common management of bulk monkeypox cases will be difficult in the African continent simply because the health system is not well developed. There are even African countries that do not establish monkeypox laboratory detection facilities yet. As a result, the outbreak is very likely to spread to the remaining non-endemic African countries, or who knows whether it has already occurred and been misdiagnosed.

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Not commissioned, internally peer-reviewed.

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Not applicable as no animal study was conducted.

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No funding.

Author contribution

Melaku Ashagrie Belete: Conceptualization, Data curation, Writing-Original draft preparation. Madhavan Yasasve: Data curation, Writing-Original draft preparation. Muthupandian Saravanan: Conceptualization, Writing-Reviewing and Editing, Visualization and Supervision.

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Guarantor

Muthupandian Saravanan.

Data statement

All data are available in the manuscript.

Declaration of competing interest

Authors declare that they have no conflicts of interest.