National Monkeypox Surveillance, Central African Republic, 2001–2021

Abstract

M onkeypox, caused by monkeypox virus (MPXV), a member of the Orthopoxvirus genus, was considered a rare emerging disease before a multinational outbreak was identified in May 2022 (1).After global smallpox eradication in 1977, monkeypox became the most concerning human Orthopoxvirus infection. Clinical manifestations of monkeypox typically resemble those of smallpox, including a febrile prodrome and subsequent disseminated maculopapular rash, including vesicles and pustules, that occurs in successive stages (2). Lymphadenopathy is a prominent feature of monkeypox and usually does not occur for smallpox and chickenpox (3). Illness is less severe and death less likely among monkeypox cases than smallpox cases, but monkeypox mortality rates vary and are higher for clade I (formerly the Congo Basin clade) than for clade II (formerly the West African clade) viruses (2). Prior smallpox vaccination can confer cross-immunity for monkeypox, but smallpox vaccination programs worldwide ended in the early 1980s (4).In 1970, a human monkeypox case was reported from Basankusu, Equateur Province, Democratic Republic of the Congo (DRC) (5). Subsequent sporadic monkeypox cases were reported among human and animal populations from remote areas of Central Africa during the 1970s and 1980s (6,7). Since 1990, increases in the frequency and scale of epidemics in Africa have been reported for clade I and, to a lesser extent, since 2000 for clade II. Since 2016, confirmed monkeypox cases have been reported in DRC, Central African Republic (CAR), Republic of Congo (hereafter Congo), Nigeria, Sierra Leone, Liberia, and Cameroon (6). The true burden, circulation rates, and geographic range of this emerging disease remain unknown because many countries lack systematic routine monkeypox surveillance and affected areas often are remote (8,9).An outbreak of human monkeypox disease occurred outside Africa in 2003, after infected animals from Ghana were imported into the United States

Investigation of a mpox outbreak in Central African Republic, 2021-2022

“…This outbreak serves as a reminder of the severity of mpox infections in Central Africa, with complications in 65% of cases, and a case fatality rate of 4%. These findings are consistent with previous reports [ 2 , 3 ] and may partly reflect the greater severity of clade 1 infections than of infections with viruses from clades 2a [ 2 , 39 , 49 ] and 2b [ 36 , 41 ], the greater vulnerability of locally infected populations with a high proportion of children and immunosuppressed individuals [ 5 ], and the limited healthcare resources in these remote areas. The trend towards mpox disease causing larger epidemics in more connected parts of Central Africa is a matter of public health concern for this subregion and beyond.…”

“…This outbreak is the largest ever described in CAR in terms of the number of confirmed cases. In a recent report of 40 outbreaks since 2001 in this country [ 3 ], the median outbreak size was 3 (IQR: 1–5) cases. The size of this outbreak may be explained by the multiple (four) waves of inter-human transmission, exceeding the number of waves observed in previous outbreaks in CAR [ 21 ] and approaching the largest ever number of waves reported in a country in which mpox is endemic: seven, in DRC [ 14 , 15 ].…”

“…Sporadic independent hMPXV cases have also been reported in Cameroon, Côte d'Ivoire, Gabon, Sierra Leone, and Liberia [ 2 ]. The number of outbreaks has been increasing globally over the last few decades [ 2 ], and in CAR since 2018 [ 3 ]. An expansion of the affected geographic area towards sub-Sahelian savannah zones in Sudan has been observed since 2005 [ 4 ] and to urban areas in Nigeria since 2017 [ 5 ].…”

Identifying the Most Probable Mammal Reservoir Hosts for Monkeypox Virus Based on Ecological Niche Comparisons

“…However, the GPS coordinates of mpox cases were not provided in previous ENM studies [ 31 , 43 , 44 , 45 ]. All of the 103 human records used in our study are index cases of known village origin [ 11 , 12 , 14 , 15 , 16 , 17 , 21 , 34 , 35 , 45 , 46 , 47 , 54 , 59 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ], for which the GPS coordinates were recovered using Google Maps ( , accessed on 22 June 2022), OpenStreetMap ( , accessed on 22 June 2022), and Joint Operational Graphic (JOG) topographic maps. Most index cases reported in previous mpox epidemics in Central Africa were young boys living in remote villages surrounded by forests [ 90 , 91 ].…”

Identifying the most probable mammal reservoir hosts for Monkeypox virus based on ecological niche comparisons

“…However, the GPS coordinates of MPX cases were not provided in previous ENM studies [27,39–41]. All the 103 human records used in our study are index cases of known village origin [9,10,12–15,19,30,31,39,43,43,49,59–78], for which the GPS coordinates were recovered using Google Maps (https://www.google.fr/maps), OpenStreetMap (http://www.openstreetmap.org), and Joint Operational Graphic (JOG) topographic maps.…”