A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
After the 2023 Equatorial Guinea Marburg virus (MARV) outbreak, surveillance of 181 persons in southern Cameroon detected MARV antibodies in 3 persons and Ebola virus antibodies in 7. Testing of 289 captured bats, including 158 Rousettus aegyptiacus bats, did not detect MARV RNA. Enhanced surveillance for regional filovirus spillover risks is warranted.
Marburg virus (MARV) and Ravn virus cause Marburg virus disease (MVD), a severe hemorrhagic fever with high case-fatality rates. MARV was first identified in 1967, and 20 MVD outbreaks have been documented since and are increasing in frequency ( 1 ). The Egyptian rousette bat ( Rousettus aegyptiacus ) is a natural reservoir for both viruses ( 2 ). Several outbreaks were epidemiologically linked to exposures in caves or mines harboring rousette bat colonies ( 3 , 4 ). The source of many index cases, including the 2023 Equatorial Guinea outbreak, remains unidentified ( 5 ).
On February 13, 2023, Equatorial Guinea declared its first MVD outbreak in Kie-Ntem Province with 15 confirmed cases and 11 deaths, a 73% case-fatality rate; another 23 probable cases all resulted in death. The cases occurred across 5 transmission chains from 1 viral infection. The outbreak ended on June 8, 2023 ( 5 , 6 ).
Southern Cameroon shares a border and extensive cross-border movements with Kie-Ntem Province, but MVD risk in Cameroon remains undefined. We conducted integrated One Health surveillance in Cameroon border communities to assess filovirus circulation risk through human seroprevalence surveys, bat sampling, and environmental investigations.
Figure 1 . Study area of One Health surveillance for MARV in communities bordering Equatorial Guinea Marburg outbreak, Cameroon, 2023. A) Locations in Equatorial Guinea with confirmed and probable MVD cases during the...
We conducted cross-sectional seroepidemiologic surveys in 14 villages and settlements in the Olamze district, southern Cameroon, at the Equatorial Guinea border, during July–August 2023, ≈1 month after the outbreak conclusion ( Figure 1 ; Appendix Figure 1 ). We enrolled 181 volunteer participants through household visits. We documented symptoms and MARV exposures that occurred 3 weeks before enrollment. We detected filovirus-specific antibodies by using a multiplex bead-based immunoassay ( 7 ). For MARV antigens (nucleoprotein [NP], glycoprotein 1 [GP1], and 40-kDa viral protein [VP40]), we established cutoffs as mean + 3 SD of 92 seronegative reference samples from unexposed persons. We defined human seropositivity as reactivity to > 2 antigens above established cutoffs ( Appendix Table 1).
Volunteer participants were a mean age of 48 years (range 6–80 years); 76 (42%) were female and 105 (58%) male. Recent symptoms were reported by 27% (n = 49) of participants; 13% (n = 24) reported fever, 12% (n = 21) reported headaches, 10% reported myalgia, and 9% reported extreme fatigue. One child reported mild epistaxis (0.6%) ( Appendix Table 2).
Ten percent (n = 18) of participants traveled to Equatorial Guinea within 3 weeks before enrollment. Four (2.2%) participants had contact with persons experiencing fever, fatigu…