Serological evidence of rift valley fever Phlebovirus and Crimean-Congo hemorrhagic fever orthonairovirus infections among pygmies in the east region of Cameroon

Abstract

BackgroundRift Valley Fever Phlebovirus (RVFV) and Crimean-Congo Hemorrhagic Fever Orthonairovirus (CCHFV) specific antibodies had been documented among humans in urban settings of the southwestern and northern Cameroon in the late 1980s. Recently, evidence for enzootic circulation of RVFV was reported among livestock in both rural and urban settings in Cameroon. However, current estimates of human exposure to RVFV and CCHFV are still to be documented in Cameroon, especially in rural areas. The aim of this study was to assess the seroprevalence of RVFV and CCHFV in rural settings in the Southeastern rain forest of Cameroon.ResultsUsing Enzyme-linked Immunosorbent Assays, the presence of RVFV and CCHFV Immunoglobulin G antibodies was investigated in plasma samples originating from 137 Pygmies from four villages of the East region of Cameroon. The studied population was found to be 12.4% (17/137) and 4.4% (6/137) seropositive for RVFV and CCHFV, respectively. The rates of RVFV IgG were comparable between the age groups and sex. Conversely, the rate of CCHFV IgG was significantly higher among the 41–60 years old participants (p = 0.02).ConclusionsThis study provides a substantial evidence of the circulation of RVFV and CCHFV among rural inhabitants of the East region of Cameroon.

Risk factors associated with exposure to Crimean-Congo haemorrhagic fever virus in animal workers and cattle, and molecular detection in ticks, South Africa

“…An increase in seroprevalence over time is possible but must be cautiously interpreted due to geographic variations between the studies, demographics and testing methods, as ELISAs are more sensitive than the immunofluorescence assays used previously and therefore we likely had fewer false negatives [ 48 , 49 ]. Human seroprevalences reported elsewhere in rural Africa ranged from 4.4% in Cameroon in 2005–12 [ 50 ] to 13.1% in Senegal in 1989 [ 51 ]. We also identified an expected association with seroprevalence and age among the farmers.…”

Crimean–Congo Hemorrhagic Fever Virus: Advances in Vaccine Development

“…African countries from which CCHF has been reported include Burkina Faso, Central Africa Republic, Democratic Republic of Congo, Egypt, Kenya, Mauritania, Namibia, Nigeria, South Africa, Senegal, Sudan, Tanzania, and Uganda 1,[7][8][9][10][11][12][13][14][15][16] and countries yet to report CCHF but with evidence of viral circulation either from serological surveys or CCHFV isolation from ticks include Algeria, Benin, Cameroon, Equatorial Guinea, Ethiopia, Ghana, Guinea, Mali, Madagascar, Morocco, Mozambique, Niger, Somalia, Tunisia, and Zimbabwe. 1,[17][18][19][20][21][22][23][24][25][26][27][28][29][30] The presence of CCHFV in Somalia was suggested after evidence of the CCHFV in Hyalomma ticks obtained from Somali cattle and sheep exported to the United Arab Emirates. 28 In the Middle East, the disease has been described in Iran, Iraq, Saudi Arabia, Oman, and the United Arab Emirates.…”

Geographical Variability Affects CCHFV Detection by RT–PCR: A Tool for In-Silico Evaluation of Molecular Assays

“…Moreover, pairwise distances between sequences were calculated using the Kimura model. In agreement with previous works, branch positions, pairwise distances, and collection countries were used to identify separate CCHFV clades within the phylogenetic tree [5,9,10,11,12,13,14,15,16,17,18,19,20,21,22].…”

“…Based on geographical origin and phylogenetic analyses of the S gene segment, CCHFV has been previously classified into six main geographical clades [4]—three predominantly diffused in Africa (Clades I-III) [9,10], two in Europe (Clades V and VI) [11,12,13], and one in Asia (Clade IV) [14,15,16,17].…”