A systematic review of Crimean-Congo Haemorrhagic fever virus in Sub-Sahara Africa, 1969-2022
Authors: Shaibu Joseph Ojonugwa , Daodu Olufemi B. , Akinyemi Kabiru Olusegun , Audu Rosemary Ajuma , Bola Oyefolu Akeeb O. 
Published: November 2022

ABSTRCT

In Sub-Saharan Africa, CCHFV has been reported in some of the countries with resultant seroprevalences ranging from 1.65-44%, 0.37-75%, 19-74% amongst humans, ticks and cattle respectively using ELISA technique. Strains classified as Africa clade 1,2 and 3 have been established to be circulating in Sub-Saharan Africa from few molecular studies carried out. CCHFV has part of its nomenclature rooted in Africa, however, the actual spread of the virus across sub-Saharan Africa is poorly known. This paucity of knowledge is attributed to less work done in the quest to understand this virus better. Most researches, which were quite limited, carried out across Africa were on antibody detection using ELISA methods with little information on molecular characterization. The aim of this review is to harmonize the studies carried out in Sub-Saharan Africa on CCHFV between 1969 -2022 with respect to seroprevalence, viral identification and isolation, molecular characterization and genomic analysis. Articles are retrieved from public databases such as google search, PubMed, Google scholar and ResearchGate, filtered using PRISMA concept and data extracted from eligible articles and analyzed. In this study the overall average seroprevalence of CCHFV in Humans, Ticks, Cattle, sheep and Goats are 13.6%, 18.1%, 44.3%, 11.3%, 16.3% respectively. South Africa has the highest seroprevalence (20.8%) among humans and Uganda (2.5%) has the lowest. The prevalence of CCHFV in many African countries is still yet unknown though there is clear evidence of exposure of people within the region to CCHFV. Limitations in sensitivity and specificity of diagnostic techniques such as agar gel precipitation test, haemagglutination test and complement fixation test used at some instance suggest a need for more reliable techniques.

Author’s summary

Crimea-Congo haemorrhagic fever virus is carried by ticks. It has a high fatality rate among humans. It is implicated in haemorrhagic fever with bleeding through the nose and mouth. CCHFV is fast spreading across the world but little is known it in Sub-Saharan Africa. Many individuals in this region are herders, they are daily exposed to ticks; they regularly come down with febrile illnesses that are most times misdiagnosed as either malaria or typhoid. In the course of treating for malaria or typhoid, some die. There is no awareness ongoing in the communities about this infection and its danger to the population, preventive measures with respect to personal hygiene, cleanliness of the abattoirs and general environments and the need to seek medical attention and avoid self-medication. In this review it is shown that there is evidence of spread of CCHFV in Sub-Saharan Africa, however, there is paucity of information. This lack is as result of many factors such as lack of funds for research, porous security that makes it difficult tracing, lack of effective diagnosis of viral pathogens and so on.