**7. Genotypic distribution of HBV**

Hepatitis B virus until now has been reported to have 10 genotypes (A–J) with identified peculiar distribution based on regions to its high degree of genetic heterogeneity [5, 60–62]. HBV genotyping is significant in diverse ways. First, it provides global data on the genotypic distribution of the virus including phylogenetic and phylogeographic evidence. Second, it justifies the relationship between the viral strain and course of disease. It makes us understand the role of human migration on the evolution of the virus [63, 64].

One of the three genotypes A, D, and E is predominantly circulating in Africa depending on the country. Genotype A is found in the Southern and Eastern regions, and genotype D is predominantly circulating in the Northern Africa region. Genotype E is more in most of SSA regions including Nigeria; this report excludes Uganda and Cameroon which are predominant with the A genotype [5, 60, 64, 65]. Genotype A is prevalent in Europe and Southeast Asia, including the Philippines [43, 66]. Genotypes B and C are predominant in Asia [67]; genotype D is common in the Mediterranean area, the Middle East, and India; genotype F is common in Central and South America [66]. Genotype G has been identified in Germany and France [67]. Genotype I has been detected in Laos, Vietnam, and China [68, 69], while the newest genotype J was identified in the Ryukyu Island in Japan [70, 71].
