Abstract
Globally, hepatitis B virus (HBV) infection is a major global health problem, with an estimated 296 million infections worldwide, and about 5% of them had hepatitis delta virus (HDV) infection as well. Hepatitis D virus (HDV) infection is endemic in the Middle East. Hepatitis D virus (HDV) infection has been considered a serious neglected pandemic, particularly in developing Countries. Combined HDV-HBV infection produces more severe liver affection than HBV alone. Effect varies between coinfection and superinfection. In this book chapter, we will highlight four main points. Firstly, the prevalence of hepatitis D virus infection among HBsAg positive individuals globally and in MENA Region (Middle EAST and North Africa); secondly, the clinical, laboratory, and virological characters of HDV infected patients; thirdly, the need for improving the laboratory diagnostic tests and initiating patient data registries and blood screening; and lastly, the efficacy of new drugs for chronic hepatitis D on coinfected patients.