Hepatitis A and E: not to be forgotten.

2014 
The World Health Organization (WHO) estimates that every year hepa -titis A virus (HAV) infection causes nearly 1.4 million new cases worldwide and the hepatitis E virus (HEV) is re-sponsible for 20 million new infections and over 3 million acute cases. Although in most cases HAV and HEV infections are self-limiting, HAV is estimated to kill 100 000 people each year [1] and HEV nearly 60000 people annually [2]. Pregnant women are at risk of more severe disease, obstetric complications and increased mortality if infected in the third trimester of pregnancy. The faecal–oral route is a well-established mode of transmission for both HAV and HEV and in the case of HEV infec-tion person-to-person transmission is also an important factor in sporadic cases [3]. Outbreaks of HAV and HEV are therefore manifestations of the poor sanitation practices and lack of clean water supplies often found in developing countries. Humanitarian crises with large refugee populations can also be fertile ground for hepatitis outbreaks alongside cholera or other waterborne outbreaks, as was recently seen among Syrian refugees in Iraq [4]. Understanding the importance of the risk of hepatitis outbreaks in displaced populations can help in identifying out-breaks quickly and responding to them in a timely manner to reduce mortality and morbidity. HAV has 7 genotypes, with little variation in their clinical expression. HEV has 4 genotypes with quite differ-ent clinical expressions, responsible for different disease manifestations across developing and developed countries. In developing countries genotype 1 is largely responsible for outbreaks and sporadic cases, via contamination of water and the fecal–oral route. Excep-tions include Mexico in South America and countries in Africa, where genotype 2 is more common [5]. Neither HAV nor HEV have chronic states, although HEV is reported in immunocompro-mised people [6]. Acute HAV infection is often clini-cally indistinguishable from other caus-es of acute viral hepatitis, and laboratory confirmation is necessary. Diagnosis of HEV has its own challenges, which may result in an underestimation of the disease burden [6]. HAV has a very effective vaccine available, and the first vaccine for HEV was approved in China in December 2011, although it is not yet used in any other countries. Whereas HAV seroprevalence increases with age and comes close to 100% in highly endemic countries by the age of 5 years, HEV seroprevalence tends to stay be-tween 5%–60% [7]. In 2010, the WHO World Health Assembly adopted resolution WHA63.18, which called for the pre-vention and control of viral hepatitis, with a focus on HBV and HCV [8]. This resolution came after Member States and WHO understood the gravity of spread of viral hepatitis. In 2012, on the occasion of World Hepatitis Day, Dr Ala Alwan, WHO Regional Director for the Eastern Mediterranean, urged all stakeholders to combine their efforts to confront and combat this silent epi-demic of hepatitis. Many countries of the Eastern Mediterranean Region (EMR) are cur-rently going through major social and political upheavals. With active or proxy wars engulfing many countries in the Region, the public health structures are under stress, creating ideal conditions for the spread of all infectious diseases, especially those spread by contaminated water and lack of sanitation services. Except for a few published articles and outbreak reports, however, very limited data are available about the prevalence of HAV and HEV from these countries or from the Region in general [9–12]. One major reason for this knowledge gap is that we are not looking for the evidence. In most developing countries, including most of those of the EMR, HEV is not routinely considered when a physician asks for investigations into a suspected case of viral hepatitis. Added to the diagnostic challenges is the fact that a majority of hepatitis-infected per-sons do not develop an acute condition that requires major health care interven-tion. HAV is in the same class, with few symptomatic cases reaching health-care settings, and as it is self-limiting in most cases, it is neither investigated nor re-ported to surveillance systems as HAV. Physicians also do not consider HAV or HEV to be serious illnesses, even though fulminant hepatitis, hepatic failure and death can occur from both infections.More than 40% of the population of the EMR lives in just 2 countries, Egypt and Pakistan, both of which are consid-ered endemic for HBC and HCV [8]. In Pakistan, the Field Epidemiology Labo-ratory Training Programme is collecting information about acute viral hepatitis cases via 5 sentinel sites throughout the country [13]. According to reports from the Pakistan viral hepatitis surveillance system HAV—responsible for more
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