The World Health Organization (WHO), alongside the Centers for Disease Control and Prevention (CDC), and other organizations including the Pakistan Field Epidemiology Laboratory Training Program (FELTP) all joined forced to produce the first of its kind manual on Hepatitis E outbreaks. This manual aims to provide information about methods used for investigating outbreaks of Hepatitis E, while also listing measures used for the disease’s prevention and control. It also serves as a reference source about the causative agent – known as the hepatitis E virus (HEV), while offering a description of its epidemiology and the clinical manifestations of the disease and diagnosis.
It is anticipated that the manual will especially be of use to those who may be involved in planning and executing responses to Hepatitis E outbreaks. It serves field specialists working in communities or refugee settings. The manual is also set to especially offer valuable information to public health authorities and health-care workers. It may also be useful for medical professionals and humanitarian health agencies working in outbreak areas, and decision makers.
The WHO Regional Office for the Eastern Mediterranean and Country Office, Islamabad, Pakistan were involved in organizing the face-to-face meetings with reviewers working on this project, while the FELTP was instrumental in hosting the three-day meeting.
In its introductory section, the manual outlines the symptoms and risk factors characterizing the disease, whereby it indicates that Hepatitis E occurs around the world both in the form of outbreaks and sporadic cases. According to the manual, outbreaks of this disease frequently occur in countries with limited access to essential water, sanitation, hygiene, and health services. In such cases, it may affect several hundred to several thousand persons at a time.
In recent years, some outbreaks have occurred in areas of conflict and humanitarian emergencies, such as war zones, camps for refugees, or within internally displaced populations. The manual highlights the fact that an estimated 20 million infections and 3.3 million symptomatic cases of Hepatitis E occur annually worldwide, bringing about an estimated 56 600 deaths.
It is further stated that cases and outbreaks of this disease often go undiagnosed and that they are mistaken for other forms of viral hepatitis. This is due to the similarity of symptoms related to this disease in comparison with other forms of acute viral hepatitis. Another contributing factor to misdiagnoses is the limited availability and use of specific diagnostic tests for the disease. Under such indications, medical and public health personnel may have little previous experience in detecting and handling outbreaks of Hepatitis E. The available guidance on the subject is also limited while responses from health administrators and field workers to such outbreaks may be inadequate and/or delayed.
The lack of correct information, inadequate communication of key messages, and limited engagement and preparedness at the community level may lead to much concern in affected and at-risk populations. Within such circumstances the outcome may entail costly emergency care and related services. Therefore, the manual serves to fill in this information gap. It may serve as a catalyst for health promotion and prevention activities, while also playing a pivotal role in ensuring early, appropriate and equitable health-care services in response to Hepatitis E outbreaks. This will in-turn improve public health outcomes, especially in resource-limited settings.
Furthermore, the manual provides valuable information about the disease itself and its geographical distribution, whereby it states that high frequency of the disease is seen primarily in low-income countries where contamination of drinking water supplies and lack of proper sanitation are common. In most parts of Asia and Africa, waterborne outbreaks of Hepatitis E are common. Some outbreaks have also been reported from Mexico. In areas where hepatitis E disease is infrequent, the occasional sporadic cases are believed to be due to zoonotic spread through the consumption of undercooked meat.
The manual also outlines the means of disease transmission. In this section, it states that in regions where Hepatitis E disease and outbreaks are frequent, fecal–oral transmission is the most common route of transmission of infection. Fecal contamination of drinking water supplies is the most common mode of spread of Hepatitis E. It is also plausible that foodborne and other fecal–oral modes of transmission play a role in the transmission of hepatitis E in these regions. This is because of the relatively long incubation period of Hepatitis E, it is difficult to attribute the disease to consumption of a particular food. Some outbreaks have been reported during the dry season which is possibly related to increased concentration of contaminants in reduced river water flow, leaky water pipes that pass through soil contaminated with human feces etc.
Most of the initial published data showed that transmission of HEV through interpersonal close contact is infrequent. However, transmission of HEV infection from mother to infant and through blood transfusion has been reported. These modes appear to account for only a small proportion of Hepatitis E cases, and have not been shown to be responsible for disease outbreaks.
The manual also provides inside about the demographic distribution of the disease, whereby it shows that outbreaks of Hepatitis E are highest among adolescents and young adults of 15–40 years, while infection with HEV amongst young children is less likely to lead to disease. The disease appears to be somewhat more common among men than women, while HEV infection in pregnant women is associated with an increased likelihood of symptomatic disease, fulminant hepatic failure, and death. The fatality rate among pregnant women who develop the disease may be as high as 15–20%. Persons with pre-existing chronic liver disease are also at an increased risk of severe illness. In this situation, even mild liver damage may reduce liver function to a level that is life threatening
For further clarity users of the manual will benefit from a full listing of disease symptoms. In this section it is stated that the illness generally begins as an acute viral syndrome with symptoms such as mild fever, chills, headache, and fatigue, often associated with marked loss of appetite, aversion to food, upper abdominal discomfort, nausea, and vomiting. Some patients may also have generalized itching. Within a few days of the onset of these non-specific symptoms, the affected persons also develop dark urine and/or yellow discoloration of the sclera of the eyes. Clinical examination may further reveal slight enlargement of the liver and spleen, amongst other symptoms.
The manual offers lists of tests needed for disease detection, while also outlining the modes of treatment and preventative actions to be taken. It also offers a step-by-step guide for responding to Hepatitis E outbreaks, basic epidemiological measures to be taken, steps to patient management, and desired trends for community engagement and communication. It also gives its users a comprehensive outline on how to communicate findings, not to mention an in-depth description of available vaccination schemes, means to communicate findings, governance in times of outbreaks, and instructions for communicating findings.
In its appendices users will also find a full list of relevant forms and templates including; a list of direct and indirect tests for diagnoses, line listings and spot maps, instructions for specimen collection and storage, case studies for effective community engagements, templates for collecting information, templates for outbreak investigations, questions to assess outbreak investigations, a standard survey, and more.
The release of this manual, available through the WHO website, serves to improve public health standards. It is designed to elevate quality of care offered to communities around the globe.