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Human physiology, hazards and health risks
Published in Stephen Battersby, Clay's Handbook of Environmental Health, 2023
Revati Phalkey, Naima Bradley, Alec Dobney, Virginia Murray, John O’Hagan, Mutahir Ahmad, Darren Addison, Tracy Gooding, Timothy W Gant, Emma L Marczylo, Caryn L Cox
Hepatitis A is an enterically transmitted infection of the liver. The incidence has been decreasing in higher-income countries over the last five decades with the highest incidence in these countries in those aged 15–34 years. The infection leads to a clinical picture that ranges from no symptoms to mild, non-specific nausea and vomiting through to hepatitis (liver inflammation and jaundice) and rarely liver failure. Diagnosis is by serology to identify specific antibodies. There is no specific treatment but passive immunisation with immunoglobulin (HNIG) can confer protection for a limited period.
Microbial Food-borne Diseases Due to Climate Change
Published in Javid A. Parray, Suhaib A. Bandh, Nowsheen Shameem, Climate Change and Microbes, 2022
John Mohd War, Anees Un Nisa, Abdul Hamid Wani, Mohd Yaqub Bhat
Hepatitis A virus (HAV) is one among the most recurrent cause of food-borne infections. The shape of the virus is spherical containing single-stranded RNA with an icosahedral protein coat about 30 nm in diameter. HAV is a member of the family Picornaviridae (Drexler et al., 2015; Lauber and Gorbalenya, 2012). The sources of infection are contaminated water or water products (undercooked or raw shellfishes and oysters), contaminated foods, or infected food handler (Greening, 2006; Robertson et al., 1992; Hernandez et al., 1997). The virus is responsible for a severe medical condition hepatitis A disease which is characterized with inflammation of liver with symptoms like fever, diarrhea, nausea, dark urine, jaundice, light colored stools, upset stomach and pain, joint pain, loss of appetite, and rarely, it may cause renal failure and death of an individual. The WHO global hepatitis report (2017) for first time in 2015 provides the global estimate of viral hepatitis cases. As per the report, roughly 4% of the global population lives with hepatitis (viral) and about 1.34 million deaths per year occur due to this disease. Since 2000, the deaths due to viral hepatitis has increased by 22%. The World Health Assembly in May 2016 authorized the global health sector strategy on viral hepatitis 2016–2021 which calls for the eradication of viral hepatitis as a public health danger by 2030 (reducing morbidity by 90% and mortality by 65%).
Vaccines, Hepatitis B and Insulin Production
Published in Debabrata Das, Soumya Pandit, Industrial Biotechnology, 2021
Bacterial vaccines are killed vaccines, whereas the viral vaccines are those among the inactivated vaccines. Typhoid is one of the examples of killed vaccines; it was the first one to be produced and was used among English troops in the late 19th century. Inactivated vaccines such as polio and hepatitis A are currently in circulation in the UK, and the most common killed vaccine in many countries is the whole cell pertussis vaccine. The adaptive immune response that the killed/inactivated vaccine generates is directed against a much broader range of antigens (Ellis and Brodeur, 2012). When injected with the vaccine, whole organism phagocytosis occurs. Hepatitis A is an example of an inactivated vaccine. Its protective efficacy is more than 90%. The vaccine is formalin inactivated, the cell culture is adapted and it is a strain of HAV. When injected it gives rise to neutralizing antibodies.
Pathogen contamination of groundwater systems and health risks
Published in Critical Reviews in Environmental Science and Technology, 2023
Yiran Dong, Zhou Jiang, Yidan Hu, Yongguang Jiang, Lei Tong, Ying Yu, Jianmei Cheng, Yu He, Jianbo Shi, Yanxin Wang
Compared with pathogenic bacteria and protozoa, viruses exhibit the physiological and etiological features that make them a greater threat to groundwater safety. Small size (0.02–0.2 mm), high titers excreted in the feces (105–1011/g stool), low infectious doses (i.e., from <1 to more than 1000 plaque-forming units (PFUs)) and highly variable lethality of enteric viruses facilitate their migration and increase the risks of waterborne diseases (Table S2 and the references therein). While viral pathogens can cause a variety of illnesses, acute gastrointestinal illness is most commonly reported (Table S2). Enteric viruses primarily infect hosts in the intestinal tract, causing stomach or intestine inflammations, infectious diarrhea, fever, nausea, vomiting, stomach pain, dehydration, or weight loss. Other diseases such as polio-like illness, aseptic meningitis, epidemic conjunctivitis, and hand, foot, and mouth have been reported for Enterovirus-infected patients. Infection by Hepatitis A and E viruses can lead to fever, nausea, jaundice, and liver failure (Krauss and Griebler, 2011) (Table S2).