Revised August 2, 2021 Chlamydia trachomatis imposes a tremendous burden on human health because it is one of the most common causes of bacterial infection. Worldwide in 2011, an estimated 21 million people had active trachoma, which is an ocular…
Reviewed for currency February, 2020 Prions are the transmissible agents of a class of neurodegenerative diseases of humans and other mammals. Prions differ from other infectious agents in that they contain no information-bearing nucleic acid. Rather, they are composed mainly,…
Revised March 29, 2022 Hepatitis E virus (HEV) is a ribonucleic acid (RNA) virus that causes a viral hepatitis that is indistinguishable from other forms of viral hepatitis. The World Health Organization (WHO) estimates a global incidence of 20 million…
Reviewed for currency February, 2020 Viral gastroenteritis is caused largely by noroviruses and sapoviruses (see Chapter 176 ) and by rotaviruses (see Chapter 150 ). Astroviruses are also established as important causes of gastroenteritis, albeit substantially less frequently than the…
Reviewed for currency November, 2019 Revised February 20, 2021 Acute infectious gastroenteritis is an exceedingly common and widespread illness throughout the world. Noroviruses are major causes of this illness, which is generally self-limited but can result in hospitalization, mortality in…
Rhinoviruses are among the most frequent causes of viral infections in humans. They are the major cause of the common cold and are significant contributors to other upper respiratory syndromes as well as certain lower respiratory illnesses. The term common…
Hepatitis A is generally an acute, self-limited infection of the liver by an enterically transmitted picornavirus, hepatitis A virus (HAV). Infection may be asymptomatic or result in acute hepatitis. Rarely, fulminant hepatitis can ensue. Although the duration and severity of…
Historical Background The initial two serotypes of the genus Parechovirus were isolated in 1956 from children with diarrhea. On the basis of the scheme used at that time for the classification of the enteroviruses, they were classified as echovirus (E)…
This chapter covers human disease caused by the group A coxsackieviruses (CVs), group B CVs, echoviruses (Es), and the numbered enteroviruses (EVs), which are distributed among four species, EV-A to EV-D, of the genus Enterovirus. Viral diseases caused by the…
Revised February 13, 2021 Polioviruses are the cause of poliomyelitis, a systemic viral infection that predominantly affects the central nervous system (CNS), causing paralysis. The name of the disease ( polios, “gray”; myelos, “marrow” or “spinal cord”), now commonly shortened…