In December 2019, a cluster of patients with pneumonia of unknown etiology were identified in Wuhan, a city of 11 million residents in South Central China. RNA extracted from bronchoalveolar fluid provided the complete genome of a novel betacoronavirus named…
Definition Human coronaviruses are a frequent cause of respiratory illness. Seasonal human coronaviruses (CoV) 229E, OC43, NL63, and HKU1 generally cause mild, self-limited upper respiratory tract infections, including about 15 to 30% of all common colds ( Chapter 329 ).…
Definitions Human adenoviruses, which are members of the Adenoviridae family and the Mastadenovirus genus, are divided into seven species (A, B, C, D, E, F, and G; Table 333-1 ). Modern sequencing and molecular diagnostics have identified over 80 serotypes.…
Definition Influenza is an acute febrile respiratory viral illness that usually occurs in annual outbreaks of varying severity and occasionally causes worldwide epidemics (pandemics). Increasingly, sporadic zoonotic infections, sometimes associated with limited human-to-human transmission, are being reported. Influenza viruses infect…
Epidemiology The human parainfluenza viruses are ubiquitous, with a worldwide geographic distribution. , Their transmission is principally by large-particle fomites via close person-to-person contact. Parainfluenza virus activity displays both endemic and epidemic patterns, with each serotype preferring different age groups…
Respiratory Syncytial Virus Definition Respiratory syncytial virus (RSV), which causes yearly winter outbreaks in temperate climates, is the most important cause of bronchiolitis and pneumonia in young infants, a common cause of illness in older children and young adults, and…
Definition The common cold is a clinical syndrome characterized by upper respiratory signs and symptoms (e.g., rhinorrhea, sneezing, nasal obstruction), which are frequently accompanied by sore throat, cough, and general malaise. The common cold is among the most prevalent of…
Although some viral infections are self-limited, others can cause significant morbidity and mortality. Effective therapy is available for many of these infections. This chapter reviews currently available antiviral agents for the treatment of infections caused by viruses other than human…
Definition Nematode infections are highly prevalent, affecting millions of people worldwide. Nematodes are complex, nonsegmented roundworms with specialized organs that include a protective outer coating or cuticle, a complete and functional gastrointestinal tract, and muscular, nervous, and reproductive systems. Most…
Schistosomiasis Definition Schistosomiasis, which is classified as a neglected tropical disease, is a parasitic infection caused by the trematode worms (blood flukes) of the genus Schistosoma. It has been reported in 78 countries worldwide, with 290 million people infected and…