Coxsackievirus B1 is one of six serotypes of coxsackievirus B, classified under Enterovirus B in the family Picornaviridae. The virion is a non enveloped icosahedral particle about 30 nm in diameter containing a single‑stranded positive sense RNA genome. It infects humans via the fecal–oral route and respiratory droplets and replicates primarily in the mucosa of the gastrointestinal and upper respiratory tract. CVB1 is notable because it can cause severe disease in newborns, including sepsis‑like illness, myocarditis and hepatitis, and it has been implicated in pancreatic beta‑cell injury.
Structure, replication and pathogenesis
Like other enteroviruses, Coxsackievirus B1 encodes a polyprotein that is proteolytically cleaved into structural proteins VP1‑VP4 and non‑structural proteins involved in replication and protease functions. The genome replicates in the cytoplasm of infected cells using an RNA‑dependent RNA polymerase. The virion is stable over a range of pH values, permitting passage through the stomach. After entering the host, CVB1 replicates in the oropharyngeal and intestinal epithelium and disseminates via the bloodstream. It can infect a wide range of tissues, including myocardium, pancreas, liver and central nervous system. In neonates, immature immune responses allow high viral loads, which can lead to multiorgan dysfunction. Studies have suggested that CVB1 infection of pancreatic islet cells may initiate autoimmune processes contributing to type 1 diabetes. The virus circulates worldwide, with seasonal peaks in late summer and autumn. There are no specific antiviral drugs or vaccines; prevention relies on good hygiene.
Clinical manifestations and notable cases
Coxsackievirus B1 infection often causes nonspecific febrile illness with sore throat, abdominal pain or rash. However, severe presentations can occur, particularly in newborns and young infants. During increased activity of CVB1 strains in the United States in 2007–2008, several infants developed sepsis‑like illness with myocarditis and hepatitis requiring hospitalisation. CVB1 can also cause meningitis, encephalitis or pleurodynia (a severe chest pain known as “devil’s grip”). Adults usually experience mild, self‑limited illness but may develop pericarditis or pancreatitis. Transmission occurs through contact with contaminated feces, respiratory secretions and surfaces. Hand washing, disinfecting shared objects and avoiding contact with infected individuals are important preventive measures, especially around newborns. Coxsackievirus B1 is a small RNA virus that can cause a spectrum of disease ranging from mild febrile illness to life‑threatening multiorgan infection in neonates. Awareness of its potential severity, particularly in very young infants, underscores the need for hygiene and prompt medical evaluation when severe symptoms develop. Related Terms: Coxsackievirus B2, Coxsackievirus B3, Coxsackievirus B4, Enterovirus B, Myocarditis