The most famous enterovirus, the poliomyelitis virus, is discussed above under Major Vaccine-Preventable Viral Infections. Other clinically relevant enteroviral infections are discussed in this section.
1. COXSACKIEVIRUS INFECTIONS
Coxsackievirus infections cause several clinical syndromes. As with other enteroviruses, infections are most common during the summer. Two groups, A and B, are defined either serologically or by mouse bioassay. There are more than 50 serotypes.
The clinical syndromes associated with coxsackievirus infection are summer grippe; herpangina; epidemic pleurodynia; aseptic meningitis and other neurologic syndromes; acute nonspecific pericarditis; myocarditis; hand, foot, and mouth disease; epidemic conjunctivitis; and other syndromes.
1. Summer grippe (A and B)
A febrile illness, principally of children, summer grippe usually lasts 1–4 days. Minor upper respiratory tract infection symptoms are often present.
2. Herpangina (A2–6, 10; B3)
There is sudden onset of fever, which may be as high as 40.6°C, sometimes with febrile convulsions. Other symptoms are headache, myalgia, and vomiting. The sore throat is characterized early by petechiae or papules on the soft palate that ulcerate in about 3 days and then heal. An outbreak in Taiwan with A2 was associated with herpangina and paralysis and coincided with an enterovirus 71 outbreak, characterized by hand, foot, and mouth disease. Dual A6/A10 outbreaks are reported from Europe. Treatment is symptomatic.
3. Epidemic pleurodynia (Bornholm disease) (B1–5)
Pleuritic pain is prominent. Tenderness, hyperesthesia, and muscle swelling are present over the area of diaphragmatic attachment. Other findings include headache, sore throat, malaise, nausea, and fever. Orchitis and aseptic meningitis occur in less than 10% of patients. Most patients are ill for 4–6 days.
4. Aseptic meningitis (A and B) and other neurologic syndromes
Fever, headache, nausea, vomiting, stiff neck, drowsiness, and CSF lymphocytosis without chemical abnormalities may occur, and pediatric clusters of group B (especially B5) meningitis are reported. Focal encephalitis and transverse myelitis are reported with coxsackievirus group A and acute flaccid paralysis with group B in India. Disseminated encephalitis occurs after group B infection, and acute flaccid paralysis is reported with both coxsackievirus groups A and B. An outbreak of aseptic meningitis occurred in central China (Gansu Province) in 2008, with 85 cases reported of coxsackie A9 disease.
5. Acute nonspecific pericarditis (B types)
Sudden onset of anterior chest pain, often worse with inspiration and in the supine position, is typical. Fever, myalgia, headache, and pericardial friction rub appear early and these symptoms are often transient. Evidence for pericardial effusion on imaging studies is often present, and the occasional patient has a paradoxical pulse. Electrocardiographic evidence of pericarditis is often present. Relapses may occur.