Enterovirus infections

Enterovirus infections cause Herpangina, Hand-foot-and-mouth disease, Epidemic pleurodynia, Coxsackievirus infection, Echovirus infection, and Enteroviral hemorrhagic conjunctivitis. About 80% of enterovirus infections occur in infants, children, and adolescents.

CASES/YEAR
40,000,000 (US); 1,000,000,000 (Global)
CATEGORY
AGENT TYPE
Viruses
OTHER NAMES
Herpangina; Hand-foot-and-mouth disease; Epidemic pleurodynia; Coxsackievirus infection; Echovirus infection; Enteroviral hemorrhagic conjunctivitis;
ACUITY
Acute-Moderate
INCUBATION
3-6 days with range of 2 days to 2 weeks; [Cecil, p. 2206]
INITIAL SYMPTOMS
Infection is subclinical in 90% of individuals. The most common syndrome is febrile illness in infants, toddlers, and young children. Common findings are fever, lethargy, irritability, vomiting, diarrhea, exanthem, and cold symptoms. [Cecil, p. 2206]
PRECAUTIONS
Standard; "Use Contact Precautions for diapered or incontinent children for duration of illness and to control institutional outbreaks." [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
EPIDEMIOLOGY & FINDINGS:
Human enteroviruses include coxsackieviruses and echoviruses. Classified conventionally into five subgenera: enteroviruses, echoviruses, coxsackieviruses (A & B), and polioviruses. See "Poliomyelitis" covered separately. About 80% of enterovirus infections occur in infants, children, and adolescents. Most cases are asymptomatic. The most common type of illness is a simple febrile illness lasting a few days, often with upper respiratory tract symptoms. "Disease syndromes characteristic of enteroviruses (e.g., aseptic meningitis, pericarditis) are infrequent manifestations of infection. A 4-year longitudinal family-based study in New York City detected 291 enteroviral infections, none producing "characteristic" illnesses, and only 6 with exanthems." [PPID, p. 2213-7]

"The four species (human enterovirus [EV] A to D) within the genus contain more than 100 serotypes." Clinical syndromes of enteroviral infections include: acute meningitis, encephalitis, paralysis, exanthems, hand-foot-and-mouth disease, herpangina, myopericarditis, pleurodynia, and acute hemorrhagic conjunctivitis. Enteroviruses cause most cases of viral meningitis in both adults and children. As in poliomyelitis, a biphasic fever pattern may occur. Enteroviruses cause less than 5% of encephalitis cases in industrialized countries. EV-A71 can cause a severe form of brainstem encephalitis with secondary noncardiogenic pulmonary edema with a high prevalence in countries of the Asia-Pacific Rim. Complications include limb atrophy and weakness. Except for EV-A71, the paralytic disease caused by enteroviruses is less severe than polio--patients are more likely to have muscle weakness, not flaccid paralysis. Some enterovirus infections are accompanied by maculopapular rashes resembling those of rubella or roseola. Echovirus 9 and coxsackievirus A9 infections are associated with petechial and purpuric rashes. [PPID, p. 2227-30] Swimming is a risk factor for enteroviral encephalitis. [PPID, p. 1229t]

Typically, enteroviruses first infect the respiratory system or GI tract followed by viremia and infection of secondary sites. Prolonged excretion of virus in stool is common. Enteroviruses are the most likely cause of exanthems in children during the summer and fall. [ID, p. 1224, 2047-51] Complications after epidemic myalgia include pneumonia, orchitis, pericarditis, meningitis, and rarely, myocarditis in adults. [CCDM, p. 193] Among cases in which the causal agent is determined, enteroviruses cause up to 90% of aseptic meningitis in children and young adults. About 1/3 of acute myocarditis cases are caused by enteroviruses. Pulmonary hemorrhage is a complication of hand-foot-and-mouth disease. [Harrison ID, p. 924-5] Enteroviral infections (aseptic meningitis, hemorrhagic conjunctivitis, exanthems, and respiratory infections) generally have a benign course. [Merck Manual, p. 1538-9] Enterovirus d68 caused severe respiratory infections in school children in summer/fall 2014 mostly in the Midwest (1035 cases reported in 47 states as of 2014). [ABX Guide]

HFMD
Hand-foot-and-mouth (HFMD) disease usually lasts about a week beginning with 5-10 sores anywhere in the mouth. Vesicles of the hands and feet follow the mouth sores. The vesicles are 3-7 mm in diameter surrounded by erythema. The infection is highly contagious. The vesicular rash appears in almost all cases involving pre-school age children, in about 40% of cases involving school-age children, and in only about 10% of adult cases. [ID, p. 1223] Epidemics of enterovirus 71 with severe neurological disease (neurogenic pulmonary edema in fatal cases) have been reported in China and SE Asia since 2008. [ABX Guide] The severe and often fatal brainstem encephalitis cause by EV-A71 is usually preceded by HFMD or herpangina. [PPID, p. 2228] "The large-scale epidemics occurring in the Far East have led to the development of an EV-A71 vaccine that has recently undergone a successful phase III trial, with greater than or equal to 90% efficacy against EV-A71-associated HFMD." [PPID, p. 2236]

HERPANGINA:
Herpangina (sores limited to mouth and throat) is, like HFMD, usually caused by Coxsackie A. [ABX Guide] "The fever subsides in 2 to 4 days, but the ulcers may persist for up to a week. Patients with herpangina do not appear very ill and require only symptomatic treatment for sore throat." [PPID, p. 2230-1]

PLEURODYNIA
Patients with pleurodynia typically have sharp, spasmodic pain in the chest or upper abdomen. Epidemics occurring every 10 to 20 years have been reported. The onset of pain is abrupt with no prodromal symptoms. Some patients have fever, sore throat, and headache. Less than 10% of patients have aseptic meningitis or orchitis. [PPID, p. 2231]

MYOPERICARDITIS:
Enteroviruses cause at least 1/3 of all acute viral myocarditis cases. Patients, often adolescents or young adults, have dyspnea, chest pain, and fever. In 2/3 of cases, the cardiac symptoms are preceded by an upper respiratory tract infection 7 to 14 days earlier. [PPID, p. 2232]

ACUTE HEMORRHAGIC CONJUNCTIVITIS
See "Conjunctivitis."
DIAGNOSTIC
Confirmed = positive culture or PCR of normally sterile fluid/tissue; CSF PCR yields >80% vs. 30% for culture; [ABX Guide] Cell culture (slow & laborious) has been supplanted by NAA testing (rapid & sensitive); [PPID, p. 2217]
SCOPE
Global
SIGNS & SYMPTOMS
  • >fatigue, weakness
  • >fever
  • >fever, biphasic or relapsing
  • >myalgia
  • E dysphagia
  • E pharyngitis
  • E rhinitis
  • E stomatitis
  • G abdominal pain
  • G diarrhea
  • G nausea, vomiting
  • H lymphadenopathy
  • N confusion, delirium
  • N headache
  • N lethargy
  • N muscle weakness
  • N paresthesia
  • N seizure
  • N stiff neck
  • O conjunctivitis, acute
  • O oculoglandular syndrome
  • R chest pain
  • R cough
  • R dyspnea
  • R hemoptysis
  • S papules or plaques
  • S petechiae and ecchymoses
  • S pustule
  • S rash (exanthem)
  • S rash on palms
  • S skin blister or vesicles
  • S ulcer of skin
  • S urticaria
  • *cranial neuropathy
  • *encephalitis
  • *epididymo-orchitis
  • *glomerulonephritis
  • *hepatitis
  • *meningitis
  • *myelitis
  • *myocarditis
  • *pancreatitis
  • *paralysis
  • *parotitis
  • *pericarditis
  • *pneumonia
  • *pneumonitis
  • *pulmonary edema
  • *rhabdomyolysis
  • *shock
  • *stupor, coma
  • *uveitis
ANTIMICROBIC

No

VACCINE

No

ENTRY
Inhalation, Ingestion, Skin or Mucous Membranes (Includes Conjunctiva), Swimming
SOURCE
Person-to-Person, Human Fecal-Oral, Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Human
RISK FACTORS
TREATMENT
No specific antiviral treatment; [CCDM, p. 193]
DRUG LINK
REFERENCES FOR CASES/YEAR
1. (US) Estimated 5-10 million cases in US every year; [Harrison ID, p. 923] Estimated 30-50 million infections per year and 10-15 million symptomatic cases; [Cecil, p. 2205]
2. (Global) More than 50% of nonpolio enteroviruses are subclinical; Specific clinical syndromes occur in a minority of infections. Infections more common in children and in poor and tropical regions of the world. [Harrison ID, p. 923] Estimated 1 billion infections per year; [Cecil, p. 2205]