Enteroviruses

When spring arrives and we think of rebirth, love and allergies, children are beset by a whole new crop of viruses. While influenza may be more famous and more feared, the Enterovirus family of germs is actually a common cause of office visits for a variety of complaints. Since their original identification in the 1960's, Enteroviruses have been found to comprise over 70 strains and include such famous groups as polioviruses (3 types), Coxsackie A (24 types), Coxsackie B (6 types), Echoviruses (34 types), and the eponymous Enteroviruses (4 types). Of these, poliovirus has been almost completely eliminated worldwide, but pockets of stubborn resistance remain in war-torn areas of the world, and small Caribbean outbreaks have occurred around the turn of the millennium.

The remaining strains are of the most interest in the United States and for parents and pediatricians alike. They represent the most common cause of summertime gastrointestinal illness associated with a whole host of clinical syndromes. These syndromes are also unique in that patients develop both respiratory and gastrointestinal symptoms whereas most other viruses remain within one organ system. Presenting symptoms include simple illness (headache, upper respiratory symptoms, sore throat, body aches, gastrointestinal symptoms, fever or no fever, with or without an accompanying rash) to fairly severe conditions including viral meningitis and myocarditis.

The Coxsackie viruses (named for the home town of the first patient, Coxsackie, N.Y., just south of Albany) usually cause more headache, fever and sore throat complaints. The Echoviruses (Extra Cytoplasmic Human Orphan-describes their growth characteristics in viral cultures) usually cause more gastrointestinal symptoms. Frequently we can identify the virus by the symptoms, but more often, the different strains have symptoms that are so similar that we only know the family and not the particular strain.

A well-known set of symptoms is the Hand-Foot-Mouth syndrome, which comprises ulcers in the mouth and similar lesions on the arms and legs, all of which are painful. This presentation seems to be more common late in the summer, often in August. HFAM disease is typically caused by Coxsackie A16, may be caused by Coxsackie A10 or A5, or rarely by Enterovirus 71. Since different strains can cause the same rash, or occasionally like Coxsackie A9 the same strain can cause different rashes, this family, which causes most of the summer time viral illnesses, can be very confusing. Overall, the enteroviral illnesses appear to be epidemic in proportions during the summer; however, this is more likely due to the large number of possible available strains to which children are exposed and the resultant large number of cases of illness.

Years ago, such diseases certainly existed, but were simply described as "summer viruses" and patients were told to rest drink fluids and take analgesics for relief. Today, we offer a name of the likely germ and a description of the possible symptoms, but the treatment remains the same. The preferred analgesic is more likely to be ibuprofen, because of its anti-inflammatory effects as well as superior pain relief. We also will use small amounts of codeine containing medications to help relieve pain when children are trying to sleep.

The incubation period for Enteroviruses is three to five days. While the child is most contagious when the fever is greatest, the patient and shed live viruses for up to four weeks orally and up to eight weeks rectally. We don't recommend quarantine for nearly that long, but isolation when the child is the most uncomfortable is important. The following chart will help with the care.

Parents will often be misinformed that the disease is Hoof and Mouth disease, but that remains in the veterinary world. Interestingly, the same type of viruses (picornavirus) is implicated in this animal disease with similar ulcers in the mouth. Fortunately, humans are able to grasp the need to remain hydrated and can be treated with intravenous fluids should the occasional patient become dehydrated. Cows, sadly, cannot overcome the discomfort and waste away, failing to drink. This is the reason that such an epidemic is considered catastrophic in the cattle and dairy industries. Humans battle back fairly rapidly as children, but often are symptomatic for up to 2 weeks.

As time goes by, children have fewer and fewer episodes. During the first several years of life, we have seen as many as five episodes in one summer. By the school years, kids have less than one significant illness due to Enteroviruses per year on average. As teens and adults, we experience on such illness about every five to ten years, unless exposed frequently to small children. This is quite auspicious, as it seems that it takes adults longer to recover from the fatigue and discomfort associated with enteroviral infections; patients report feeling out of sorts for up to 3-4 weeks.