Diseases & Conditions


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Adenovirus


A type of virus that causes upper respiratory infections producing symptoms resembling those of the common cold. Adenoviruses include 49 DNA-containing viruses identified by sequential letters and numbers that can cause infection in eyes, upper respiratory tract, and the gastrointestinal system. Although characteristics of the adenoviruses vary, they are all transmitted either by direct contact, by fecal-oral transmission, or by contact with contaminated water. Respiratory infections caused by adenoviruses occur by contact with infectious material from another person or object; secretions from the respiratory tract may contain the virus. The virus also can survive for many hours on inanimate objects such as doorknobs, hard surfaces, and toys. Transmission of the digestive strain of the virus usually occurs by fecal-oral contact. This usually occurs from poor hand-washing or from eating or drinking contaminated food or water. Some types of adenoviruses are capable of establishing persistent infections in tonsils, adenoids, and intestines without causing any symptoms; shedding can occur for months or years. After the initial illness fades away, the virus can persist in the tonsils, adenoids, and other lymph tissue. Adenoviruses do not become latent like the HERPES virus but instead reproduce constantly and slowly. Epidemics of disease with fever and CONJUNCTIVITIS are associated with waterborne transmission of some adenovirus types, usually involving poorly chlorinated swimming pools and small lakes. Symptoms Respiratory infections may develop between two days and two weeks after exposure and are characterized by common cold symptoms, sore throat, fever, severe or nonproductive cough, swollen lymph nodes, and headache. Intestinal tract infections may appear from three to 10 days after exposure, usually among children under age four. They begin with an abrupt watery diarrhea, fever, and abdominal swelling and tenderness. These symptoms may last from one to two weeks. Although outbreaks of adenovirus-associated respiratory disease have been more common in the late winter, spring, and early summer; these infections can occur throughout the year. Treatment Most infections are mild and do not need to be treated. Because there is no treatment specifically tailored to this virus, serious adenovirus illness can be managed only by treating symptoms and complications. Treatment for respiratory infection may include fluids, bronchodilator medications to open the airways, or supplemental oxygen through a mask, nasal prongs, or an oxygen tent. A child who becomes very sick with adenovirus may require mechanical ventilation or a respirator to assist with breathing for a period of time. Treatment for intestinal infection may include fluids (water, formula, breast milk, and/or special electrolyte-containing fluids such as Pedialyte). Very young children should NOT be rehydrated with soda, juices, or sports drinks. Children may be given solid foods if they are able to tolerate them. Complications Children who develop PNEUMONIA from adenovirus may develop chronic lung disease. Very rarely, this strain of the virus has a 10 percent mortality rate. Children with weakened immune systems are at risk for developing a more severe infection from adenoviruses. A severe complication of intestinal adenovirus is intussusception, an intestinal blockage that occurs when one part of the intestine slides over another section like a telescope. This is a medical emergency and most often occurs in infants under 1 year of age. The symptoms of intussusception may include bloody or “currant jelly” stool, vomiting, abdominal swelling, knees flexed to chest, loud cries of pain, weakness, and lethargy. Prevention Strict hand-washing is important to prevent the spread of adenoviruses to other infants, children, and adults. There are vaccines for adenovirus serotypes 4 and 7, but these are available only to prevent infection among military recruits. Strict infection control practices are effective at stopping outbreaks of adenovirus-associated disease in hospitals; adequately chlorinating pools can prevent swimming pool-associated outbreaks of adenovirus conjunctivitis.