There are many viruses that can cause disease in humans and animals. Of those, the adenoviruses cause quite a few of the unpleasant symptoms of illness that people acquire, such as respiratory illness, gastroenteritis, ear infections, meningitis and cystitis. Adenoviruses cause everything from common colds to pneumonia and bronchitis.

Adenoviruses are able to survive for long periods outside the human body, and that's one reason that health professionals tell us to practice good infection control by doing lots of hand washing. Adenovirus infections are transmitted by direct contact, coughs and sneezes, fecal-oral transmission, and sometimes by waterborne transmission (some summer outbreaks have been linked to swimming pool use). Depending on the type of adenovirus, infected individuals can be asymptomatic but still shed the virus for a long time. The virus can live on contaminated surfaces for weeks.

During periods of crowding and/or stress, adenoviruses can cause ARD, or acute respiratory distress, in which breathing is difficult, and the oxygen levels in the blood drop quickly to a lower than normal level. What was once a virus regarded as a fairly harmless childhood infection producer is actually getting some more notice as a potentially life-threatening pathogen. Illness from adenovirus infections (primarily from Ad-4 and Ad-7 varieties — 51 adenovirus strains have thus far been identified) was common in military boot camps, and was first recognized during World War II.

Much like the 1918 flu virus that killed so many, adenovirus attacks healthy young people as well as debilitated or immuno-compromised people. A vaccine was developed that was in common use at military bases until the 1990s when it was discontinued. Now, Barr Pharmaceuticals is working on another vaccine for the military. A problem that was once nearly eradicated resurfaced, as infection rates went up when the older vaccine ran out.

Now, there is new concern about a genetically different strain of an old adenovirus, first identified back in the 1950s. Adenovirus-14 (Ad-14) has been identified as responsible for quite a few community-acquired pneumonias during the 2006-2007 season and the death of one healthy newborn.

Clusters of Ad-14 infections occurred in New York, Oregon, Texas (first at Lackland Air Force Base, but spread to other bases that received their recruits) and Washington.

The emergence of this new, more severe, version of Ad-14 is prompting public health officials to suggest that anyone whose cold symptoms, such as coughing or runny nose, worsen instead of resolve, or who experience trouble breathing, should consult with their doctor. Physicians noticing such symptoms in their patients can send a sample for testing, then monitor the patient daily until they begin to get better. Because those who deteriorate from this infection may do so very quickly, daily monitoring enables them to get the medical attention they may need in time.

Despite the nuisance infections that adenoviruses cause, or the increased risk from this new variety, Ad-14, some researchers are investigating the use of other adenoviruses as a possible delivery system for cancer-busting agents. So, like anything else, there is, perhaps, a silver lining. However, there is currently no vaccine to prevent illness associated with the new Ad-14, so it is wise for us all to remember to practice good hygiene and infection control in our daily lives. Hand-washing, not going to school or to work ill, and keeping office, school and household surfaces clean (heat and bleach kill adenoviruses on environmental surfaces), all contribute to fewer infections and more chance at wellness for us all.

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Anne Springer is the public relations director of SeniorCare Inc., which serves Beverly, Essex, Gloucester, Hamilton, Ipswich, Manchester, Rockport, Topsfield and Wenham. Its mission is to provide and coordinate services to elders, enabling them to live independently and remain part of their community.