Treatment of gastrointestinal viruses

The most common enteric viruses responsible for diarrhoea are rotavirus, enteric adenoviruses, caliciviruses including the Norwalk agent and astrovirus. These infections are usually mild to moderate in severity, self-limiting and of short duration and thus, specific antiviral therapy is not recommended. The standard management of these infections is restoration of fluid and electrolyte balance and then maintenance of hydration until the infection resolves. WHO oral rehydration therapy (ORT) was introduced about 30 years ago and has saved the lives of many infants and young children. During the last 10 years it has become evident that the efficacy of ORT can be increased by reducing the osmolality of the WHO oral rehydration solution (ORS) to produce a relatively hypotonic solution. Hypotonic ORS appears to be safe and effective in all forms of acute diarrhoea in childhood. Complex substrate ORS, which is also usually hypotonic, has been shown to have increased efficacy in cholera but not in other bacterial or viral diarrhoeas. Nevertheless, the scientific rationale for using rice or resistant starch as substrate in ORS is of physiological interest. Other treatments such as hyperimmune bovine colostrum, probiotics and antiviral agents are largely experimental and have not been introduced into routine clinical practice. Cytomegalovirus (CMV) infection of the gastrointestinal tract occurs mainly in the immunocompromised although it has been reported in immunocompetent individuals. CMV infects both the oesophagus and colon to produce oesophagitis, often with discrete ulcers, and colitis, respectively. Both conditions can be treated with ganciclovir or foscarnet. Failure to respond to monotherapy is an indication to use both agents concurrently.