Giardia surveillance in Scotland, 1988–2003

Abstract

The aim of the study presented here was to analyse the epidemiology of Giardia infection in Scotland over a 16-year period and to describe trends of infection with this parasite. Data on Giardia infections has been collected from laboratories in Scotland since 1969 through voluntary laboratory reporting. Health Protection Scotland (HPS) is responsible for the national surveillance of infectious diseases in Scotland. In industrialised countries, the flagellated protozoan parasite Giardia is referred to as a re-emerging infectious disease because of its increasingly recognised role in outbreaks of diarrhoeal disease in daycare centres and in waterand foodborne outbreaks [1, 2]. It is now clear that the morphological group Giardia duodenalis (synonyms: Giardia intestinalis and Giardia lamblia) is a species complex comprising a series of what appear to be largely host-adapted assemblages/species. Giardia duodenalis assemblages A and B infect both human and non-human hosts, with assemblage A being associated with greater zoonotic potential [3]. In most people who contract giardiasis, there are two clinical phases: acute and chronic. The acute phase is shortlived and is characterised by flatulence with sometimes sulphurous belching and abdominal distension with cramps. Diarrhoea is initially frequent and watery but later becomes bulky, sometimes frothy, greasy and offensive. In chronic giardiasis, malaise, weight loss and other features of malabsorption may become prominent. Stools are usually pale or yellow and are frequent, of small volume and, occasionally, episodes of constipation intervene with nausea and diarrhoea precipitated by the ingestion of food. Trans-