in vitro culture and isoenzyme analysis of giardia lamblia

passes unnoticed, is debatable. Although the parasite is frequently harboured by
apparently symptom less persons who transmit cysts to the environment, this may
give rise to symptomatic infections in other individuals.
The clinical course of acute giardiasis is easily recognised in travellers to endemic
areas as they present with sudden onset illness during or shortly after travel
(8rodsky et al., 1974). The predominant features of acute giardiasis are explosive
diarrhoea, abdominal discomfort, nausea, headache and bloating. Symptoms can
complicate steatorrhoea and malabsorption in up to 25% of patients (Hjelt et al.,
1992) and often cause weight loss (Gerhard, 1989; Heinz, 1988; Meloni et al.,
1988; Ukoli, 1984). Frequently, the infection is self-limiting; however, it is
estimated that 20 -50% of symptomatic patients will proceed to the chronic stage
of the disease. The symptoms can persist for weeks, months or several years.
Smith et al. (1982), described two and a half years of persistence of symptoms in
a patient with giardiasis, while Tandon and colleagues (1977) reported the
duration of diarrhoeal symptoms varying from two months to 12 years.
There is increasing evidence that G.lamblia infection is very debilitating particularly
in younger hosts. Although children apparently tolerate these infections, their
physical and mental development is severely retarded. Farthing et al. (1986)
studied the impact of Giardia infection on the growth of infants and children, and
found that it had had deleterious effects. The rate of weight gain was significantly
lower in the second year of life in Giardia infected children, when compared to that
of uninfected children. The duration of Giardia episodes and their association with
diarrhoea appeared to be the most important factors associated with growth
disturbance. Similarly, Hjelt et al. (1992) illustrated that giardiasis had a negative
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