Research abstract:

Cryptosporidium and Giardia are protozoan intestinal parasites which may present as asymptomatic infections in humans or cause severe and prolonged diarrhea. Studies over the last two decades show an association between these two pathogens, and various sequelae after the parasite has been successfully eradicated either by medication or by the host immune system.

In endemic countries, Giardia infection has been associated with later wasting and poor cognitive function, while growth faltering, stunting, and reduced physical fitness have been shown after Cryptosporidium infections. More recently, outbreaks of Giardia and Cryptosporidium in non-endemic settings have shown association between infections with these pathogens and long-term sequelae including not only long-lasting abdominal symptom but also extra-intestinal symptoms such as chronic fatigue and joint pain.

More studies are needed to confirm these associations and determine mechanisms and causality in order to identify effective prevention and treatment alternatives.

Long-Term Consequences of Cryptosporidium and Giardia Gastroenteritis by Kurt Hanevik Protozoa (R Mejia, Section Editor) in Current Tropical Medicine Reports, pp 1–5 [published online: 22 June 2016]