Giardia and Cryptosporidium in the Netherlands

Abstract number: 1134_02_331

Kortbeek L.M., Mank T.G.

Objectives:

•  The studies were designed to get an insight into the incidence of protozoal-, bacterial-, and viral infections in patients with diarrheal complaints in different groups: patients consulting their general practioner and the dutch population. Here we focus on Giardia and Cryptosporidium

•  To decrease diagnostic deficit

•  Study the risk factors

Methods:

Three studies were designed and conducted :

•  ‘Haarlem’study: 1994–1996, general practitioners, Haarlem region

•  NIVEL: Case-control study in sentinel General practitioners practices (1996–1999)

•  SENSOR: prospective population based cohort study with a nested case-control study in the Dutch population. (1999)The studies differ in inclusion criteria and the diagnostic laboratory techniques used, esp. virological stool examinations

Results:

Incidence of gastroenteritis in the NIVEL (GP) study (after correction) was 79.5 per 10,000 personyears. This means that 80.000–130.000 persons will consult a GP annually for gastroenteritis. Incidence of gastroenteritis in the population- based study was 283 per 1000 personyears. Giardia was detected in 14.8% of the cases in Haarlem, in 5.4% of the cases in the NIVEL study and 3.3% of the controls. For Cryptosporidium this was resp 3.3%, 2.1% and 0.2%. The diagnostic deficit decrease substantialy by testing for viral pathogens like NLV. Detection of pathogens was influenced by age, season and duration of symptoms. We were able to construct an algoritm for diagnostic workup in GI patients.The main riskfactors for Giardia are:

•  swimming OR: 6.8 ( 95%CI: 2.4–19.3) multivariate OR: 15.6 (3.2–77.1);

•  contacts with person with GE 7.1 (1.8–26.6); Multivar.OR 28.6 (3.2–255.6)

•  family member attending primary school: 2.8 (1.4–5.8); multivar. OR 2.5 (1.0–6.3) .The population attributable risk fraction (PARF) for all these factors was 49% in the GP patients and 76% for patients in the general population.

Conclusion:

•  Giardia lamblia and Cryptosporidium are important pathogens in gastro-enteritis patients in the Netherlands.

•  If transmission through water, infected persons and through school contacts could be eliminated, about 50–76% of Giardia gastro-enteritis could be prevented.

•  Giardia lamblia is the most frequently found potentially pathogenic intestinal protozoal species in patients with diarrheal complaints in the Netherlands