Toddler son dipped hands in rainwater and licked them. has had on and off hiccuping and throwing up for 3 days, no other symptoms. chance of parasite?

Very doubtful!: It would be most unusual to contract a parasite from rainwater. Parasites usually happen after international trips in areas where parasites are endemic. Symptoms usually are bloody diarrhea, sometimes anemia. Diagnosis by stool studies and blood tests. Hiccuping not at all related. Vomiting more likely a viral illness -- treat with clear liquids.