Unlike the very muddy waters of the Amazon River itself, its lagoons and smaller tributaries, the Iriri has very few mosquitoes and is a very long way from population centers. However, there is always a slight risk and some care should be taken accordingly. The only hours of any significant risk of the malarial mosquito are, an hour at dawn and an hour around dusk. Suitable repellent is more than adequate. Malarial prevention is recommended by travel clinics and, it seems, are much improved in recent years as regards side-effects. Taking them or not is purely a matter of personal preference.

Yellow Fever, Hepatitis A and Tetanus are all a good idea when travelling to the tropics. Aside from this, there is only minimal bug nuisance. Some midge activity in the early part of the evening is usually seen of by repellent and there are no mosquitoes at night.