I have begun working in an aerial mosquito spraying program in order to squash any mosquito borne diseases that might put our residents at risk. It is a lengthy permitting process and comes at an inopportune time considering it seems as if every which way you turn some needy cause is begging for money. I have just started the research end of this quest and don't have anything to report yet.
I have contract dengue in the past (there are 4 strains) and it is very unpleasant. Malaria is a worry too.
If you are concerned about the situation at the Holy Cross school you can either ask the principal about the situation or you can contact the local Health Inspector and ask him to make an on-site assessment.
To put things into perspective, please remember that the description you made above describes many subdivisions on the island.
The swamps and lagoons have a certain smell that is evidence of the degrading of biological matter. The ground water in many areas has a strong sulphurous smell.
If the school is closed down the children, in many cases, will be spending their days in areas with similar conditions of the school area, the difference would be that they won't be receiving an education.
Sometimes you have to weigh up the different evils and choose the lesser path.