Fevers and agues are prevalent owing to bad drainage and the overflowing of the river; and the death-rate is higher than the birth-rate.
It is subject, however, to extreme and rapid variations in temperature, to alternations of dry and humid winds (the latter, called catias, being irritating and oppressive), to chilling night mists brought up from the coast by the westerly winds, and to other influences productive of malaria, catarrh, fevers, bilious disorders and rheumatism.
Malarial fevers make their appearance in places where the forest has been recently felled, or where the surface earth has been disturbed.
The valley regions are tropical, and malarial fevers are common.
Remittent fevers (as well as intermittents) vary considerably in intensity; some cases are intense from the outset, or pernicious, with aggrava tion of all the symptoms - leading to stupor, delirium, collapse, intense jaundice, blood in the stools, blood and albumen in the urine, and, it may be, suppression of urine followed by convulsions.