Malaria.
I got malaria in the lowveld way back in 1965...they said there was no malaria in the area but I can assure you there was. I have had about six or seven re-ocurrances and it is quite debilitating. In the service we were given paludrine and one was expected to take it...it had little to no effect since people still managed to contract the disease.
I have lived in Somalia and in Nigeria and I have to say that malaria never once visited me in these particular areas. As some of the contributors have suggested...get a good grade net and sleep in that. The mosquitos tend to inhabit the dark areas of a house or room so it is useful to spray under the beds, cupboards, wardrobes and anywhere where you think they might be lurking. Wear lond sleeved shirts at night and expose only the minimum. A repellent helps at night...just before going to bed another spray of the room in all thne areas mentioned would be useful.
Places my maleria recurred...UK (twice), France (once) ME (four times).
Hope this is of use!
NC43