Table 3.

Incubation periods

Incubation period	Infection
Short (<10 days)	Acute gastroenteritis (bacterial, viral)
	Arboviral infections (e.g. dengue, chikungunya)
	Meningitis (bacterial, viral)
	Relapsing fever (Borrelia spp.)
	Respiratory tract infection (bacterial, viral including influenza)
	Rickettsial infection (e.g. tick typhus, scrub typhus)
Medium (10–21 days)	Bacterial •Brucellosis •Enteric fever (typhoid and paratyphoid fever) •Leptospirosis •Q fever
	Fungal •Coccidioidomycosis •Histoplasmosis (can be as short as 3 days)
	Protozoal •Chagas' disease (acute) •Malaria (Plasmodium falciparum) •East African trypanosomiasis (Trypanosoma brucei rhodesiense)
	Viral •CMV, EBV, HIV, viral haemorrhagic fevers
Long (>21 days)	Bacterial •Brucellosis •Tuberculosis
	Fluke •Schistosomiasis, acute (Katayama fever)
	Protozoal •Amoebic liver abscess •Malaria (including Plasmodium falciparum) •West African trypanosomiasis (Trypanosoma brucei gambiense) •Visceral leishmaniasis
	Viral •HIV •Viral hepatitis (A–E)

CMV, cytomegalovirus; EBV, Epstein–Barr virus; HIV, human immunodeficiency virus.

Adapted from British Infection Society recommendations. See: Johnston V, Stockley JM, Dockrell D, et al. Fever in returning travellers presenting in the United Kingdom: recommendations for investigation and initial management. J Infect 2009; 59: 1–18.