Table 1. In vitro antibiotic susceptibility of R. prowazekii, Breinl (ATCC VR-142) and

Madrid E (ATCC VR-233) strains. The minimum antibiotic doses or MAD (mg/egg)

allowing a DMST > 2.5 days in the embryonated egg model, and MICs (mg/L) obtained

in cell culture models are presented.

Table 2. Recommendations for antibiotic treatment of R. prowazekii infections.

Condition	antibiotic	dose	duration	References
epidemic typhus in adult and in child > 8 years and Brill Zinsser disease	1. doxycycline	100 mg b.i.d. p.o. (i.v. in case of severe disease)	7-14 days	(9, 13, 16, 35)
	2. doxycycline	100-200 mg p.o.	single dose	(9, 10, 13, 27)
	3. chloramphenicol	500mg every 6 hours	7-14 days	(9, 13)
epidemic situation	doxycycline to all suspected cases	100 mg b.i.d. p.o.	2 days	(29, 30)
child of less than 8 years old	1. doxycycline	100-200 mg p.o.	single dose
child of less than 8 years old	2. chloramphenicol	50mg/Kg/day in divided doses every 6 hours	7-14 days