Table 3.

Incidence rate ratios of human brucellosis between periods 1997–1998 and 2000–2002

Period	Incidence rate ratio*	95% C.I.
2000–2002 vs 1997–1998	0.15	0.10 – 0.23
2000–2002 (bv**) vs 1997–1998	0.13	0.09 – 0.20
2000–2002 (av***) vs 2000–2002 (bv**)	0.20	0.08 – 0.52

* Poisson regression

** before vaccination

*** after vaccination