Brazil's Health Ministry says the current outbreak has grown so large because it is hitting densely populated areas.
Brazil Health Ministry officials have confirmed 846 cases of yellow fever, including 260 deaths.
The Kebbi, Nigeria Commissioner for Health has reported 36 cases of yellow fever in eight local government areas of the state.
Brazil has confirmed 723 yellow fever cases with 237 deaths from July 1, 2017 to February 28, 2018, while over the same period in 2017, 576 yellow fever cases with 184 deaths were confirmed.
From July 1, 2017 to February 20, 2018, Brazil has confirmed 545 cases of yellow fever, with 164 deaths.
The Brazil Ministry of Health has confirmed 545 yellow fever cases with 164 deaths between July 1, 2017 and February 20, 2018.
Brazil's health ministry’s weekly yellow fever update showed a steep rise in confirmed cases, which are now at 353, an increase of 140 cases from the previous week.
From July 1, 2017 to February 6, 2018, 353 cases of yellow fever were confirmed in Brazil, of which 98 died.
The Brazil Ministry of Health reported 213 cases of yellow fever, including 81 deaths from July 1, 2017 to January 30, 2018.
Brazilian authorities aim to vaccinate almost 22 million people, but due to vaccine shortages 16.5 million will be given only partial doses.