Health Professionals

Clinical Updates

21 February 2013

Recent yellow fever activity update: Chad, Côte d’Ivore, Nigeria

In Africa, 34 countries are considered at risk of yellow fever (YF) [1]. Since 2000, 18 YF endemic countries in Africa have reported cases to the World Health Organization (WHO), with the greatest burden of disease occurring in West Africa [2]. Outbreaks have also been reported in Central and East Africa [3]. Country reporting systems and the level of information sent to the WHO differ. Case numbers and outbreaks reported may not accurately represent YF activity.


As of December 2012, two yellow fever cases were confirmed in Goz Beida and Guereda. Intensive surveillance in Chad also reported 139 suspected cases and nine deaths. The Ministry of Health in Chad is launching an emergency mass-vaccination campaign on 22 February 2013 [4].

Côte D’Ivoire

In 2012, the WHO Regional Office for Africa reported four cases of YF, including one death [5].


As of 8 February 2013, the Federal Ministry of Health have reported 38 suspected cases of YF in 10 states (Abia, Adamawa, Akwa Ibom, Bayelsa, Benue, Gombe, Imo, Kano, Ondo and Sokoto) [6].

Advice for health professionals

Under International Health Regulations (2005) countries are no longer required to automatically report YF outbreaks to WHO [7]. Surveillance and reporting in YF risk countries can be poor. When undertaking YF risk assessment, health professionals should refer to individual country information where details relating to YF disease risk areas and recommendations for YF vaccination are given. 

In addition, health professionals are encouraged to access the NaTHNaC Outbreak Surveillance Database where verified and unverified outbreaks of YF are posted.

Advice for travellers

YF is transmitted to non-human primates or humans via the bite of an infected mosquito. In Africa, the virus is transmitted via the bite of Aedes spp. mosquitoes that feed predominantly during daylight hours.

Travellers should take mosquito bite avoidance measures and seek advice regarding YF vaccination before travelling to YF risk areas. YF vaccination is recommended for personal protection for all travellers aged nine months and older to countries with a risk of YF.

Full details of YF vaccination recommendations can be found on the NaTHNaC’s Country Information Pages. Details of the countries that require proof of YF vaccination as a condition of entry (under the International Health Regulations (2005) are also provided.


1. World Health Organization: Yellow Fever Vaccination Recommendations in Africa, 2011. [Accessed 21 February, 2013]. Available at:


2. World Health Organization: Global Alert and Response (GAR). 2013. The West African situation. (Accessed 21 February, 2013). Available at:


3. World Health Organization: Global Alert and Response (GAR). Yellow fever. 2013. (Accessed 21 February, 2013). Available at:

4. World Health Organization. Yellow fever in Chad. 14 February 2013. (Accessed 21 February, 2013). Available at:

5. World Health Organization Regional Office for Africa. Outbreak Bulletin 2 (10). 07 February 2013. (Accessed 21 February, 2013). Available at:

6. Federal Ministry of Health - Nigeria. 08 February 2013. Update on Epidemics. Week 5 (28th Jan – 2nd Feb 2013). (Accessed 21 February, 2013). Available at:


7. World Health Organization. International Health Regulations. About the IHR. 2013. [Accessed 21 February, 2013]. Available at: