WHO EMRO Weekly Epidemiological Monitor: Volume 11, Issue 46 (18 November 2018)
Current major event
Chikungunya update: Sudan
Sudan has had a major outbreak of Chikungunya since July 2018. A total of 20,110 cases have been reported since the outbreak began. No new cases of the disease were reported during the week ending 11th November 2018.
Chikungunya is self-limiting and has a low mortality rate. Chikungunya can easily be mistaken for other arboviral diseases such as dengue, as they share similar initial clinical presentation and are transmitted through a common vector – the Aedes mosquito.This vector is present in most of the countries of Eastern Mediterranean Region (EMR).
In the EMR, Chikungunya was detected for the first time during serological surveys conducted in Pakistan in 1983. In 2011, Yemen reported the first outbreak of the disease in the Region; there were a total of over 15,000 suspected cases and 104 suspected deaths during this outbreak. In 2017, Pakistan reported a major outbreak of Chikungunya with over 8000 cases in multiple provinces. Sporadic cases of the disease have been reported from Saudi Arabia and Sudan.
The current outbreak of Chikungunya in Sudan was concentrated in the Kassala state, with Kassala locality as the epi-center. The outbreak subsequently spread to other parts of the country; states that have reported at least one case of Chikungunya since the beginning of the outbreak include Red Sea (192 cases), Gdarif (7 case), Al Gezeera (6 case), West Darfur (2 case), Sennar, and River Nile reported one case each. While the peak incidence of the disease was observed between the months of September and early October 2018, there has been an overall decreasing trend from the second week of October, (Please see graph).
Even though the vector for the disease is known to be present in the country, other factors that are believed to have played a part in the large outbreak of Chikungunya include population movement, climate change, poor water and sanitation conditions, water supply and storage (containers), and high population density areas that increase contacts between vectors and humans.
Key outbreak containment measures have included vector control to interrupt transmission of the disease; enhanced surveillance of the disease for early detection of cases and monitoring of effectiveness of outbreak response efforts; vector surveillance to monitor mosquito density and impact of vector control; and community awareness campaigns to reduce the risk of infection in the affected areas. These response measures were undertaken by the Ministry of Health with the support from WHO and other partners.