Dengue in Africa (Update 2)

The World Health Organisation reports continuing transmission of dengue in countries across Africa. The latest WHO update of 29 December 2017 reports the following:

Burkina Faso: 14 445 cases (including 29 deaths) have been reported between 1 January and 10 december 2017. The outbreak has been declining since the end of october 2017. Most (62%) cases have been reported in the central region, notably in the capital Ouagadougou.

Cote d'Ivoire: 1 421 cases (including 2 deaths) have been reported between 22 April and 16 December 2017. The outbreak is centred on the capital Abidjan and has been declining since the end of August 2017.

Mali: 429 cases (no deaths) were reported between 1 August and 10 december 2017. All of these were in the capital, Bamako and the Kati health district northwest of Bamako. The outbreak is declining with no suspected cases reported since 9 December 2017.

Mauritania: between 30 November and 13 December, 37 cases of dengue were reported, Of these cases, 3 were dengue haemorrhagic fever.

Senegal: between 28 September and 17 December 2017, 783 (no deaths) were reported.Laboratory confirmed cases were reported from the Louga region (128), Fatick (2), Mbour (1), and Dakar (5).

Seychelles: between 20 July and 28 November 2017 4233 cases (no deaths) were reported from all regions of the three main islands (Mahe, Praslin, and La Digue).

Sudan: between 2 October and 8 December 2017, the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) reported 137 suspected dengue cases (including 3 deaths). These were were reported from Khartoum, Kassala, East and West Darfur, South Kordofan, Red Sea, River Nile and Gezira States. Most cases (118) were reported from Kassala State.

Advice for Travellers

Dengue is the second most common identified cause of febrile illness in returning travellers and the number of cases in travellers continues to increase. All travellers to endemic regions are potentially at risk of dengue fever and should be aware of this infection. Prevention relies on avoiding mosquito bites.

Aedes mosquitoes are particularly persistent and aggressive and bite between dawn and dusk.

Methods of bite avoidance include:

• Wearing long, loose, lightly coloured clothing to cover up the skin during the day.
• The use of insect repellent containing DEET applied to any exposed skin between dawn and dusk.
• When sunscreen and DEET are used together, DEET should be applied after sunscreen. The effectiveness of repellent reduces more rapidly than sunscreen, therefore, repellent may have to be reapplied on top of sunscreen.
• The use of permethrin, impregnated mosquito nets protects against early morning bites and should also be used when sleeping during the day.
• The use of air conditioning if available and/or mesh screening of windows and doors.
• Eradication of mosquito breeding sites around accommodation/home (e.g. open containers, old tyres or flower pots that may collect water).

Vaccine

There is no vaccine against dengue fever licensed in the UK.

At present the World Health Organisation (WHO) is trialling several candidate vaccines against dengue fever.

• Dengvaxia®, developed by Sanofi Pasteur MSD, is the first vaccine to be licensed for the prevention of dengue.
• It is a live, attenuated, recombinant, tetravalent vaccine approved for use in people 9–45 years of age living in highly endemic regions on a 3 dose schedule.
• Prior dengue infection increases the efficacy of the vaccine; efficacy is reduced in populations with low previous exposure to dengue and may lead to increased rates of hospitalisation due to severe dengue.M
• Mexico, Costa Rica, the Phillippines and Brazil are the first countries to have granted marketing authorization for Dengvaxia®. December 2017 - use of this vaccine is currently under review due to safety concerns.

For further information see Dengue Fever.