Dengue blood testing kit. Diagnostic kit to test human blood for antibodies to the dengue fever viruses. Dengue fever is a flu-like illness that can involve a rash. The viruses are passed to humans by mosquito bites. Infection by one of the dengue viruses provides an immunity to that virus. However, a second infection with another one of the dengue viruses can lead to a more serious, haemorrhagic (bleeding) form of the disease. Blood tests can help determine who is at risk from such secondary infections. There is no treatment for the disease, only management of the symptoms. Pest control measures are used to prevent infection. Photographed at the Pedro Kouri Institute, Cuba.