It's my first night on duty as a registrar in a busy Sydney ED. A young aboriginal man, just off the coach from northern Queensland, is brought onto the ward screaming with pain. Nursing staff undress him carefully and record his vital signs. He is tachycardic, hypotensive and pyrexic (40 degrees C). He has a widespread petechial rash and is bleeding from his nose and mouth. His clothes are stained with melaena. It was like nothing I’d seen before. Fortunately my colleagues knew exactly what they were dealing with – a life threatening case of Dengue Fever.
Dengue virus is transmitted through the bite of the Aedes mosquito. According to the World Health Organisation, 40% of the world's population live in areas where the virus can be transmitted. Infection is often asymptomatic, but a small proportion can develop shock (Dengue Shock Syndrome) and blood loss (Dengue Haemorrhagic Fever). As many as 20,000 people die from these complications each year.
Despite rapid administration of intravenous crystalloid and blood products the patient died the next day from a massive intracerebral haemorrhage.
A volunteer from Townsville releasing Wolbachia-infected mosquitoes
I was therefore glad to read last week about the success of the first large scale release of Wolbachia-infected mosquitoes into parts of Queensland. Bred in captivity, these mosquitoes are unable to transmit the Dengue virus. With the help of local residents it has been possible to establish a population of Wolbachia-infected mosquitoes over an area of 66 sq km. As a result there has not been a single case of Dengue Fever in the last four years. Details of the study can be found here.