TOKYO, Japan, September 16, 2014 (AMG) – Japan has been hit by a dengue fever epidemic for the first time since 1945, with figures suggesting that at least 96 people have caught the mosquito-borne viral infection since August this year.

Yoyogi Park in Tokyo is believed to be the centre of the current outbreak, although two cases have been reported from outside this area in recent days.

Japan has experienced imported cases of dengue from returning travellers in the past, but this is the first time in 70 years that domestic mosquitoes have transmitted the disease. An unusually wet summer has been blamed by the authorities for fuelling the outbreak, but the number of mosquito vectors is expected to reduce dramatically by autumn as the weather changes.

In an effort to contain the epidemic, signs have been placed around the park – which has been closed – warning people in the vicinity to cover bare skin and use insect repellent to prevent bites. Authorities have sprayed pesticides and drained lakes for additional precautions.

Dengue causes symptoms including fever, severe headache, muscle and joint pain, nausea, swollen glands and a rash. The vast majority of patients recover from infection, however, it is a leading cause of death among children in Latin America and the Caribbean, as well as some parts of Asia. Approximately 500,000 cases of dengue haemorrhagic fever occur each year, which can have a fatality rate as high as 20% if early care is not given.

While there are no vaccines available for Dengue Fever, an experimental vaccine trial carried out this year with 20,000 children aged 9 to 16 years living in Latin America and the Caribbean proved to be 60% effective.

Climate links feared: The mosquitoes that transmit Dengue Fever are predominantly found in tropical and sub-tropical regions, prompting concerns voiced at a recent conference held in Geneva that global warming may be contributing to its worldwide spread. Higher temperatures and greater humidity may cause mosquitoes to live longer, increasing the likelihood they are able to transmit not only dengue but malaria as well.

Prior to 1970, nine countries reported dengue haemorrhagic fever whereas today it is been seen in over 100 countries. The disease infects 100 million people annually and around 40% of the world’s population lives in an area where it is endemic.

The United Nations will convene a conference of world leaders on climate change in New York from September 22-28, where it is that hoped climate sensitive infectious diseases, such as dengue and malaria, will be discussed and decisive action taken.

Dengue Fever hits Japan for the first time in 70 years

Deborah Almond

Deborah Almond is AMG's Health Editor and an infectious disease specialist, with experience in sexual and reproductive health and malaria in pregnancy. She holds an MSc from the London School of Hygiene & Tropical Medicine and a BSc from University College London.

Category: Health