Which diseases are spread by the Aedes (African mosquito) mosquito?

Diseases Spread by Aedes Mosquitoes

Aedes mosquitoes transmit four major viral diseases: dengue, yellow fever, chikungunya, and Zika virus. 1

Primary Diseases Transmitted

Dengue Fever

• Dengue is the most common arboviral infection encountered in returning travelers, with a global annual incidence of 50-100 million cases per year and reported from over 100 countries. 1
• The disease presents with fever, headache, retro-orbital pain, myalgia, arthralgia (particularly back pain), and rash, with an incubation period of 4-8 days (range: 3-14 days). 1, 2
• Approximately 15% of dengue cases can progress to dengue hemorrhagic fever or dengue shock syndrome, characterized by plasma leakage, thrombocytopenia, and potentially fatal complications. 2, 3
• Worldwide dengue case numbers increased ten-fold from 2000 to 2019, reaching 5.2 million registered infections. 1

Yellow Fever

• Yellow fever causes approximately 200,000 infections annually, primarily in tropical and subtropical regions of Africa and South America. 1
• The disease has a 20% mortality rate in severe cases, with approximately 15% of infected individuals experiencing severe progression including jaundice, hepatitis, renal failure, hemorrhagic symptoms, and multi-organ failure. 1
• Both Aedes aegypti and Aedes albopictus serve as vectors, with urban yellow fever transmitted person-to-person by Ae. aegypti breeding in domestic containers. 1

Chikungunya

• Chikungunya has an incubation period of 2-3 days (range: 1-12 days) and presents with fever, headache, myalgia, and characteristic polyarthralgia or arthritis. 1
• A major epidemic originating in Mauritius spread to large areas of south and Southeast Asia, with transmission documented in Italy in 2007, marking its emergence in Europe. 1
• The disease is increasingly reported in travelers returning to Europe from endemic areas. 1

Zika Virus

• Zika virus poses particular risk during pregnancy, with vertical transmission occurring in approximately 20-40% of pregnancies and potential for severe fetal complications including microcephaly and neurological disabilities. 1
• The virus can selectively infect the placenta and trigger inflammatory immune responses at the feto-maternal interface. 1

Vector Species and Transmission Patterns

Primary Vectors

• Aedes aegypti is the principal vector for all four diseases, breeding in domestic and peridomestic water containers (water jars, barrels, drums, tires, tin cans) in close association with humans. 1
• Aedes albopictus serves as a secondary vector, particularly for yellow fever and dengue, and has spread into 129 countries over the past five decades. 1, 4
• Both species are day-biting mosquitoes that thrive in urban environments. 1, 3

Geographic Distribution and Spread

• Climate change, rising temperatures, and increased humidity are creating favorable mosquito survival conditions in previously unaffected areas, with southern and central European countries experiencing heightened impact. 1
• Ae. albopictus has established populations in the Netherlands, Germany, Switzerland, the UK, and numerous southern to mid-European nations. 1
• Mathematical models predict Ae. aegypti presence along the Mediterranean coast by 2090 under various climate change scenarios. 1

Clinical Implications and Co-infection Risk

The same Aedes mosquito species can transmit multiple viruses simultaneously in overlapping locations, creating complex surveillance and control challenges. 1

• Current surveillance systems focus on single diseases despite multiple infections clustering in the same communities and individuals. 1
• Co-circulation of dengue, chikungunya, Zika, and yellow fever in the same geographic areas requires integrated vector management approaches rather than disease-specific interventions. 1

Critical Pitfalls to Avoid

• Do not assume Aedes-transmitted diseases are limited to tropical regions—climate change and globalization have facilitated vector spread into temperate zones including Europe and North America. 1
• Pregnant women require heightened vigilance for Zika and dengue infections due to risks of vertical transmission and maternal complications. 1, 3
• Failure to recognize warning signs of severe dengue (persistent vomiting, abdominal pain, mucosal bleeding, rising hematocrit with falling platelets) can result in preventable mortality. 2, 3