Vector-borne diseases

Climate change is altering the distribution patterns of mosquitoes, making it easier for them to appear in regions where they were not seen before. Warmer temperatures and changes in rainfall patterns create favourable mosquito breeding and survival conditions. This has led to:

– Geographic expansion: mosquitoes along with Aedes albopictus (tiger mosquito) are becoming established in higher latitudes, including parts of Europe and North America.

– Prolonged seasonality: Longer and cooler seasons allow mosquitoes to survive and breed longer.

– Increased disease incidence: Due to their increased presence, more areas are at risk of mosquito-borne disease outbreaks.

– Aedes aegypti: Main transmitter of dengue, chikungunya, Zika and yellow fever. Predominantly found in tropical and subtropical areas.

– Aedes albopictus (Asian Tiger Mosquito): Transmits dengue and chikungunya. It is spreading in Europe, especially in southern and central countries.

– Anopheles spp.: Transmitters of malaria, present in tropical areas and some temperate regions.

– Culex spp: Known to transmit West Nile virus, common in urban and rural areas.

Mosquito-borne diseases are caused by viruses and parasites that mosquitoes carry and transmit to humans through their bites. Some of the most common diseases include:

1. Dengue
   • Vector: Aedes aegypti and Aedes albopictus mosquitoes.
   • Causative Agent: Dengue virus (DENV).
   • Symptoms: High fever, headache, pain behind the eyes, muscle and joint pain, rash, and in severe cases, dengue haemorrhagic fever.
   • Prevention: Elimination of mosquito breeding sites, use of repellents, mosquito nets and protective clothing.
2. Malaria
   • Vector: Anopheles mosquitoes.
   • Causative Agent: Plasmodium spp. (P. falciparum, P. vivax, P. malariae, P. ovale, P. knowlesi).
   • Symptoms: Fever, chills, sweating, headache, nausea and vomiting, anaemia and, in severe cases, organ dysfunction and death.
   • Prevention: Use of insecticide-treated bed nets, indoor spraying with insecticides, prophylaxis with antimalarial drugs.
3. Zika
   • Vector: Aedes aegypti and Aedes albopictus mosquitoes.
   • Causal Agent: Zika virus.
   • Symptoms: Mild fever, rash, conjunctivitis, muscle and joint pain, headache. In pregnant women, may cause microcephaly in fetuses.
   • Prevention: Mosquito control, use of repellents, avoid pregnancy in areas of active transmission.
4. Chikungunya
   • Vector: Aedes aegypti and Aedes albopictus mosquitoes.
   • Causative Agent: Chikungunya virus.
   • Symptoms: High fever, severe joint pain, muscle pain, rash, fatigue.
   • Prevention: Elimination of mosquito breeding sites, use of repellents, mosquito nets and protective clothing.
5. Yellow Fever
   • Vector: Aedes aegypti mosquito.
   • Causative Agent: Yellow fever virus.
   • Symptoms: Fever, headache, jaundice, muscle pain, nausea and vomiting, liver and kidney failure in severe cases.
   • Prevention: Vaccination, mosquito control.
6. Lyme disease
• Vector: Ticks of the genus Ixodes.
• Causative agent: Bacterium Borrelia burgdorferi.
• Symptoms: Erythema migrans (bull’s eye rash), fever, headache, fatigue, arthritis, neurological and heart problems.
• Prevention: Wear protective clothing, check for ticks after outdoor activities, use repellents.
7. Japanese encephalitis
   • Vector: Culex mosquito.
   • Causative agent: Japanese encephalitis virus.
   • Symptoms: Fever, headache, vomiting, confusion, convulsions, and in severe cases, inflammation of the brain (encephalitis).
   • Prevention: Vaccination, mosquito control.

1. Vector control
   • Eliminate breeding sites: Remove or treat containers with standing water where mosquitoes can breed.
   • Insecticides: Use of insecticides indoors and outdoors to reduce vector populations.
   • Mosquito nets: Use of insecticide-treated mosquito nets to protect against mosquito bites at night.
2. Personal Protection
   • Insect Repellents: Apply repellents to exposed skin and clothing.
   • Protective Clothing: Wear long-sleeved clothing and long trousers, especially in areas of high transmission.
   • Vaccination: For some diseases along with yellow fever and Japanese encephalitis, effective vaccines are available.
3. Education and Awareness
   • Awareness Campaigns: Inform the community about the importance of vector prevention and control.
   • Community Involvement: Encourage active community participation in vector control activities.
4. Surveillance and Rapid Response
   • Vector Monitoring: Constant surveillance of the vector population and disease cases.
   • Rapid Response: Implement control measures quickly upon detection of outbreaks to prevent spread.