Model Answer
0 min readIntroduction
Vector-borne diseases represent a significant global public health challenge, accounting for over 17% of all infectious diseases and more than 700,000 deaths annually (WHO, 2023 - knowledge cutoff). These illnesses are transmitted by vectors – living organisms, typically arthropods like mosquitoes, ticks, fleas, and sandflies – that carry pathogens between hosts. Climate change, urbanization, and increased international travel are exacerbating the spread of these diseases, necessitating robust surveillance and control measures. Understanding these diseases and the international frameworks designed to combat them is crucial for effective public health interventions.
What are Vector-Borne Diseases?
Vector-borne diseases are illnesses caused by pathogenic microorganisms (viruses, parasites, bacteria) that are transmitted to humans and other vertebrate animals by vectors. The vector acts as an intermediary, acquiring the pathogen from an infected host and transmitting it to a susceptible host during feeding or other contact. The disease transmission cycle involves the pathogen, the vector, the reservoir host (where the pathogen naturally resides), and the human host.
Five Vector-Borne Diseases and Their Vectors
Here's a list of five vector-borne diseases, specifying the vector responsible for transmission:
| Disease | Vector | Geographical Distribution (General) |
|---|---|---|
| Malaria | Anopheles mosquitoes | Tropical and subtropical regions globally, particularly Africa, Asia, and South America |
| Dengue Fever | Aedes aegypti and Aedes albopictus mosquitoes | Tropical and subtropical regions worldwide, increasingly expanding due to climate change |
| Zika Virus Disease | Aedes mosquitoes (primarily Aedes aegypti) | Tropical and subtropical regions, with outbreaks in the Americas and Pacific Islands |
| Lyme Disease | Blacklegged ticks (Ixodes scapularis and Ixodes pacificus) | North America, Europe, and parts of Asia |
| Chikungunya | Aedes aegypti and Aedes albopictus mosquitoes | Africa, Asia, Europe, and the Americas |
International Travel Health Regulations (IHR) to Check Spread
The International Health Regulations (IHR) (2005), legally binding on 196 countries, are a crucial framework for preventing and controlling the international spread of diseases, including vector-borne diseases. The IHR aim to provide public health security by establishing requirements for surveillance, reporting, and response to public health events.
Key Provisions of IHR relevant to Vector-Borne Diseases:
- Surveillance and Reporting: Countries are required to develop and maintain core public health capacities, including surveillance systems to detect and report events that may constitute a Public Health Emergency of International Concern (PHEIC).
- Designated Ports and Airports: The IHR designate specific ports and airports where health measures can be implemented to prevent the introduction and spread of diseases.
- Health Certificates and Vaccination Requirements: The IHR allow for the implementation of health certificates and vaccination requirements for travelers from areas with a high risk of specific vector-borne diseases (e.g., Yellow Fever vaccination).
- Vector Control Measures: The IHR encourage countries to implement vector control measures at ports and airports, such as disinsection of aircraft and ships.
- Emergency Provisions: The IHR provide a framework for responding to PHEICs, including the declaration of a PHEIC by the WHO Director-General and the implementation of temporary recommendations to prevent the international spread of disease.
The WHO plays a central role in coordinating the implementation of the IHR, providing technical assistance to countries, and monitoring global health risks. The IHR are periodically reviewed and updated to address emerging health threats and improve global health security.
Conclusion
Vector-borne diseases pose a persistent threat to global public health, demanding a multi-faceted approach encompassing vector control, disease surveillance, and international collaboration. The International Health Regulations (IHR) provide a vital framework for coordinating global efforts to prevent and control the spread of these diseases. Strengthening national public health systems, investing in research and development of new tools, and addressing the underlying drivers of disease emergence, such as climate change and urbanization, are essential for mitigating the impact of vector-borne diseases in the future.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.