Activity No. 12. Biology and Control of Vectors in Parasitology

Sample Rubric

SUMARY

1. Fasciolosis: Lymnnea spp., Fossaria spp., Succinea and Pseudosuccinea spp.

2. American trypanosomiasis: Triatoma spp., Rhodnius spp., Panstrongilus spp.

3. African trypanosomiasis: Glossina spp.

4. Leishmaniasis: Phlebotomus spp., Lutzomyia spp

5. Malaria: Anopheles spp.

6. Filariasis: Simulium spp., Aedes spp., Culex spp, Mansonia spp.

INTRODUCTION

Vectors are living organisms that can transmit infectious diseases between humans or from animals to humans. Many of these vectors are bloodsucking insects, which ingest disease-producing microorganisms during a blood meal from an infected host (human or animal) and later inject it into a new host during their subsequent blood meal. Mosquitoes are the best-known disease vector. Others include ticks, flies, sandflies, fleas, triatomine bugs, and some freshwater aquatic snails.

Every year there are more than 700 000 deaths from diseases such as malaria, dengue, schistosomiasis, human African trypanosomiasis, leishmaniasis, Chagas disease, yellow fever, Japanese encephalitis, and onchocerciasis, globally.

The major vector-borne diseases, together, account for around 17% of all infectious diseases. The burden of these diseases is highest in tropical and subtropical areas and they disproportionately affect the poorest populations. Since 2014, major outbreaks of dengue, malaria, chikungunya yellow fever, and Zika have afflicted populations, claimed lives and overwhelmed health systems in many countries.

Distribution of vector-borne diseases is determined by complex demographic, environmental and social factors. Global travel and trade, unplanned urbanization and environmental challenges such as climate change can impact on pathogen transmission, making transmission season longer or more intense or causing diseases to emerge in countries where they were previously unknown.

Changes in agricultural practices due to variation in temperature and rainfall can affect the transmission of vector-borne diseases. The growth of urban slums, lacking reliable piped water or adequate solid waste management, can render large populations in towns and cities at risk of viral diseases spread by mosquitoes. Together, such factors influence the reach of vector populations and the transmission patterns of disease-causing pathogens.

OBJECTIVES

- Mention the vectors involved in the transmission of parasitic infections.

- Describe the evolution of the different species responsible for the transmission of parasitic infections.

- Describe the biologic and ecologic characteristics of the vectors responsible for the transmission of parasitic infections.

- Describe the primary and secondary epidemiologic factors that play a role in the prevalence of vector-transmitted infections.

- Explain the strategies recommended to control vector transmitted infections.

DEVELOPMENT

For each of the vectors involved in the transmission of parasitic infections, the student will describe the following elements through a PowerPoint presentation:

- Taxonomy of the vector

- Global distribution of the vector

- Morphologic characteristics of the vector.

- Vector behavior (habitat, lifespan, reproduction, feeding behavior).

- The life cycle of the vector.

- Pathogenic significance

- Primary and secondary epidemiological factors.

- Control strategies for each one of the vectors under study.

- Each group should create a model, drawing, poster or any artistic representation of the vector under study.

Evaluation Rubric (PDF)