Pests are a major threat to health worldwide, ranging from mosquitoes and other insects that transmit debilitating diseases through bites, to rodents that contaminate food and surfaces around homes and businesses. Rodents are also secondary hosts for a large number of diseases transmitted by the parasites that they carry into the human environment — ticks, lice, fleas and mites.

The population at risk is immense: 6 billion people are estimated to be at risk from gastrointestinal diseases transmitted by pests and 3 billion from malaria alone, according to WHO. The economic implications of these diseases are also immense in both developing and developed countries. In developing countries, large proportions of the population suffer debilitating diseases, overwhelming health services. In developed countries businesses suffer stock and product loss and loss of sales, and health systems bear added costs of both preventable and new emerging diseases.

The threat of pest-borne diseases is growing due to climate change, international travel, globalisation of trade and increasing urbanisation taking over the natural habitats of disease-bearing pests. A better understanding of these diseases is essential for managing them in the future.


A) Dengue

  • Insects: Mosquitoes

  • Organism: Dengue virus

B) Malaria

  • Insect: mosquitoes

  • Organism: Protozoan, Plasmodium falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi

C) Asthma

  • Insect: House dust mites & Cockroaches.

  • Organism: none known (allergic response).

D) Amoebic dysentery

  • Insects: cockroaches, flies

  • Organism: protozoan, Entamoeba histolytica

E) Anthrax

  • Insect: horse fly, deer fly, house fly, blow fly, mosquitoes.

  • Organism: bacteria, Bacillus anthrax

F) Chikunguya fever

  • Insect: mosquitoes

  • Organism: virus, Chikunguya virus.

G) Cholera

  • Insect: House Fly, Blow Fly, Flesh Fly

  • Organism: bacteria, Vibrio cholera.

H) Salmonellosis

  • Insect: house flies, blow flies, flesh flies, cockroaches

  • Organism: bacteria, Salmonella enterica


As we humans take over and expand our activities into the remaining natural environment we come into closer contact with more species of rodents and more diseases.

Apart from rats and mice, other well-known rodents that can carry diseases and come into human contact include prairie dogs, groundhogs, ground squirrels, lemmings and voles.

In fact, rodents are thought to be responsible for more deaths than all the wars over the last 1,000 years.

A) Salmonellosis

B) Rat-bite fever

C) Plague