How many of the following diseases are vector-borne?

Malaria, Dengue, Common cold, Filariasis, Chikungunya, Ascariases, Typhoid, Pneumonia

The correct option is D Four

• Malaria is caused by a protozoan Plasmodium. Its vector is female Anopheles mosquito.
• Dengue fever is caused by retroviruses. Its vector is Aedes aegypti mosquito.
• Common cold is caused by Rhinoviruses and is transmitted through the inhalation of droplets from the cough or sneezing.
• Filariasis is caused by the filarial nematode Wuchereria. Its vectors are Culex and Aedes mosquito.
• Chikungunya fever is caused by Alphavirus. Its vector is Aedes mosquito.
• Ascariasis is caused by the helminthic worm Ascaris lumbricoides. It is transmitted through contaminated food and water.
• Typhoid fever is caused by Salmonella typhi. It is transmitted through contaminated food and water.
• Pneumonia is caused by Streptococcus pneumonia. It is an infection that spreads by the airborne droplets.

Hence, vector-borne diseases are Malaria, Dengue, Filariasis, and Chikungunya.

So, the correct answer is 'Four'.