---
title: "Water vector diseases"
subject: "Water Supply Engineering"
chapter: 4
key: "semester_5/water_supply_engineering:water-vector-disease"
source: https://www.bctengineer.com/q/semester_5/water_supply_engineering/water-vector-disease
site: BCT Engineering
---

# Water vector diseases

Water Supply Engineering · Chapter 4: Quality of Water

- Asked in: 2070 Asar, 4 marks
- Video: [Water Related disease in Nepali | water borne disease| water vector disease | water based | washed](https://www.youtube.com/watch?v=ZC_ukqIiB7U) — Civil Engineering Power
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/water_supply_engineering/water-vector-disease
- Whole chapter: https://www.bctengineer.com/md/semester_5/water_supply_engineering/chapter-4

## Question

What do you understand by water vector disease? Describe any two types of water vector diseases.

## Short answer

Water vector diseases are transmitted by insects breeding in water. Malaria is caused by Plasmodium via Anopheles mosquitoes in stagnant water; dengue is caused by a virus via Aedes mosquitoes in clean stored water.

## Answer

**Water-related insect vector diseases** (water vector diseases) are diseases transmitted by insects that breed in water or bite near water. The pathogen is not in drinking water; it is carried by the insect (vector) from an infected to a healthy person.

#### Two examples
**1. Malaria**
- Cause: Plasmodium parasite.
- Vector: female Anopheles mosquito, which breeds in stagnant, clear water (ponds, paddy fields, puddles).
- Transmission: the mosquito bites an infected person, picks up the parasite, and transmits it when it bites another person.
- Symptoms: fever with chills and sweating.

**2. Dengue**
- Cause: Dengue virus.
- Vector: Aedes aegypti mosquito, which breeds in clean water held in containers, tyres and water tanks.
- Transmission: by the bite of an infected mosquito, mainly in the daytime.
- Symptoms: high fever, severe headache, joint pains and rash.

Other water-related vector diseases are yellow fever (Aedes), Japanese encephalitis and filariasis (Culex), and river blindness (Simulium blackfly).

#### Control
Drain stagnant water, cover storage tanks, use larvicides and fish that eat larvae, use bed nets and repellents, spray insecticides, and give community awareness.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. In water vector diseases the pathogen is carried by:
   A. insects that breed in or near water
   B. drinking water
   C. unwashed hands
   D. lack of water
   Answer: A. The pathogen is not in drinking water. (Key point: Definition)

2. Malaria is transmitted by:
   A. Aedes aegypti in tyres
   B. female Anopheles breeding in stagnant clear water
   C. houseflies
   D. Cyclops
   Answer: B. Cause is Plasmodium. (Key point: Malaria vector)

3. Dengue vector Aedes aegypti breeds in:
   A. sewage only
   B. fast rivers
   C. clean water held in containers, tyres and tanks
   D. salt water
   Answer: C. It bites in the daytime. (Key point: Dengue)

4. Control of these diseases includes:
   A. increasing chlorine
   B. softening water
   C. vaccinating wells
   D. draining stagnant water, covering tanks, larvicides, bed nets
   Answer: D. These reduce vector breeding and bites. (Key point: Control)

## Related in Water Supply Engineering

- [Water washed diseases and prevention](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Awater-washed-diseases) — Water Supply Engineering, chapter 4, asked 2×
- [Water-based diseases](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Awater-based-diseases-define) — Water Supply Engineering, chapter 4, asked 2×
- [Fecal-oral disease transmission route](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Afecal-oral-route) — Water Supply Engineering, chapter 4, asked 7×
- [Waterborne diseases, transmission, prevention](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Awater-borne-diseases) — Water Supply Engineering, chapter 4, asked 3×
- [Water supply system and historical development](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Aws-historical-development) — Water Supply Engineering, chapter 1

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