Read the given passage and answer the following questions.
Maintenance of personal and public hygiene is very important for prevention and control of many infectious diseases. Measures for personal hygiene include keeping the body clean; consumption of clean drinking water, food, vegetables, fruits, etc. Public hygiene includes proper disposal of waste and excreta; periodic cleaning and disinfection of water reservoirs, pools, cesspools and tanks and observing standard practices of hygiene in public catering. These measures are particularly essential where the infectious agents are transmitted through food and water such as typhoid, amoebiasis and ascariasis. The advancements made in biological science have armed us to effectively deal with many infectious diseases. The use of vaccines and immunisation programmes have enabled us to completely eradicate a deadly disease.
Which among the following measures is used to control or eliminate the vectors?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → All of these.
Malaria, filariasis, dengue and chikungunya are carried by mosquitoes, which are vectors. The most important way to control these diseases is to control or remove the vectors and the places where they breed. Mosquito larvae grow in still water, so stopping water from collecting and using fish that eat the larvae both cut down their numbers.
Option (1) Avoiding stagnation of water in and around residential areas. — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Avoiding stagnant water around homes removes the breeding places of mosquitoes.
Option (2) Use of mosquito nets. — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Mosquito nets keep the adult mosquitoes away from people.
Option (3) Introduction of Gambusia fish in ponds. — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Gambusia is a fish that feeds on mosquito larvae, so putting it in ponds cuts down their numbers.
NCERT Extract:
Common Diseases in Humans – “… For diseases such as malaria and filariasis that are transmitted through insect vectors, the most important measure is to control or eliminate the vectors and their breeding places. This can be achieved by avoiding stagnation of water in and around residential areas, regular cleaning of household coolers, use of mosquito nets, introducing fishes like Gambusia in ponds that feed on mosquito larvae, spraying of insecticides in ditches, drainage areas and swamps, etc.”