Consider the following statements.
I. Getting vaccinated is recommended to prevent infections.
II. Diseases such as polio, diphtheria, pneumonia and tetanus have been controlled to a large extent by the use of vaccines.
III. Controlling or eliminating vectors is essential in diseases like malaria and filariasis.
IV. Culex mosquitoes are responsible for transmitting both dengue and chikungunya.
Which of the statements given above are correct?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → I, II and III
Infectious diseases are prevented in two main ways. Vaccines prepare the body to fight a pathogen before it attacks. For diseases spread by insect vectors, the vectors and their breeding places are controlled.
Statement I: Getting vaccinated is recommended to prevent infections. — True. Vaccines and immunisation programmes have wiped out smallpox and controlled many other infections.
Statement II: Diseases such as polio, diphtheria, pneumonia and tetanus have been controlled to a large extent by the use of vaccines. — True. These four are the diseases the book names as controlled by vaccines.
Statement III: Controlling or eliminating vectors is essential in diseases like malaria and filariasis. — True. Malaria and filariasis spread through mosquitoes, so control of the vectors and their breeding places is the most important measure.
Statement IV: Culex mosquitoes are responsible for transmitting both dengue and chikungunya. — False. NCERT names Aedes mosquitoes as the vectors of dengue and chikungunya, not Culex mosquitoes.
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. … Such precautions have become more important especially in the light of recent widespread incidences of the vector-borne (Aedes mosquitoes) diseases like dengue and chikungunya in many parts of India. 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 like smallpox. A large number of other infectious diseases like polio, diphtheria, pneumonia and tetanus have been controlled to a large extent by the use of vaccines.”