The number of people diagnosed with dengue fever (contracted from the bite of a mosquito) in north India is twice the number diagnosed last year. Municipal authorities have concluded that measures to control the mosquito population have failed in this region. Which one of the following statements, if true, does not contradict this conclusion?
A high proportion of the affected population has returned from neighbouring countries where dengue is prevalent
More cases of dengue are now reported because of an increase in the Municipal Office’s administrative efficiency
Many more cases of dengue are being diagnosed this year since the introduction of a new and effective diagnostic test
The number of people with malarial fever (also contracted from mosquito bites) has increased this year