The mosquito: Why the ‘little fly’ of many diseases survives efforts to eradicate it

No longer an irritating nuisance, these tiny creatures have caused millions of deaths worldwide. Closer home as many as 11,26,661 cases of malaria were identified with 287 deaths in the country in 2015.

Specimens of Aedes aegypti mosquito are exhibited during a campaign to raise awareness of preventing the entry of the Zika virus into the country, at the Health Ministry in Lima, Peru

Dengue took 200 lives and infected as many as 97,740 persons according to the National Vector borne disease control programme of the Union Ministry of Health and Family Welfare.

Mosquitoes simply cannot be wished away. Like the human race, the mosquito wants to ensure its survival through successive progeny. It is now considered one of the most dangerous creatures due to its ability to spread diseases, says Maharashtra’s surveillance officer Dr Pradip Awate.

This blood-sucker has been increasing manifold: the Centre for Disease Control (CDC), Atlanta estimates that annually the mosquito bites more than 700 million people. No longer an irritating nuisance, these tiny creatures have caused millions of deaths worldwide. Closer home as many as 11,26,661 cases of malaria were identified with 287 deaths in the country in 2015. Dengue took 200 lives and infected as many as 97,740 persons according to the National Vector borne disease control programme of the Union Ministry of Health and Family Welfare.

The threat of these small spindly insects remains constant. The emergence of a little-known virus – Zika – from an African forest is the latest alarm to the world. The same mosquito infects people with dengue and chikungunya viruses. What causes these deadly flying creatures to proliferate and kill?

According to Emory University’s environmental scientist’s Gonzalo Vazquez-Prokopec in an interview in the Science Daily in January this year, aedes aegypti are like “the roaches” of the mosquito world, perfectly adapted to living with humans, especially in urban environments. The scientist who studies vector-borne diseases says that while mosquitoes that carry malaria only feed during the evening, the aedes aegypti feeds almost exclusively on humans and bites primarily during the daytime.

Global warming is having a real impact with the encroachment of mosquito-borne diseases on new territory, including southern Europe. Mosquito-borne illnesses also include West Nile virus, elephantiasis, yellow fever and others but these infections are normally restricted to certain geographic areas. For instance dengue hemorrhagic fever is a viral, mosquito borne illness usually regarded only as a risk in the tropics.

However, cases of dengue fever have now been popping up in the US along the Texas-Mexican border where it has never been seen before. In 2015 it was also reported that, due to climate change, mosquitoes had started to spread historically rare diseases to Europe – malaria to Greece, West Nile virus to eastern Europe and chikungunya to Italy and France.

Mosquitoes are a perfect example of one of the many organisms that can host diseases, explains Dr Mahendra Jagtap, Joint Director of Health (Entomology), Maharashtra.

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Human infection with a mosquito-borne virus occurs when a female mosquito bites someone while its immune system is still in the process of destroying the virus’s harmful coding. When a mosquito bites, she also injects saliva and anti-coagulants into the blood which may also contain disease-causing viruses or other parasites. This cycle can be interrupted by killing the mosquitoes, isolating infected people from all mosquitoes while they are infectious or vaccinating the exposed population.

Presently there is no vaccine yet and killing mosquitoes can be labor-intensive and expensive. Moreover despite all the buzz about genetically modified mosquitoes (where the male of the species can be sterilized making the killers kill themselves) few believe they represent a silver bullet against mosquito-borne diseases.

Authorities in India that is now home to dengue and chikungunya are gearing up to tackle the Zika viral infection transmitted by aedes aegypti. Clearly, these aggressive daytime biters are spreading fast and while the solution may lie in not getting bitten by covering up, scientists and researchers are now looking at newer ways to tackle this menace.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More