By Dr. Joyita Chowdhury, Senior Scientific Officer at India Health Fund
“जलं जीवनम् – water is life”. The banks of the big rivers have been the cradle of all the civilizations. Water and sewage management were given high priority within public health since the ancient time. Excavations showed evidence of paved streets, homes with bathroom facilities and water pipes, and the streets with sunken sewers. This proves the awareness of people about the association between hygiene and diseases. Cholera was the first studied and documented waterborne disease outbreak in the 19th century. Since then, there have many such outbreaks in different parts of the world.1
Around 37.7 million Indians are estimated to be affected by water-borne or faeco-orally transmitted diseases like cholera, diarrhoea, typhoid and viral hepatitis annually, 1.5 million children are estimated to die of diarrhoea alone, and 73 million working days are lost due to water-borne disease each year.2,3 The economic burden is estimated at $600 million a year.2
Diseases like Malaria, Dengue, Chikungunya, Zika, Japanese Encephalitis (JE), Lymphatic Filariasis (LF) and Leptospirosis which are transmitted through vectors like mosquitos and ticks, could be water related, though they are not transmitted by the faeco-oral route.4,5 Malaria causing female anopheles mosquito thrives in polluted water bodies, brackish water, irrigation wells, cisterns, fountains, overhead tanks, seepage water, disused tyres, metal scraps, earthen pots with water hung for birds etc.5,6,7 Anophelese fluviatilis breeds in streams and paddy fields.8 Aedes aegypti, the Dengue vector, grows in fresh water pools,5 while JE vector breeds in tanks, seepage and streams.6 Amongst other weather conditions, prolonged rains, stagnant water and floods aid in disease transmission.9
Rapid urbanization has led to expanding number of vehicles and thus used tires, heavy use of plastic and disposable materials, water collection breeding sites in private and public spaces. Such large number and diverse vector breeding sites and the vector transmission pattern make tracing and implementation of effective vector control a big challenge.10 There has been high dengue incidence every year in southern states due to rainfall. JE cases surge in the rainy season with temperature between 30-44° Celsius.11 Risk of other infectious diseases like Cholera and Leptospirosis goes high due to heavy rainfall and floods and human contamination of water supply.10,12 On the other hand, droughts can increase the incidence of diarrhoea and diseases, such as scabies, conjunctivitis and trachoma, which arises due to poor hygiene.12
Govt of India and various government bodies like municipal corporations have adopted various strategies for water management such as drainage of gutters, different vector control measures.10 streamlining, channelizing, desilting, de-weeding, and trimming of drains and community awareness of good practices.10 13 Technical guidance to the concerned agencies and legislative measures to discourage creation/proliferation of vector breeding are also implemented by the Govt.14
Vector borne diseases are a major public health issue globally for humans, livestock, companion animals, and wildlife. Total economic burden from malaria in India is estimated to be around US$ 1940 million and that of Dengue to be $5.71 billion.15,16 Robust measures like integrated and round the year surveillance system, new vector control strategies and awareness of human behavior pattern are the urgent need of the hour.13 The social determinants of health which influences the epidemiology of VBDs like access to clean water and sanitation, urbanization and current agricultural practices can be managed through intersectoral efforts.11,17
While the Govt enforces several measures, collective participation in the community would augment those efforts. Innovations like micro devices to disinfect water utilizing visible spectrum of light, nanotechnology-based water filters and novel water harvesting technologies can be developed for water sanitation. There are examples of innovative water management across the globe like algae-based wastewater treatment systems where biofilm made of a consortium of algae and bacteria, attached to the wheels supply oxygen to the wastewater while removing nutrients.18 Serious games can be developed like adding a Malaria Pokemon at locations of standing water which can be “captured” by removing the standing water.19 The mapping of water bodies and human activities in water logged areas by citizens with access to satellite imagery and geospatial information could help to locate trash or stagnant water and also identify the high risk population eg WeSenseIt.20 New technologies like eSOS smart toilet whose sensor not only separates the sludge to be processed into water and fertilizer at the right time, but also, tracks the individual user’s data to identify malnourishment or dehydration at an early stage could be breakthrough in India where water, sanitation and hygiene are a big challenge.20
Concerted and united effort towards water management will thus keep the menace of vector borne diseases under check
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