ZSI study finds human blindness-causing blackfly in rivers flowing through Darjeeling, Kalimpong
The Zoological Survey of India (ZSI) has recently spotted blackflies, which serve as carriers of a worm causing human blindness, in many rivers flowing through the northern parts of West Bengal.
Locally called 'pipsa' or 'potu', the blood-sucking flies were found in rivers in areas such as Darjeeling and Kalimpong that serve as the insect's breeding grounds. The finding raises concern as the areas draw many tourists throughout the year.
'Whether Darjeeling or Kalimpong, both places are favourites among Bengalis on the tourism map, making them socio-economically significant. People visit these places throughout the year. Visitors may unknowingly get bitten by these blood-sucking flies while enjoying themselves. Although local people are more vulnerable to these flies, the risk of blindness remains a concern,' Dr Dhriti Banerjee, Director of the Zoological Survey of India.
ZSI scientists have, however, confirmed that no individual has so far been diagnosed with the infection called 'river blindness' in the region.
According to the World Health Organization (WHO), the blindness caused by the worm called Onchocerca volvulus is among the most neglected tropical diseases.
'When these blood-sucking blackflies bite humans, the worms enter the human body from the fly. Initially, the worms form nodules under the skin. As they grow, they travel through the bloodstream to the eyes, ultimately resulting in blindness,' explained a scientist.
The first step towards protecting people from the infection is to identify and control the vector – the black fly, and therefore, better identification of the disease carrier is essential for improved treatment, said the scientists at the Diptera division of the ZSI in a statement.
'These black flies of the Simuliidae family are extremely small. They are barely noticeable to the naked eye. Before one realises it, the fly has already sucked blood and departed. Many species in this family look almost identical externally. In scientific terms, distinguishing between two different species of Simuliidae flies based on external characteristics is quite difficult and time-consuming. Sometimes accurate species identification is not even possible,' said Dr Banerjee.
Amid rising health concerns posed by the presence of the blackfly, researchers from the Diptera division have used DNA from these flies as a means of identification. The method employed for identifying the flies is called DNA barcoding.
Dr Atanu Naskar, scientist at the ZSI's Diptera division, revealed that they conducted their research in eight locations across Darjeeling and Kalimpong districts of West Bengal, which are part of the Central Himalayan region, and collected blackfly samples.
After preliminary segregation based on external characteristics, DNA barcoding methods were used to identify the species.
Ark Mukherjee, a senior research fellow at the Zoological Survey of India and one of the researchers involved in the blackfly study, explained, 'First, DNA was collected from the legs of the blackfly samples, and then that DNA was barcoded.'
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
&w=3840&q=100)
Business Standard
6 hours ago
- Business Standard
From compliance to confidence: Toward transparent and trusted food systems
Every year on June 7, World Food Safety Day reminds us of a simple but critical truth: access to safe food is a shared responsibility and a public good. The theme for World Food Safety Day 2025 is "Food safety: science in action". This theme highlights the crucial role of scientific knowledge in ensuring food safety, from developing safe practices to addressing foodborne illnesses, according to the World Health Organization (WHO). With consumers growing more vocal about what goes into their food and increasing scrutiny of terms like 'flavour enhancers' and 'chemical preservatives', conversations around food safety have moved from niche policy circles to public discourse. Against this backdrop, a recent Stakeholder Engagement Workshop on Food Additive Safety and Toxicity(SEW FAST), hosted by CSIR-IITR and the Food Future Foundation, took place in Lucknow. It brought together scientists, industry experts, and regulators to examine the persistent gulf between public perception and scientific evidence around food additives. Food additives play a crucial role in preservation, taste enhancement, stability, and nutritional fortification of food. They are especially important in ensuring food safety and security in a country as vast and diverse as India. From ensuring shelf-life in variable hot and humid climates to supporting sodium-reduction strategies through flavour modulators, additives serve both technological and public health purposes. Still, public wariness around food additives remains. A clear example is monosodium glutamate (MSG), which has faced more scrutiny than most. Recent scientific and regulatory evaluations conducted by authoritative bodies across the world, including Food Standards Australia New Zealand, European Commission, WHO, Food and Agriculture Organization (FAO), the US Food and Drug Administration (FDA) and even Food Safety and Standards Authority of India (FSSAI) have consistently affirmed its safety. Yet, legacy perceptions persist which feed certain warning labels. The time has now come to bring regulatory clarity to food additives such as MSG and re-establish public trust through evidence-based policymaking. MSG is a naturally derived sodium salt of glutamic acid, an amino acid abundantly found in foods like tomatoes, mushrooms, cheese, and even human breast milk. It enhances flavor through the umami taste, helping make food more palatable, especially for vulnerable populations like the elderly. It has been misrepresented as harmful for far too long, and it is essential to address this gap between perception and scientific reality. In India, food products containing MSG are still required to carry a warning label: 'Not Recommended for Infants and Pregnant Women.' While this requirement reflected the precautionary approach of its time, today's scientific landscape has evolved significantly. Comprehensive global reviews have reaffirmed the safety of MSG, including for sensitive populations, which is less than 1 per cent. As science progresses, policy must have the flexibility to evolve with it ,creating a balance between local relevance and global alignment, ensuring that regulations protect public health, support trade, and respect India's unique characteristics. Updating labelling practices in line with current evidence offers an opportunity not only to align with international standards, but also to strengthen consumer confidence and encourage innovation. This matters for public health. For example, MSG has the potential to support sodium reduction strategies. MSG contains only about 12 per cent sodium, compared to 39 per cent in table salt. Replacing salt partially with MSG in recipes can reduce overall sodium content by up to 30 per cent without sacrificing taste, which is a benefit recognised by the US Institute of Medicine and numerous public health experts. So, what can we do with this knowledge? As consumer awareness grows and food systems become more complex, our regulatory frameworks must evolve. A few principles can guide this shift: Existing models often assume worst-case scenarios of daily maximum consumption. Instead, the country needs an India--specific Food Additive Intake Model (FAIM), based on real dietary data, population groups (infants, elderly, pregnant women), and seasonal consumption. This would enable more realistic estimation of scenario on daily exposure as well as also less than life time, apart from chronic exposure, and may reduce excessive conservatism in identifying safety margin. Regulatory decisions must be communicated to the consumer with clarity, especially the difference between hazard (potential harm) and risk (likelihood of harm) in simple terms. Establishing interdisciplinary advisory councils and platforms for consumer-scientist dialogue can help demystify policies and enhance public trust. India's precautionary labeling laws, such as those on MSG, have not kept pace with recent development of science. As seen in the iron-fortified rice precedent, labels can be updated when evidence evolves. Doing so signals regulatory maturity and consumer respect. It's a collaborative and dynamic process, far from a mere legacy. The theme of World Food Safety Day 2025 reminds us, in the subject of MSG, the crucial role of scientific knowledge in ensuring food safety, from developing safe practices. Regulations must be proactive and forward-looking, not merely reactive. By embedding science into the policymaking process, and not just at the end, we can anticipate risks better and foster innovation responsibly. The goal is not to silence scrutiny, but to enable informed scrutiny. As India prepares to take greater leadership in global food policy, let us ensure our food additive regulations are not just robust, but also scientifically rational. In the case of food additives, that means recognizing the overwhelming scientific consensus, removing unnecessary warnings, and allowing science, not stigma to guide the way.
Time of India
6 hours ago
- Time of India
Flatworm species that regenerates found in Pashan Lake
Pune: A PhD student and and her research guide from Modern College of Arts, Science, and Commerce, Ganeshkhind, discovered a new species of planarian worm in Pashan Lake. According to PhD student Mithila Chinchalkar and her research guide Ravindra Kshirsagar from the department of zoology, this is the first time since 1983 that a new species of planarian was scientifically recorded in India. "This specimen was deposited at the Zoological Survey of India (ZSI). We named it Dugesia punensis to give credit to its place of discovery, in Pune," said Kshirsagar. The paper was published recently in Records of the Zoological Survey of India. Scientists explained that planarians are aquatic flatworms known for their regenerative capabilities. "Even if their body is cut into pieces, each piece can regenerate into a complete organism. Hence, they are very important in stem cell research also," said Kshirsagar. Chinchalkar described the discovery as fascinating. "We were screening the water bodies in and around Pune to study the aquatic biodiversity as a part of my PhD thesis." "We were doing this for the past three years. Planarian worms are found in stagnant water," said Chinchalkar. "The moment we saw this flatworm through the microscope, we knew it was something different. The regenerative potential of this worm is 14 days, compared to others whose regenerative span is about 18 days or more. The morphology is also different from others. It is more delicate than ones," said Chinchalkar, who wants to study stem cell characterisation. Kshirsagar says that they studied external morphology, anatomical features, and finally did the genomic sequencing to establish that the species was indeed new. "We sent the study paper with all the data a year ago, and finally it was published in the journal on June 1," said Kshirsagar. "Identifying this new species is important, as this is one of the best organisms to study stem cells and how regeneration occurs. From the field of medicine to organ regeneration, studying these species will help us understand the mechanism behind regeneration better," said Ravindra Kshirsagar.
The Hindu
6 hours ago
- The Hindu
Exposomics for better environmental health
The focus for World Environment Day in 2025 (June 5) is on ending plastic pollution. Micro-plastics represent one of the many thousands of chemical, physical and biological hazards that lurk in the air, water and living spaces for which we have neither the sensory capabilities nor sensing technologies to measure exposure and assess health risks. Thus, reducing the environmental disease burden continues to be a daunting challenge for public health. In India, rapid economic growth is increasing the scale and the complexity of environmental exposures and the interdependencies between the living environment and lifestyles. With India already accounting for nearly 25% of the global environmental disease burden, there is a need to develop newer paradigms for environmental management that rest on integrated health risk assessments. These must include all environmental factors into the study of disease development. The piece-meal approaches that define our current framing on environment or health indicators are likely to exaggerate environmental health inequities and result in spiralling health costs. We must embrace new and cutting-edge scientific developments in the field of 'exposomics' to gain a more complete picture of disease etiologies over the life course and develop holistic prevention strategies. Strategic investments in long-term environmental health surveillance that integrate novel environmental and biomonitoring efforts with digital health and data science platforms are critical. Environmental disease burden The World Health Organization (WHO) began estimating the environmental disease burden in 2000, which is the basis for the modern estimation approach being adopted in the Global Burden of Disease, Injuries, and Risk Factor (GBD) study. Each cycle of the GBD identifies risk factors with the greatest attributable health burden. In the latest cycle (2021) that included 88 risk factors, environmental and occupational (OEH) risk factors in the GBD were responsible for 18.9% (12.8 million) of global deaths and 14.4% of all disability-adjusted life years (DALYs), led by ambient PM 2.5 air pollution (4.2% DALYs, 4.7 million deaths) and household air pollution from the use of solid fuels for cooking (3.9% DALYs, 3.1 million deaths). In India, nearly three million deaths and 100 million deaths are attributable to occupational and environmental health (OEH) risks. OEH risk factors in India are also estimated to account for more than 50% of the attributable burden for non-communicable diseases including ischemic heart disease, stroke, chronic obstructive lung disease, lung cancer, asthma and, more recently, diabetes and chronic kidney disease. Risk factors such as lead exposures can have grave developmental health impacts for children under five, with India accounting for up to 154 million or 20% of the total estimated IQ points lost globally in children under five. What are we missing? The GBD results provide a strong and robust body of evidence to initiate actions for cleaner air, safer water and better sanitation. However, the current environmental burden of disease addresses only a limited number (around 11) of categories of environmental risk factors as there is a paucity of human exposure data. Several environmental risk factors that can contribute to significant health burdens are currently not included in the GBD. These include various chemical exposures, risks from complex mixtures such as micro-plastics and solid waste and physical hazards such as environmental noise. More importantly, environmental risk factors interact in complex ways with metabolic (high blood pressure or high fasting plasma glucose) and behavioural risk factors (smoking and unhealthy diets) as well as underlying genetic susceptibility and upstream health determinants (such as socio-economic status) to produce a health impact within populations. Risk estimates are often derived for single risk factors; while confounding is often well adjusted in long-term cohort studies, complex mixtures and interactions over a life course have not been adequately explored. Finally, climate change can magnify hazards posed by multiple environmental risk factors, such as heat, air pollution, vector-borne diseases, storms and flooding, and wildfires. Climate change may reduce crop yields, reduce agricultural worker productivity, disrupt food security and affect food supply chains. Depression, anxiety and other mental health outcomes, driven by both ecological concerns and direct health impacts of climate-sensitive environmental risk factors such as fine particulate matter, are also important to consider. Several of these risk factors can occur together, resulting in compound events and synergistic effects. These hazards can further amplify health impacts among populations with inadequate access to health systems or healthy food systems. Methods and data are not yet available to support inclusion of these important risk factors in the global burden of disease assessments. Thus, the current environmental burden of disease estimates are not only a conservative underestimates but also do not provide an adequate means of prioritising against competing risk factors to develop holistic, scalable preventive health strategies. The human exposome The global human genome project (1990-2003) revolutionised our ability to explore the genetic origins of disease. However, it also revealed the limited predictive power of individual genetic variation for many common diseases. Genetic factors for example, contribute to less than half of the risk of heart disease, which is a leading source of mortality. The success in mapping the human genome has fostered the complementary concept of the 'exposome'. The exposome is defined as the measure of all the exposures of an individual in a lifetime and how those exposures relate to health. Traditional environmental health studies include hypothesis-driven methods which have focused on one or a class of environmental exposures at a few time points. These fail to account for the complex interactions of exposures across the lifespan, on human health. Exposomics aims to bridge this gap by understanding how external exposures from physical, chemical, biological and psycho-social environments interact with diet and lifestyle and internal individual characteristics such as genetics, physiology, and epigenetics to create health or disease. This would allow the generation of an atlas of exposure wide associations (EWAS) to complement genome-wide associations (GWAS) and enable discovery-based analysis of environmental influences on health. The exposome requires synchronisation of several inter-disciplinary technologies which include real time sensor based personal exposure monitoring with wearables; untargeted chemical analyses on human biomonitoring samples; testing on human-relevant micro-physiological systems (also known as organs-on-a-chip) wherein in vitro models replicate the structure and function of human organs or tissues to understand the mechanistic basis of biological response; and big data, and artificial intelligence (AI) to mine data and generate integrated pieces of evidence. Given that capacities and resources to generate exposomics data are not widely available, an immediate need for the exposomic framework to become a reality is also the creation of a data ecosystem in which harmonised data can be found, accessed, and shared through sustained and interoperable data repositories. Mainstream environment within health Exposome frameworks may seem implausible or irrelevant in India where the implementation of environmental health management programmes faces numerous hurdles. But, leapfrogging to technology and data-driven approaches is not new to the health sector. Exposomics offers unprecedented potential to mainstream environmental risks within public health programmes by generating more accurate predictive models for many chronic diseases while also enabling precision medicine. Unbridled investments in capacity building and synchronising available analytical, environmental and public health infrastructure offer the promise of addressing the concerns of our populations with unprecedented cost-effectiveness. The time is ripe for the Indian environmental health community to engage and contribute to the global momentum on the science of exposomics. Future celebrations of World Environment Day may soon focus on why the human exposome project can be the best prescription for holistic prevention efforts that preserve and promote health equity. Dr. Kalpana Balakrishnan is Dean (Research), Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai
