MEV 018: Unit 10 – Water Borne, Food Borne and Vector Borne Diseases

-

 UNIT 10: FOOD, WATER, AND VECTOR BORNE DISEASES

10.1 Introduction

Food, water, and vector-borne diseases remain significant public health challenges, especially in developing countries. These diseases arise from contamination or improper handling of food and water, or through transmission via disease-carrying organisms (vectors) like mosquitoes, flies, and ticks. Rapid urbanization, poor sanitation, climate change, and inadequate hygiene practices contribute to the spread of such diseases. This unit explores their classification, transmission, pathogenesis, diagnosis, and preventive strategies.

10.2 Food Borne Diseases

Food-borne diseases are illnesses caused by the ingestion of contaminated food containing pathogenic microorganisms or toxic substances. These diseases can range from mild gastroenteritis to severe and life-threatening infections.

10.2.1 Classification of Food Borne Diseases

Food-borne diseases are classified into:

  • Infections: Caused by ingesting food containing live pathogens (e.g., Salmonella, E. coli, Listeria).
  • Intoxications: Caused by toxins produced by microbes in food (e.g., Clostridium botulinum, Staphylococcus aureus).
  • Toxin-mediated infections: Organisms produce toxins in the intestines after ingestion (e.g., Clostridium perfringens).

10.2.2 Transmission

Transmission typically occurs through:

  • Improper cooking or storage
  • Cross-contamination between raw and cooked foods
  • Poor personal hygiene of food handlers
  • Use of contaminated water in food preparation

10.2.3 Pathogenesis

Pathogens enter the gastrointestinal tract and:

  • Adhere to intestinal mucosa
  • Multiply and produce toxins
  • Cause inflammation, diarrhea, vomiting, and in severe cases, systemic infection

10.2.4 Diagnosis and Treatment

  • Diagnosis: Based on symptoms, food history, and laboratory testing (stool culture, ELISA for toxins, PCR).
  • Treatment: Supportive care (rehydration, electrolyte replacement), antibiotics in severe cases, and antitoxins where applicable.

10.2.5 Prevention and Control

  • Ensure food safety practices (clean, separate, cook, and chill)
  • Promote hand hygiene among food handlers
  • Use safe water in food preparation
  • Enforce food safety regulations and public awareness campaigns

10.3 Water Borne Diseases

Water-borne diseases are caused by drinking or coming into contact with water contaminated by pathogenic microorganisms. These diseases are prevalent in areas with poor sanitation and unsafe drinking water.

10.3.1 Introduction to Water Borne Diseases

These include both bacterial (e.g., cholera, typhoid), viral (e.g., hepatitis A and E), and protozoal (e.g., amoebiasis, giardiasis) infections.

10.3.2 Transmission

Pathogens enter the water supply through:

  • Fecal contamination from open defecation or sewage leaks
  • Flooding and natural disasters disrupting sanitation
  • Use of untreated surface water

10.3.3 Pathogenesis

  • Cholera: Vibrio cholerae releases enterotoxins causing severe diarrhea
  • Typhoid: Salmonella typhi invades the intestinal wall leading to systemic illness
  • Hepatitis A: Virus infects liver causing jaundice and liver inflammation

10.3.4 Diagnosis

  • Stool, urine, and blood cultures
  • Serological tests for viruses (e.g., HAV IgM for hepatitis A)
  • Water sample testing for fecal coliforms and pathogens

10.3.5 Prevention and Control

  • Ensure safe drinking water through treatment (boiling, chlorination, filtration)
  • Promote sanitation and hygiene (hand washing, toilet use)
  • Improve sewage management and wastewater treatment
  • Implement health education and vaccination (e.g., typhoid, hepatitis A)

10.4 Vector Borne Diseases

Vector-borne diseases are illnesses transmitted through vectors such as mosquitoes, ticks, sandflies, and fleas. These vectors transmit viruses, bacteria, or parasites from one host to another.

10.4.1 Introduction to Vector Transmitted Diseases

These diseases are closely linked with environmental factors such as climate, water stagnation, and poor waste disposal, which provide breeding grounds for vectors.

Common Vector-Borne Diseases:

  • Malaria
  • Dengue
  • Chikungunya
  • Zika virus
  • Lyme disease
  • Leishmaniasis

10.4.2 Important Vectors

  • Mosquitoes: Anopheles (malaria), Aedes (dengue, chikungunya), Culex (filariasis)
  • Ticks: Lyme disease, tick-borne encephalitis
  • Sandflies: Leishmaniasis
  • Tsetse flies: Sleeping sickness

10.4.3 Transmission

Vectors become infected by feeding on infected hosts, then transmit pathogens during subsequent bites. Environmental factors like water stagnation and unclean surroundings increase vector populations.

10.4.4 Pathogenesis

  • Malaria: Plasmodium parasites infect red blood cells, causing fever, chills, and anemia
  • Dengue: Dengue virus leads to high fever, rash, and hemorrhagic symptoms
  • Leishmaniasis: Parasite infects skin or internal organs (visceral form)

10.4.5 Prevention and Control

  • Vector control: Insecticide-treated nets, larvicides, indoor spraying
  • Environmental management: Eliminate standing water, improve drainage
  • Personal protection: Use of repellents, wearing protective clothing
  • Vaccination and prophylaxis: Available for some diseases (e.g., yellow fever, malaria prophylaxis)

10.5 Let Us Sum Up

This unit provided a comprehensive overview of three major groups of communicable diseases: food-borne, water-borne, and vector-borne. These diseases continue to pose serious health challenges, especially in developing regions with inadequate sanitation and public health infrastructure. Prevention relies heavily on improved hygiene, clean water access, food safety, and effective vector control measures. Community awareness and government action are essential for disease reduction and better health outcomes.

10.6 Key Words

  • Food Borne Diseases: Illnesses caused by consumption of contaminated food.
  • Water Borne Diseases: Diseases transmitted through unsafe drinking water.
  • Vector Borne Diseases: Diseases spread through organisms like mosquitoes and ticks.
  • Pathogenesis: Biological mechanism through which a disease develops.
  • Transmission: The route through which pathogens are spread from one host to another.
  • Prevention and Control: Strategies to minimize disease incidence and transmission.

 

Comments

Post a Comment

Popular Posts

Jcert Class 8 Daffodil Chapter 1a: The Naive Friends Solutions

-
Chapter 1a : The Naive Friends Answer the following questions: 1. Which questions made Keshav and Shyama curious about the egg? Ans.         How did the chick come out? How big would the eggs? How many? What colours would they? What did they eat? Such types of questions made Keshav and Shyama curious about the egg. 2. What three things did the children do to protect the eggs? Ans.         The children done three things are: (i)          Adjustment of food. (ii)        Adjustment of water. (iii)      Adjustment of roof. 3. Why did Keshav think of making a cushion for the eggs? Ans.         When Keshav saw the egg on direct sun light, he thaught making a cushion for the eggs. 4. What excuse did Keshav give for not showing the eggs to Shyama? Ans.     ...
Read more

Jcert Class 8 भाषा मंजरी Chapter 3 मित्रता Solutions

-
अध्याय - 3 : मित्रता 1. आप किस प्रकार कह सकते हैं कि मित्रों के चुनाव की उपयुक्तता पर हमारे जीवन की सफलता निर्भर करती है? उ. मित्रों के चुनाव की उपयुक्तता पर हमारे जीवन की सफलता निर्भर करती है क्योंकि संगति का गुप्त प्रभाव हमारे आचरण पर पड़ता है और यदि हमें अच्छी संगति, अच्छे मित्र मिलते हैं तो वे हमें सफलता की ओर ले जाते हैं जबकि बुरी संगति हमारे जीवन को खाक में मिला देती है।  2. 'विश्वासपात्र मित्र जीवन की एक औषध है।' आशय स्पष्ट कीजिए। उ. 'विश्वासपात्र मित्र जीवन की एक औषध है'- ऐसा इसलिए कहा गया है कि यदि हमें विश्वासी मित्र मिल गया तो हम अपने जीवन में चाहे जैसा भी कदम उठाएँ, उस कदम की आलोचना करके वह हमें सही दिशा की ओर उन्मुख करेगा। हम अपनी गलती रूपी बीमारी को उसकी आलोचना रूपी औषधि से दूर कर सकेंगे।  3. मित्र का चुनाव करते समय हमें किन बातों का ध्यान रखना चाहिए? उ. मित्र का चुनाव करते समय हमें निम्नलिखित बातों का ध्यान रखना चाहिए हमारे अच्छे विचारों (संकल्पों) को दृढ़ करने वाला हो। हमें दोषों और त्रुटियों से बचाए। हमारे सत्य, पवित्रता ...
Read more

Jcert Class 8 भाषा मंजरी Chapter 8 अमरूद का पेड Solutions

-
अध्याय - 8 : अमरूद का पेड 1. लेखक को क्यों लगता है कि इन सब पिछड़े खयालातों का हमारे घर में गुजर नहीं हो सकेगा। उ. अमरूद के पेड़ को देखकर सबसे पहले बाबू कन्हैयालाल की बूढ़ी पत्नी ने एक दिन टोका कि पश्चिम की तरफ अगर मकान का मुखड़ा हो और सामने ही अमरूद का पेड़ तो 'राम-राम बड़ा अशुभ होता है और माँ के चेहरे पर थोड़ा-सा भय दिखा पर लेखक को विश्वास था कि इन सब पिछड़े खयालातों का हमारे घर में गुजर नहीं हो सकेगा क्योंकि उसके घर के लोग आधुनिक विचारधारा के थे उसकी माँ सत्याग्रह के दिनों में अजमेर में लम्बा जेल कर चुकी है। पिताजी खुद राजनैतिक सामाजिक उदारता वाले आदमी थे। बुआ ने विवाह नहीं किया था, पढ़ने-लिखने में ही अपनी सम्पूर्ण जिन्दगी लगा दी और समाज कोई चुनौती देने का साहस नहीं कर सका। साथ ही परिवार के सभी लोगों में पिछड़ेपन के प्रति भर्त्सना का भाव था। 2. अमरूद के पेड़ की छाया किस प्रकार लेखक को उनके भाई-बहनों के साथ जोड़ती है ? उ. अमरूद के पेड़ की छाया लेखक को उसके भाई-बहनों के साथ जोड़ती है। वे सभी अमरूद की छाया में बेंत की कुर्सियों पर बैठ चर्चाएँ करते थे जिससे उनके बीच...
Read more