Mahesh Shinde s Dnyanadeep's IAS For UPSC - IAS / IPS / IFS. UPSC Pre Brain Teaser. Science (Diseases Caused by Mcroorganisms)

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1 Science (Diseases Caused by Mcroorganisms) Microbes or Microorganisms Microorganisms [microbes] include bacteria, fungi, protozoa, some algae, viruses, viroids and also prions that are proteinacious infectious agents. Viruses reproduce only inside the cells of the host organism, which may be a bacterium, plant or animal. Microorganisms may be single-celled like bacteria, some algae and protozoa, or multicellular, such as algae and fungi. They can survive under all types of environment, ranging from ice cold climate to hot springs and deserts to marshy lands. Microorganisms like amoeba can live alone, while fungi and bacteria may live in colonies. Diseases Caused by Microorganisms Disease Causative Mode Of Type Of Details Agent Transmission Organism Affected Diseases Caused By Bacteria Acne vulgaris Propionibacterium Direct contact/ Humans/ Skin disease that occurs when hair (or simply acne acnes close contact Adolescents follicles become clogged with dead skin or pimples) cells and oil from the skin. Causes = = Genetics + Excessive growth of the bacteria Propionibacterium acnes. Anthrax Bacillus Contact with Most animals Causes skin infections and Gastrointestinal anthraces infected meat including (GI) infection that are fatal. humans French scientist Louis Pasteur developed the first effective vaccine in Cholera Vibrio cholerae Water/food Humans Effects small intestine. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it (1)

2 leads within hours to severe dehydration and electrolyte imbalance. Citrus Canker Xanthomonas Air Citrus fruit Infection causes lesions on the leaves, stems, axonopodis plants and fruit of citrus trees. Diptheria Corynebacterium Air/direct Humans Symptoms: sore throat and fever. diphtheriae contact The neck may swell in part due to large lymph nodes. Complications may include myocarditis, inflammation of nerves, kidney problems, and bleeding problems due to low blood platelets. Myocarditis may result in an abnormal heart rate and inflammation of the nerves mayresult in paralysis. Pneumonia Streptococcus Air borne Humans Pneumonia is an inflammatory condition of [caused by pneumoniae and droplets of the lung affecting primarily the microscopic bacteria or Haemophilus sneeze air sacs known as alveoli. viruses] influenzae Peptic ulcers Helicobacter Humans Ulcers in the lining of stomach and pylori starting part of small intestine Plague Yersinia pestis Air/ direct Humans Unhygienic conditions is the main cause. [You contact know why Surat is one of the cleanest cities in India?] The symptoms of plague depend on the concentrated areas of infection in each person: bubonic plague in lymph nodes, septicemic plague in blood vessels, pneumonic plague in lungs. Tuberculosis Mycobacterium Air Humans Tuberculosis generally affects the lungs, but tuberculosis can also affect other parts of the body. Most infections do not have symptoms, known as latent tuberculosis. About 10% of latent infections eventually progresses to active dis- (2)

3 ease which, if left untreated, kills about half of those infected. The classic symptoms of active TB are a chronic cough with bloodtinged sputum, fever, night sweats, and weight loss. Typhoid Salmonella typhi Water Humans Often there is a gradual onset of a high fever over several days. Weakness, abdominal pain, constipation, and headaches also commonly Diseases Caused By Viruses AIDS Human Blood Humans and Severely weakens immunity and makes Immunodeficiency exchange primates way for a number of other pathogens. Virus (HIV) Chicken Pox varicella zoster Air/contact Humans Chickenpox, also known as varicella, is a virus (VZV) highly contagious disease. The disease results in a characteristic skin rash that forms small, itchy blisters. Less severe than small pox. Almost eradicated after the invention of vaccination. Small Pox Variola major Air/contact/ Humans One of the highly dreaded diseases that is and Variola minor water highly contagious. Almost eradicated after the invention of vaccination. Chikungunya Chikungunya Aedes mosquitoes, Causes severe joint pains. Animal reservoirs virus such as A. aegypti of the virus include monkeys, birds, cattle, and A. albopictus and rodents. This is in contrast to dengue, for which primates are the only hosts Cold, influenza hino viruses Air borne Humans Summer are hostile for the virus. occur. (flu) and most droplets of sneeze Most common during winter months. coughs (3)

4 Dengue fever Flavivirus Female Aedes Humans high fever, headache, vomiting, muscle and mosquito joint pains, and a characteristic skin rash. In a small proportion of cases, the disease develops into the life-threatening dengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets and blood plasma leakage, or into dengue shock syndrome, where dangerously low blood pressure occurs. Ebola Ebola virus Animal to man Humans and Ebola infection shows a sudden onset of the Some Animals disease resulting initially in flu-like symptoms: fever, chills and malaise. As the disease progresses, it results in multisystem involvements indicated by the person experiencing lethargy, nausea, vomiting, diarrhoea and headache. Foot and Picornavirus Close-contact Animals Serious problem to animal farming in India. Mouth Disease [genus animal-to-animal Aphthovirus] spread Hepatitis B hepatitis B Blood Exchange, HumansAffects the liver. Acute as well as virus (HBV) STD [Sexually chronic. transmitted disease] Measles measles virus Air Humans Complications occur in about 30% and may include diarrhea, blindness, inflammation of the brain, and pneumonia among others. Polio or Poliovirus Water/faecal- Humans Weak muscles leading to deformations. Poliomyelitis mouth Zika Zika virus Aedes mosquitoes, Humans such as A. aegypti and A. albopictus (4)

5 Diseases Caused By Protozoans Amoebiasis Entamoeba Contaminated Humans Symptoms may include abdominal pain, (amoebic histolytica Water/food mild diarrhoea, bloody diarrhea or severe dysentery) colitis with tissue death and perforation. This last complication may cause peritonitis. People affected may develop anemia due to Dysentery Leishmania loss of blood. Kala-Azar or Leishmania Sandflies Humans This disease is the second-largest parasitic Visceral genus killer in the world (after malaria). leishmaniasis The parasite migrates to the internal organs such as the liver, spleen (hence visceral ), and bone marrow, and, if left untreated, will almost always result in the death of the host. Signs and symptoms include fever, weight loss, fatigue, anemia, and substantial swelling of the liver and spleen. Malaria Different species Female Humans Malaria causes symptoms that typically of Plasmodium Anopheles include fever, fatigue, vomiting, and (P. vivax, P. malaria mosquito headaches. In severe cases it can cause and P. falciparum) yellow skin, seizures, coma, or death. Sleeping Trypanosoma Infected Humans Initially, in the first stage of the disease, there Sickness tsetse fly are fevers, headaches, itchiness, and joint pains. This begins one to three weeks after the bite. Weeks to months later the second stage begins with confusion, poor coordination, numbness and trouble sleeping. Yellow Vein Bhendi yellow Insect Okra plant Okra are dwarfed, malformed. Mosaic of Okra [Ladies finger] vein mosaic virus (5)

6 Diseases Caused By Fungi ingworms Fungi belonging Skin-skin Humans The fungi that cause parasitic infection, to the genera Micr contact collectively dermatophytes, feed on keratin, Trichophyton and the material found in the outer layer of skin, Epidermophyton hair, and nails. ust of wheat Puccinia rust Air/seeds Wheat and Wheat leaf rust is a fungal disease that fungus other crops affects wheat,barley and rye stems, leaves and grains. In temperate zones it is destructive on winter wheat because the pathogen. overwinters. Infections can lead up to 20% yield loss exacerbated by dying leaves which fertilize the fungus. (6)