{"id":5572,"date":"2026-01-06T22:20:34","date_gmt":"2026-01-06T16:50:34","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=5572"},"modified":"2026-01-07T11:23:41","modified_gmt":"2026-01-07T05:53:41","slug":"communicable-diseases","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/communicable-diseases\/","title":{"rendered":"Communicable Diseases"},"content":{"rendered":"

A\u00a0communicable disease<\/strong>\u00a0spreads from person to person or from animal to person. Communicable diseases are sometimes referred to as\u00a0\"infectious\" or \"transmissible\"\u00a0<\/strong>diseases. These diseases constitute a significant global health concern, impacting individuals, communities, and nations alike.<\/p>\r\n

Communicable diseases are caused by a diverse array of pathogens such as bacteria, viruses, fungi, and protozoa, and have the potential to transform into pandemics\u00a0like Coronavirus<\/strong>\u00a0(Covid-19<\/strong>).<\/p>\r\n

Causes and Spread of Communicable Diseases<\/h2>\r\n

Communicable diseases are\u00a0caused by pathogens<\/strong>\u00a0such as bacteria, viruses, fungi, and protozoa that can be spread from one person to another. They can be transmitted through the following ways:<\/p>\r\n

    \r\n\t
  • Direct contact:<\/strong>\u00a0When a person comes into contact with the bodily fluids of an infected person, such as\u00a0blood, saliva, urine, or faeces<\/strong>.<\/li>\r\n\t
  • Indirect contact:<\/strong>\u00a0When a person comes into contact with an object that has been contaminated with the bodily fluids of an infected person, such as a doorknob, light switch, or toy.<\/li>\r\n\t
  • Airborne transmission:<\/strong>\u00a0When a person breathes in infected droplets that have been released into the air when an infected person coughs or sneezes.<\/li>\r\n\t
  • Vector-borne transmission:<\/strong>\u00a0When a person is bitten by an infected insect or arthropod, such as a mosquito, tick, or flea.<\/li>\r\n<\/ul>\r\n

    Symptoms<\/strong><\/h3>\r\n
      \r\n\t
    • Symptoms vary according to the disease. Some people will have no symptoms at all. They can, however, still spread the pathogen.<\/li>\r\n\t
    • Some symptoms are caused by the pathogen directly damaging the\u00a0body's cells<\/strong>. Others are caused by the immune system's response to the infection.<\/li>\r\n\t
    • Some communicable diseases are mild, with symptoms lasting only a few days. Some, on the other hand, can be serious and even fatal. The severity of symptoms can vary depending on a person's overall health and immune function.<\/li>\r\n<\/ul>\r\n

      Communicable Diseases Caused by Bacteria<\/h2>\r\n

      Bacteria are single-celled, microscopic organisms and can cause infections that harm the body.<\/p>\r\n

      \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
      Disease<\/strong><\/td>\r\nDescription<\/strong><\/td>\r\n<\/tr>\r\n
      Tuberculosis (TB)<\/strong><\/td>\r\n\r\n

      - Caused by\u00a0Mycobacterium tuberculosis.<\/strong><\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Through the air from one person to another, sneeze or spit.<\/p>\r\n

      - Not spread by hand shaking, food or drink sharing food or drink or touching bed linens or toilet seats.<\/p>\r\n

      -\u00a0Symptoms:\u00a0<\/strong>Cough over 3 weeks, chest pain, fatigue, fever, sweating.<\/p>\r\n

      -\u00a0Treatment:<\/strong>\u00a0Vaccine:\u00a0BCG<\/strong>\u00a0and Antibiotics: Streptomycin<\/p>\r\n

      -\u00a0Initiatives:<\/strong><\/p>\r\n

        \r\n\t
      • National Strategic Plan to end TB<\/strong>\u00a0in India by 2025<\/li>\r\n\t
      • Nikshay Portal:\u00a0<\/strong>Online portal launched in 2012 for Drug-Resistant TB<\/li>\r\n\t
      • TB Harega Desh Jeetega Campaign<\/strong>\u00a0in 2022 by the Ministry of Health and Family Affairs<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n
      Leprosy (Hansen's disease)<\/strong><\/td>\r\n\r\n

      - Caused by\u00a0Mycobacterium leprae<\/strong><\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Through droplets from the mouth and nose with close contact.<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Red skin patches, numbness, effect on peripheral nerves.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>Curable with multidrug therapy (rifampicin, dapsone and clofazimine) and BCG (Bacillus Calmette-Guerin) vaccine.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Whooping cough (Pertussis)<\/strong><\/td>\r\n\r\n

      - Caused by\u00a0Bordetella pertussis<\/strong><\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Through sneezes or coughs from one person to another.<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Cough, fever, Apnea and cyanosis in babies<\/p>\r\n

      Treatment:\u00a0<\/strong>Diphtheria, tetanus, and pertussis (DTaP) vaccines<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Salmonellosis<\/strong><\/td>\r\n\r\n

      - Caused by\u00a0Salmonella<\/strong><\/p>\r\n

      -\u00a0Symptoms:\u00a0<\/strong>Fever, abdominal pain, diarrhoea, nausea and vomiting.<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Through the food chain, person-to-person transmission through the faecal-oral route.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>Treatable through electrolyte replacement and routine antimicrobial therapy.<\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

      Communicable Diseases Caused by Viruses<\/h2>\r\n

      Viruses are microscopic pathogens that carry genetic material. They must enter the cells of other living beings to replicate. They use the cell's machinery to duplicate themselves once inside.<\/p>\r\n

      \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
      Disease<\/strong><\/td>\r\nDescription<\/strong><\/td>\r\n<\/tr>\r\n
      Polio<\/strong><\/td>\r\n\r\n

      - Caused by the\u00a0poliovirus<\/strong>, mainly affects children under 5 years of age<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Mainly through the faecal-oral route, contaminated water or food, spread from person to person possible.<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Effect on the nervous system; can lead to paralysis<\/p>\r\n

      -\u00a0Treatment:<\/strong>\u00a0No cure, prevention through oral polio vaccine and inactivated polio vaccine<\/p>\r\n

      - India became\u00a0polio-free in 2014<\/strong>.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Acquired immunodeficiency syndrome (AIDS)<\/strong><\/td>\r\n\r\n

      - Caused by the\u00a0Human Immunodeficiency Virus<\/strong>\u00a0(HIV).<\/p>\r\n

      - Destroys the WBC and infection-fighting CD4 cells of the immune system<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Loss of immune cells, weight loss, tiredness<\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Through sexual contact, blood, needles, mother to infant (cannot be transmitted through saliva or sweat)<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>No cure<\/p>\r\n

      -\u00a0ELISA Test:\u00a0<\/strong>Diagnosis test for HIV<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Japanese encephalitis<\/strong><\/td>\r\n\r\n

      - Caused by the bite of an infected mosquito with Flavi Virus<\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Spread to humans through bites from infected mosquitoes of\u00a0Culex species<\/strong><\/p>\r\n

      -\u00a0Symptoms:\u00a0<\/strong>Fever, headache, vomiting, disorientation, coma, and seizures<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>No cure for the disease, prevention through vaccination<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Ebola<\/strong><\/td>\r\n\r\n

      - Caused by infection with one of the Ebola virus strains.<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0From person to person through direct or indirect contact with infected people\u2019s blood, body fluids or secretions.<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Fever, fatigue, headache, muscle pain and chills.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>Drug treatment through Inmazeb and Ansuvimab, prevention through vaccination (Vaccines<\/strong>: Ad5-EBOV and rVSV\/Ad5)<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Hepatitis<\/strong><\/td>\r\n\r\n

      - Caused by a variety of infectious hepatitis viruses<\/p>\r\n

      -\u00a0Five strains:\u00a0<\/strong>Hepatitis A, B, C, D and E<\/p>\r\n

        \r\n\t
      • Hepatitis\u00a0D\u00a0<\/strong>infections only occur in people who have been infected with the Hepatitis\u00a0B<\/strong>\u00a0virus.<\/li>\r\n\t
      • Hepatitis\u00a0B and C<\/strong>\u00a0can cause both acute and chronic disease.<\/li>\r\n<\/ul>\r\n

        -\u00a0Transmission:\u00a0<\/strong>Transmitted through direct or indirect contact such as sexual practice, faecal routes or ingestion of contaminated food and water.<\/p>\r\n

        -\u00a0Symptoms:<\/strong>\u00a0Fatigue, itching, dark-coloured urine, fever, malaise, diarrhoea, abdominal discomfort, and jaundice.<\/p>\r\n

        -\u00a0Treatment:<\/strong>\u00a0Prevention through vaccination, vaccines available for Hepatitis\u00a0A, B and E<\/strong>, No vaccine for Hepatitis\u00a0C<\/strong><\/p>\r\n

        -\u00a0National Viral Hepatitis Control Program:\u00a0<\/strong>By 2030, eliminate viral hepatitis as a public health threat.<\/p>\r\n

        -\u00a0Nobel Prize for Medicine or Physiology in 2020:\u00a0<\/strong>For the discovery of the Hepatitis C virus<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Zika<\/strong><\/td>\r\n\r\n

      - Caused primarily by bites of\u00a0Aedes mosquitoes<\/strong>\u00a0(similar to dengue)<\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Through blood transfusion, sexual contact, and to babies from infected mother during pregnancy or childbirth.<\/p>\r\n

      -\u00a0Effect:\u00a0<\/strong>It can lead to neuropathy, Guillain-Barr\u00e9 syndrome, and myelitis.<\/p>\r\n

      -\u00a0Symptoms:\u00a0<\/strong>Fever, pain, headache, and conjunctivitis.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>No specific treatment and no approved vaccine for prevention.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Dengue<\/strong><\/td>\r\n\r\n

      - Caused primarily by bites of\u00a0Aedes mosquitoes<\/strong>\u00a0(Same causes Zika).<\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Spread to humans by the bite of infected mosquitoes.<\/p>\r\n

        \r\n\t
      • It cannot be transmitted from person to person directly. However, maternal transmission is possible. (Spain reported the first sexual transmission of Dengue).<\/li>\r\n<\/ul>\r\n

        -\u00a0Symptoms:<\/strong>\u00a0High fever, severe headache pain behind the eyes muscle and joint pains nausea vomiting swollen glands rash.<\/p>\r\n

        -\u00a0Treatment:<\/strong>\u00a0No specific treatment (vaccine in development)<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Nipah<\/strong><\/td>\r\n\r\n

      - Caused by fruit bats (natural reservoir of virus)<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Transmission from animals to humans, contaminated foods, direct transmission from human to human possible.<\/p>\r\n

      -\u00a0Symptoms<\/strong>: Fever, headaches, myalgia, vomiting, can lead to acute respiratory infection and encephalitis<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>No specific treatment or vaccine is available either for people or animals.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Influenza<\/strong><\/td>\r\n\r\n

      - An acute respiratory infection caused by influenza viruses<\/p>\r\n

      -\u00a0Four types:\u00a0<\/strong>Influenza A, Influenza B, Influenza C and Influenza D.<\/p>\r\n

        \r\n\t
      • Only influenza A viruses have been linked to the pandemic.<\/li>\r\n\t
      • Influenza D viruses are primarily found in cattle.<\/li>\r\n<\/ul>\r\n

        -\u00a0Transmission:\u00a0<\/strong>Transmitted from person to person through cough or sneeze, droplets containing viruses.<\/p>\r\n

        -\u00a0Symptoms:<\/strong>\u00a0Fever, cough, body aches, sore throat and fatigue.<\/p>\r\n

        -\u00a0Treatment:<\/strong>\u00a0Treatment through the use of influenza drugs, and prevention through vaccination.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Monkeypox<\/strong><\/td>\r\n\r\n

      - Caused by monkeypox virus (a species of the genus Orthopoxvirus).<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Skin rash, fever, headache, pain, tiredness, and swollen lymph nodes.<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Transmitted from animals to humans, transmission from person to person through direct physical contact with blood, bodily fluids, or mucosal lesions of an infected animal.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>Early and supportive care, prevention through vaccination.<\/p>\r\n

        \r\n\t
      • Vaccines and therapeutics developed for smallpox can be used in some circumstances.<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n
      Marburg virus disease (MVD)<\/strong><\/td>\r\n\r\n

      - Caused by a genetically unique\u00a0zoonotic\u00a0<\/strong>Marburg virus of the\u00a0filovirus\u00a0<\/strong>family.<\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Human-to-human transmission through direct contact with the blood, bodily fluids or secretions of infected people, indirect contact through surfaces and materials contaminated with these fluids.<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Haemorrhagic fever, diarrhoea, severe pain, vomiting etc.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>No approved vaccines or antiviral treatments.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Coronavirus\u00a0<\/strong>(Covid-19)<\/td>\r\n\r\n

      - Caused by the\u00a0SARS-CoV-2<\/strong>\u00a0coronavirus<\/p>\r\n

      -\u00a0Symptoms:\u00a0<\/strong>Fever, chills, headache, appetite loss, sore throat etc.<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Transmission from human to human through close contacts.<\/p>\r\n

      -\u00a0Treatment:\u00a0<\/strong>Isolation and preventive care, vaccination (Covishiled, Covaxin etc).<\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

      Communicable Diseases Caused by Protozoa<\/h2>\r\n

      Protozoa are unicellular microscopic eukaryotes with a relatively complex internal structure and metabolic activities. Following are the diseases caused by Protozoa:<\/p>\r\n

      \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
      Disease<\/strong><\/td>\r\nDescription<\/strong><\/td>\r\n<\/tr>\r\n
      Malaria<\/strong><\/td>\r\n\r\n

      - Caused by a\u00a0plasmodium\u00a0<\/strong>parasite (P. falciparum and P. vivax)<\/p>\r\n

      -\u00a0Transmission:<\/strong>\u00a0Transmission to people via the bites of infected female Anopheles mosquitoes.<\/p>\r\n

        \r\n\t
      • However, it does not spread from person to person but transmission through blood transfusion and contaminated needles is possible.<\/li>\r\n<\/ul>\r\n

        -\u00a0Symptoms:<\/strong>\u00a0Fever, cold, headache, fatigue, seizures, and difficulty breathing, effects on RBCs.<\/p>\r\n

        -\u00a0Treatment:<\/strong>\u00a0Prevention through vaccination, vector control, and preventive chemotherapies.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Kala-azar (Leishmaniasis)<\/strong><\/td>\r\n\r\n

      - Caused by protozoan Leishmania parasites.<\/p>\r\n

      -\u00a0Transmission:\u00a0<\/strong>Transmitted via bites of infected female phlebotomine sandflies.<\/p>\r\n

      -\u00a0Symptoms:<\/strong>\u00a0Fever, anaemia, weight loss, and enlargement of the liver and spleen.<\/p>\r\n

      -\u00a0Treatment:<\/strong>\u00a0Treatable and curable, however no specific vaccines.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Amoebiasis<\/strong><\/td>\r\n\r\n

      - Caused by a parasite called Entamoeba histolytica.<\/p>\r\n

      - Commonly found in people living in tropical areas with poor sanitary conditions.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      African sleeping sickness (Trypanosomiasis)<\/strong><\/td>\r\n\r\n

      - Caused by protozoans of the genus Trypanosoma.<\/p>\r\n

      - Endemic in sub-Saharan Africa<\/p>\r\n

      - Transmission: Spread to humans by bites of tsetse flies (glossina), mother-to-child transmission, transmission through sexual contact.<\/p>\r\n

      - Antitrypanosomal treatment<\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

      Communicable Diseases Caused by Fungi<\/h2>\r\n

      Fungi are organisms that include yeasts, moulds, and mushrooms. The following are the diseases caused by fungi:<\/p>\r\n

      \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
      Disease<\/strong><\/td>\r\nDescription<\/strong><\/td>\r\n<\/tr>\r\n
      Aspergillosis<\/strong><\/td>\r\n\r\n

      - Caused by Aspergillus, a type of fungus living indoors and outdoors.<\/p>\r\n

      - Symptoms: Cough, shortness of breath, can lead to lung infections<\/p>\r\n

      - Treatment through fungal medication<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Candidiasis<\/strong><\/td>\r\n\r\n

      - Caused by a yeast called Candid<\/p>\r\n

      - It can cause infections in the bloodstream or internal organs.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Athlete\u2019s foot<\/strong><\/td>\r\n\r\n

      - Caused by a variety of different fungi<\/p>\r\n

      - Symptoms: Skin fissures or scales between toes that can be red and itchy<\/p>\r\n

      - Prevention through hygiene<\/p>\r\n<\/td>\r\n<\/tr>\r\n

      Ringworm<\/strong><\/td>\r\n\r\n

      - A circular rash caused by fungus.<\/p>\r\n

      - Symptoms: Itchy skin, ring-shaped rash, red, scaly, cracked skin, hair loss<\/p>\r\n

      - Transmission: Through close contact with an infected person such as sharing towels, bedding, or other personal items<\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>","protected":false},"excerpt":{"rendered":"

      Communicable diseases are caused by viruses or bacteria that spread from person to person. Learn about its types, prevention, examples, etc.<\/p>\n","protected":false},"author":6,"featured_media":8431,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[239],"tags":[754,40],"class_list":{"0":"post-5572","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quest-level-4","8":"tag-communicable-diseases","9":"tag-quest"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/5572","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=5572"}],"version-history":[{"count":1,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/5572\/revisions"}],"predecessor-version":[{"id":19991,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/5572\/revisions\/19991"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/8431"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=5572"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=5572"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=5572"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}