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Diseases in India for UPSC Exam

Acute Encephalitis Syndrome

  • Acute encephalitis syndrome is a severe case of encephalitis transmitted by mosquitoes and is characterized by high fever and inflammation of the brain.
Acute Encephalitis Syndrome by Legacy IAS Academy
  • The World Health Organisation (WHO) in 2006, coined the term AES to signify a group of diseases which seem similar to one another but are difficult to differentiate in the chaotic environment of an outbreak.
  • The disease most commonly affects children and young adults and can lead to considerable morbidity and mortality.
  • Causative Agents: Viruses are the main causative agents in AES cases, although other sources such as bacteria, fungi, parasites, spirochetes, chemicals, toxins, and noninfectious agents have also been reported over the past few decades. It is not vaccine-preventable.
  • Japanese encephalitis virus (JEV) is the major cause of AES in India (ranging from 5%-35%).
  • Herpes simplex virus, Nipah virus, Zika virus, Influenza A virus, West Nile virus, Chandipura virus, mumps, measles, dengue, scrub typhus, S.pneumoniae are also found as causative agents for AES.
  • Symptoms: include confusion, disorientation, coma, or inability to talk, high fever, vomiting, nausea, and unconsciousness.
  • Diagnosis: The National Vector Borne Disease Control Programme in India has set up countrywide surveillance for AES through sentinel sites with a focus on detecting Japanese encephalitis (JEV).
  • In the sentinel surveillance network, AES/JE is diagnosed by IgM Capture ELISA, and virus isolation is done in the National Reference Laboratory.

How is hypoglycaemia linked to AES?

  • Hypoglycaemia (low blood sugar) is a commonly seen sign among AES patients, and the link has been the subject of research for long.
  • The combination of AES with hypoglycaemia is unique to Muzaffarpur, Vietnam and Bangladesh.
  • A 2014 study in Muzaffarpur suggested that hypoglycaemia was the trigger that led to diagnosis of encephalitis.
  • So, Hypoglycaemia is not a symptom but a sign of AES.
  • With 98% of AES patients in Bihar also suffering hypoglycaemia, doctors are attributing deaths to the latter.

What is the litchi connect?

  • Early researches have drawn parallel between cases in Bihar’s Muzaffarpur and in Vietnam’s Bac Giang province.
  • In both places, there were litchi orchards in the neighbourhood.
  • Methylene cyclopropyl glycine (MCPG), also known as hypoglycin A, is known to be a content of litchi fruit.
  • Undernourished children who ate litchi during the day and went to bed on an empty stomach presented with serious illness early the next morning.
  • When litchi harvesting starts in May, several workers spend time in the fields.
  • There, it is common for children to feed on fallen litchis and sleep without food.
  • The toxin in litchi (MPCG) lowers blood sugar level during night, and these children are found unconscious in the morning.
  • Blood glucose falls sharply causing severe brain malfunction (encephalopathy), leading to seizures and coma, and death in many cases.

What role does malnutrition play?

  • If toxins from litchi were causing hypoglycaemia, then these cases should have remained consistent each year.
  • Also, it should have affected children of all socio-economic strata.
  • But in contrast, this year, all deaths have been recorded in the lower income groups.
  • While well-nourished children eating litchi remain unaffected even if they go to bed on an empty stomach, the under-nourished ones were at grave risk.
  • This is because under-nourished children lack sufficient glucose reserve in the form of glycogen.
  • Also, the production of glucose from non-carbohydrate source is unsafe as it is unsustainable and thus stopped midway.
  • This leads to low blood sugar level, giving way for further health complications.
  • In all, even if litchi is a triggering factor, the real cause for adverse effects is said to be malnutrition.


  • Dextrose is the name of a simple sugar that is made from corn and is chemically identical to glucose, or blood sugar.
  • Dextrose is often used in baking products as a sweetener, and can be commonly found in items such as processed foods and corn syrup.
  • For medical purposes, it is dissolved in solutions that are given intravenously, which can be combined with other drugs, or used to increase a person’s blood sugar.
  • As dextrose is a “simple” sugar, the body can quickly use it for energy.
  • Simple sugars can raise blood sugar levels very quickly, and they often lack nutritional value.

Japanese Encephalitis

  • Japanese encephalitis (JE) is one of the most common encephalitides worldwide. The disease is caused by a mosquito-borne flavivirus and is found across south and east areas of Asia. It is a zoonosis – an animal disease that can spread to humans.
  • JE virus is transmitted to humans through the bite of infected Culex mosquitoes, which lay their eggs in irrigated rice paddies and other pools of stagnant water.
  • Pigs and birds serve as amplifying vertebrate hosts. Humans are believed to be dead-end hosts. The disease outbreak usually occurs during the rainy season.
  • Case-fatality rate in severe clinical cases is estimated to be 20–30%, with young children (< 10 years) having a greater risk of severe disease and death.


  • Currently, three WHO-prequalified JE vaccines are available, all of which are safe and effective. WHO recommends use of JE vaccines in all countries where JE is recognized as a public health priority.
  • India has also launched its first indigenously produced anti- Japanese encephalitis (JE) vaccineJENVAC.

Relation between Acute Encephalitis Syndrome (AES) and Japanese Encephalitis (JE)

  • Flaviviridae is a family of viruses belonging to Flavivirus Genus. Japanese encephalitis (JE) virus is one of the member of Flaviviridae.
  • Japanese encephalitis (JE) virus causes Japanese Encephalitis Disease and it is also the most common cause of Acute Encephalitis Syndrom in India.

National Vector Borne Diseases Control Programme

  • The National Vector Borne Disease Control Programme (NVBDCP) is a comprehensive programme for prevention and control of vector borne diseases namely Malaria, Filaria, Kala-azar, Japanese Encephalitis (JE), Dengue and Chikungunya which is covered under the overall umbrella of NRHM.

Nipah Virus

  • The virus can be transmitted to humans from animals (such as bats or pigs). The disease spreads through fruit bats or ‘flying foxes,’ of the genus Pteropus, who are natural reservoir hosts of the Nipah and Hendra viruses.
  • Nipah virus infection is an emerging zoonotic disease of public health importance in the WHO South East Asia region with a high case fatality rate estimated to range between 40 and 75 per cent.
  • It was first recognised in 1998-99 during an outbreak among pig farmers in Malaysia and Singapore.
  • Human-to-human transmission of this virus has also been reported among family and care givers of infected patients.

How does Nipah spread or get transmitted?

  • The virus is present in bat urine and potentially, bat faeces, saliva and birthing fluids.
  • Furthermore, transmission between farms may be due to fomites – or carrying the virus on clothing, equipment, boots, and vehicles.

About Fruit Bat

Fruit bat

Fruit bats, as opposed to insectivorous bats, survive largely on a diet of fruit, which they locate with their sense of smell (insectivorous bats locate their prey through echolocation, i.e locating the source of the echoes of their own sound).

  • Fruit bats belong to the Pteropodidae family; those in the Pteropus genus within this family are natural hosts for the Nipah virus.
  • Fruit bats are widely found in South and Southeast Asia and are also known as flying foxes.

Nipah virus and Fruit bat connection

  • The virus survives in the bat’s body without causing disease, allowing it to jump to susceptible mammals like humans or pigs when bats come in contact with them.
  • The National Institute of Virology had found that the virus was first transmitted from fruit bats identified as Pteropus spp.
  • In Bangladeshi outbreaks, researchers found antibodies to Nipah in the Indian flying fox.

Why are so many diseases linked to bats?

All bats can carry viruses, some of them deadly like:

  • Severe Acute Respiratory Syndrome (SARS) antibodies were found in insectivorous bats.
  • Ebola antibodies were found in Hammer-headed fruit bat.
  • Indian Flying Fox, hosts over 50 viruses

With around 1,200 species, bats comprise 20% of the earth’s mammalian diversity.

Long periods of flying raises the temperatures of bats, boosting their immune responses and helps them survive the microbes’ pathogenic effects.


What is a Coronavirus?

  • Coronaviruses are a class of viruses so named because their electron microscope image resembles the corona of the sun.
  • They are usually found in animals, but sometimes get transmitted to human beings possibly through the food chain.
  • The symptoms can include fever, cough and shortness of breath.
  • This happened during the 2003 outbreak of SARS (Severe Acute Respiratory Syndrome) coronavirus that claimed close to 800 lives.
  • The current 2019 strain that had originated in China has been named as 2019 ‘novel’ coronavirus (2019-nCoV) or SARS-CoV-2.
Image result for COVID-19

What test is done for coronavirus?

The first test that samples of all suspected patients are sent for is the polymerase chain reaction (PCR) test

Are antibiotics effective in preventing or treating the COVID-19?

No. Antibiotics do not work against viruses, they only work on bacterial infections. COVID-19 is caused by a virus, so antibiotics do not work.

Is COVID-19 the same as SARS?

No. The virus that causes COVID-19 and the one that caused the outbreak of Severe Acute Respiratory Syndrome (SARS) in 2003 are related to each other genetically, but the diseases they cause are quite different.

SARS was more deadly but much less infectious than COVID-19. There have been no outbreaks of SARS anywhere in the world since 2003.

Is COVID-19 airborne?

The virus that causes COVID-19 is mainly transmitted through droplets generated when an infected person coughs, sneezes, or speaks. These droplets are too heavy to hang in the air. They quickly fall on floors or surfaces. 

You can be infected by breathing in the virus if you are within 1 metre of a person who has COVID-19, or by touching a contaminated surface and then touching your eyes, nose or mouth before washing your hands.


  • Diphtheria is an infectious disease caused by the bacterium Corynebacterium diphtheria.
  • It primarily infects the throat and upper airways, and produces a toxin affecting other organs.
  • The main characteristics are sore throat, low fever and swollen glands in the neck.
  • In severe cases, the toxin may, cause myocarditis or peripheral neuropathy.
  • The diphtheria toxin causes a membrane of dead tissue to build up over the throat and tonsils.
  • The disease is spread through direct physical contact.
  • It can also be spread from breathing in the aerosolized secretions from coughs or sneezes of infected individuals.


  • Vaccination against diphtheria has reduced the mortality and morbidity of diphtheria.
  • Treatment involves administering diphtheria antitoxin to neutralize the effects of the toxin, as well as antibiotics to kill the bacteria.
  • Diphtheria vaccine is a bacterial toxoid, ie. a toxin whose toxicity has been inactivated.


Rotavirus is a leading cause of severe diarrhoea and death among children less than five years of age.

It is responsible for around 10% of total child mortality every year.

Rotavirus-Signs and Symptoms:

  1. Kids with a rotavirus infection have fever, nausea, and vomiting, often followed by abdominal cramps and frequent, watery diarrhea.
  2. Kids may also have a cough and runny nose.
  3. Sometimes the diarrhea that accompanies a rotavirus infection is so severe that it can quickly lead to dehydration.
  4. As with all viruses, though, some rotavirus infections cause few or no symptoms, especially in adults.


Rotavirus is transmitted by the faecal-oral route, via contact with contaminated hands, surfaces and objects, and possibly by the respiratory route. Viral diarrhea is highly contagious.

Rotavirus upsc
  • Currently, two vaccines are available against rotavirus:

Rotarix (GlaxoSmithKline): is a monovalent vaccine recommended to be orally administered in two doses at 6-12 weeks.

Rota Teq (Merck) is a pentavalent vaccine recommended to be orally administered in three doses starting at 6-12 weeks of age.

Monovalent vaccine and Pentavalent vaccine

  • Monovalent vaccines are designed to immunize against a single antigen or single microorganism.
  • Pentavalent vaccine provides protection to a child from five life-threatening diseases – Diphtheria, Pertussis, Tetanus, Hepatitis B and Haemophilus Influenzae type b (Hib).


Hepatitis means inflammation of the liver. When the liver is inflamed or damaged, its function can be affected.

Causes: Heavy alcohol use, toxins, some medications, and certain medical conditions can all cause hepatitis. However, hepatitis is often caused by a virus. In the United States, the most common hepatitis viruses are hepatitis A virus, hepatitis B virus, and hepatitis C virus.

What is the difference between hepatitis A, hepatitis B, and hepatitis C?

Hepatitis A, Hepatitis B, and Hepatitis C are liver infections caused by three different viruses.

  1. Hepatitis A is usually a short-term infection and does not become a long-term infection.
  2. Hepatitis B and hepatitis C can also begin as short-term infections but in some people, the virus remains in the body, and causes chronic, or lifelong, infection.

There are vaccines to prevent hepatitis A and hepatitis B; however, there is no vaccine for hepatitis C.

Rubella and Measles

  • Rubella is a contagious, generally mild viral infection that occurs most often in children and young adults.
  • Measles is a highly contagious viral disease and is a cause of death among young children globally.
  • Though the diseases are caused by different viruses but share more or less the same symptoms, including the red rashes.
  • The Measles & Rubella Initiative, a global program, aims at eliminating both these diseases.
  • The vaccine for the diseases are provided in the form of measles-rubella (MR), measles-mumps-rubella (MMR), or measles-mumps-rubella-varicella (MMRV) combination.


  • Polio, short for poliomyelitis, or infantile paralysis, is an infectious disease caused by the poliovirus. The virus destroys nerve cells in the spinal cord causing muscle wasting and paralysis.
  • There are three wild types of poliovirus (WPV) – type 1, type 2, and type 3. People need to be protected against all three types of the virus in order to prevent polio disease
  • Symptoms: Many people who are infected with the poliovirus don’t become sick and have no symptoms. However, those who do become ill develop paralysis, which can sometimes be fatal

Is it Curable?

  • There is no cure for polio, it can only be prevented. Polio vaccine, given multiple times, can protect a child for life.
  • Vaccine contains weakened-virus activating an immune response in the body, building up antibodies against virus.

What is Vaccine derived Polio Virus?

  • These are rare strains of poliovirus that have genetically mutated from the virus strain contained in the oral polio vaccine(OPV) administered to children. 90% of VDPV cases were due to the type 2 component in OPV

Does Polio still exist?

  • Polio does still exist, although polio cases have decreased by over 99% since 1988, from an estimated more than 350 000 cases to 22 reported cases in 2017. 
  • Today, only 3 countries in the world have never stopped transmission of wild polio virus (Pakistan, Afghanistan and Nigeria).

World Polio Day was established by Rotary International on 24th October to celebrate the birth of Jonas Salk, who developed a vaccine against poliomyelitis.


  • Dengue fever is a tropical disease that is borne by mosquitoes. It is caused by the dengue virus. 
  • Dengue is spread by several species of female mosquitoes of the Aedes variety, specifically of the A.aegypti.
  • The ideal conditions for this species of mosquitos are usually between the latitudes of 35° North and 35° South with an elevation of 1000 metres (3300 ft).
  • Even though humans are the primary host of the virus, non-human primates are also carriers.
  • A single bite is more than enough to be a cause for infection.
  • A female mosquito that bites a person infected person with dengue becomes itself infected during the initial 2-10 day febrile period.
  • After 8 – 10 days, the virus spreads to other tissues including the mosquitoes salivary glands and is subsequently released into its saliva. As per the research conducted on this species, the mosquito remains infected.
Dengue Fever - Symptoms, Causes and Preventive Measures of Dengue

Kyasanur Forest Disease

  • It is caused by Kyasanur Forest disease Virus (KFDV), a member of the virus family Flaviviridae.
  • It was first identified in 1957 in a sick monkey from the Kyasanur Forest in Karnataka. Since then, between 400-500 humans cases per year have been reported.
  • KFD is endemic to the Indian state of Karnataka.
  • Rodents, shrews, and monkeys are common hosts for KFDV after being bitten by infected Hard ticks (Haemaphysalis Spinigera). KFDV can cause epizootics (outbreak of disease in animals) with high fatality in primates.
  • Transmission: To humans, it may occur after a tick bite or contact with an infected animal (a sick or recently dead monkey).
  • Signs and Symptoms: After an incubation period of 3-8 days, the symptoms like chills, fever, headache, severe muscle pain, vomiting, gastrointestinal symptoms and bleeding may occur. Patients may experience abnormally low blood pressure, and low platelet, red blood cell, and white blood cell counts.
  • Diagnosis: It can be diagnosed in the early stage of illness by molecular detection by Polymerase Chain Reaction (PCR) or virus isolation from blood. Later, serologic testing using enzyme-linked immunosorbent serologic assay (ELISA) can be performed.
  • Treatment and Prevention: There is no specific treatment for KFD although a vaccine is available.

New anti-tuberculosis drug

Food & Drug Administration (FDA) has approved a new drug Pretomanid for treating drug-resistant tuberculosis — multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB).

Key facts:

  1. Pretomanid is only the third new anti-TB drug approved for use by FDA in more than 40 years.
  2. Pretomanid will be part of the three-drug regimen for drug approval by the European Medicines Agency (EMA).
  3. The duration of treatment for drug-resistant TB can be drastically cut from 18-24 months to just six-nine months when pretomanid drug is used along with two already approved drugs — bedaquiline and linezolid.
  4. The all-oral, three-drug regimen can also vastly improve the treatment success rate and potentially decrease the number of deaths due to better adherence to treatment.

What is tuberculosis (TB)?

It is a disease caused by bacteria that are spread from person to person through the air. TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine.

In most cases, TB is treatable and curable; however, persons with TB can die if they do not get proper treatment.

How widespread is MDR-TB and XDR-TB? 

People with TB who do not respond to at least isoniazid and rifampicin, which are first-line TB drugs are said to have MDR-TB.

People who are resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs (amikacin, kanamycin, or capreomycin) are said to have XDR-TB.


A group of bacteria that can cause food-borne illnesses known as salmonellosis.

How widely is it spread?

  • According to estimates by the US Centers for Disease Control and Prevention (CDC), Salmonella causes 1.2 million illnesses, 23,000 hospitalisations and about 450 deaths in the United States every year.
  • In a majority of these cases — roughly 1 million — food is the source of the illness.
  • The World Health Organisation (WHO) identifies Salmonella as one of four key global causes of diarrhoeal diseases.


  • Salmonella bacteria are widely distributed in domestic and wild animals. They are prevalent in food animals such as poultry, pigs, and cattle, as well as in pets, including cats, dogs, birds, and turtles.
  • Salmonella can pass through the entire food chain from animal feed, primary production, and all the way to households or food-service establishments and institutions.


  • The Bluetongue (BT) virus is an insect-transmitted viral disease of domestic and wild ruminants that includes the camelid species. 
  • The disease is widespread among the sheep, goats, cattle, buffaloes and camels in the country. 
  • With the help of the Kit “Bluetongue: Sandwich ELISA for detection of Antigen”, the Bluetongue Virus can be controlled with the vaccination of susceptible animals, vector control and quarantine of infected animals with the good management practices. 
  • Apart from the vaccination, the early diagnosis and isolation of the infected animals are one of the commonly suggested preventive methods for controlling the spreading of the disease. 

Lymphatic filariasis

  • Commonly known as elephantiasis, is a neglected tropical disease.
  • Infection occurs when filarial parasites are transmitted to humans through mosquitoes.
  • Infection is usually acquired in childhood causing hidden damage to the lymphatic system.
  • The painful and profoundly disfiguring visible manifestations of the disease, lymphoedema, elephantiasis and scrotal swelling occur later in life and can lead to permanent disability.
  • The parasites are transmitted by four main types of mosquitoes: Culex, Mansonia, Anopheles and Aedes.
  • It is transmitted by different types of mosquitoes for example by the Culex mosquito, widespread across urban and semi-urban areas, Anopheles, mainly found in rural areas, and Aedes, mainly in endemic islands in the Pacific.

Elephant Endotheliotropic Herpesvirus

Elephant Endotheliotropic Herpesvirus (EEHV) is a rare disease that has killed five elephants in Odisha.

  • EEHV is as a type of herpes virus that can cause a highly fatal hemorrhagic disease in young Asian elephants between the ages of 1 and 12.
  • If a young elephant dies before reproducing, it affects the population of the species as a whole in the concerned geography.
  • When EEHV is triggered, the elephant dies of massive internal bleeding and symptoms which are hardly visible, like reduced appetite, nasal discharge, and swollen glands.
  • The disease is usually fatal, with a short course of 28-35 hours.
  • There is no cure for herpes viruses in animals or in humans

Vaccine for Alzheimer’s Disease

China recently announced that a new drug, meant to potentially treat Alzheimer’s disease, will be available to Chinese patients by the end of this year.

Called GV-971 or “Oligomannate”, it is a seaweed-based drug, administered orally.

What is Alzheimer’s?

  • It is a progressive brain disorder that typically affects people older than 65. When it affects younger individuals, it is considered early onset.
  • The disease destroys brain cells and nerves, and disrupts the message-carrying neurotransmitters.
  • Eventually, a person with Alzheimer’s loses the ability to perform day-to-day activities.

There is no cure for Alzheimer’s, because its exact causes are not known. Most drugs being developed try to slow down or stop the progression of the disease.

Avian Botulism at Sambhar Lake

  • The avian botulism is a neuro-muscular illness caused by Botulinum (natural toxin) that is produced by a bacteria — Clostridium botulinum.
  • The bacteria is commonly found in the soil, rivers, and seawater. It affects both humans and animals.
  • The bacteria also need anaerobic (absence of oxygen) conditions and do not grow in acidic conditions.
  • It affects the nervous system of birds, leading to paralysis in their legs and wings.
  • The outbreaks of avian botulism tend to occur when average temperatures are above 21 degrees celsius, and during droughts.

There are two theories:

  1. The bacteria is also found in the gills and digestive tracts of healthy fish. It reproduces through spores and these spores remain dormant for years. They are resistant to temperature changes and drying. Under favourable conditions, the spores are activated. After the monsoon, when the water levels receded, there might have been an increase in salinity levels which could have led to the death of these living organisms. At this point in time, the spores could have been activated.
  2. ‘A bird-to-bird cycle’ could also have led to the tragedy. In such an event, maggots feeding on dead birds can concentrate the toxin. Birds feeding on dead birds can get affected. This was observed in Sambhar too as researchers found only insectivorous and omnivorous birds affected and not herbivores.

Bombay Blood Group

  • Under the ABO blood group system, blood group are classified into four common blood groups i.e. A, B, AB and O.
  • Each red blood cell has antigen over its surface, which helps determine which group it belongs to.
  • For instance, in the AB blood group, both antigens A and B are found. A will have A antigens; B will have B antigens. In O, there are no A or B antigens.
  • The A, B, and O blood groups were first identified by Austrian immunologist Karl Landsteiner in 1901.
  • The Bombay blood group (also called hh), is deficient in expressing antigen H.
  • It means the RBC of hh blood group has no antigen H.
  • Often the hh blood group is confused with the O group. The difference is that the O group has Antigen H, while the hh group does not.
  • The rare Bombay blood group was first discovered in Mumbai (then Bombay) in 1952 by Dr Y M Bhende.
Bombay Blood Group UPSC

This group is generally not stored in blood banks, mainly because it is rare and the shelf life of blood is 35-42 days.


  • Leprosy is one of the oldest diseases known to man. East Africa is the more likely place of origin of leprosy.
  • Leprosy also known as Hansen’s disease (HD), is a chronic infection caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis.
  • Leprosy is not highly infectious. It is transmitted via droplets, from the nose and mouth, during close and frequent contacts with untreated cases. Untreated, leprosy can cause progressive and permanent damage to the skin, nerves, limbs and eyes.
  • In 1982 multi drug therapy (MDT) consisting of Rifampicin, Clofazimine and Dapsone were identified as cure for leprosy on recommendation of WHO came into use.

Typbar TCV Vaccine

Hyderabad-based Bharat Biotech has developed a typhoid vaccine (Typbar TCV) which has better efficacy than the previously used vaccinations in preventing typhoid fever.

Conjugate vaccines are made using a combination of two different components. In Typbar TCV, an antigen is chemically linked to a carrier protein to create more powerful combined immune response.

The conjugate vaccine can be given to babies as young as six months, while the other two typhoid vaccines — polysaccharide typhoid vaccine and live, weakened typhoid vaccine cannot be given to children below two years of age.


  • Typhoid fever is caused by the highly contagious Salmonella Typhi bacteria. The bacteria spread through contaminated food or water.
  • Symptoms are prolonged fever, headache, nausea, loss of appetite, and constipation or sometimes diarrhoea.


Chikungunya viral (CHIKV) infection:

  • It is a viral disease (genus Alphavirus) which is transmitted to humans by infected mosquitoes, most commonly, Aedes aegypti and Aedes albopictus, two species which can also transmit other mosquito-borne viruses, including dengue.
  • These mosquitoes can be found biting throughout daylight hours, though there may be peaks of activity in the early morning and late afternoon.
  • It causes fever and severe joint pain. The name chikungunya originates from a verb in the Kimakonde language, meaning ‘to become contorted’. This refers to the ‘stooped’ appearance of those suffering with joint pain.
  • It occurs mainly in Africa, Asia and the Indian subcontinent.

Recent development:

  • The antibodies were developed following decade-long research on the CHIKV infection at the ILS laboratory headed by Dr. Soma Chattopadhyay, a senior molecular virologist.
  • With no prior antibodies reported against CHIKV, Dr. Chattopadhyay’s group was the first to develop antibodies against the non-structural proteins – nsP1, nsP3 and nsP4 of CHIKV.
  • She has been selected for the Biotech Product, Process Development and Commercialisation Award 2019 by the Department of Biotechnology.


  • Diabetes is a metabolic disease that causes high blood sugar. The hormone insulin moves sugar from the blood to cells to be stored or used for energy.
  • With diabetes, body either doesn’t make enough insulin or can’t effectively use the insulin it does make.
  • Untreated high blood sugar from diabetes can damage nerves, eyes, kidneys, and other organs.

Different types of diabetes:

  • Type 1 diabetes:It is an autoimmune disease. The immune system attacks and destroys cells in the pancreas, where insulin is made. It’s unclear what causes this attack. About 10 percent of people with diabetes have this type.
  • Type 2 diabetes: It occurs when body becomes resistant to insulin, and sugar builds up in your blood.It stems from a combination of genetics and lifestyle factors.
  • Pre-diabetes: It occurs when blood sugar is higher than normal, but it’s not high enough for a diagnosis of type 2 diabetes.
  • Gestational diabetes:It is high blood sugar during pregnancyInsulin-blocking hormones produced by the placenta cause this type of diabetes.

Diabetes affects the five major organs namely, Kidney, Heart, Blood vessels, Nervous System, and Eyes (retina).


  • Fluorosis is a slow, progressive, crippling disease which affects every organ, tissue and cell in the body.
  • According to WHO, the fluoride concentration in drinking water should not exceed 1.5mg/l.
  • Thus fluorosis is caused by excessive exposure to fluoride, beyond a concentration of 1.5 mg/l.
  • It adversely affects the foetal cerebral function and neurotransmitters. Reduced intelligence in children is associated with exposure to high fluoride levels.
  • Dental fluorosis is a defect in the tooth enamel caused by excessive fluoride consumption, is not treatable and the strains are permanent.
  • Skeletal fluorosis is developed by the disturbance of calcium metabolism in the formation of bones in the body. It results in the softening and weakening of bones, resulting in deformities.
  • The main source of fluoride in groundwater is the rocks such as charnockite, quartzite, pegamatite, laterite etc.

West Nile virus (WNV)

  • West Nile Virus (WNV) is a member of the flavivirus genus and belongs to the Japanese encephalitis antigenic complex of the family Flaviviridae.
  • West Nile Virus (WNV) can cause neurological disease and death in people. WNV is commonly found in Africa, Europe, the Middle East, North America and West Asia.
  • WNV is maintained in nature in a cycle involving transmission between birds and mosquitoes. Humans, horses and other mammals can be infected.
West Nile Virus UPSC

Human Papilloma Virus (HPV)

  • ‘Human Papilloma Virus (HPV)’ causes penile cancer in men and cervical, vaginal, anal & vulvar cancer in women.
  • It can also cause throat or rectum cancer in both men and women.
  • The virus is transmitted through intimate contact like – sexual intercourse, oral or anal sex.
  • It poses a higher risk for HIV-infected persons, smokers, and people dependent on hormonal contraceptives.
  • The Vaccine – In India, two vaccines namely “Gardasil” & “Cervarix” are available.

Global Syndemic

  • A syndemic is defined as “the presence of two or more disease states that adversely interact with each other”.
  • A Lancet Report states that the pandemics of obesity, under nutrition, and climate change are interlinked.
  • It terms it as “global syndemic”.
  • They represent as the paramount challenge for humans, the environment and our planet that presses the need for urgent action.
  • Until now, undernutrition and obesity have been seen as polar opposites.
  • But the report states that they are both driven by the same unhealthy, inequitable food systems, underpinned by the same political economy that is focused on economic growth.
  • Few instances are-
  1. Climate change > extreme weather events > increased food insecurity >under nutrition
  2. Climate change > increased prices of fruit and vegetables > increasing consumption of processed foods > obesity
  3. Foetal and infant under nutrition > risk of adult obesity.
  • Not a single country has reversed the obesity epidemic across the world.

Oxytocin ban

  1. xytocin has also been dubbed the hug hormone, cuddle chemical, moral molecule, and the bliss hormone due to its effects on behavior, including its role in love and in female reproductive biological functions in reproduction.
  2. Oxytocin is a hormone that is made in the brain, in the hypothalamus. It is transported to, and secreted by, the pituitary gland, which is located at the base of the brain.
  3. It acts both as a hormone and as a brain neurotransmitter.
  4. The release of oxytocin by the pituitary gland acts to regulate two female reproductive functions: Childbirth and Breast-feeding.

Reasons behind the ban are:

  1. Misuse in diary industry: Oxytocin is a naturally-occurring hormone that causes uterine contractions during labour and helps new mothers lactate. However, the drug is misused in the dairy industry where livestock is injected with Oxytocin to make them release milk at a time convenient to farmers.
  2. Oxytocin is also used to increase the size of vegetables such as pumpkins, watermelons, eggplants, gourds, and cucumbers.

Universal Immunization Programme

  • Universal Immunization Programme was launched in 1985.
  • The program now consists of vaccination for 12 diseases:
  1. tuberculosis
  2. diphtheria
  3. pertussis (whooping cough)
  4. tetanus
  5. poliomyelitis
  6. measles
  7. Hepatitis B
  8. diarrhoea
  9. Japanese Encephalitis
  10. Rubella
  11. Pneumonia( Heamophilus Influenza Type B)
  12. Pneumococcal diseases (Pneumococcal Pneumonia and Meningitis)
  • The Indradhanush mission, launched in 2014, is to fast track the universal immunization programme.
  • The mission aims at increasing the immunisation coverage to 90% by 2018.

Intensified Mission Indradhanush

  • Mission Indradhanush was launched in 2014 to achieve full immunisation coverage for all children and pregnant women at a rapid pace.
  • Intensified Mission Indradhanush (IMI) was launched from Vadnagar in 2017 and its second version (2.0) 2.0 is going to be launched from Dec 2, 2019.
  • Through IMI, Government aims to reach each and every child upto 2 years of age and all those pregnant women who have been left uncovered under the routine immunisation programme/Universal Immunisation Programme (UIP).
  • It aims to achieve targets of full immunization coverage in 272 districts in 27 States.
  • It shall be implemented in the block level (652 blocks) in Uttar Pradesh and Bihar.
  • It will focus on urban, underserved population and tribal areas.
  • It consists of 4 rounds of immunization that will be conducted in the selected districts and urban cities between Dec 2019 – March 2020.
  • The UIP basket has vaccines for ten diseases i.e

1. BCG for TB, OPV for poliomyelitis,

2. monovalent measles vaccine for measles,

3. Rota Virus vaccine for Diarrhoea,

4. JEV for Japanese Encephalitis &

5. Pentavalent Vaccine for DPT (diphtheriapertussis i.e whooping cough & tetanus) and

6. Vaccine for Hepatitis B & Pneumonia due to Hib.

7. Measles-rubella vaccine (MR) is also added now to the UIP


  • An electronic cigarette (or e-cig) is a battery-powered vaporizer that mimics tobacco smoking. It works by heating up a nicotine liquid, called “juice.”
  • E-cigarettes contain potentially harmful substances – such as heavy metals like lead, volatile organic compounds and cancer-causing agents.
  • Availability of flavour variants and attractive designs are adding to allure of devices and globally there was an increasing trend of e-cigarettes consumption among youth and adolescents.
  • As e-cigarettes contain nicotine and not tobacco, they do not fall within the ambit of the Cigarettes and Other Tobacco Products (Prohibition of Advertisement and Regulation of Trade and Commerce, Production, Supply and Distribution) Act, 2003 (COTPA), which mandates stringent health warnings on the packaging and advertisements of tobacco products.


  • Nicotine is a plant alkaloid that contains nitrogen, which is found in several types of plants, including the tobacco plant and can also be produced synthetically.
  • Nicotine is both a sedative and a stimulant.
  • Nicotine is used as a direct substance in e-cigarettes and the content ranges up to 36 mg/mL. Although regular cigarettes too have nicotine, but it ranges between 1.2 to 1.4 mg/mL.
  • Recently, Karnataka has notified nicotine as Class A poison.

List of Various Deficiency Diseases

List of Various Deficiency Diseases BY Legacy IAS Academy


Name of disease Caused by Parts of body affected Method of spread Type of Vaccination
Influenza A myxovirus (RNA virus) Respiratory passages: epithelial lining of trachea and bronchi. Droplet Infection Killed virus
Common cold Large variety of viruses, commonly rhino-virus (RNA Virus) Respiratory passages Droplet Infection Intramuscular injection.
Smallpox Variola virus (DNA virus) Respiratory passages, then skin Droplet Infection (Wounds in skin) Living atteneuated virus applied by scratching skin, no longer carried
Chickenpox Varicella- zoster Blistering Skin rash Air-borne droplets Living attenuated virus
Mumps A paramyxovirus (RNA virus) Respiratory passages, infection via blood, salivary glands, testes in adult males Droplet infection Living attenuated virus
Measles A paramyxovirus (RNA virus) Respiratory passages, spreading to skin and intestines. Droplet infection Living attenuated virus
German measles (Rubella) Rubella virus Respiratory passages, lymph nodes in neck, eyes and skin. Droplet infection Living attenuated virus, more essential for girls because disease causes complication in pregnancy.
Poliomyelitis (polio) Poliovirus (RNA Virus) Pharynx and intestines, then blood; occasionally motor neurons in spinal cord, paralysis may occur. Droplet infection or via human faeces Living attenuated virus given orally
Yellow fever An arbovirus i.e arthropod-borne virus (RNA Virus) Lining of blood vessels and liver Vector- arthropods e.g ticks, mosquitoes Living attenuated virus
AIDS Retrovirus (RNA virus) Skin Cancer Sexual intercourse homo- and hetrosexuals Not available
Ebola haemorrhagic fever Ebola Virus disease (EVD) Fatal Illness in Humans, Fever It is transmitted to people from wild animals and spreads in the human population through human-to-human transmission. No licensed Ebola vaccine is available
Zika disease Zika Virus (mosquito borne disease) Causes mild illness in the people like dengue, yellow fever Basically Infection in pregnant women is linked to abnormally small heads in their babies. No vaccine available

List of Bacterial Diseases of Humans:

Name of disease  Caused by Parts of body affected Method of spread Type of vaccination or antibodies
Diphtheria Corynebacterium diphtheria Upper respiratory tract, mainly throat also toxin affects heart. Droplet infection Toxoid
Tuberculosis (TB) Mycobacterium tuberculosis Mainly lungs Droplet infection, Drinking milk from infected cattle. BCG living attenuated bacteria. Antibiotics e.g. streptomycin.
Whooping cough (Pertussis) Bordetella pertussis Upper respiratory tract, inducing violent coughing Droplet infection Killed bacteria
Gonorrhoea Neisseria gonorrhoeae Reproductive organs: mainly mucous membranes of urinogenital tract. Newborn infants may acquire serious eye infections if they pass through infected birth canal. Contagion by sexual contact Antibiotics, e.g. penicillin, streptomycin
Syphilis Treponema pallidum Reproductive organs, then eyes, bones, joints, central nervous system, heart and skin. Contagion by sexual contact Antibiotics. e.g. penicillin
Tetanus Clostridium tetani Blood. Toxin produced which affects motor nerves of spinal cord and hence muscles, causing lockjaw and spreading to the muscles. Wound infection Toxoid
Cholera Vibrio cholera Alimentary canal: mainly small intestine. Faecal contamination (a) food – or water borne of material contaminated with faeces from infected person. (b) handling of contaminated Objects. (c) vector, e,g. flies moving from human faeces to food. Killed bacteria: short-lived protection and not always effective Antibiotics e.g. tetracyclines, chloramphenicol.
Typhoid fever Salmonella typhi Alimentary canal, then spreading to lymph and blood, lungs, bone marrow, spleen. Same as cholera Killed bacteria (TAB vaccine)
Bacterial dysentery Shigella dysenteriae Alimentary canal, mainly ileum and colon Same as cholera No vaccine.
Bacterial food poisoning (gastro enteritis or salmonellosis) Salmonella spp. Alimentary canal Mainly foodborne meat from infected animals from poultry and pigs. Also via faecal contamination as cholera Antibiotic. e.g. tetracyclines.

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December 2023