DISEASES: Communicable & Non-Communicable Health Threats, Tuberculosis to COVID-19

• Diseases are abnormal conditions that have a specific set of signs and symptoms.
• Diseases can have an external cause, such as an infection, or an internal cause, such as autoimmune diseases.
• Types of Diseases:

A communicable disease is one that is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; breathing in an airborne virus; or by being bitten by an insect. Ex: HIV, TB, Malaria etc.,

How do these communicable diseases spread?

Some ways in which communicable diseases spread are by:

1. Physical contact with an infected person, such as through touch (staphylococcus), sexual intercourse (gonorrhea, HIV), fecal/oral transmission (hepatitis A), or droplets (influenza, TB)
2. Contact with a contaminated surface or object (Norwalk virus), food (salmonella, E. coli), blood (HIV, hepatitis B), or water (cholera);
3. Bites from insects or animals capable of transmitting the diseases (mosquito: malaria and yellow fever; flea: plague); and
4. Communicable Diseases travel through the air, such as tuberculosis or measles.

Diseases: Tuberculosis (TB) Overview

• According to WHO, TB is one of the top 10 causes of death worldwide and the leading cause of death from a single infectious agent (ranking above HIV/AIDS).
• TB is caused by the bacillus Mycobacterium tuberculosis.
• The disease typically affects the lungs (pulmonary TB) but can also affect other sites (extrapulmonary TB).
• India’s TB burden is the highest in the world, followed by Indonesia and China.
• TB is a disease of poverty, and economic distress, vulnerability, marginalization, stigma and discrimination are often faced by people affected by TB (WHO).

Diseases: National Strategic Plan to end TB in India by 2025

• It provides goals and strategies for the country’s response to the disease during the period 2017-2025.
• It targets to eliminate TB five years ahead of the global End TB (by 2030) targets under SDGs to attain the vision of a TB-free India.
• TB elimination has been integrated into the four strategic pillars of “Detect – Treat – Prevent – Build” (DTPB).

Diseases: Diarrhoea

• Loose, watery stools that occur more frequently than usual.
• It is primarily caused when there is a reduction in the absorption of fluid by intestines or an increase in the secretion of fluid or speedy passage of stool through intestines.
• Diarrhoea is classified into two types, namely:

1. Acute diarrhoea: may last for 2 or 3 days, but not more than a week. It is not a life-threatening condition and can be cured by taking relevant medications.
2. Chronic diarrhoea: may last for 1 or 2 weeks, but it can last much longer. This is usually due to other underlying gastrointestinal diseases.

• Symptoms: Loose stools, Vomiting, Nausea, Cramps, The feeling of a bowel movement, Abdominal pain, Fever, Bloody stools (rare cases)
• Treatment: Generally, acute diarrhoea will recede on its own, within 2 to 3 days without any treatment. But it is advised to consult the physician regardless.

Diseases: Anthrax

• Anthrax is one of the serious infectious diseases caused by gram-positive, rod-shaped bacteria known as Bacillus anthracis.
• Anthrax can be found naturally in soil and commonly affects domestic and wild animals around the world.
• Affects animals such as cattle, sheep, and goats more often than people. People can get anthrax from contact with infected animals, wool, meat, or hides.
• Spread: It does not spread directly from one infected animal or person to another; it is spread by spores. These spores can be transported by clothing or shoes.
• Symptoms: People may experience pain in the chest or muscles, Skin blister, dark scab, Ulcers, fever or malaise, respiratory distress or shortness of breath, coughing, headache, itching, nausea, sore throat, or swollen lymph nodes.
• Treatment: The standard treatment for anthrax is a 60-day course of an antibiotic. Examples include ciprofloxacin (Cipro) or doxycycline (Doryx, Monodox).
• The anti-anthrax vaccines available in the market generate an immune response against a Bacillus protein-protective antigen– a protein that helps in the transport of bacillus toxins inside the cells.

Diseases: Leprosy

• Leprosyis one of the chronic, curable infectious diseases mainly causing skin lesions and nerve damage.
• Caused by: bacterium Mycobacterium leprae. It mainly affects the skin, eyes, nose and peripheral nerves.
• Symptoms include light-colored or red skin patches with reduced sensation, numbness and weakness in hands and feet.
• Mode of Transmission: Mainly by breathing airborne droplets from the affected individuals. It can be contacted at any age.
• Treatment: Leprosy can be cured with 6-12 months of Multi-Drug Therapy (MDT). Early treatment avoids disability.
• Rifampicin and clofazimine are now combined with dapsone to treat multi-bacillary leprosy.

DISEASES: ACQUIRED IMMUNODEFICIENCY SYNDROME/AIDS

• Caused by the Human Immunodeficiency Virus (HIV).
• HIV is a lentivirus, which is a sub-classification of the retrovirus. It causes the HIV infection which over time leads to AIDS.
• HIV demolishes a particular type of WBC (White Blood Cells) and the T-helper (CD4) cells.
• Unlike some other viruses, the human body can’t get rid of HIV completely, even with treatment. So once a person gets HIV, currently, there is no cure for it.

DISEASES: POLIO

• It is one of the highly infectious viral diseases which invades the nervous system and can cause irreversible paralysis within hours.
• There are three individual and immunologically distinct wild poliovirus strains: Wild Poliovirus Type1 (WPV1), Wild Poliovirus Type 2 (WPV2) and Wild Poliovirus Type 3 (WPV3).

DISEASES: Vaccines

DISEASES: Polio Status in India

• India launched the Pulse Polio Immunization Programme in 1995 brought down polio cases from 50,000-100,000 each year in the 80s to zero in 2012.
• In January 2014, India was declared polio-free after three years on zero cases.
• India introduced the injectable polio vaccine in the Universal Immunization Programme to reduce chances of Vaccine Derived Polio Virus (VDPV), which continues to happen in the country.

DISEASES: GLOBAL POLIO ERADICATION INITIATIVE

• Public-private partnership to eradicate polio worldwide
• It has five partners, the WHO, Rotary International, the US Centers for Disease Control and Prevention, UNICEF, Bill & Melinda Gates Foundation and GAVI, the vaccine alliance.

DISEASES: ZIKA VIRUS

• Zika is one of the viral infection diseases spread by Aedes aegypti
• In most cases, there are no symptoms. In a few cases, Zika can trigger paralysis (Guillain-Barré Syndrome).
• In pregnant women, it may cause subsequent birth defects. When present, symptoms are mild and last less than a week. They include fever, rash, joint pain and red eyes.
• There’s no vaccine or specific treatment. Instead, the focus is on relieving symptoms and includes rest, rehydration and acetaminophen for fever and pain.
• Aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen should be avoided.

DISEASES: DENGUE

• Dengue is a viral disease transmitted mainly through female mosquitoes of the species Aedes Aegypti, which thrives in tropical climates.
• Symptoms include high fever, headache, rash and muscle and joint pain.
• The disease may develop into a life-threatening dengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets and blood plasma leakage.
• Recently, Spanish health authorities confirmed the world’s first case of dengue being transmitted through sex.
• Treatment includes fluids and pain relievers. Severe cases require hospital care. Medication example, Analgesic.

DISEASES: JAPANESE ENCEPHALITIS (JE)

• Japanese encephalitis is a virus spread by the bite of infected mosquitoes. It’s more common in rural and agricultural areas.
• Caused by a Flavi Virus that affects the membranes around the brain.
• A major cause of Acute Encephalitis Syndrome (AES) in India transmitted to humans through bites from infected mosquitoes of the Culex species.
• Treatment involves supportive care. A vaccine is available.
• JE vaccination is also included under the Universal Immunization Program.

DISEASES: FLU/INFLUENZA

• A common viral infection that can be deadly, especially in high-risk groups.
• The flu attacks the lungs, nose and throat. Young children, older adults, pregnant women and people with chronic disease or weak immune systems are at high risk.
• Symptoms include fever, chills, muscle aches, cough, congestion, runny nose, headaches and fatigue.
• Treatment: Flu is primarily treated with rest and fluid intake to allow the body to fight the infection on its own.
• There are four species of Influenza Virus viz. Influenza-A, Influenza-B, Influenza-C, and Influenza-D.
• Human influenza A and B viruses cause seasonal epidemics of disease (known as the flu season).
• Influenza type C infections generally cause mild illness and are not thought to cause human flu epidemics.
• Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people.
• The common Influenza outbreaks caused by Influenza-A strains include

1. H1N1 (Swine Flu)
2. H5N1, H5N8, H2N9 (Bird Flu)

DISEASES: NIPAH

• Zoonotic virus (it is transmitted from animals to humans)
• Transmission: Nipah virus can be transmitted to humans from animals (such as bats or pigs), or contaminated foods and can also be transmitted directly from human-to-human.
• Symptoms: (similar to that of influenza) fever, muscle pain, and respiratory problems.
• Inflammation of the brain causing disorientation.
• There are currently no drugs or vaccines specific for Nipah virus infection.

DISEASES: CORONA

• Coronaviruses are a large family of viruses that circulate among a range of animals, such as bats, cats, and birds.
• The virus causes respiratory and gastrointestinal symptoms in humans with infectious diseases ranging from the common cold to more severe diseases such as Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and CoVID-19.

NOTE:

• The SARS coronavirus is thought to have evolved from bats to civet cats to humans in the Guangdong province of southern China in 2002.
• The MERS coronavirus evolved from bats to camels to humans in Saudi Arabia in 2012.
• The CoVID-19 virus was first identified in Wuhan (Hubei province), China in 2019

DISEASES: Coronavirus Disease 2019 (COVID-19)

• COVID-19 is an infectious disease caused by a newly discovered coronavirus. COVID-19 is a Zoonotic disease.
• Symptoms: mild to moderate respiratory illness and recover without requiring special treatment. Older people and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness. (WHO)
• Vaccine: Currently under development. Few approved drugs include Pfizer (USA), Covaxin, Covishield (India).

DISEASES: HEPATITIS

• Hepatitis refers to an inflammatory condition of the liver.
• It’s commonly caused by a viral infection, but there are other possible causes of hepatitis. These include autoimmune hepatitis and hepatitis that occurs as a secondary result of medications, drugs, toxins, and alcohol.
• Hepatitis Types:
• Hepatitis B and C can cause chronic hepatitis and are responsible for 96% of overall hepatitis mortality.
• Hepatitis A and E usually cause acute hepatitis.
• Note: Hepatitis D infections occur only in those who are infected with Hepatitis B Virus.
• There are vaccines to prevent Hepatitis A, B and E. However, there is no vaccine for Hepatitis C.
• Nobel Prize for Medicine or Physiology, 2020 for the discovery of the Hepatitis C virus– Harvey J Alter, Charles M Rice and Michael Houghton.

National Viral Hepatitis Control Program

• It aims to reduce morbidity and mortality due to viral hepatitis.
• Vision: Ending viral hepatitis as a public health threat by 2030 in the country.

DISEASES: EBOLA

• Also called Ebola Hemorrhagic Fever, caused by Ebola virus that causes severe bleeding, organ failure and can lead to death.
• Humans may spread the virus to other humans through contact with bodily fluids such as blood.
• Initial symptoms include fever, headache, muscle pain and chills. Later, a person may experience internal bleeding resulting in vomiting or coughing blood.
• Treatment is supportive hospital care like oxygen therapy, IV fluids.
• Medication: Blood transfusion.

DISEASES: MALARIA

• Malaria is a disease caused by a plasmodium parasite, transmitted by the bite of infected female Anopheles
• Symptoms are chills, fever and sweating, usually occurring a few weeks after being bitten.
• Treatment includes antimalarial drugs.

RELATED INFORMATION

• World’s first vaccine against a parasitic disease: Mosquirix
• Recently, Algeria and Argentina have been officially recognized by the WHO as malaria-free.
• WHO’s E-2020 initiative: It is part of the Global Technical Strategy for Malaria 2016-2030 endorsed by WHO which aimed to dramatically lower (or eliminate) the global malaria burden over these 15 years.

DISEASES: KALA AZAR/BLACK FEVER

• It is a neglected tropical disease affecting almost 100 countries including India, caused by infection with Leishmania parasites.
• Also known as Dumdum fever. It spread through sandfly bites.
• Symptoms: some people have no symptoms. For others, symptoms may include fever, weight loss and swelling of the spleen or liver.
• There are three types of leishmaniasis:

1. Visceral leishmaniasis, which affects multiple organs and is the most serious form of the disease.
2. Cutaneous leishmaniasis, which causes skin sores and is the most common form.
3. Mucocutaneousleishmaniasis, which causes skin and mucosal lesions.

• Visceral leishmaniasis which is commonly known as Kala-azar in India is fatal in over 95% of the cases if left untreated. This type of leishmaniasis affects the internal organs, usually the spleen, liver and bone marrow.
• Medication exists to kill the parasites. If left untreated, severe cases are typically fatal.

NON-COMMUNICABLE DISEASES (NCDS)

• NCDs also known as chronic diseases tend to be of long duration and are the result of a combination of genetic, physiological, environmental and behaviours factors.
• The main types of NCDs are:
• Cardiovascular diseases (like heart attacks and stroke),
• Cancers,
• Chronic respiratory diseases (such as chronic obstructive pulmonary disease and asthma)
• NCDs disproportionately affect people in low and middle-income countries where more than three-quarters of global NCD deaths occur – WHO

DISEASES: NCDs and India

• According to Indian Council of Medical Research (ICMR) report titled “India: Health of the Nation’s States”:

1. Contribution of NCDs to total death in the Country was 61.8% in 2016, as compared to 37.9% in 1990.
2. In the States of Kerala, Goa and Tamil Nadu, due to epidemiological transition, fewer deaths are recorded for Communicable, maternal, neonatal and nutritional diseases, thereby raising the share of NCDs in total deaths.
3. Risk factors for NCDs inter alia include ageing, unhealthy diet, lack of physical activity, high blood pressure, high blood sugar, high cholesterol and overweight.

• According to ‘National Non-communicable Disease Monitoring Survey (NNMS):

1. Two in five adults have three or more risk factors for NCDs in India.
2. Overweight or obese: More than 1 in every 4 adults and 6.2% of adolescents
3. Raised blood pressure: Almost 3 out of 10 adults
4. Raised blood glucose:3%.
5. Insufficient physical activity: More than 2 in 5 adults and 1 in 4 adolescents.
6. One in every three adults and more than one-fourth proportion of men used any form of tobacco and consumed alcohol in the past 12 months respectively.

DISEASES: HEALTH MISSIONS

DOWNLOAD PDF