Human health

• Disease is an abnormal condition of the body or mind that causes discomfort, difficulty to function, or stress to an individual.
• Examples of infectious diseases include tuberculosis, flu, ringworm, tinea, leptospirosis, dengue fever, malaria fever, and Zika fever
• Examples of non-infectious diseases include cancer, hypertension, diabetes, asthma, and cardiovascular diseases.
• Pathogens can be transmitted from an infected person (host) to another through air, water, contact, or vectors.
• Infectious diseases can be transmitted from one individual to another, while non-infectious diseases cannot.
• Infectious diseases are caused by infection of pathogens directly through mediums and vectors, while non-infectious diseases are caused by genetic factors or lifestyle.
• Infectious diseases are spread by pathogens, which are organisms that cause diseases such as viruses, bacteria, protozoa, fungi, and worms.
• Airborne diseases are transmitted through pathogen-containing droplet sprays from the mouth and nose of an infected person through sneezing, coughing, talking, yawning, or breathing.
• Bacteria in the spit (saliva) of an infected person can dry up and form spores which are spread together with the dust in the air.
• Ways to prevent airborne diseases include covering the mouth and nose when sneezing, coughing, or yawning, not spitting everywhere, avoiding crowded places, and ensuring the living place gets enough light as ultraviolet rays can kill certain microorganisms in the air.
• Examples of airborne diseases include tuberculosis, flu, severe acute respiratory syndrome (SARS), influenza A (H1N1), chickenpox, and Covid-19.
• Waterborne diseases occur in areas with inadequate water supply and poor sanitation.
• When someone uses a toilet built over a river, faecal pathogens enter the river and pollute the water.
• A person can become infected by pathogens when they drink the contaminated water.
• Floods can also contribute to the spread of waterborne diseases.
• Ways to avoid waterborne diseases:

  Add chlorine into swimming pools and water supply systems.

  Build toilets with good sanitation.

  Boil drinking water properly.

  Wash hands with soap after using the toilet.
• Example of waterborne diseases: Cholera, Typhoid, Amoebic dysentery.
• Example of diseases transmitted through contact: Ringworm and Tinea.
• Ringworm and Tinea are caused by fungi and can be transmitted by accidentally touching the infected skin or wearing the clothes of an infected person.
• Example of diseases transmitted through sexual intercourse: Syphilis, Gonorrhoea, AIDS.
• AIDS is caused by the HIV virus and can be transmitted through sexual intercourse, blood, and syringe-sharing among patients and drug addicts.
• Some pathogens are transmitted through animals.
• Animals that transmit these pathogens are called vectors.
• Salmonella typhi is transmitted by cockroaches and flies, causing symptoms such as fever, intestinal bleeding, and red rashes. It is transmitted through contaminated food and water.
• Zika virus is transmitted by Aedes mosquitoes and causes symptoms such as fever, rashes, joint pain, and conjunctivitis.
• Dengue virus is transmitted by mosquitoes and causes symptoms such as joint pain, fever, headache, and watery eyes.
• Malaria is transmitted by anopheles mosquitoes and causes symptoms such as shivering, fever, and sweating. It is caused by the Plasmodium malariae parasite.
• Leptospirosis is caused by the Leptospira sp. bacteria and is transmitted through contaminated soil, food, and water. Symptoms include fever, headache, and muscle pain. It is transmitted by rats.
• Cholera is caused by the Vibrio cholerae bacteria and is transmitted through contaminated food and water. Symptoms include diarrhea and vomiting. Flies can also transmit cholera.
• A mosquito that already has pathogens in its salivary glands sucks the blood of an uninfected person, spreading the infection throughout their body.
• Another mosquito that bites the infected person can transmit the disease to another victim.
• A fly that lands on dirt with pathogens on its legs and body can transmit the pathogens to food, which can enter the body of a person who eats the contaminated food.
• Mechanism to prevent the spread of infectious diseases:

  Primary Stage: Improving health by strengthening the body's defense system and maintaining a healthy lifestyle.
• Mechanism to prevent the spread of infectious diseases:

  Secondary Stage: Determining transmission of infections through active and passive case detection, giving early treatment to patients, and separating patients from others.
• Mechanism to prevent the spread of infectious diseases: Tertiary stage

  Controlling vector populations by destroying vector breeding and hiding places, fogging to kill vectors and enforcing laws by issuing compounds to owners of dirty food premises
• Mechanism to prevent the spread of infectious diseases: Tertiary stage

  Protecting hosts by using mosquito nets or mosquito coils and

  wearing thick clothes
• Physical activity can help maintain a healthy weight and improve body composition by increasing muscle mass and reducing body fat.
• Exercise can improve mental health by reducing symptoms of depression and anxiety and boosting overall mood.
• Regular exercise can help reduce the risk of chronic diseases such as heart disease, diabetes, and certain types of cancer.
• Regular exercise can improve cardiovascular health by strengthening the heart and improving blood circulation.