Topic outline
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In this unit you will learn about:
- The importance of immunity and health
- Understand factors which affect health and immunity
- Understand the importance of good personal hygiene
- The meaning of disease and infection
- The common ways of transmisssion of common infections and diseases
- Identify ways to prevent and control the transmission of common diseases and infections
- How common sexually transmitted diseases including HIV are transmitted
- Identify ways to prevent the spread of STI's
- The importance of curative health
- The importance of care and support for people living with HIV
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Health is the state of physical, mental, and social well-being. It is not just being free from disease.
Factors can work together to affect physical and mental health. Diseases stop part of the body from working properly. A disease is a disorder that affects an organism's body, organs, tissues, or cells.
Factors that can have major effects on physical and mental health include:
- diet
- lifestyle factors such as alcohol and other drugs
- stress
- situations that may occur in a person's life
Immunity is the ability of the body to defend itself against disease-causing organisms.
Everyday our body encounters different types of bacteria and viruses, (sometimes called pathogens or microorganisms) but only a few cause diseases. The reason is our body can release antibodies against these and protect the body. This defence mechanism is called immunity.
Defence mechanisms help the body protect itself against the entry of microorganisms and diseases.
These defence mechanisms are:
- Skin – a barrier to microorganisms.
- Mucous membranes – present in the respiratory system to trap microorganisms.
- Blood clotting – stops blood escaping and prevents the entry of microorganisms where the skin has been damaged.
- white blood cells
If a microorganism does enter, then they may cause illness, but the body has a second line of defence to stop or minimise this infection. This is called the immune system. As a part of this there are two types of white blood cell called phagocytes and lymphocytes.
Phagocytes
Phagocytes surround any pathogens in the blood and engulf them. They are attracted to pathogens and bind to them.
The phagocytes membrane surrounds the pathogen and enzymes found inside the cell break down the pathogen to destroy it. As phagocytes do this to all pathogens that they encounter, they are called 'non-specific'.
Lymphocytes
Lymphocytes are another type of white blood cell. They recognise proteins on the surface of pathogens called antigens. Lymphocytes detect that these are foreign not naturally occurring within your body and produce antibodies. This can take a few days, during which time you may feel ill. The antibodies cause pathogens to stick together and make it easier for phagocytes to engulf them.
Some pathogens produce toxins which make you feel ill. Lymphocytes can also produce antitoxins to neutralise these toxins. Both the antibodies and antitoxins are highly specific to the antigen on the pathogen, thus the lymphocytes that produce them are called 'specific'.
If your body encounters a particular antigen, your lymphocytes might recognise it. If they do, they clone themselves to make enough antibodies to destroy the pathogen. Memory cells are also created which remain in your bloodstream and produce a quick response if the antigen is encountered again. You are then said to be immune.
Credit: Fuse Schools - Global Education.
The best immunity comes from having fought off a disease. However, in some cases such as a serious disease that could prove fatal when first infected, vaccination is used.
There are three different types of immunity:
Natural immunity happens after you get infected by a pathogen and your immune system responds by making antibodies to it. The infection could make you sick. But if you’re exposed to that germ in the future, your body’s defenses spot it and fight back with antibodies. This makes you less likely to get infected again.
Natural immunity to a disease weakens over time, though. How quickly or slowly this happens depends on the disease. For example, if someone gets natural immunity from a COVID-19 infection, the immunity may fade after 3 months. On the other hand, a child who gets measles is unlikely to ever catch it again.Vaccine-Induced Immunity
Vaccines can protect your immune system against diseases without making you sick. They safely boost your immunity by using a killed or weakened version of a germ to teach your body’s defenses to fight back against the real thing. Even though they can bring on side effects, they rarely make someone seriously ill.Vaccine-induced immunity and natural immunity are both types of active immunity. That’s the medical term for when you’re exposed to something that causes your immune system to make antibodies to a disease.
Passive Immunity: This is the other main type of immunity. Instead of your body making antibodies, you get passive immunity by receiving antibodies from another source. Passive immunity is fast acting and only works for a short period.
Breastfeeding provides a baby with natural passive immunity.
Anti-venom provides artificial passive immunity after a poisonous bite.
Herd Immunity: This when a contagious disease, like Covid-19, stops spreading easily because enough people in the community (or “herd”) have become immune to it. This can be because of natural active immunity, vaccine-induced immunity, or passive immunity.
Credit: Science Sauce
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Good manners help in maintaining a healthy lifestyle including eating habits, sleeping patterns and physical exercises. Certain good manners that people should learn are empathy, self-consciousness, helpfulness, being thankful, gratitude towards others, respect to elders and discipline.
In general, hygiene refers to a series of practices that protect the health from diseases. Personal hygiene refers to maintaining the body’s cleanliness.
Image: Emma Harrage. CC BY
Puberty causes many changes in your body. Most girls begin puberty between ages 8 and 14, with an average of 11. Girls develop more quickly than boys and most finish puberty within four years. Most boys begin puberty between ages 9 and 14, with an average of 12. Most boys finish puberty within six years.
The changes happen because of sex hormones produced by the testes in boys and by the ovaries in girls. Some changes happen in boys and girls, while others just happen in boys or girls. Here are some changes that happen to both boys and girls:
- underarm hair grows
- pubic hair grows
- body smell gets stronger
- emotional changes
- growth rate increases
In order to have good personal hygiene, it is important to develop and maintain good habits including:
- Regular hand washing, including after using the toilet
- Taking regular showers or baths
- Brushing your teeth at least twice a day
- Taking care of and cleaning your nails
- Washing and brushing your hair regularly
- Covering your mouth while sneezing or coughing
- Washing your clothes often
- Regularly cleaning your home
- Making sure that food is stored and cooked correctly
If you do these then you will be able to protect yourself from harmful bacteria and viruses that can make you sick. These habits will also make you less smelly!
Credit: amaze.org. Taking Care of Your Body During Puberty.
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When you have an infection, you have a medical condition that occurs when one or more microorganisms, such as bacteria, viruses, or fungi, invade and multiply in or on your body. This will cause tissue injury or disease.
An infection may or may not cause symptoms, and it may be localized or affect the whole body. An infection may also be transmissible or communicable to other hosts.
A disease is an abnormal condition that affects the structure or function of an organism or part of it, and that is not due to external injury.
A disease may have symptoms, and may be caused by environmental factors, an infection, genetic flaws, or combinations of these factors. A disease can often be passed from one person to another, and cause difficulties.
Pathogens are disease-causing viruses, bacteria, fungi, or protists, which can infect animals and plants. Humans have an immune system, which can defend them from pathogens.
Pathogens
A pathogen is a microorganism that causes a disease. There are four main types of pathogens: viruses, bacteria, protists, and fungi.
All types of pathogens have a simple life cycle. They infect a host, reproduce themselves or replicate if it is a virus, spread from their host and infect other organisms.
Diseases caused by pathogens are called communicable diseases. This means they can be transferred from one person to another.
All organisms are affected by pathogens. Even bacteria are infected by certain types of viruses. Some of these infections can be transferred to organisms of a different species.
Transmission
Transmission can occur in several important ways, as shown in the table below:
Type
Examples
Direct contact
This can be sexual contact during intercourse or non-sexual contact, like shaking hands.
Water
Dirty water can transmit many diseases, such as the cholera bacterium.
Air
When a person who is infected by the common cold sneezes, they can spray thousands of tiny droplets containing virus particles to infect others.
Unhygienic food preparation
Undercooked or reheated food can cause bacterial diseases like Escherichia coli which is a cause of food poisoning.
Vector
Any organism that can spread a disease is called a vector. Mosquitos cause malaria. The mosquito is the vector.
Credit: Let's Learn Public Health. Infectious Diseases: A Beginner's Guide to the Basics
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Epidemic, endemic, and pandemic diseases
Credit: RicochetScienceEndemic
Endemic: The amount of a particular disease that is usually present in a community.
Endemic diseases include malaria, bilharzia, measles, gonorrhea, and syphilis.
Malaria is an endemic disease prevalent in Africa, Asia, Latin America, and the Middle East. It is transmitted by a parasite. They destroy the red blood cells in the spleen and liver. This causes anemia in the patients and can prove fatal if left untreated. According to recent research, 200 to 500 million people suffer from malaria every year out of which 1.5 to 2.7 million do not survive.
Measels is a very infectious viral disease that is often caught by young children. It is transmitted through the air in tiny droplets after an infected person sneezes. It causes a fever and skin rash. Many children are given vaccines against measles. Infection can cause more serious effects like infertility in adults who did not catch the disease as children.
An outbreak of measles can form an epidemic.
Syphilis is a sexually transmitted disease. Sores develop on genitals of men and women. Syphilis spreads through contact with these sores. After the initial infection, the bacteria can remain inactive in the body for decades before becoming active again.
Gonorrhea is a sexually transmitted disease. Signs and symptoms in men include painful urination, pus-like discharge from the penis, and pain or swelling in one testicle. The signs and symptoms in women include increased vaginal discharge, painful urination, vaginal bleeding after intercourse, and abdominal or pelvic pain.
The spread of both diseases is easily preventable by following safe sex measures including wearing a condom.
Epidemics
Epidemic: An increase — often sudden — in the number of cases of a disease above what is normally expected in that population in a specific area.
Tuberculosis (TB) is an infectious disease that most often affects the lungs and is caused by a type of bacteria. It spreads through the air when infected people cough, sneeze, or spit. Tuberculosis is preventable and curable.
About a quarter of the global population is estimated to have been infected with TB bacteria. About 5–10% of people infected with TB will eventually get symptoms and develop TB disease. Those who are infected but not (yet) ill with the disease cannot transmit it. TB disease is usually treated with antibiotics and can be fatal without treatment.TB infection occurs more often in people with HIV/AIDS and in those who smoke. TB is one of the top causes of death in people who have HIV. Furthermore, people who have HIV are 18 times more likely to develop active TB.
In 2018, tuberculosis was the leading cause of death worldwide from a single infectious agent.
Credit: TED-ed. What makes tuberculosis (TB) the world's most infectious killer?Plague There are three types of plague. Bubonic plague is the most common and is caused by being bitten by a flea. The disease starts with fever, chills, head, and body aches as well as weakness, vomiting, and nausea. Without treatment, plague results in the death of 30% to 90% of those infected.
There have been three pandemics caused by the plague claiming the lives of millions of people.
In the 1347, Europe experienced the deadliest disease outbreak in history when the second pandemic of bubonic plague killed one-third of the European human population.
Cholera is an extremely virulent disease that can cause severe acute watery diarrhoea. It takes between 12 hours and 5 days for a person to show symptoms after ingesting contaminated food or water. Cholera affects both children and adults and can kill within hours if untreated.
During the 19th century, cholera spread across the world from the Ganges delta in India. It then became a pandemic as it spread to all other continents killing millions of people. Cholera is now endemic in many countries.
Pandemics
Pandemic: An epidemic that has spread over several countries or continents and affects many people.
Credit: TED-ed. How pandemics spread.Influenza Commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus.
The 1918 flu pandemic was a deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case was March 1918 in Kansas, United States. By 1920, an estimated 500 million people across the globe had been infected in four waves. Estimates of deaths range from 17 million to 50 million, making it one of the deadliest pandemics in history.
Covid-19 The COVID-19 pandemic, also known as the coronavirus pandemic, was a global pandemic of coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus was first identified in an outbreak in the Chinese city of Wuhan in December 2019. Attempts to contain it there failed, allowing the virus to spread to other areas of Asia and later worldwide.
COVID-19 symptoms range from undetectable to deadly, but most commonly include fever, dry cough, and fatigue. Severe illness is more likely in elderly patients and those with certain underlying medical conditions. COVID-19 transmits when people breathe in air contaminated by droplets and small airborne particles containing the virus. The risk of breathing these in is highest when people are in close proximity, but they can be inhaled over longer distances, particularly indoors. Transmission can also occur if contaminated fluids reach the eyes, nose, or mouth, or, more rarely, through contaminated surfaces.
Infected individuals are typically contagious for 10 days and can spread the virus even if they do not develop symptoms.
Mutations have produced many strains (variants) with varying degrees of infectivity and virulence.
The World Health Organization (WHO) began referring to it as a pandemic on 11 March 2020. As of 7 May 2023, the pandemic had caused 765,222,168 cases and over seven million confirmed deaths, making it one of the deadliest in history.
Confirmed deaths per 100,000 population as of 18 January 2023 are shown on the map below:
Image: Dan Polansky. CC By SA 4.0
The WHO declared the pandemic over on the 6th of May 2023 declaring that Covid-19 no longer represents a "global health emergency". Officials said the virus's death rate had dropped from a peak of more than 100,000 people per week in January 2021 to just over 3,500 on 24 April 2023.
Scientists believe that Covid-19 will eventually become endemic.
Credit: Scientificus. History of Coronavirus in 90 Seconds | First 500 million Case
Other pandemics are listed in the table below:
Disease
Death Toll
Date
Location
1
Second plague pandemic
Bubonic plague
75–200 million
1346 –1353
Europe, Asia, and North Africa
2
Spanish flu
Influenza
17–100 million
1918 –1920
Worldwide
3
First plague pandemic
Bubonic plague
15–100 million
541 – 549
North Africa, Europe, and Western Asia
4
HIV/AIDS epidemic
HIV/AIDS
42 million (as of 2023)
1981–present
Worldwide
5
COVID-19 pandemic
COVID-19
7 million
2019 - 2023
Worldwide
6
Third plague pandemic
Bubonic plague
12–15 million
1855 –1960
Worldwide
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Non-communicable diseases are chronic health conditions that are not contagious to others. These have genetic, lifestyle, or environmental causes rather than viral or bacterial, and they are characterized as health conditions that:
- Aren’t caused by acute infections or illness
- Result in long-term health issues
- Require long-term treatment and care, such as lifestyle changes or medication
Health conditions that are considered non-communicable diseases include:
- Cancer
- Cardiovascular disease
- Diabetes
- Chronic lung illnesses
- Injuries that cause permanent damage
- Arthritic conditions
Non-communicable diseases are the number one cause of death and disability around the world. Worldwide statistics regarding non-communicable diseases show that:
- Non-communicable diseases kill 41 million people worldwide on an annual basis. This accounts for 71% of all deaths globally.
- Each year, 15 million people around the world die prematurely between the ages of 30 and 69 years old from a non-communicable disease. Cardiovascular diseases make up most non-communicable disease deaths. Since 2000, the largest increase in deaths has been for this disease, rising by more than 2 million to 8.9 million deaths in 2019. In Tanzania in 2019, 15.4% of deaths were from cardiovascular disease.
Cardiovascular diseases. These conditions affect your blood vessels and heart. They include coronary heart disease, heart attack, and stroke. Cardiovascular diseases may alter your quality of life and left untreated can be life threatening.
Cancer. This disease happens when cells in your body mutate and begin dividing and growing. There are many kinds of cancer that can develop anywhere in the body. Although most are determined by genetics or environmental factors, a few forms of cancer can be caused by viruses such as HPV or hepatitis.
Chronic respiratory diseases. These health conditions impact your lungs in the long term and do not usually subside. The most common chronic respiratory conditions are asthma and chronic obstructive pulmonary disease (COPD). Without proper treatment, these diseases may cause permanent damage to your lungs and airways.
Diabetes. If your body cannot regulate the levels of sugar in your blood, you may have diabetes. It is incurable, although it can be controlled. Once you receive a diabetes diagnosis, you must change your diet and maintain recommended dosages of medication to prevent the condition from worsening.
Not all non-communicable diseases are preventable, but you can lower your risk by maintaining healthy habits.
Risk Factors
Anything that increases a chance of developing a disease is called a risk factor. Risk factors can be part of a person's lifestyle, or substances that a person consumes or their environment. Some diseases are caused by an interaction between risk factors. Some risk factors have been proved to cause a disease. We know that smoking can cause lung cancer. Long term alcohol abuse can cause liver cirrhosis. Obesity can cause Type 2 diabetes.
Risk factors:
- Smoking.
- Long-term alcohol use.
- Lack of physical activity.
- An unhealthy diet – Cut back on fatty and processed foods and make sure you get plenty of fruits, vegetables, and whole grains.
- High blood pressure.
- Obesity.
Credit: Cognito. GCSE Biology - Is Your Lifestyle Really a Personal Choice? - Lifestyle & Risk Factors
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STI's and STD's
Sexually transmitted diseases (STDs) begin as sexually transmitted infections (STIs). Infection occurs when a sexually transmitted bacteria, virus, or other microbe enters the body and begins multiplying. Once established, the infection may progress into a disease an STD.
Common STI's include gonorrhea and syphilis which have previously been discussed.
Others which are very common are:
Image: Emma Harrage. CC BY
HPV: Human Papillomavirus or HPV is a group of viruses that can lead to warts, genital warts or even cancer. Most HPV types do not cause damage to human body and clear up shortly after infection. Sexually active individuals are in danger of becoming infected with every second person having it at some point of life. Young people are encouraged to take HPV vaccines, preventing from dangerous types of the virus, while women are recommended to have regular Pap smear tests.
Credit: TED-ed. The most common STI in the world
Chlamydia: One of the most widespread sexually transmitted infections, Chlamydia can lead to serious complications if not treated timely. The infection affects mainly women and some may have no symptoms at all.
In other cases, the infected person may experience abnormal vaginal discharge or urinating discomfort. It is important to locate and take measures as soon as possible before Chlamydia damages the uterus, fallopian tubes, reproductive system, which may end in infertility.
Herpes: Herpes is one of the most common diseases transmitted through all types of sexual contact as well as simple touching. Oral herpes can cause blisters or cold sores on the lips, on or inside the mouth. Genital herpes can involve sores, blisters, itching in genital area or even urinating problems. However, most of the times the virus shows no symptoms at all and a person can be unaware of it.
There are medicines keeping herpes symptoms subdued and limiting transmission. However, once in your body, there is no cure to get rid of it.
Trichomoniasis is caused by a microscopic, one-celled parasite called Trichomonas vaginalis. This organism spreads during sexual intercourse with someone who already has the infection.
The organism usually infects the urinary tract in men, but often causes no symptoms. Trichomoniasis typically infects the vagina in women. When trichomoniasis causes symptoms, they may appear within five to 28 days of exposure and range from mild irritation to severe inflammation.
HIV: Human Immunodeficiency Virus (HIV) is a virus that attacks and destroys the body’s T lymphocytes. The reduction in the number of T lymphocytes in the body due to HIV can then lead to the development of Acquired Immune Deficiency Syndrome (AIDS). Individuals with AIDS have a weakened immune system and so are more vulnerable to opportunistic infections.
Prevention and treatment
There are several ways to protect yourself against catching an STD:
- Abstinence - The most reliable way to avoid infection is to not have sex (i.e., anal, vaginal or oral).
- Vaccination - Vaccines are safe, effective, and recommended ways to prevent hepatitis B and HPV. HPV vaccination is recommended for preteens ages 11 or 12 up to age 26, if not vaccinated already. You should also get vaccinated for hepatitis B if you were not vaccinated when you were younger.
- Reduce Number of Sex Partners - Reducing your number of sex partners can decrease your risk for STDs. It is still important that you and your partner get tested, and that you share your test results with one another.
- Mutual Monogamy - Mutual monogamy means that you agree to be sexually active with only one person, who has agreed to be sexually active only with you. Being in a long-term mutually monogamous relationship with an uninfected partner is one of the most reliable ways to avoid STDs. But you must both be certain you are not infected with STDs. It is important to have an open and honest conversation with your partner.
- Use Condoms - Correct and consistent use of the male latex condom is highly effective in reducing STD transmission. Use a condom every time you have anal, vaginal, or oral sex.
STDs/STIs caused by bacteria or parasites can be treated with antibiotics. The treatments, complications, and outcomes for viral STIs depend on the virus. Treatments can reduce the symptoms and the progression of most of these infections but not cure them.
Credit: Medical Centric. Sexually Transmitted Diseases (STDs), Causes, Signs and Symptoms, Diagnosis and Treatment.
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HIV stands for human immunodeficiency virus.
HIV is transmitted by body fluids:
- Unprotected sex is responsible for the majority of HIV transmissions globally
- The second most frequent mode of HIV transmission is via contaminated blood and blood products. Blood-borne transmission can occur through needle sharing during intravenous drug use, needle-stick injury in health professionals, transfusion of contaminated blood or blood products, or medical injections with unsterilized equipment.
- The third most common way HIV is transmitted worldwide is from an untreated mother to her child during pregnancy, childbirth, or breastfeeding. If the mother is infected with HIV, there is about a 15% chance that the virus will be transmitted to her infant through her breast milk.
Image: Waglione. CC BY SA 3.0
The virus infects the lymphocytes (T helper cells) of the body's immune system. Immediately after infection, people often suffer mild flu-like symptoms. During this time, the virus rapidly replicates causing a high viral load in the person’s blood and a drop in the number of lymphocyte cells. The body responds by producing more lymphocyte cells and they start killing HIV-infected cells.
Consequently, the viral load starts to decline, and the number of lymphocyte cells recovers. However, the virus is not eliminated and remains in the body.
Without treatment, person may be infected for up to 20 years before they develop any symptoms of HIV. Symptoms which may occur are shown in the diagram below:
Image: Mikael Häggström. CCO
Most infected individuals will eventually progress to AIDS if their HIV infection is not treated. AIDS is diagnosed when the lymphocyte cell count falls below 200 per microliter of blood or when the infected individual starts to develop opportunistic diseases.
Patients with AIDS will eventually develop an illness which will kill them because they do not have an immune system which is strong enough to fight off an infection. These common diseases include pneumonia, yeast infection and cancer.
In addition, many AIDS patients develop HIV wasting syndrome, in which they lose weight and muscle mass and experience extreme fatigue and weakness. People with AIDS also frequently experience long fevers, night sweats, swollen lymph nodes, and diarrhea.
Credit: Stanford Center for Health Education. What is HIV / AIDS and how does it affect your body?
HIV is easily diagnosed with a blood test. HIV/AIDS is an uncurable disease. Antiretroviral drugs are available which reduce the amount of virus in your body and slow down the progression but there is no known cure. Trials into a vaccine to prevent HIV infections have begun with promising results.
Credit: Stanford Center for Health Education. What to expect when beginning treatment for HIV/AIDS
Stop the Spread
To prevent the spread of the disease the use of condoms is recommended, and disposable gloves should be used where there is any danger of contact with contaminated blood.
HIV transmission through intravenous drug use can be reduced through needle exchange programs or the substitution of prescription drugs for illegal drugs.
Anti-retroviral drugs can be taken 2 - 3 days after you suspect you have been exposed to the virus and significantly reduce the chances of transmission.
Rates of mother-to-child transmission can be reduced to about 1 percent by giving antiretroviral medications to the mother during pregnancy and to the infant after birth. Bottle feeding a baby instead of breastfeeding takes away the risk of HIV transmission through breast milk.
HIV/AIDS is one of the world’s most fatal infectious diseases – particularly across Sub-Saharan Africa, where the disease has had a massive impact on health outcomes and life expectancy in recent decades.
Image: OurWorldinData.org. CC BY
Global HIV statistics:
- 38.4 million people globally were living with HIV in 2021.
- 1.5 million people became newly infected with HIV in 2021.
- 650 000 people died from AIDS-related illnesses in 2021.
- 28.7 million people were accessing antiretroviral therapy in 2021.
- 84.2 million people have become infected with HIV since the start of the epidemic.
- 40.1 million people have died from AIDS-related illnesses since the start of the epidemic.
- In 2021, there were 38.4 million people living with HIV.
- 36.7 million adults (15 years or older).
- 1.7 million children (0–14 years).
- 54% of all people living with HIV were women and girls.
- At the end of December 2021, 28.7 million people were accessing antiretroviral therapy, up from 7.8 million in 2010.
- In sub-Saharan Africa, six in seven new HIV infections among adolescents aged 15–19 years are among girls. Girls and young women aged 15–24 years are twice as likely to be living with HIV than young men
Source: UNaids.org
Image: WHO. CC BY-NC-SA 3.0 IGO
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There are many misconceptions about HIV and AIDS. Knowing the realities is important to help prevent the spread of HIV and reduce the stigma associated with it.
Credit: A Positive Life. The stigma around HIV.
Myth: HIV can be transmitted through nonsexual contacts such as kissing, sharing a glass, spitting, sitting on a public toilet seat, and coughing or sneezing.
Reality: HIV has not been shown to be transmissible through such contacts. People can safely interact and have casual contact with HIV-infected individuals without fear of acquiring the virus.
Myth: AIDS is a death sentence.
Reality: Not anymore. When AIDS was first discovered, there was no effective treatment available—and a diagnosis was considered a death sentence. Now, this is no longer true, thanks to the development of revolutionary treatment methods. Today, over 27 million people living with HIV are accessing treatment that allows them to live healthy, normal lives. Over the past two decades, the global rollout of treatment has saved nearly 17 million lives from AIDS-related deaths.
Myth: There is a cure for HIV/AIDS
Reality: You may have seen news that a few patients were cured of HIV through a clinical trial. While this exciting progress signifies new innovations and advancements in the AIDS fight, health experts caution that this treatment is considered very risky and is not yet scalable. Though there is no proven cure for HIV, current antiretroviral medications allow HIV-positive people to live healthy lives with roughly the same life expectancy as those who are HIV-free.
Myth: People who have HIV should not have babies
Reality: Incorrect. When HIV-positive pregnant women adhere to life-saving HIV treatment throughout their pregnancy and during breastfeeding, they can give birth to HIV-free children. Ending mother-to-child transmission of HIV is a crucial piece to ending AIDS as an epidemic by 2030. Worldwide, 84% of HIV-positive pregnant women are receiving this life-saving treatment for the prevention of mother-to-child transmission of HIV, a massive scale-up from 45% in 2010. Prevention services need to be scaled up to ensure that every child, everywhere is born HIV-free.
Receiving a diagnosis of HIV can be a life-changing event. Most people with HIV can live long and healthy lives if they get and stay on treatment. There will be a period of adjustment. People who are newly diagnosed can feel many emotions—sadness, hopelessness, and even anger.
Many people who have just learned their HIV diagnosis wonder whether and how to tell others about it. You don’t have to tell everyone that you have HIV. Whether and how you disclose your status to others is your decision.
There are many things you can do to support a friend or loved one who has been recently diagnosed:
- Listen. Being diagnosed with HIV is life-changing news. Listen to your loved one and offer your support. Be available to have open, honest conversations about HIV. They may want to connect with you in the same ways they did before they were diagnosed. Do things you did together before their diagnosis; talk about things you talked about before their diagnosis. Show them that you see them as the same person and that they are more than their diagnosis.
- Learn. Educate yourself about HIV: what it is, how it is and is not transmitted, how it is treated, and how people can stay healthy with HIV.
- Encourage treatment. Starting treatment with antiretroviral therapy, adhering to medication, people with HIV can reduce the amount of HIV in their blood to an undetectable level. People with HIV who take HIV medicine exactly as prescribed and get and keep an undetectable viral load can stay live long and healthy lives and will not transmit HIV to their HIV-negative partners through sex.
- Support medication adherence. It’s important for people with HIV to take their HIV medicine exactly as prescribed.
- Get support. Take care of yourself and get support if you need it. Turn to others for any questions, concerns, or anxieties you may have, so that the person who is diagnosed can focus on taking care of their own health.
If you are the sexual partner of someone who has been diagnosed with HIV, you should also get tested so that you know your own HIV status.
Credit: AMAZE Org. Living with HIV.
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Prevention and control of infections and disease
The transmission of pathogens can be prevented or reduced in several ways.
Good hygiene: the primary way to prevent infections.- Wash your hands well. You probably wash your hands after using the bathroom, before preparing or eating food, and after gardening or other dirty tasks. You should also wash your hands after blowing your nose, coughing, or sneezing; feeding or stroking your pet; or visiting or caring for a sick person.
Image: perpetuallypeeved.com. CCA BY ND 3.0
- Cover a cough. Cover your mouth and nose with a tissue when you sneeze or cough, then dispose of it. If no tissue is handy, cough or sneeze into your elbow rather than into your hands.
- Wash and bandage all cuts. Any serious cut or animal or human bite should be examined by a doctor.
- Don't share dishes, glasses, or eating utensils.
- Avoid direct contact with napkins, tissues, handkerchiefs, or similar items used by others.
- Practice good food-safety techniques to avoid getting sick
Although most cases of food-borne infection are not dangerous, some can lead to serious medical conditions, including kidney failure and meningitis. You can prevent infections by food-borne pathogens in your household by preparing and storing foods safely.
- Wash fruits, and vegetables under running water before cooking or eating them.
- Wash your hands with soap and water before and after you handle raw meat.
- Separate raw foods and cooked foods. Don't use the same utensils or cutting boards with cooked meat that were used to prepare the raw meat without washing between uses.
- Cook foods thoroughly
- If you know the tap water is not clean, boil all tap water before drinking and brushing your teeth.
Image: ClipArt best.com. CCOVaccinations are essential if you are to avoid getting sick. Vaccines reduce risks of getting a disease by working with your body’s natural defences to build protection. When you get a vaccine, your immune system responds. The WHO lists 34 diseases for which vaccines are available, some of which are listed below:
Cholera Measles Tetanus Covid-19 Meningitis Tuberculosis Dengue fever Monkeypox Typhoid fever Diphtheria Mumps Yellow fever Ebola Polio Smallpox Influenza Rabies Malaria 
Image: OurWorldinData.org. CC BYThe goal in public health is the eradication of a disease through vaccination. This has been achieved for smallpox and almost achieved for polio. The world has been able to reduce the number of polio cases from over 350,000 per year in the 1980s to just 42 cases in a year.
The WHO estimates that 2 to 3 million deaths are prevented every year through immunization against diphtheria, tetanus, whooping cough, and measles.
In general:
- Children should receive the recommended childhood vaccinations.
- Adults should make sure their vaccinations are up to date.
How to prevent infections by sexual transmission
The only sure way to prevent sexually transmitted diseases is to not have sexual intercourse or other sexual contact. That's not an option for most people, so the next best choice is to follow these safer sex guidelines:
Engage in sexual contact only with one partner who is having sex only with you.
Both you and your partner should be tested for HIV and other sexually transmitted diseases and use a condom.Avoiding bug-borne pathogens
Both mosquitos and ticks are carriers of viruses and bacteria. Both have been associated with serious epidemics in the last decade.
Ticks are widespread and can transmit a variety of diseases, including Lyme disease and many others. They live in grassy and brushy areas and are most prevalent during wet seasons. A common hiding place is in wet leaves. They often infest animals, including field mice and deer. And they may be transported into your home by your pets.
The following can help prevent infections from bug bites:
- If you are in an area where insect-borne disease, like malaria, is present, use an insect repellent, sleep under a mosquito net, and take anti-malarial tablets.
- Drain any standing water near your home to prevent mosquitoes from breeding.
- Remove any ticks which you find on your body. Wash the area of the tick bite thoroughly with antiseptic. Watch the area closely for a couple of weeks for signs of rash or swelling.
Using animal-control to prevent infections
Controlling the population of rats in and near your home can help you avoid pathogens spread by rodents and help control the population of ticks that spread disease. Rodents can harbor a few pathogens, including plague. Other wild animals can also transmit rabies and other infections. The following measures can help you avoid getting sick from diseases transmitted by animals:
- Keep food and rubbish in covered.
- Seal holes and cracks in your home to deter rodent access.
- Clear brush and junk away from the foundation of your home.
- When outdoors, do not disturb rodent burrows or handle rodents.
- Stay clear of wild animals.
- Keep your pets/farm animals away from wild animals, too. Dogs, cats, or any other type of warm-blooded animal can pick up rabies from wild animals and pass rabies along to people.
Credit: Fuse Schools - Global Education. How are pathogens spread and controlledDifferent types of medicines are available to treat many different diseases. Some medicines only treat the symptoms and others cure the disease by killing the pathogens.
Antibiotics
Antibiotics are substances that slow down or stop the growth of bacteria. They are commonly prescribed medicines; examples include penicillin and amoxicillin. These can be taken to cure the disease by killing the pathogen, but only cure bacterial diseases and not viral ones.
Penicillin was the first antibiotic discovered in 1928 by Alexander Fleming. He noticed that some bacteria he had left in a petri dish had been killed by the naturally occurring Penicillium mould.
Antibiotics damage the bacterial cells but do not damage the host cells. They have the ability to cure some bacterial diseases that would have previously killed many people. Since their introduction, they have had a large influence on the world's health and death rate.
Different bacteria cause different diseases. One antibiotic may only work against one type of bacteria, or a few types. This means that a range of different antibiotics is needed for the treatment of the whole range of bacterial diseases.
Viral diseases cannot be cured by antibiotics, as they reproduce inside the host cells. It is very difficult to develop antiviral drugs, as they might damage the host cell whist killing the virus. Antiviral drugs only slow down viral development, and viruses change their antigens quickly which means new drugs must be generated regularly.
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