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UNIT 16 : Reducing Risk of STIs and HIV na AIDS
Key unit competency
To be able to apply the knowledge of STI and HIV transmission, prevention and treatment in sexual decision.
Learning objectives
After studying this unit, I should be able to:
• Explain how STIs and HIV are transmitted, treated and prevented.
• State that abstinence is the most effective protection against HIV and other STIs.
• Explain that sexual health services can help people access personal risks and perceived vulnerability about safer sexual practices.
• State that culture, gender and peer norms can influence decision making about sexual behaviour.
• Recognise symptoms and complications of STIs and HIV.
• Demonstrate communication skills in negotiating safer sex and refusing unsafe sexual practices.
• Explain how culture and gender affect personal decision making regarding sexual relationship.
• Appreciate behaviours that reduce the risk of STIs and HIV transmission.
Introduction
You may have fallen sick and was taken to a health facility. Did you like being there? What could you have done to prevent such a situation?
Now, look at the picture alongside. What massage is being relayed in the picture? Which other ways can we use to reduce HIV and AIDS? How about other Sexually Transmitted Infections (STI's)?
16.1 Transmission of STIs
Safe sex practices can help us prevent contracting sexually transmitted diseases. On the other hand, irresponsible sexual behaviour increases chances of individuals contracting sexually transmitted infections.
Most sexually transmitted diseases can be treated and cured. This becomes easy when diagnosis is done early and treatments starts during the early stages of the disease. It is therefore important for sexually active persons to visit health centres regularly for check ups. Though there is still no cure for HIV, early detection of the disease makes its management easy. This enable patients to live a normal life.
Activity 16.1: Transmission of chlamydia, gonorrhea, syphilis and HIV infection
What to do
1. Work in groups.
2. Each group will discuss only one disease under the following headings;
• Causative agent (include scientific name)
• Incubation period
• Mode of transmission
3. Write your findings in a Manila paper.
4. Present your work to the rest of the class.
Sexually transmitted infections (STIs) are transmitted by infected persons to healthy persons during sexual intercourse.
Examples of these diseases are chlamdia, gonorrhoea, syphillis and, HIV and AIDS. They are discussed below:
1. Chlamydia
Chlamydia is caused by the bacterium Chlamydia trachomatis. The disease is spread by oral, vaginal or anal sex, and also through touch, for example, touching the eyes with a contaminated hand, may lead to conjunctivitis. Chlamydia can also be passed to the infant during birth.
It causes inflammation of the cervix in women, urethra and rectum in both men and women. Occasionally, other parts of the body like eyelids and throat may be affected. Other complications like pelvic inflammatory disease (PID) or infertility may occur from this infection. Any sexually active person is at risk of contracting the disease. However, it is more common in young people. The disease is known as a ‘silent’ infection because it is mainly asymptomatic, thus the symptoms can be mild or be confused with gonorrhea.
Signs and symptoms of chlamydia
In males
• Pain when passing out urine.
• White discharge from the penis.
• The testicles may be painful or swollen.
• Swelling of skin around the anus.
In females
• Painful and frequent urination.
• Smelly yellowish and abnormal vaginal discharge.
• Pain in the lower abdomen.
• Swollen skin in the vagina or around the anus.
Treatment
Chlamydia is easily treated using antibiotics.
2. Gonorrhoea
Gonorrhoea is transmitted through sexual contact with the penis, vagina, mouth or anus of an infected partner. Gonorrhoea can also be spread from mother to baby during childbirth.
Gonorrhoea is caused by a bacterium called Neisseria gonorrhoeae. The bacteria attaches on the epithelial cells of the vagina or male urethra. This results in inflammation and discharge of pus. If left untreated, the infection spreads to the other reproductive parts and may eventually block the passages resulting to infertility.
Signs and symptoms of gonorrhoea
Some men with gonorrhea may have no symptoms at all. However, men who do have symptoms may have:
• A burning sensation when urinating.
• A white, yellow, or green discharge from the penis.
• Painful or swollen testicles (although this is less common).
Most women with gonorrhea do not have any symptoms. Even when a woman has symptoms, they are often mild and can be mistaken for a bladder or vaginal infection. Women with gonorrhea are at risk of developing serious complications from the infection, even if they do not have any symptoms. Symptoms in women can include:
• Painful or burning sensation when urinating.
• Increased vaginal discharge.
• Vaginal bleeding between periods.
Treatment
Gonorrhea can be treated using antibiotics like penicillin.
3. Syphilis
Syphilis is transmitted from person to person by direct contact with a syphilitic sore, known as a chancre. Chancres occur mainly on the external genitals, vagina, anus or in the rectum. Chancres also can occur on the lips and in the mouth. Transmission of syphilis occurs during vaginal, anal or oral sex.
Syphilis is caused by a bacteria called Treponema pallidum. The bacterial infection progresses through several stages.
• In the primary stage, small hard painless sores develop at the site of infection usually the penis and the vagina.
• The disease enters secondary stage several weeks later characterised by rashes on the skin and mild fever. These symptoms subside after a few weeks followed by a latent asymptomatic period.
• In the tertiary stage, lesions develop and cause extensive tissue damage that may lead to paralysis, insanity, blindness and eventually death.
Treatment
Antibiotics like penicillin, erythromycin or tetracycline are used to treat syphilis although some strains can be resistant to certain antibiotics.
Activity 16.2: Interactive talk
1. Your teacher will organise for a medical personnel to talk to you about transmission of HIV.
2. Prepare questionnaires you will use.
3. Engage the medical officer during the talk.
4. Write short notes during the presentation.
5. Share your finding with the rest of the class.
Transmission of HIV (Human immunodeficiency virus) infection
HIV is the virus that causes AIDS (Acquired immune deficiency syndrome). It is mainly transmitted through:
a) Certain body fluids: blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids and breast milk from a person who has HIV. These fluids must come in contact with a mucous membrane or damaged tissue or be directly injected into the bloodstream (from a needle or syringe) for transmission to occur. Mucous membranes are found inside the rectum, vagina, penis and mouth.
b) Having anal or vaginal sex with someone who has HIV without using a condom or taking medicines to prevent or treat HIV. Anal sex is the highest-risk sexual behavior. Vaginal sex is the second-highestrisk sexual behavior.
c) Sharing needles or syringes or other equipment used to prepare drugs for injection with someone who has HIV.
d) Mother to child during pregnancy, birth or breastfeeding. Although the risk can be high if a mother is living with HIV and not taking medicine.
e) Being stuck with an HIVcontaminated needle or other sharp object. This is a risk mainly for health care workers.
Note: In some rare cases, HIV has been transmitted through:
a) Receiving blood transfusions, blood products, organ or tissue transplants that are contaminated with HIV.
b) Eating food that has been prechewed by an HIV-infected person. The only known cases are among infants.
c) Being bitten by a person with HIV. There is no risk of transmission if the skin is not broken.
d) Contact between broken skin, wounds or mucous membranes and HIV-infected blood or bloodcontaminated body fluids.
e) Deep, open-mouth kissing if both partners have sores or bleeding gums. HIV is not spread through saliva.
f) Oral sex.
Sexual education
• Be aware of sugar mummies and sugar daddies. They lure young people with money and promise good life in exchange for sexual favours. Such acts could lead to transmission of STIs and, HIV and AIDS.
• Abstinence is the most effective protection against STIs and, HIV and AIDS.
Self-evaluation Test 16.1
1. Which is the most effective protection against HIV and other STIs?
2. Given the following STIs: Gonorrhoea, syphilis, chlamydia and HIV. Choose the ones that can be prevented?
3. What is the common transmission mode for all the STIs?
16.2 Ways of reducing STIs and HIV infection
Discussion corner
1. Discuss the following:
• Ways of reducing STIs and HIV infection.
• Ways of prevention and treatment of STIs and HIV infection.
• Role of artificial contraceptives (barrier method- male and female condoms) and their correct use.
2. Present your work to the rest of the class
The following are ways of reducing STIs and HIV infection:
a) Abstinence is the only sure way to prevent STIs.
b) Being faithful to one trusted partner.
c) Using condoms every time when engaging in sexual intercourse. Condoms are not 100% effective at preventing disease or pregnancy. However, they are extremely effective if used properly.
d. Reduce the number of sexual partners.
e. Avoid sharing towels or underclothing.
f. Get a vaccination for hepatitis B.
g. Get tested for HIV.
h. Avoiding alcohol consumption and abuse of drugs. Individuals who are drunk or on drugs often fail to have safe sex.
Activity 16.3:
Role play
1. Discuss with your classmates the following:
• Refusal skills that can be employed regarding sex.
• Harmful effects of consuming alcohol and drugs.
• The importance of voluntary counselling and testing (VCT) centres.
• How culture, gender and peer norms can influence decision making about sexual behaviour.
2. Prepare a skit to dramatise your content and present it to the rest of the class.
Treatment of STIs and HIV
Activity 16.4: Visit to a health centre
1. Your teacher will organise for a visit to a health centre.
2. Prepare a questionnaire to use during the visit.
3. Engage the officer in charge with the following guiding questions
• Does the centre offer sexual health services?
• Do they have a VCT centre that offers pre- and post – test counselling?
• How do they handle People living with HIV and AIDS (PLWHA)?
4. Write a report and present your work in class.
Treatment of STIs and HIV is based on their causative agents.
1. Bacterial STIs can be cured using antibiotics if treatment begins early enough. Antibiotics, often in a single dose, can cure many sexually transmitted bacterial and parasitic infections, including gonorrhoea, syphilis, chlamydia and trichomonasis. Treatment of gonorrhoea and chlamydia is always done at the same time because the two infections often appear together.
2. Viral STIs cannot be cured, but the symptoms can be managed with medications. For instance there is a vaccine against hepatitis B, but it will not help if you already have the disease.
3. HIV cannot be cured but can be managed. A person may choose to visit a voluntary counselling and testing (VCT) centre to undergo HIV and AIDS counselling. After conselling he or she can make an informed decision about whether to be tested for HIV or not.
At the VCT centre pre-test and posttest counselling is offered to assist people to learn more about their status. Counselling involves getting information and learning how to live positively with the virus. This means learning to accept the fact that one is HIV-infected, seeking emotional support, eating a healthy diet, learning how to control the amount of stress in our life, making sure there is no re-infection and planning for the future.
Sex education
Post-Exposure Prophylaxis (PEP) or short-term anti-retroviral therapy (ART) can reduce the likelihood of HIV infection after potential exposure.
Antiretroviral therapy (ART) is the use of HIV medicines to treat HIV infection. People on ART take a combination of HIV and AIDS drugs every day. People infected with HIV and AIDS should start ART as soon as possible. ART cannot cure HIV and AIDS, but helps people infected to live longer and healthier lives. ART also reduces the risk of HIV and AIDS transmission.
Potential risks of ART include unwanted side effects from HIV and AIDS drug interactions. This includes not taking drugs every day as required. It could lead to drug resistance and treatment failure.
Health Check!
• Do not try to treat a sexually transmitted disease on your own. These diseases are contagious and serious. You must see a doctor.
• Antibiotics that are used to treat STIs should never be shared. It is also important to take the entire drug prescribed, even if the symptoms go away.
• Never, take someone else's medication to treat your infection; it may make it more difficult to treat.
• If someone is pregnant and have an STI, prompt treatment can prevent or reduce the risk of infection of your baby.
Self-evaluation Test 16.2
1. What happens in a VCT centre?
2. What do you understand by the term ART?
Unit summary
• Sexually transmitted infections are also known as sexually transmitted diseases (STDs) or venereal diseases (VD) and are commonly spread through sexual contact.
• Bacterial STIs include: Chlamydia, gonorrhoea, syphilis among others.
• Viral STIs include genital herpes, genital warts and HIV among others.
• Abstinence is the most effective way of preventing STIs; some vaccines are however, used to reduce the risk of infections such as hepatitis B and some strains of HPV (human papiloma virus)
• Bacterial infections can be easily cured using antibiotics but viral infections like HIV, genital warts and HPV are controlled but cannot be cured. • Post –exposure prophylaxis can reduce the likelihood of HIV infection.
Glossary
A
Abiotic - physical factors in the environment that affect living organisms. They include; wind, humidity, sunlight, soil and atmospheric pressure among others.
Abortion - deliberate physical or chemical termination of human pregnancy.
Aboral - relating to or denoting the side or end that is furthest from the mouth, especially in animals that lack clear upper and lower sides, such as echinoderms.
Abstinence - act of restraining oneself from indulging or doing something; for example, restraining oneself from having sex.
Active transport - movement of particles against a concentration gradient.
Active site- a region on an enzyme that binds to a protein or other substance during a reaction.
Aerencyma tissue - A spongy tissue with large intercellular air spaces that is found in aquatic plants. It provides buoyancy and allows the circulation of gases.
Aerosol - a substance enclosed under pressure and able to be released as a fine spray.
Agglutination - the clumping together in suspension of antigen-bearing cells, micro-organisms or particles in the presence of specific antibodies.
Amenorrhea - absence of menstruation for at least three months
Appendage - a structure that attaches to another part of the body.
Antagonistic muscles - a muscle that opposes the action of another, for example, the biceps and triceps.
Antibody - proteins found in plasma that are responsible for mediation of immunity in body fluids.
Antibiotic - a drug derived from bacteria or fungus and is used to treat bacterial infections.
Anti-retroviral (ARV) - drugs to maximally suppress the HIV virus and stop the progression of HIV disease.
Antigen - any substance that stimulates response of a specific immune system.
Articulate - meet at a point to form a joint.
Arthritis – a condition that causes pain and inflammation in a joint.
Autoimmune - a condition arising from an abnormal immune response to a normal body part.
B
Biotic - activities of living organisms that affect an ecosystem.
Bilateral symmetry - symmetrical arrangement of an organism or part of an organism along a central axis.
Bilirubin - a yellow pigment produced from the breakdown of heme in the worn out red blood cell.
Biodiversity - variety and variability of life forms on earth.
Biome - large ecological areas on the earth's surface, with fauna and flora (animals and plants) adapting to their environment.
Biuret test- a test that uses a reagent (a solution of copper sulfate (CuSO4) and sodium hydroxide (NaOH)) used to determine the presence of peptide bonds in protein.
Bowman’s capsule - the filtration unit of the glomerulus and has tiny slits in which filtrate may pass through into the nephron.
Bone – a rigid body tissue consisting of cells compressed into hard intercellular material.
C
Capillarity - the ability of a narrow tube to draw a liquid upwards against the force of gravity.
Carrier protein - a protein that transports specific substance across the cell membrane.
Cartilage - tough elastic tissue.
Catalyst - a substance that causes a chemical reaction to occur but is not itself involved in the reaction.
Cephalothorax – a term referring to the fused head and thorax occurring in many arthropods, particularly crustaceans and arachnids.
Chaetae - bristles made of chitin that are found on bodies of annelids.
Cholesterol - a fatty substance made in the body and found in certain foods. Some cholesterol are harmful others are useful to the body.
Carapace - hard structure made of chitin that covers the dorsal part of an animal and protects internal organs.
CD4 cell - white blood cells that play an important role in the immune system.
Cheliserae - a pair of appendages modified to form poison glands or mouthparts.
Chitin - a tough, semitransparent substance that is the main component of the exoskeletons of arthropods.
Concentration gradient - the gradual difference in concentration of a dissolved substance in a solution between a region of high density and one of lower density.
Contraceptives - a device or drug that prevents pregnancy.
Cortex - the outermost (or superficial) layer of an organ.
Crustaceans - animals that usually have a hard covering, or exoskeleton, and two pairs of antennas, for example, crabs and lobsters.
D
Denature - change the original or natural structure.
Destarch - process of eliminating starch from leaves by allowing the plant to use up the starch previously synthesized.
Deamination - the removal of an amino group from an amino acid or other compound.
Detrivours - an organism (as an earthworm or a fungus) that feeds on dead and decomposing organic matter.
Detoxification - the metabolic process by which toxins are changed into less toxic or more readily excretable substances.
Diffusion - the movement of molecules from areas of higher concentration to areas of lower concentration.
DCPIP – (Dichlorophenolindophenol) a reagent used to measure the amount of ascorbic acid (vitamin C) in fruits and plant material.
E
Edaphic - Relating to soil, especially as it affects living organisms.
Endocytosis - the transport of solid matter or liquid into a cell by means of a vacuole or vesicle.
Endoskeleton - internal support structure made of bone or cartilage.
Enzyme – substrate complex- intermediate formed when a substrate molecule interacts with the active site of an enzyme.
Epidermis - protective outermost portion of the skin.
Epidemiology - the study of how often diseases occur in different groups of people and why.
Exoskeleton - external support structure that protects the internal organs.
Exocytosis - is a process by which a cell transports secretory products through the cytoplasm to the plasma membrane.
Eukaryotic – containing nucleus bound by a nuclear membrane.
Exhalation - the act of breathing out air.
F
Flaccid - soft, flabby and weak.
Food testing - a process used to check that a food is safe and that it does not contain harmful contaminants.
Flexion - the action of bending, especially the bending of a limb or joint.
G
Glomerula filtrate - the renal fluid in the blood filtered across the capillaries of the glomerulus.
H
Haemocoel - a body cavity (as in arthropods or some molluscs) that contains blood or hemolymph and functions as part of the circulatory system.
Halophytes - A plant that can tolerate a high concentration of salt in the soil.
Homeotherm - an organism that maintains its body temperature at a constant level, usually above that of the environment, by its metabolic activity.
Host - an organism that harbours a parasitic.
Hydrophytes – aquatic plants.
Hypotonic - solution that has a lower osmotic pressure than another solution.
Hypertonic – a solution where the concentration of solutes is greater outside the cell than inside it.
I
Immunisation - the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine.
Immune response - any reaction by the immune system.
Inhalation - the action of breathing in.
Insulin - a hormone made by the pancreas that allows the body to regulate glucose.
Isotonic - two solutions having the same osmotic pressure across a semipermeable membrane.
J
Joint - A point of articulation between two or more bones.
K
Key and lock mechanism - the hypothesis that helps explain some of the ways that enzymes work.
L
Lateral line - a visible line along the side of a fish consisting of a series of sense organs that detect pressure and vibration.
Lesion - injured or diseased structure or part of tissue or organ.
Lignin - an organic substance in plants binding the cells, fibres and vessels which forms wood.
Ligament - a short, flexible, fibrous connective tissue that connects two bones or cartilages or holds together a joint.
M
Menopause – a period when a woman stops having periods and is no longer able to get pregnant naturally.
Mesophyte - a plant growing under conditions of well-balanced moisture supply.
Metabolism - all chemical reactions involved in maintaining the living state of the cells and the organism.
Moulting - periodic shedding of the cuticle in arthropods or the outer skin in reptiles.
Millon’s test – a chemical test that detect the presence of proteins in a food sample.
Multicellular - an organism that is made up of many cells.
Muscle - a tissue composed of cells or fibers, the contraction of which produces movement in the body.
N
Nephrone - the basic structural and functional unit of the kidney.
Notochord - a flexible rod-like structure that exists in bodies of vertebrates at some point in their lives.
Non-reducing sugars – sugars such as sucrose that cannot be oxidized.
O
Oral - relating to the mouth.
Omnivorous - an animal that eats food from both plants and animals.
Osmosis - the movement of water from a less concentrated solution to a more concentrated solution through a partially permeable membrane.
Osteoporosis - condition that weakens bones, making them fragile and more likely to break.
P
Passive - allowing what happens, without active response or resistance.
Pathogen - a parasite that causes disease.
Pedipals - segmented appendages attached to the cephalothorax of arachnids.
Pinocytosis - the ingestion of liquid into a cell by the budding of small vesicles from the cell membrane.
Pith - the soft, spongy tissue in the centre of the stems of most flowering plants, gymnosperms and ferns.
Potometer - a device used for measuring the rate of water uptake of a leafy plant shoot.
Phagocytosis - the process by which a cell engulfs material.
Plastids – are organelles that are the main site of photosynthesis in eukaryotic cells.
Pseudopodia - temporary or semipermanent extension of the cytoplasm, used in locomotion and feeding in some protozoa.
Pooter - a device used to pick up small invertebrates without harming them.
Poikilotherm - an organism that cannot regulate its body temperature.
Plasmolysis - the contraction of the protoplasm of cells within plants due to the loss of water through osmosis.
Phloem - part of a vascular bundle that conducts sugars and other metabolic products downward from the leaves.
R
Receptor - a protein molecule that receives chemical signals from outside a cell.
Reducing sugars - any sugar such as glucose which is capable of being oxidised.
Respiratory surfaces - a special area that is developed in order to satisfy the requirements for gaseous exchange in larger organisms.
S
Septa - walls that divide internal body cavities or chambers.
Sessile – an organism, fixed in one place (immobile).
Selective reabsorption - The absorption of some of the components of the glomerular filtrate back into the blood as the filtrate flows through the nephrons of the kidney.
Sexual response - is the arousal of sexual desire, during or in anticipation of sexual activity.
Sexuality - the whole way a person goes about expressing himself or herself as a sexual being.
Source – the sites in a plant where net fixation of carbon dioxide occurs.
Sign - evidence of disease as seen by the examining physician. Sink-the sites in a plant where assimilates are stored or used.
Spermicide – This comprise of creams, gels, foams and other suppositories that prevent sperm from moving.
Substrate - the substance on which an enzyme acts.
Sutures - a seam like immovable junction between two bones, such as those of the skull.
Synovial - a lubricating fluid secreted by certain membranes, for example, in joints.
Symptoms - evidence of disease perceived by the patient.
T
Tentacles - a slender, flexible limb or appendage in an animal.
Tendon - A band of tough, fibrous, inelastic tissue that connects a muscle to a bone.
Transpirational pull - a mechanism by which trees draw water through their roots.
Translocation - the movement of materials from leaves to other tissues throughout the plant.
Tracheid - a type of water-conducting cell in the xylem that lacks perforations in the cell wall.
Turgor pressure - the pressure of water against the inside wall of a plant cell.
U
Ultrafiltration – a process in the kidney in which urea, salt, water and glucose are taken out of the blood.
Urologist - a physician who specialises in diseases of the urinary tract and the male reproductive system.
V
Vaccine - preparation of weakened form of a pathogen such as killed microbe, altered microbes or derivative form of pathogens.
Vasectomy - a permanent method of birth control where sperm ducts are cut and the ends are sealed to prevent sperm from entering the ejaculate.
Vascular bundles - Xylem and phloem tissues.
Vector – an organism that transmits a disease or parasite from one animal or plant to another.
Verigated – having different colours.
Ventilation - the movement of air between the environment and the lungs via inhalation and exhalation.
Vessel element - An elongated, waterconducting cell in xylem.
W
Wall pressure - pressure exerted by the flow of water through a semipermeable membrane separating two solutions with different concentrations of solute.
Wilting - loss of turgidity and rigidity that occurs when the rate of water loss is greater than the rate of water uptake.
X
Xylem – a vessel in plants that transport water from roots to shoot and leaves, it also transports some nutrients.
Xerophytes – plants that grow in areas with very little water.
References
• J. Akatsa, H mwaura (2008); Longhorn secondary Biology, Longhorn Publishers; Nairobi, Kenya
• J.Mwaniki , G Geoffrey (2013); Fundamentals of Biology, Longhorn Publishers: Dar es Salaam, Tanzania
• D. Nserebo et al (2015); Excel & Succeed Biology, Longhorn Publishers: Malawi
• D.G. Mackean (2012); GCSE Biology (Third edition); CGP Books
• Michael Roberts (1986); Biology - A Functional Approach (Fourth Edition); Oxford publishers
• Rod Seeley, Stephens Tate; (2002) Anatomy and physiology; McGraw-Hill Global Education Holdings