S4.4.8 Chapter 8

Sexual health

How do people protect themselves from infections and pregnancy during sex?

Your guess

Pick one before you read on. It is fine to be wrong.

Your guess

A Washing straight after sex prevents both.
You picked A. Read on. At the end, the chapter comes back to your guess.
B The pill prevents both pregnancy and infections.
You picked B. Read on. At the end, the chapter comes back to your guess.
C A condom, used correctly every time, greatly cuts the risk of both.
You picked C. Read on. At the end, the chapter comes back to your guess.
D If both people look healthy, there is nothing to prevent.
You picked D. Read on. At the end, the chapter comes back to your guess.

By the end you can

Explain how sexually transmitted infections spread and how to prevent them
Describe how common methods of contraception prevent pregnancy

Some infections pass from one person to another mainly through sex. They are called sexually transmitted infections, or STIs. Anyone who has sex can catch one. Most can be cured or kept under control, and the risk of catching one can be cut.

The pathogens live in body fluids, such as semen, fluid from the vagina and blood. Some also live in sores or on the skin of the genitals. They pass between people in vaginal, anal and oral sex.

Genital herpes, HPV and syphilis can also pass by close contact between the skin of the genitals. HIV, syphilis and hepatitis B can pass in blood, for example on a shared needle.

Several can pass from a mother to her baby, in pregnancy or at birth. HIV can also pass in breast milk. STIs do not spread by hugging, shaking hands or sharing cups and plates.

Three common STIs are caused by bacteria: chlamydia, gonorrhoea and syphilis. Three are caused by viruses: genital herpes, HPV and HIV. HPV is short for human papillomavirus. HIV is short for human immunodeficiency virus.

See it three ways

As a picture

In words

A bacterium is a living cell, so antibiotics can kill it. Chlamydia, gonorrhoea and syphilis are cured this way. A virus is not a cell. It has none of the parts that antibiotics attack, so antibiotics do not harm it. Herpes and HIV cannot yet be cured, but medicines can control them. The body often clears HPV by itself.

Antibiotics cure the three caused by bacteria. The three caused by viruses have no cure yet.

Signs can include sores, warts, an unusual discharge from the penis or vagina, itching, or pain when passing urine. But many people with an STI have no signs at all, often for months or years.

Chlamydia, the most common STI caused by bacteria, often shows no signs. So a person can look and feel well and still pass an infection on. Only a test shows for sure. A health worker or a clinic can test, using urine, a swab or a little blood.

A wrong idea many people have

You can tell if someone has an STI by looking at them.

Why it feels right: People who are ill often look ill. Sores and rashes can be seen.

The test that breaks it: Many people with chlamydia, gonorrhoea or HIV have no signs at all for a long time. They look and feel well, yet they can pass the infection on.

What is true: Nobody can tell by looking, not even a doctor. Only a test shows whether a person has an STI.

Left untreated, some STIs cause lasting harm. Chlamydia and gonorrhoea can damage the oviducts, so that a woman may not be able to become pregnant. This is called infertility. They can also harm the epididymis, the coiled tube beside each testis.

Untreated syphilis can damage the heart, the brain and the nerves years later. Some kinds of HPV can cause cancer of the cervix and some other cancers. Several STIs can harm a baby in pregnancy or at birth.

A screening test of the cervix can find cells that HPV has changed, long before a cancer starts. A health worker can then remove them.

STIs caused by bacteria are cured with antibiotics from a health worker. They are taken exactly as the health worker says, to the end. Some gonorrhoea has become resistant to several antibiotics, so a health worker chooses the medicine. Old or shared medicine is not used. Being cured of an STI does not protect a person for the future. They can catch the same infection again. So both partners are tested and treated before they have sex again.

STIs caused by viruses cannot yet be cured. Medicines can control herpes and HIV. Herpes sores can be made shorter and less frequent. HIV treatment lets people live long, healthy lives. Taken as a health worker directs, it lowers the virus until a test cannot find it. Then HIV does not pass on through sex.

The chapter Malaria, HIV and tuberculosis explains how HIV attacks the immune system.

The words by each arrow are ways to break the chain at that step.

A condom is a thin cover that stops semen, fluid from the vagina and blood passing between partners. A male condom fits over the erect penis. A female condom lines the vagina.

Used correctly every time, condoms greatly lower the risk of STIs, including HIV. Correctly means a new condom each time, put on before any genital contact and kept on to the end.

Never use two condoms at once, because they rub together and tear. Condoms protect less against herpes, HPV and syphilis on skin that the condom does not cover.

Vaccines protect against HPV and hepatitis B. They train the body before it ever meets the virus, so they work best given before a person has ever had sex. Not having sex removes the risk from sex. Having sex with one partner, when both have been tested and neither has other partners, lowers it a lot.

Some ideas do not work. Washing after sex, or passing urine after it, does not prevent infection. By then the pathogens have reached the moist lining inside the body, where washing cannot reach. The pill and every other method of contraception except condoms give no protection against STIs.

Contraception means ways to prevent pregnancy. A pregnancy starts when a sperm meets an egg in an oviduct, and the fertilised egg settles in the uterus lining. Each method breaks this path at one place or more.

Draw it first

Draw the route from sperm to egg

1 Sperm are made in a testis. They travel along the sperm duct and out through the urethra in the penis.
2 In sex, semen goes into the vagina. Sperm swim through the cervix and the uterus into an oviduct, where one may meet an egg. Hormonal methods also act at the ovary, by stopping an egg being let go.

The cervix is where hormones thicken the mucus and a diaphragm sits. A coil sits in the uterus. Female sterilisation cuts or blocks the oviducts.

A vasectomy cuts or blocks each sperm duct. A male condom covers the penis and catches the semen.

A barrier method puts something in the way of the sperm. Male and female condoms catch the semen, so sperm never reach the cervix.

A diaphragm is a soft dome put over the cervix before sex and left in place for some hours after. It is used with a gel that kills sperm. A health worker shows how to fit it.

A hormonal method gives the body hormones like the ones the ovaries make. The pill is taken by mouth on a regular plan. The injection is given every few months. The implant is a small, soft rod under the skin of the upper arm and lasts some years.

Most hormonal methods stop ovulation, which is when an ovary lets go of an egg. With no egg, there is nothing to fertilise. They also make the mucus at the cervix thick, so sperm cannot swim through it.

The chapter Hormones and the menstrual cycle, in the book Nerves, hormones and balance, explains how these hormones work. Vomiting, bad diarrhoea and some other medicines can stop the pill working. A health worker can say which.

A coil is a small device that a health worker places inside the uterus. It can stay there for years. A hormonal coil thickens the mucus at the cervix and keeps the uterus lining thin.

A copper coil has no hormones. The copper harms sperm, so they rarely reach or fertilise an egg. It may also stop a fertilised egg settling in the uterus lining. This is why a copper coil fitted a few days after sex still works as emergency contraception.

Sterilisation is an operation that is meant to be permanent. In a man, each sperm duct is cut or blocked. This is called a vasectomy. Semen still comes out, but with no sperm in it.

For some weeks after a vasectomy, sperm are still in the tubes. Other contraception is needed until a test shows none are left. In a woman, each oviduct is cut, blocked or sealed, so egg and sperm cannot meet.

At the cervix, hormones make the mucus thick. At the ovaries, no egg is let go, because the hormones hold back FSH and LH from the pituitary gland.

Natural methods mean avoiding sex on the days when an egg could be fertilised. An egg lives for up to about a day after ovulation, but sperm can live for several days inside the body.

The egg lives after ovulation, and sperm live inside the body. So sex several days before ovulation can still lead to pregnancy.

Cycles vary, so these days are hard to know. Pulling the penis out before semen comes is not reliable either, because some sperm can come out earlier. So natural methods are much less reliable than the others.

Emergency contraception can prevent pregnancy after sex with no contraception, or when a condom breaks. There is an emergency pill, or a health worker can fit a copper coil. The coil is the most effective. The pill works best the sooner it is taken.

A health worker, a clinic or a pharmacy can help quickly. The emergency pill mainly delays ovulation. So it does not work if an egg has already been let go. It does not work once a pregnancy has started, and it does not harm one.

The copper coil is the most effective. It is fitted by a health worker. Both are used within a few days of sex.

Washing the vagina after sex does not prevent pregnancy, because sperm reach the cervix within minutes.

How well does each method work? The implant, the coils and sterilisation work very well, because there is nothing to remember. The pill, the injection and the male condom work very well when they are used correctly every time.

In real life people forget pills or slip with condoms, so these fail more often. The diaphragm, the female condom and natural methods are less reliable. Every method can have side effects, and these vary between people. A health worker can explain the choices.

The STIs column says whether the method also stops STIs. Only condoms do. Some people use a condom as well as another method.

If used right means they work very well when used correctly every time. A missed pill, a late injection or a slip with a condom makes them fail more often. The diaphragm and the female condom fail more often than these even when used right.

Try it

Sort the slips

You need: paper, a pencil.

Tear paper into slips. Write one on each: condom, diaphragm, combined pill, implant, vaccine, test and treat.
Write three headings. A: stops sperm meeting the egg. B: stops an egg being released. C: stops an infection passing.
Put each slip under every heading it fits. If a slip fits two headings, write it again for the second one.
On another slip, write a help list. Write kinds of people and places that can help, such as a health worker or a clinic.

What you will see: The combined pill and the implant land under A and B, because they stop ovulation and thicken the mucus. Only the condom lands under a pregnancy heading and under C.

If you cannot try it, this is what happens.

Sex needs consent from both people. Consent is a free yes, with no fear and no pressure. A person who is asleep, very drunk or scared cannot give it. A child cannot consent to sex, and sex with a child is always wrong.

See a health worker soon after sex with no condom, or if a condom breaks. See one too if you notice sores, an unusual discharge or pain when passing urine. After forced sex, go as soon as you can. A health worker can help prevent pregnancy and HIV, test and treat infections, and treat any injury. Medicine to prevent HIV must start as soon as possible, within three days, so do not wait.

If one person does not listen, tell another, and keep telling until someone helps.

Where to get help. A health worker, a clinic or a pharmacy can test for STIs, treat them and give contraception. They deal with these questions every day, calmly. You can also talk to an adult you trust.

Key words

sexually transmitted infections: infections that pass from person to person mainly through sex. Also called STIs.
condom: a thin cover that stops semen and body fluids passing between partners.
contraception: ways to prevent pregnancy.
barrier method: contraception that puts something in the way of the sperm.
hormonal method: contraception that uses hormones to stop ovulation or thicken the mucus at the cervix.
coil: a small device placed in the uterus by a health worker. It may hold copper or a hormone.
sterilisation: an operation that cuts or blocks the sperm ducts or the oviducts, meant to be permanent.
emergency contraception: a pill or a copper coil that can prevent pregnancy after sex with no contraception.

Back to your guess

The answer is C: A condom, used correctly every time, greatly cuts the risk of both.

Washing prevents neither. The pill prevents pregnancy but not infections. Many infections show no signs at all. Of all the methods of contraception, only condoms also protect against infections.

Keep it

Copy this into your exercise book.

Many STIs show no signs, so testing matters. Bacterial ones are cured. Herpes and HIV can be controlled. Contraception breaks the path from sperm to egg. Only condoms also stop STIs. Nobody may touch you without your yes.

Draw: Draw the route testis, sperm duct, penis, vagina, cervix, uterus, oviduct. Draw the ovary beside the oviduct. Mark where each method breaks the path.