Transmission
Bacteria called Chlamydia trachomatis causes Chlamydia. It can be transmitted during all kinds of sexual intercourse if no condom is used. It can be transmitted to a baby during delivery, resulting in eye and chest infections.

Symptoms
Symptoms of Chlamydia normally occur one to three weeks after infection. However, many people who have Chlamydia are unaware that they have the infection. It is thought that as many as 75% of women with Chlamydia, and 50% of men with Chlamydia have no symptoms.

Where symptoms do occur, in men it usually consists of a milky discharge from the penis, particularly in the morning, and a burning sensation when urinating. The testicles can swell and be very painful.

Women with Chlamydia may notice a milky discharge from the vagina and/or lower abdominal or back pain, or pain when having sex. There may also be vaginal bleeding during sex and bleeding between periods. There may also be pain urinating.

If Chlamydia is left untreated it can lead to pelvic inflammatory disease (PID) in women, which can cause ectopic pregnancy and infertility. Men can become infertile. Men and less frequently women may develop Reiter's syndrome (sore eyes and joints, skin rashes) as a result of chlamydia and this can lead to disabling arthritis.

Diagnosis
Chlamydia is diagnosed by taking a swab from the penis or cervix or vivo-vaginal area or by a simple urine test. The swabs can be a little uncomfortable but are very quick to take. Some clinics also examine a urine sample for evidence of infection with Chlamydia.

It can, however, take up to a week for tests to show if Chlamydia is present and it is important to contact your clinic for the result of your test so treatment can be given if the infection has been detected so make sure you contact your clinic for your results.

Treatment
Chlamydia is treated with antibiotics. Normally this consists of a seven-day course of Doxycycline, or a single dose of Azithromycin. It's important to take all your tablets to ensure that the infection is eradicated from your body. It's also important to try and ensure that your partner receives treatment before you have sex again. Symptoms may persist for a few days after taking Azithromycin as the antibiotic takes time to work.

You will be advised not to have sex (even with a condom) until your treatment period is finished. This is to prevent reinfection.

Transmission
Genital warts are a sexually transmitted infection caused by the human papilloma virus (HPV). They can be contracted during unprotected anal, vaginal or oral sex. It can also be transmitted by close physical contact with the genital warts themselves, as these may shed the wart virus.

Symptoms
Genital warts look just like warts which may appear on other parts of the body – usually small lumps on the skin with a slightly rough texture. Some people who contract the wart virus do not have visible warts or do not notice them. In women, warts may appear on the inside or outside of the vagina, or on the neck of the cervix, or around the anus. In men, warts may appear on the tip or shaft of the penis, the scrotum, or around the anus.

Some forms of the genital warts virus are associated with an increased risk of cervical or anal cancer, and this risk might be increased even further in people with HIV. However, having visible warts does not mean you have the wart virus that is linked with cancer.

Diagnosis
Genital warts are diagnosed by visual and manual examination of the genital and anal area.

A Pap smear is a procedure designed to detect pre-cancerous cellular changes called dysplasia early, before cancer develops. Most women know the Pap smear as a 'cervical smear'. Pap smears involve taking a small scraping of cells from the cervix. When these cells are examined under a microscope, it is possible to see if there are any changes in the cells which suggest a risk that cancer could develop in the future.

HIV-positive women are recommended to have Pap smears when they are first diagnosed with HIV, six months later, and then once a year. The value of screening the anal canal for pre-cancerous cells is being studied.

A type of testing called liquid cytology can also detect the wart virus linked to cancer and is gradually replacing Pap smears.

Treatment
Infection with the genital wart virus is cured by your own immune system and this can take a long time. Treatment to remove the visible wart involves either the warts being painted with a chemical that burns them, freezing, laser surgery or a new self-applied cream. These procedures may feel a little uncomfortable.

Transmission
Gonorrhea is a bacterial STI and can be passed on during all kinds of sex. Untreated gonorrhea can make a person with HIV more infectious. Having gonorrhea can also make it more likely that an HIV-negative person will be infected if they are exposed to the virus. Gonorrhea can also be passed on from mother to baby during childbirth, and can cause infection in the baby's eyes, with a high risk of blindness if left untreated.

Symptoms
Symptoms of gonorrhea usually appear between two and ten days after infection. However, some people may not realize they have the infection as symptoms may not always be present, or may be very mild. In men, symptoms usually consist of a yellowish or greenish discharge from the penis and burning when passing urine. The testicles may also hurt and swell.

Symptoms in women can include a burning sensation when passing urine and a discolored or bloody discharge from the vagina.

If left untreated, gonorrhea can cause more serious health problems, including pelvic infections in women resulting in pain, infertility, and ectopic pregnancy, and testicular problems and narrowing of the urethra in men.

Untreated gonorrhea can also spread to the bloodstream leading to fevers, and can affect the joints, causing arthritis and swelling.

Diagnosis
To test for gonorrhea, a swab is taken from the tip of the penis, urethra, and throat or from the cervix. The swabs can be a little uncomfortable. A urine sample may be taken instead. It is usually possible to tell immediately from examination of the swabs if gonorrhea is present in the penis, and in many cases the cervix, but gonorrhea in the throat can only be diagnosed later. However, whatever the site of infection, it can take up to three days for testing to provide conclusive results. It is important, therefore, to contact your clinic for the result of your test.

Treatment
Gonorrhea is treated with antibiotics. Treatment is normally given by injection. You will be asked to return seven days later for tests to see that you have been cured. It is very important not to have any kind of sex during this period as you may be re-infected with gonorrhea, or pass the infection to your partner.

Transmission
Hepatitis A is a virus which affects the liver and is transmitted through contact with infected faces (excrement, shit) normally in contaminated food. Once you have had hepatitis A you cannot get it again, but some people do have relapses.

Symptoms
Hepatitis A can cause a short-term mild illness, and symptoms can include a yellowing of the skin and eyes (jaundice), extreme tiredness, weight loss, vomiting, diarrhoea, dark urine and pale stools. Symptoms can be made worse by drinking alcohol, tea or coffee and eating fatty food. People normally get better in a couple of weeks.

Treatment
Treatment for hepatitis A consists of rest, drinking fluids, and avoiding alcohol and recreational drugs. It's also important not to take paracetamol whilst you are recovering from hepatitis A. Hepatitis A can last longer and be more severe in people with HIV and weakened immune systems. If you have hepatitis A it might be necessary to stop taking anti-HIV drugs for a time as most medicines are broken down by the liver and when the liver is inflamed by hepatitis A side-effects can become worse.

Vaccination
Unlike most infections considered in this section, a vaccination against hepatitis A is available and everybody with HIV is recommended to have it if they do not have natural immunity to the infection. The vaccination consists of two injections given over six months.

Transmission
Hepatitis B is passed on by contact with the blood, semen, saliva, or vaginal fluids of an infected person, and is easily passed on during unprotected sex and from a mother to her baby during delivery. It is many times more infectious than HIV.

Symptoms
When someone first becomes infected with hepatitis B, they may develop jaundice (yellowing of the eyes and skin), lose their appetite, have pain in the abdomen, malaise, nausea, vomiting, muscle and joint aches or fever. These symptoms can be very serious or in very rare cases even fatal. However, most people do not notice any symptoms on infection.

Diagnosis
Blood tests can detect the presence of hepatitis B antibodies, which show that you have been exposed to, and have cleared the virus. If you have been exposed and have not developed this protective immunity, then fragments of the virus itself, called hepatitis B surface antigen (HBsAg), will persist in your blood. This means that you are a chronic carrier and are capable of infecting other people. A sub-group of carriers also test e-antigen positive and this means that their hepatitis infection is highly infectious to others.

Treatment
During the initial period of infection with hepatitis B it's important to take lots of rest, drink plenty of fluids, not to take paracetamol, and to avoid alcohol and recreational drugs.

If you are HIV-positive and have chronic hepatitis B infection then you must receive care from a doctor skilled in the treatment of both HIV and hepatitis.

Vaccination
Unless you are naturally immune, you are recommended to receive hepatitis B vaccination. This consists of course of three injections given over several months. People with HIV can lose their immunity to hepatitis B as their immune system weakens and should have this checked regularly.

Transmission
Hepatitis C is normally transmitted by blood-to-blood contact. Sexual practices which involve contact with blood, having syphilis at the time of hepatitis C infection also appear to be factors involved in the infection's transmission.

Symptoms
The effects of infection with hepatitis C vary. Less than 5% of people who contract the virus develop acute hepatitis symptoms such as jaundice and nausea at the time of infection, and a significant minority may experience no symptoms at any stage. For those who do, common symptoms include extreme tiredness and depression.

HIV infection can make the diagnosis of hepatitis C more difficult as infection may not show up on antibody tests in HIV-infected people.

Treatment
Current practice is to start treatment for hepatitis C only if liver function is consistently abnormal. The goals of treatment are to cure hepatitis, to normalize liver enzymes (a marker of liver function), to lower hepatitis C viral load, to improve liver inflammation and to prevent progression to cirrhosis or liver cancer.

An outbreak of herpes involves painful sores or ulcers that affect the mouth, genitals or anus. Herpes is caused by a common virus called herpes simplex virus (HSV).

Once you are infected, the virus stays in nerve cells for life. You may not know that you are infected with HSV. Most of the time it is dormant and causes no symptoms. From time to time flare-ups can occur, especially if you have a weakened immune system. Even among people without HIV, stress, a common cold or exposure to strong ultra-violet light can cause an outbreak of active herpes.

There are two main types of HSV which both cause oral and genital infection. HSV-1 usually causes oral herpes or cold sores – tingling or painful spots on the edge of the lip where it meets the skin of the face. These can occasionally develop on the nostrils, on the gums or on the roof of the mouth. It can also cause genital infection.

Painful genital or anal ulcers, sometimes accompanied with fever, headache, muscle ache and malaise can be caused by HSV-1 and HSV-2. Herpes lesions often start as numbness, tingling or itching. This feeling indicates that the virus is travelling up a nerve to the skin. There it causes small bumps that rapidly develop into small inflamed fluid-filled blisters. These burst and crust over, typically taking one or two weeks to heal in people with normal immune systems.

Transmission
The virus can be passed from person-to-person by contact between these lesions and mucous membranes e.g. kissing, and sexual contact.

Herpes may also be transmitted when sores are not present, if HSV is replicating and infectious HSV particles are being shed from the skin or, more likely, from mucous membranes. HIV-positive people may experience such shedding more frequently.

Having genital herpes increases the risk of transmission/acquisition of HIV.

In people with HIV, herpes recurrences can be frequent, severe and long lasting. Sometimes the lesions can become infected with other bacteria or fungi. As well as causing large oral and genital lesions, herpes can occasionally affect the throat and eye.
Diagnosis

HSV is diagnosed by growing (culturing) the virus from a swab taken from a lesion, or by using a fluorescent screening test to detect the virus. A test that looks directly for the virus's genetic material is used for research purposes but is not generally available. Herpes in the oesophagus (gullet) or colon may be examined using fibre-optic instruments.

Treatment and preventing recurrances
Herpes infections are treated with acyclovir. Other treatments for herpes include valacyclovir, known by the brand name Valtrex, and famcyclovir.

Acyclovir is taken in tablet form (200 to 800 mg five times a day for 5 to 10 days) to treat serious attacks of oral herpes and genital or anal ulcers. Although effective at a different dosage at preventing outbreaks of herpes, once an attack of genital herpes is established acyclovir often provides minimal benefit. It is also given as an intravenous drip (5 to 10 mg/kg every 8 hours) for very severe attacks. Acyclovir has very few side-effects. Acyclovir cannot eliminate HSV so herpes attacks may recur. Acyclovir cream is available from chemists to treat cold sores; however, many doctors question how effective it really is. Some people find that salt baths, ice packs (wrapped in a towel), lidocaine gel, pain killers and rest help relieve symptoms.

Acyclovir may be taken on a regular basis to prevent recurrent attacks of herpes (400mg twice daily).

Transmission
Non-specific urethritis (NSU) is an inflammation of the tube which urine and semen pass through in a man's penis, the urethra. This inflammation can be caused by several sexually transmitted infections transmitted during all kinds of sex. However, very rarely it can have a non-sexual cause, such as friction during sex.

Symptoms
Symptoms of NSU normally develop within a week or so of infection, although some irritants, such as soap, can cause symptoms to occur almost immediately. However it is estimated that as many as 50% of men with NSU have no symptoms at all.

When symptoms do occur, they normally consist of pain or a burning sensation when passing urine, more frequent urination and a white or cloudy discharge from the tip of the penis which may be particularly noticeable first thing in the morning.

Diagnosis
NSU is diagnosed by taking a swab from the penis. This can be uncomfortable but is very quick to take. A urine sample may also be looked at for evidence of infection.
In many cases it will be possible to tell instantly if NSU is present, but it can take up to a week for tests to show if chlamydia, the symptoms of which can resemble NSU, is present.

Treatment
NSU is treated with antibiotics. Normally this consists of either a seven-day course of doxycycline or a single dose of azithromycin. It is important to take all your tablets to ensure that the infection has been eradicated from your body. Symptoms may persist for a few days after taking azithromycin as the antibiotic takes time to work.

You will be advised not to have sex (even with a condom) until your treatment period has finished. Your partner, wherever possible, should also receive treatment. This is to cure them and to prevent reinfection.

Pubic lice, also called 'crabs' are small insects that resemble crabs because of their claws, which allow them to hold onto pubic hair (body hair near the genitals and anus). Although crabs are particularly fond of pubic hair, they can live in hair in other parts of the body, particularly the armpits, and even in the eyebrows and eyelashes, although this is uncommon.

Transmission
Crabs are normally picked up and passed on during sex, though any form of intimate bodily contact can be enough to pass them on. They can also be picked up from sharing towels, bedding or clothing, but this is less common.

Symptoms and diagnosis
Some people notice the infestation within hours, but others do not become aware that they have crabs for several weeks. Crabs are very small and can be very difficult to see, but symptoms usually include an intense itching in the groin, and some people notice the lice eggs firmly attached to pubic hair. Small spots of blood may appear on underwear or sheets.

Treatments
Lotions such as malathion (Derbac M) are available from chemists, without prescription, for getting rid of crabs, or free of charge from sexual health and GUM clinics. It is important to follow the instructions properly as improper use could mean that you fail to clear the infestation, and using too much could provoke an allergic reaction. Do not use Derbac M or similar lotions after a hot bath.

Shaving pubic hair will not get rid of crabs. It is important to wash all clothes, towels and bedding you have used since you were infected with crabs on a hot cycle when you start treatment. You should also ensure that your partner, or people with whom have had intimate bodily contact, or shared a bed, use treatment at the same time as you to avoid reinfestation.

Scabies is a skin disease caused by a mite that burrows under the skin causing intense itching, usually most notable at night.

Transmission
It is easy to pick up scabies, any skin contact is sufficient, and sharing towels or bedding is enough for transmission to occur.

Symptoms
Scabies are invisible to the naked eye, but leave red 'track marks' in the skin. Usually scabies affect the hands between the fingers, the genitals, breasts, buttocks, abdomen and feet. Norwegian scabies can occur in HIV-positive who have weak immune systems. White flakes appear on the skin in mounds and cause intense itching.

Treatment
The same lotions used to treat crab infestations are also effective against scabies, although it may be necessary to leave the lotion on the body for longer (usually 24 hours). It should be applied to the whole body, other than the face and scalp, and reapplied to the hands after hand-washing. After treatment, the itch can get worse temporarily. In this case, hydrocortisone cream can be applied, and the itch should not be scratched. Do not use scabies treatment after a hot bath.

Clothing, towels and bedding should be washed on a hot cycle to avoid infecting others or yourself. As with crabs, it is important that anybody who you think might have been infested at the same time as you, and with whom you are in intimate contact, treats themselves at the same time as you to avoid reinfestation.

Neither scabies nor crabs can pass on HIV. People with long-standing crab and scabies infestations can feel generally unwell (which is the origin of the term 'lousy') and if left untreated, scabies can cause severe skin irritation.

Syphilis is a bacterial infection. There are three stages to the disease: primary syphilis; secondary syphilis and tertiary syphilis. During the primary and secondary stages the disease is highly contagious.

Transmission
Syphilis can be contracted from contact with syphilitic sores during all kinds of sex. It can also be transmitted by close physical contact with secondary syphilitic rashes and lesions, which can be anywhere on the body, and from contact with blood. Syphilis can also be transmitted from mother-to-baby.

Untreated primary and secondary syphilis can make a person with HIV more infectious. Having syphilis may also makes it much more likely that an HIV-negative person will be infected with HIV if exposed to the virus.

Symptoms
Syphilis can cause a range of symptoms or none at all. In the early stage of disease, symptoms may be easily missed. Syphilis can progress more quickly and severely in people with HIV, and may present slightly different symptoms.

Shortly after becoming infected with syphilis (primary syphilis) a small sore, spot or ulcer (called a chancre) may appear at the site of infection, usually on the penis, in or around the anus or vagina or in the mouth. The chancre does not hurt and usually heals quite quickly. It can be accompanied by swollen glands.

Secondary syphilis can cause a rash on the body, palms and soles, swollen glands, fever, muscle pain, headache, ringing in the ears, and in rare cases, meningitis. The rash and sores are highly infectious. Secondary syphilis normally develops within six months of exposure.

Tertiary syphilis can develop about ten years or more after infection and can cause damage to almost all the heart, the brain (neurosyphilis), the bones and the skin (gumma). If left untreated syphilis can cause death.

Diagnosis
A general sexual health check-up will include a blood test for syphilis, and any lesions will be swabbed. Many HIV clinics now test for syphilis as part of their routine HIV care. It can take up to three months for the body to develop antibodies to the bacteria that cause syphilis, so a test taken shortly after exposure may not detect infection. There is some evidence to suggest that tests for syphilis are not as reliable in HIV-positive people. If brain involvement is suspected, a lumbar puncture (often called a 'spinal tap') may be carried out to assess the extent of disease.

Treatment
Syphilis is usually treated with a course of penicillin injections. People who are allergic to penicillin are given a course of doxycyline tablets. To ensure that the syphilis is completely cured it is vital to have all your prescribed injections or take all your medication. To avoid infecting other people with syphilis, or being reinfected with the bacteria, it is important to avoid sex altogether until treatment has been completed and you have been given the all clear.

Follow-up blood tests will be carried out at intervals of 1, 2, 3, 6 and12 months to ensure the infection has gone.

Trichomonas vaginalis is a common sexually transmitted infection caused by a tiny parasite.

Transmission
Trichomonas is spread by unprotected sex between men and women.

Symptoms
In women symptoms can include a heavy vaginal discharge, vaginal itching, lower back-pain, pain during sex and a frequent need to urinate. Often men have no symptoms, but when they do a discharge from the penis, a burning pain when urinating and increased need to urinate are most common.

Diagnosis
Swabs taken from the vagina or penis are examined for the presence of trichomonas under a microscope, and it is often possible to tell immediately if infection is present. Swabs can also be cultured with results available in a week.

Treatment
Trichomonas is treated with antibiotics. It is important to take all your tablets to ensure that the infection has been eradicated from your body. You will be asked to return a week later for a test to see that you have been cured. You will be advised not to have sex (even with a condom) until your treatment period has finished and your partner(s) has received treatment. This is to prevent reinfection.

Transmission
In humans, both Mycoplasma and Ureaplasma species may be transmitted by sexual contact, vertically from mother to offspring (either at birth or in utero), or by nosocomial acquisition through transplanted tissues.

Symptoms
Ureaplasma species are causes of nonchlamydial nongonococcal urethritis in men. Usually your first symptoms from ureaplasma and mycoplasma are burning on urination, a feeling that you have to urinate all the time, terrible discomfort when the bladder is full and vaginal itching, odor or discharge. Other first symptoms include itchy eyes, a cough or a burning in your nose.

Diagnosis
Swabs taken from the vagina or penis are examined for the presence of Mycoplasma or Ureaplasma under a microscope.

Treatment
Since mycoplasmas lack a cell wall, the penicillins and cephalosporins are ineffective. The antibiotics of choice are tetracycline (adults only) and erythromycin. Prevention is a problem due to the long duration of the disease. It is problematic to isolate patients to avoid close contact for a long period of time. No vaccines are currently available.

Genital HPV infection is a sexually transmitted disease (STD) that is caused by human papillomavirus (HPV). Human papillomavirus is the name of a group of viruses that includes more than 100 different strains or types. More than 30 of these viruses are sexually transmitted, and they can infect the genital area of men and women including the skin of the penis, vulva (area outside the vagina), or anus, and the linings of the vagina, cervix, or rectum.

Transmission
The types of HPV that infect the genital area are spread primarily through genital contact. Most HPV infections have no signs or symptoms; therefore, most infected persons are unaware they are infected, yet they can transmit the virus to a sex partner.

Symptoms
Most people who have a genital HPV infection do not know they are infected. The virus lives in the skin or mucous membranes and usually causes no symptoms. Some people get visible genital warts, or have pre-cancerous changes in the cervix, vulva, anus, or penis. Very rarely, HPV infection results in anal or genital cancers.

Diagnosis
Most women are diagnosed with HPV on the basis of abnormal Pap tests. A Pap test is the primary cancer-screening tool for cervical cancer or pre-cancerous changes in the cervix, many of which are related to HPV.

Treatment
There is no "cure" for HPV infection, although in most women the infection goes away on its own. The treatments provided are directed to the changes in the skin or mucous membrane caused by HPV infection, such as warts and pre-cancerous changes in the cervix.

CMV is a member of the herpesvirus family, which includes the herpes simplex viruses and the viruses that cause chicken pox (varicella-zoster virus) and infectious mononucleosis (Epstein-Barr virus). CMV is found in body fluids, including urine, saliva (spit), breast milk, blood, tears, semen, and vaginal fluids. Once CMV is in a person's body, it stays there for life.

Transmission
Transmission of CMV occurs from person to person, through close contact with body fluids (urine, saliva, breast milk, blood, tears, semen, and vaginal fluids), but the chance of getting CMV infection from casual contact is very small.

Symptoms
Most healthy children and adults infected with CMV have no symptoms and may not even know that they have been infected. Others may develop a mild illness. Symptoms may include fever, sore throat, fatigue, and swollen glands. But these are also symptoms of other illnesses, so most people don't know it when they get CMV.

Diagnosis
A blood test for IgG antibodies (special immune system proteins) is how your doctor can determine whether you've ever been infected with CMV.

Treatment
Scientists are working on CMV vaccines and are looking for other ways to prevent congenital (meaning present at birth) CMV. For now, there are no treatments for pregnant women whose fetuses might be infected with CMV. Current drugs that are effective against CMV have serious side effects and are not approved for use in pregnant women.