Lymphogranuloma venereum (LGV) is a form of the common sexually transmitted infection chlamydia. It is caused by specific strains of the Chlamydia Trachomatis bacteria (strain L1, L2 or L3) and is more invasive (i.e. gets into the tissue of the body) than more common types of Chlamydia.

LGV is common in parts of Africa, Asia, and South America but has been rare in Western Europe for many decades. Before 2003, few cases were reported in the UK and most of these were thought to have been contracted abroad. In 2004 a cluster of LGV infections was seen amongst gay men who had attended sex parties in the Netherlands. The infection was quickly spread across Western Europe and cases have also been reported in the United States.

The number of cases of LGV in the UK has been rising steadily, and the infection is now well-established in this country. Most of these cases are in HIV-positive gay men.  

Symptoms can be complex and severe causing inflammation, lymph node infection, fever, muscular pain and general ill health. Symptoms can develop on different parts of the body, such as the genitals, the anus, rectum, oral cavity and lymph nodes.

There are three stages of infection and symptoms vary depending on which part of the body is infected.

Stage one: A small painless blister or sore appears where the infection first entered the body. This may go unnoticed.

Stage two: Inflamed and swollen lymph glands may then appear in the groin, armpit or neck. Anal infection can cause painful ulcerations, discharge and bleeding. Fever may develop.

Stage three: If left untreated the symptoms can become more severe causing lasting damage to infected tissue and general health. Scarring, swelling and deformity in infected areas has also been reported. Complications of the untreated infection may require surgery

Some people with LGV may not experience any symptoms but they can still pass the infection on to their sexual partners.

Like all sexually transmitted infections, anyone who has unprotected vaginal, anal and/or oral sex can catch LGV.

Most cases reported in the UK have been in gay men and particularly high rates of LGV have been seen in HIV-positive gay men. Infection with another sexually transmitted infection (such as gonorrhoea, syphilis, hepatitis C, and genital herpes) is also common for those with LGV.

The majority of LGV outbreaks in the UK have occurred in London or Brighton, although many areas of the UK have now reported cases.

Information from the UK and other European countries indicate that LGV is also mainly affecting HIV-positive gay men who have unprotected sex and who are involved in 'hard' sex scenes and fisting. Sharing of sex toys can also lead to LGV transmission.

The risk of LGV infection can be reduced by using condoms consistently and correctly during sex and using latex gloves for fisting. Using condoms with shared sex toys or cleaning them thoroughly with hot soapy water between uses also reduces the risk.  

To diagnose LGV a doctor will have to take a sample from the urethra, rectum, or other parts of the body, depending on the symptoms and sexual practices. If this sample is found to be positive for chlamydia, the bacteria will have to be checked at a specialist lab to confirm that the strain is LGV.

Most testing for sexually transmitted infections is done in sexual health clinics (often called genitourinary medicine or GUM clinics) but some GPs and young people's sexual health services also offer general sexual health check-ups. Many HIV clinics now offer sexual health screens as part of their service. If you are concerned that you might have LGV, then it's a good idea to make sure that you tell the doctors or nurses at the clinic you are attending.

Most cases of LGV can be treated using a 21-day course of the oral antibiotic doxycycline. This antibiotic is also used to treat other sexually transmitted infections (and some other infections), but in shorter courses.

In severe cases, the late complications of LGV infection may need surgical repair.

It is important that you do not have sex if you have LGV, or any other sexually transmitted infection, until follow-up tests confirm that you no longer have the infection.

Sexual partners who may have been at risk of infection should also, if possible, be identified, tested and treated.