Sexually transmitted infections (STIs)
Sexual and reproductive health
STIs are spread primarily through person-to-person sexual contact. There are over 30 different sexually transmissible bacteria, viruses and parasites. Several STIs, particularly HIV and syphilis, can be transmitted through blood products and tissue transfer, and from mother to child during pregnancy and childbirth.

Transmission
Sexual infections are transmitted during unprotected sexual intercourse (both heterosexual and homosexual – anal, vaginal or oral). Some of the infectious agents, such as HIV, hepatitis B and syphilis, can also be passed on from an infected mother to her unborn or newborn baby and can be transmitted via blood transfusions. Hepatitis B and HIV infections may also be transmitted through contaminated blood products, syringes and needles used for injection, and potentially by unsterilized instruments used for acupuncture, piercing and tattooing.

Risk of injury
Sexually transmitted infections may cause acute and chronic illness, infertility, long-term disability and death, with severe medical and psychological consequences for millions of men, women and children.
Symptoms of STIs may be absent, mild and transient, or (as with gonorrhoea, chancroid, herpes simplex virus) acute. Many STIs can have severe long-term consequences. In adults, chlamydia and gonorrhoea may lead to complications such as infertility, chronic illness and potentially fatal ectopic pregnancy. Chlamydia, gonorrhoea and syphilis can produce serious and often life-threatening conditions in fetuses and newborn babies, such as congenital syphilis, pneumonia and low birth weight.
Apart from being serious diseases in their own right, sexually transmitted infections increase the risk of contracting or transmitting HIV infection. Other viral infections, such as herpes simplex virus type 2 (causing genital ulcer) or human papillomavirus (causing cervical cancer) are becoming more prevalent. The presence of an untreated disease (ulcerative or non-ulcerative) can increase by a factor of up to 10 the risk of becoming infected with HIV. Individuals with HIV infection are also more likely to transmit the infection to their sexual partner if either of them already has a sexually transmitted infection. Early diagnosis and treatment of all sexually transmitted infections are therefore important.
Some of the most common sexually transmitted pathogens can be divided into bacteria, viruses and parasites.

Common bacteria
• Neisseria gonorrhoeae (causes gonorrhoea or gonococcal infection)
• Chlamydia trachomatis (causes chlamydial infections)
• Treponema pallidum (causes syphilis)
• Haemophilus ducreyi (causes chancroid)
• Klebsiella granulomatis (previously known as Calymmatobacterium granulomatis, causes granuloma inguinale or donovanosis)

Common viruses
• HIV (causes AIDS)
• Herpes simplex virus type 2 (causes genital herpes)
• Human papillomavirus (causes genital warts and certain subtypes lead to cervical cancer in women)
• Hepatitis B virus (causes hepatitis and chronic cases may lead to cancer of the liver)
• Cytomegalovirus (causes inflammation in a number of organs including the brain, eye and bowel)

Parasites
• Trichomonas vaginalis (causes vaginal trichomoniasis)
• Candida albicans (causes vulvovaginitis in women and inflammation of the glans penis and foreskin in men)

Prophylaxis
Appropriate information about safe sex, risks and preventive measures, and provision of adequate means of prevention, such as condoms, are considered to be the best prophylaxis. Vaccination against hepatitis B is to be considered . Preventive vaccines against oncogenic types of human papillomavirus are now available in some countries.
The most effective way to avoid acquiring or avoiding a STI is to refrain from sexual intercourse (oral, vaginal or anal)or to restrict the exercise of that communication in a long-term relationship with the spouse does not carry any type of infection mentioned , which the parties shall be faithful to one another in respect of sexual relations.
When used properly, latex condoms ensure high effectiveness in reducing the transmission of HIV and other sexually transmitted infections, including gonorrhea, chlamydia infection, and trichomoniasis

Source: WHO
2019-01-27 19:48:36