Sexually Transmitted Infections (STIs) and Pregnancy

Sexually transmitted diseases (STD), (aka venereological diseases, sexually transmitted infections (STI) are infectious diseases, which are mainly transmitted and spread via sexual contact.

The diseases transmitted that particular way only are Syphilis, gonorrhea, donovanosis, chancroid, but there are many more, that are transmitted via sexual contact together with the other ways of transmission: parenteral (HIV, hepatitis, C hepatitis), direct contact (scabies), vertical (chlamydia, HIV).

Major Facts on Sexually Transmitted Infections

  • More than 1 million people get one sexually transmitted infection (STI) every day.
  • According to research cases, every year 500 million people come down with one of four STIs: chlamydia, gonorrhea, syphilis, and trichomoniasis.
  • More than 530 million people have the herpes simplex virus (HSV-2).
  • More than 290 million women have human papillomavirus (HPV)
  • Many STIs go without symptoms.
  • Some STIs can triple the risk of acquiring HIV.
  • STIs can have severe complications beyond the immediate impact of the infection through mother-to-child transmission of infections and chronic diseases.
  • Drug resistance, particularly for gonorrhea, is a big threat to reducing the STI impact worldwide.

What are Sexually Transmitted Infections and How do they Spread?

Sexually Transmitted Infections, pathogens of which are more than 30 different bacteria, viruses, and parasites, spread mainly through sexual contact, including vaginal, anal, and oral sex.

Some STIs can be transmitted by skin-to-skin sexual contact. The microorganisms that cause STIs can also be spread through blood transfusion and tissue transfer. Many STIs, including chlamydia, gonorrhea, hepatitis B, HIV, HPV, HSV-2, and syphilis, can also be transmitted from mother to child during pregnancy and childbirth.

A person may have an STI without obvious symptoms. Therefore, the term “sexually transmitted infection” is wider than the term “sexually transmitted disease” (STD). Common symptoms of STDs include vaginal discharge, urethral discharge in men, genital ulcers, and abdominal pain.

8 of 30 known pathogens are associated with the greatest incidence transmitted by sexual contact. Nowadays 4 8 infections are curable: syphilis, gonorrhea, chlamydia, and trichomoniasis. The other infections, such as hepatitis B, herpes, HIV, and HPV, are incurable, but their impact can be reduced due to treatment.


The Extent of the Problem

STIs have a profound impact on sexual and reproductive health around the world and adults often go to doctors with similar problems.

Every day more than 1 million people are infected with sexually transmitted diseases. According to research cases, 500 million people come down with one of four STDs: chlamydia, gonorrhea, syphilis, and trichomoniasis. More than 530 million people have HSV-2. More than 290 million women are infected with HPV, one of the most common STIs.

STIs may have severe complications beyond the immediate impact of the infection itself.

  • Some STIs can triple the risk of acquiring HIV.
  • STI transmission from mother to child can lead to stillbirth, neonatal death, low birth weight,

prematurity, sepsis, pneumonia, neonatal conjunctivitis, and inborn deformations. Syphilis during pregnancy leads to approximately 305,000 deaths of fetal and newborns every year, and 215,000 children are born at risk of death because of prematurity, low birth weight, or congenital disease.

  • HPV leads to 530 000 cases of cervical cancer and 275,000 deaths from it every year.
  • STIs, such as gonorrhea and chlamydia, are the major causes of inflammatory diseases of the pelvic organs, adverse pregnancy outcomes, and infertility.

How to Prevent Sexually Transmitted Infections

Consultancy and Behavioral Approaches

Consultancy and behavioral interventions offer primary prevention of STIs (including HIV) and unwanted pregnancies as well. They include:

  • Comprehensive sexuality education, consultancy on STI and HIV pre-and post-test
  • Consultancy on safe sex/risk reduction, and condom promotion
  • Interventions aimed at vulnerable groups of people such as teenagers, sex workers, men who have sex with men, and people who inject drugs

In addition, consultancy can improve people’s ability to recognize STIs’ symptoms and increase the probability that they will seek medical care or recommend it to their sexual partners. Unfortunately, public ignorance, untrained health workers, and widespread stigmatization around STIs still remain obstacles to wider and more effective adaptation of these interventions.

Barrier Methods

The proper and regular use of condoms is one of the most effective methods to protect against STIs, including HIV. Female condoms are effective and safe, but they are not used by national programs as male condoms.

Sexually Transmitted Infections Diagnosis

In high-income countries, accurate diagnostic tests for STIs are widely used. They are especially useful for the diagnosis of asymptomatic infections. However, in low- and middle-income countries, there is a deficit of diagnostic tests. And if there are tests, they are often expensive and geographically inaccessible; and patients often have to wait a long time for the results (or to come back).

The syphilis test is the only low-cost rapid blood test for STIs that is available now. This test is already used in some countries with scarce resources. This accurate test provides results in 15-20 minutes and it can be easily used with minimal training. Rapid syphilis tests are tested the number of pregnant women with syphilis. However, additional efforts are necessary for most low- and middle-income countries to ensure that all pregnant women will be tested for syphilis.

A range of rapid tests for other STIs is being developed that can potentially improve STI diagnosis and treatment, especially in countries with scarce resources.

Treatment of STIs

Nowadays some STIs can be treated effectively.

  • Three bacterial STIs (chlamydia, gonorrhea, and syphilis) and one parasitic STI (trichomoniasis) are usually treated with available effective single-dose antibiotics.
  • For herpes and HIV, antiretroviral drugs are the most effective medications plus available, they can mitigate the disease, but they can not cure the disease.
  • For hepatitis B, there are immunomodulators (interferon) and antiretroviral drugs that can help to fight the virus and prevent further liver damage.

STI resistance to antibiotics, especially gonorrhea, has increased rapidly in recent years. The origin of reduced susceptibility of gonorrhea to the drug therapy (oral and injectable cephalosporins), along with antimicrobial resistance was already shown to penicillin, sulfonamides, tetracyclines, quinolones, and macrolides make gonorrhea a multidrug-resistant microorganism. The resistance of other STIs to antimicrobials, not so widespread, is still necessary to be prevented and treated.

STI Case Management

Low- and middle-income countries are guided by STI syndromic case management, which is based on the detection of relevant symptom groups and easily recognized signs (syndromes), to begin treatment without conducting laboratory tests. This approach is often based on clinical algorithms, healthcare worker is allowed to diagnose specific infections based on syndromes.

Syndromic case management is a simple method of providing rapid treatment, and this method allows to avoid expensive and inaccessible diagnostic tests. However, some infections are missed because they go asymptomatically, i.e. many STIs globally.


Vaccines and Other Biomedical Interventions

There are safe and effective hepatitis B and HPV vaccines. These vaccines are a great achievement in the field of STI prevention. The hepatitis B vaccine is included in the childhood immunization programs in 93% of countries, and according to research 1.3 million deaths from chronic liver disease and cancer have been prevented.

The HPV vaccine is available as a component of immunization programs in 45 countries, most of which are countries with high and middle incomes. The HPV vaccine will prevent more than 4 million deaths of women in low- and middle-income countries in the near future, where most cases of cervical cancer, on condition there will be 70% vaccination coverage.

There is some progress in the research development of herpes and HIV vaccines, although adaptable vaccines have not been made yet. Vaccines for chlamydia, gonorrhea, syphilis, and trichomoniasis are in the early stages of development.

Other biomedical interventions for Sexually Transmitted Infections prevention include adult male circumcision and microbicides.

  • Male circumcision reduces the risk of heterosexual acquisition of HIV infection by approximately 60% and provides some protection against other STIs, such as herpes and HPV.
  • Clinic testing of tenofovir, which potentially prevents women from acquiring HIV, reached the stage of concept validation in 2010. Further clinical research is conducted to prove its safety and effectiveness.

Poor Awareness of Sexually Transmitted Infections Spread

It is Difficult to Change Behavior

Despite the great efforts to find simple measures for reducing the extent of sexual behavior, it is difficult to do that. Studies have shown that some groups of the population should be carefully consulted.

Poor Screening and Treating for Sexually Transmitted Infections

People face many difficulties while seeking services for STI screening and treatment. They include scarce resources, stigmatization, and low quality of services.

  • In many countries, Sexually Transmitted Infections services are separate and not available as primary health care, family planning, and other medical services.
  • Some services can not offer to screen for asymptomatic infections because of improperly trained personnel, laboratory capacity, and limited medicines.
  • The highest rates of STIs among marginalized groups such as sex workers, men who have sex with men, injecting drug users, prisoners, and young people, often do not have access to health services.
  • These methods may prevent the spread of STIs: The Main Methods of Contraception

WHO Activities

WHO develops global norms and standards to prevent and treat STIs, strengthens surveillance and monitoring systems, for example, drug-resistant gonorrhea, and prepares for STI studies.

Our tasks are focused on:

  • The achievement of the Millennium Development Goals 4, 5, and 6
  • The realization of the global strategy to prevent STI spread adopted by the World Health Assembly in 2006

the UN Secretary-General’s Global Strategy to protect the health of women and children was held in 2010 which highlights the need for a comprehensive, integrated package of essential interventions, including information and services for the prevention of HIV and other sexually transmitted infections.

WHO works with different countries to:

  1. Scale-up effective STI services including:
    • Syphilis testing and treatment, in particular for pregnant women
    • Hepatitis B and HPV vaccination.
    • Sexually Transmitted Infections case management and counseling
  2. Promote strategies to enhance STI-prevention impact including:
    • Integrate STI services into existing health systems
    • Promote sexual health
    • Measure the burden of STIs
    • Monitor and respond to STI antimicrobial resistance.
  3. Support the development of new technologies for STI prevention such as:
    • Point-of-care diagnostic tests for STIs
    • Additional drugs for gonorrhea
    • STI vaccines and other biomedical interventions