Sexually Transmitted Infections (STIs) continue to be a significant global health concern, affecting millions worldwide. These infections can have severe consequences if left untreated, making understanding their underlying pathogens and effective testing methods crucial.
This blog post will delve into the pathogens responsible for STIs, shedding light on the viruses and bacteria contributing to their transmission. By understanding these pathogens, we can take proactive steps to prevent and control the spread of STIs, safeguarding our own health and the well-being of our sexual partners. Furthermore, we will explore a cutting-edge diagnostic tool known as the Sexually Transmitted Infection RT-qPCR Panel Test.
What are the Sexually Transmitted Infections (STIs)?
Sexually transmitted infections (STIs), infections that are spread by sexual activity, are a group of infections transmitted primarily through sexual contact. They are caused by various microorganisms, including bacteria, viruses, parasites, and fungi. These infections can affect anyone engaging in sexual activity, regardless of age, gender, or sexual orientation.
Sexually transmitted diseases usually do not initially cause symptoms but carry the risk of passing the infection to others. STIs can cause pelvic pain, vaginal discharge, penile discharge, ulcers on or around the genitalia, and other symptoms and indicators. Infertility can result from some STIs [1].
There are numerous types of STIs, each with its own set of symptoms, modes of transmission, and potential health complications. About 30 different bacteria, viruses, and parasites are known to be transmitted through sexual activity. Some of the sexually transmitted infections can also be transmitted to a child from the mother during pregnancy. The highest prevalence of STIs is associated with eight infections. Syphilis, gonorrhea, chlamydia, and trichomoniasis are presently treatable. Hepatitis B, herpes simplex virus (HSV), HIV, and human papillomavirus (HPV) are the other four viruses, all of which are fatal.
What are the Pathogens of Sexually Transmitted Infections (STIs)?
The pathogens responsible for sexually transmitted infections (STIs) vary depending on the specific infection. STIs can be caused by a range of microorganisms, including bacteria, viruses, parasites, and fungi. Here are some common pathogens associated with STIs:
1) Bacteria:
- Chlamydia trachomatis: Causes chlamydia, one of the most prevalent bacterial STIs.
- Neisseria gonorrhoeae: Causes gonorrhea, which primarily affects the genital tract.
- Treponema pallidum: Causes syphilis, a sexually transmitted bacterial infection that progresses through different stages if untreated.
- Haemophilus ducreyi: Causes chancroid, an ulcerative STI more common in certain regions.
- Mycoplasma genitalium: Associated with urethritis and other genitourinary tract infections.
2) Viruses:
- Human papillomavirus (HPV): Numerous strains of HPV can cause genital warts and are associated with various cancers, including cervical, anal, and oropharyngeal cancers.
- Herpes simplex virus (HSV): HSV-1 and HSV-2 can cause oral and genital herpes, characterized by painful sores or blisters.
- Human immunodeficiency virus (HIV): HIV attacks the immune system and can lead to acquired immunodeficiency syndrome (AIDS).
- Hepatitis B virus (HBV): HBV can be transmitted sexually and causes liver inflammation, potentially leading to chronic infection.
- Hepatitis C virus (HCV): Although primarily transmitted through blood, HCV can also be transmitted sexually and causes liver infection.
3) Parasites:
- Trichomonas vaginalis: Causes trichomoniasis, a common sexually transmitted parasitic infection.
- Pubic lice (Pthirus pubis) and scabies: These parasitic infestations can be transmitted through sexual contact.
4) Fungi:
- Candida species: Candida infections can occur in the genital area, leading to yeast infections.
It is important to note that multiple pathogens can cause some STIs. Additionally, some infections may have asymptomatic carriers, making early detection and regular screening crucial for prevention and timely treatment. Practicing safe sex, such as using barrier methods like condoms and dental dams, can help reduce the risk of STI transmission.
What is the Sexually Transmitted Infection RT-qPCR Panel Test?
The Sexually Transmitted Infection RT-qPCR Panel Test is an advanced diagnostic tool used to detect the presence of specific genetic material from pathogens associated with sexually transmitted infections (STIs). RT-qPCR stands for Reverse Transcription Polymerase Chain Reaction, which is a technique that allows the amplification and detection of genetic material, such as RNA or DNA.
The panel test employs real-time polymerase chain reaction (RT-PCR) technology, which combines reverse transcription (RT) and PCR in a single step. This enables the detection and quantification of viral or bacterial genetic material in a patient’s sample, such as blood, urine, or swabs collected from the affected area.
The test is designed to identify the genetic material of various STI pathogens, including bacteria like Chlamydia trachomatis and Neisseria gonorrhoeae, and viruses such as herpes simplex virus (HSV), human papillomavirus (HPV), and human immunodeficiency virus (HIV), among others. By detecting the genetic material of these pathogens, the test can provide accurate and rapid results, aiding in the diagnosis and management of STIs.
How to Use the Sexually Transmitted Infection RT-qPCR Panel Test?
Using the Sexually Transmitted Infection RT-qPCR Panel Test typically involves several steps. Firstly, a suitable sample is collected from the patient, which may include blood, urine, or swabs taken from the affected area. Once the sample is collected, it undergoes sample preparation to extract the genetic material (DNA or RNA) of the pathogens. This involves separating the genetic material from other cellular components present in the sample. If the target pathogens have RNA as their genetic material, an additional step called reverse transcription (RT) is required. Reverse transcription converts RNA into complementary DNA (cDNA) using an enzyme called reverse transcriptase. This process enables the amplification and detection of the genetic material using PCR. The extracted genetic material, whether DNA or cDNA, is mixed with specific primers and probes designed to target the genetic sequences of the STI pathogens. These primers and probes are complementary to the genetic material of the target pathogens. The mixture is then subjected to multiple cycles of temperature changes in a PCR machine, which amplifies the targeted genetic sequences if they are present in the sample. During the PCR amplification process, the PCR machine measures the fluorescence emitted by the probes attached to the amplified genetic material. The fluorescence signal is detected in real-time and quantified by the PCR machine. This allows for the determination of whether the targeted genetic material of the STI pathogens is present in the sample and, if so, the level of its presence. The test results are interpreted based on the presence or absence of the specific genetic material of the targeted pathogens. The results are typically reported as positive, negative, or equivocal, depending on the presence and quantity of the genetic material detected.
References
[1] “Sexually transmitted infections (STIs) Fact sheet N°110”. who.int. November 2013.
