Class 21 Reproductive and Urinary Tract Infections Quiz

Reproductive and Urinary Tract Infections (and STIs)

• Mucosal membranes are key in both reproductive and urinary tracts, different from the digestive tract.
• The digestive tract is sterile at one end and contaminated at the other.
• Kidneys remove waste and excess fluids, releasing waste into the bladder.
• Waste fluid travels down ureters to the bladder, then is periodically released through the urethra.
• Sphincter muscles near the urethra keep the system closed.
• Urine flow washes away microorganisms, typically sterile.
• Urine contains organic acids and antimicrobials.
• Women have shorter urethras, increasing UTI risk.

UTI Infective Agents

• Some agents attach to urethra walls and resist urine flow.
• They withstand acid and evade macrophages.
• Common agents live near the exit point (E. coli, lactobacillus, etc.). Variants have adapted.
• Male urethras are longer, farther from the alimentary canal, and contributes to gender difference in UTIs.
• Females have shorter urethras, proximity to both the alimentary canal and vaginal opening increase potential UTI agents.
• Schistosoma hematobium infects through skin, not urethra.

Exceptions

• Schistosoma hematobium is a helminth.
• It infects through skin exposed to contaminated water.
• Helminths migrate to mate in veins around the bladder.
• Eggs penetrate vein walls and tissues. Some pass to the bladder.

More normal Bacterial cystitis (Uropathogenic E. coli)

• Pili attach to bladder epithelial receptors.
• Death/sloughing of epithelium allows bacteria to enter underlying tissue via endocytosis.
• Create intracellular communities (IBCs).
• Bacteria detach and move to bladder lumen, creating more IBCs.
• Bacteria establish chronic reservoirs in epithelium, resisting antibiotics and remaining undetected by the immune system.
• Filamentous forms help evade the innate immune response.

Genital Systems

Female

• Two ovaries, two fallopian tubes, uterus, vagina, and external genitalia (vulva).
• Ovum (egg) released each month during ovulation.
• Fertilized ovum moves via cilia to the uterus.
• Otherwise, menstruation happens.
• Cervix opens to the vagina, filled with antimicrobial mucus (except during menstruation).

Male

• Testes, tubes, ducts, glands, and penis (outside the abdominal cavity in the scrotum).
• Sperm cells collected in the epididymis, carried to the urethra by vas deferens.
• Sperm, prostate gland, and seminal vesicle secretions form semen.
• Antimicrobial properties.
• In older males, prostate can enlarge, slowing urine flow.

Genital System Diseases and STIs

• Genital system diseases can be related to UTIs.
• Microbial ecology disruptions are common, especially in the vagina (e.g., pH changes, loss of normal flora).
• Vulvo-vaginal candidiasis (yeast infections) are another type of infection.
• Local inflammation (itching, pain), and odor are common symptoms.
• These diseases are usually not transmitted between people.

Toxic Shock Syndrome

• High growth levels of one type of Staphylococcus leads to toxin secretion, especially in the presence of a protected area (e.g., tampon).

Sexually Transmitted Infections (STIs)

• STIs are generally poorly infective, requiring long-term survival in the host.
• They need contact with mucosal membranes between people (e.g., vagina, urethra, rectum, mouth).
• They can spread to pelvic areas in females and systemic infections in both sexes.
• Most STI infections initially cause no symptoms in the infected person.
• They may contribute to inflammation and cell destruction if symptomatic or untreated.
• STIs can cause permanent damage and infertility in some cases.
• The most common contributing factors to spread are commonly due to the fear or embarrassment associated with the infection and a fear from discovery.

Biggest STI "Virulence" Factors

• Fear of discovery and embarrassment are common drivers affecting spread of STIs.
• Disbelief of the disease plays a role.

Epidemiology

• STIs such as HIV are transmitted through contact with body fluids.
• Transmission risk increases with unprotected sex, open sores/inflammation & symptoms.
• Cases can be asymptomatic.
• Transmission can also occur between mother and fetus.
• Many methods exist to stop the transmission of STIs.

Bacterial STI—Syphilis

• Causative agent: Treponema pallidum (slender, motile spirochete).
• Viewed via darkfield microscopy or silver stain.
• Propels with endoflagella, allowing penetration of tissues and organs (humans only).
• Secrete enzymes to loosen mucous and have corkscrew motility aiding penetration.
• Outer membrane proteins bind to host cells and coat themselves in host proteins, inhibiting phagocytosis.

Progress of Syphilis (infective dose ~100 bacteria)

• Enters via contact, multiplies near contact area.
• Localized inflammatory response (hard chancre) develops.
• Often visible on external genitalia (e.g., penis).
• Can resolve in 2-6 weeks.
• Infection has already spread to lymph nodes and bloodstream.

Secondary Syphilis

• Asymptomatic stages of syphilis are characterized by a war between the inflammatory response and bacterial growth.
• Body can display infectious lesions on the skin and mucus membranes if the syphilis gets an upper hand.
• This can occur due to immune system stress.
• Every lesion is a potential infection source.

Tertiary Syphilis

• Systemic disease that can occur years after untreated primary or latent disease.
• Chronic granulomas (gummatous syphilis).
• Cardiovascular infections (ascending aorta, potential aneurysms).
• Neurosyphilis: inflammation of the brain.

Congenital Syphilis

• Treponema pallidum easily crosses the placenta.
• Fetal damage can occur at various stages of pregnancy.
• Damage to the fetus can range from spontaneous abortion/stillbirth to late-stage deformities (e.g., bone, cartilage, teeth, eyes).

Syphilis Transmission

• Commonly transmitted via bodily fluids, shared cooking utensils or contact with infected people.
• Transmission is commonly associated with poverty and poor sanitation.
• Historically, the spread was particularly noticeable in tropical regions with colder climate influences.

Drug Treatments

• HIV treatment focuses on preventing other infections from becoming fatal.
• Antiretroviral therapies (ART) are often successfully used in combination with other medications that are targeted to other, related diseases and infections.
• Medications can suppress symptoms and control infections.

Infection

• Viruses cannot move in mucous, needing cell membrane contact.
• Anal sex is more efficient in transmission than vaginal sex.
• Transmission can also occur through shared needles or blood transfusions.
• The virus is not transmitted through insect bites or casual contact.

Vertical Transmission

• HIV infection in mothers that is maintained at a high viral load may be vertically transmitted across the placenta.
• Vaginal birth, if not properly controlled/managed with existing medications and practices, may also increase transmission probability.
• C-sections can provide a method for reducing risk.

STIs Summary

• Prevention strategies (e.g., abstinence, monogamy, honest conversations) are important.
• STIs can be contracted with various methods of contact, so it's vital to use precautions if possible to reduce risk of transmission.
• Testing, condoms, and prophylaxis (if available) may be useful preventative measures.
• Fight against embarrassment, fear, and disbelief about STIs impacts the societal and personal levels of contracting STIs and being treated properly.

Viral STI—Human Immunodeficiency Virus (HIV)

• In 1981, a group of young men developed threatening infections.
• The infections appeared to be largely contained in this group and considered homosexual related.
• Retrospectively, this suggests HIV-related infections were already a global issue and were occurring in other populations.
• The lack of awareness in other populations suggested potentially unique factors, such as insurance status, which can impact diagnosis and treatment.

Pathogenesis of HIV

• Mutation rate is high, enabling rapid development of drug resistance.
• The virus hides in macrophages and dendritic cells, acting as reservoirs for the infection.
• HIV infection may integrate into the host genome.
• Opportunistic infections often occur due to immune system suppression.

Disease Progression

• The acute phase is often characterized by flu-like symptoms.
• Next is the clinical latency period, with viral levels suppressed due to CD4 lymphocytes.
• Then AIDS appears, with significant opportunistic infections.
• Death is often linked to opportunistic infections.

Pathology of HIV

• CD4 T cell count drops below 200, leading to opportunistic infections.
• AIDS-defining conditions like Kaposi sarcoma, Pneumocystis jirovecii pneumonia, Toxoplasma infections, Cryptosporidium increase.

Historical Background of HIV

• The disease emerged in the 1970s, first impacting certain communities (e.g., homosexual men).

• Initial misidentification and limited awareness in Africa may have led to the slow notice of the infection in the region.

• Tuberculosis rates may have disguised the emergence of HIV, obscuring the early rise of the virus.

• Additional information or further study suggestions from the document/text is required for further study notes.

Test your knowledge on reproductive and urinary tract infections, including their causes and mechanisms. This quiz will help you understand the differences in urinary tract anatomy between genders and the role of mucosal membranes. Learn about common infective agents and their characteristics.