Sexually Transmitted Diseases and Infections
Characteristics of Sexually Transmitted Diseases (STDs)
STDs are often difficult to diagnose because symptoms can be similar across different infections. Partner treatment is crucial, but treatment fidelity can be a challenge. Common prevention methods are essential in controlling the spread of STDs.
Hepatitis A Virus
Formalin can destroy the Hepatitis A virus, but it’s important to note that this will only remove dead virus particles.
Characteristics of the Tuberculosis (TB) Causative Agent
The causative agent of tuberculosis exhibits several characteristics:
- Resistance to host immune cells: It can resist phagocytosis by immune cells.
- High lipid content in the cell membrane: The membrane has a significant amount of fat.
- Low infective dose: Only 4 or 3 bacteria are sufficient to cause infection.
- Antibiotic resistance: It can be resistant to various antibiotics.
- Slow elimination by the immune system: The immune system struggles to eliminate the bacteria effectively.
Prevalence of STDs
The following are the prevalence rates of some common STDs:
- Chlamydia: 10%
- Ureaplasma: 10%
- Treponema pallidum (Syphilis): 1%
- Neisseria gonorrhoeae (Gonorrhea): 1%
- Papillomavirus (HPV): 16%
Tuberculosis Diagnosis and Symptoms
Tuberculosis is diagnosed through various methods:
- PPD or tuberculin skin test: This test assesses the body’s immune response to the bacteria.
- Culture: Growing the bacteria in a laboratory setting to confirm its presence.
- Smear and chest X-ray: Microscopic examination of sputum and imaging of the lungs to detect signs of infection.
Common symptoms of tuberculosis include:
- Pain
- Cough
- Low weight
- Chest pain
Sexually Transmitted Hepatitis Viruses
Hepatitis B and C can be transmitted sexually, although Hepatitis C transmission through this route is less likely.
STD Diagnosis from Vaginal Discharge
Several STDs can be diagnosed using a sample of vaginal discharge:
- Neisseria gonorrhoeae
- Chlamydia trachomatis
- Trichomonas vaginalis (or Mycoplasma hominis)
- Treponema pallidum (Syphilis) – note that this bacteria is not typically isolated from vaginal discharge, but can be detected through blood tests.
Urethritis in Men
The following agents can cause urethritis in men:
- Neisseria gonorrhoeae (Gonococcal urethritis)
- Chlamydia trachomatis (Non-gonococcal urethritis)
- Trichomonas vaginalis
- Mycoplasma and Ureaplasma
Enterococcus spp.
Enterococcus species are characterized by:
- High antibiotic resistance
- Causing hospital-acquired infections
- Causing urinary tract infections
Vaginal Discharge and Infection
Whitish and fishy vaginal discharge is likely indicative of Gardnerella vaginalis infection (bacterial vaginosis).
Signs and Symptoms of Hepatitis
Hepatitis can manifest with various signs and symptoms, including:
- Jaundice (yellowing of the skin and eyes)
- Fever
- Liver inflammation
- Elevated liver enzymes (transaminases and bilirubin)
Mechanism of Action of Griseofulvin
Griseofulvin inhibits fungal cell growth by binding to microtubules during mitosis, disrupting cell division.
Causative Agent of Tuberculosis
The primary causative agent of tuberculosis is Mycobacterium tuberculosis. Mycobacterium bovis can also cause tuberculosis, but it’s less common and typically occurs through the consumption of contaminated milk or dairy products from infected cattle.
Tuberculosis Management
Key aspects of tuberculosis management include:
- Free treatment: Treatment for tuberculosis is typically provided free of charge in many countries.
- Re-emerging public health problem: Tuberculosis is considered a re-emerging infectious disease due to factors like antibiotic resistance and the HIV epidemic.
- Directly observed therapy (DOT): Treatment often involves DOT, where healthcare workers observe patients taking their medications to ensure adherence.
- Monitored antibiotic intake: Antibiotic intake is closely monitored to prevent the development of resistance.
Intrahospital Infections
Intrahospital (nosocomial) infections are primarily caused by healthcare professionals not adhering to standard infection control practices.
Tuberculosis in AIDS Patients
Tuberculosis is a common cause of death in AIDS patients because the weakened immune system allows latent tuberculosis infection to reactivate.
Infective Dose of Mycobacterium spp.
The infective dose of Mycobacterium species, including Mycobacterium tuberculosis, can be as low as 4 bacteria.
STD Prevention
Condom use is a crucial personal measure for preventing STDs.
Syphilis Diagnosis
Several methods are used to diagnose syphilis:
- Darkfield microscopy: Examining a sample of fluid from a lesion under a special microscope to visualize the bacteria.
- PCR (Polymerase Chain Reaction): Detecting the bacteria’s DNA in a sample.
- Immunofluorescence: Using fluorescent antibodies to identify the bacteria in a sample.
- Blood tests: Detecting antibodies against the bacteria in the blood.
Zoonosis and Fungal Infections
Microsporum canis is a fungal agent that can be transmitted through zoonosis, meaning it can spread from animals (dogs) to humans and vice versa.
AIDS and Tuberculosis Risk
Patients with AIDS who have a decreased CD4 count are at a higher risk of developing tuberculosis due to their weakened immune system.
Antibiotic Requirements
Antibiotics used in both animals and humans should meet several requirements, including being effective against the target bacteria, having minimal side effects, and not being toxic to the body.
Tuberculosis Transmission
Tuberculosis can be transmitted through various routes:
- Inhalation (most common)
- Skin inoculation (rare)
- Ingestion (rare)
Mycoplasma
Mycoplasma species have unique characteristics:
- Sensitivity to beta-lactam antibiotics: They lack a cell wall, making them susceptible to these antibiotics.
- Urethritis: Mycoplasma hominis can cause urethritis.
- Hypersensitivity reactions: They can cause hypersensitivity reactions.
- Treatment options: They can be treated with antibiotics like amoxicillin, ciprofloxacin, and erythromycin.
Primary Mode of Infectious Disease Transmission
Person-to-person contact is the primary mode of transmission for many infectious diseases.
Mechanism of Action of Tolnaftate
Tolnaftate inhibits ergosterol synthesis in fungal cell membranes, disrupting membrane integrity and function.
Beta-Lactamase and Antibiotic Inactivation
Beta-lactamase enzymes can inactivate certain antibiotics, including cephalosporins like cephradine.
Broad-Spectrum Antibiotics
Amoxicillin is a broad-spectrum antibiotic that is effective against both Gram-positive and Gram-negative bacteria.
Candida albicans Infections
Candida albicans can cause various infections, including:
- Oral thrush (white patches in the mouth, common in babies)
- Vaginitis (inflammation of the vagina)
- Urinary tract infections
- Urethritis
Hepatitis Transmission through Blood Transfusion
Hepatitis B and C can be transmitted through blood transfusions, similar to their sexual transmission routes.
Intrahospital Infections
Several etiologic agents can cause intrahospital (nosocomial) infections:
- Pseudomonas spp.
- Acinetobacter spp.
- Klebsiella spp.
- Staphylococcus spp.
Tuberculosis as a Re-emerging Infection
Tuberculosis is considered a re-emerging infection because it was previously controlled through vaccination and public health measures, but factors like antibiotic resistance and HIV have led to its resurgence.
Systemic Fungal Infections in HIV Patients
Amphotericin B is an antifungal medication that is often used to treat systemic fungal infections in patients with HIV, especially those with weakened immune systems.
Pseudomonas aeruginosa Infections
Pseudomonas aeruginosa can cause various infections, including:
- Wound infections
- Burn infections
- Urinary tract infections
- Hospital-acquired infections
Viral Infection Diagnosis
Viral infections are diagnosed through various methods:
- Cell culture: Growing the virus in a laboratory setting.
- Serology: Detecting antibodies against the virus in the blood.
- PCR: Detecting the virus’s genetic material in a sample.
Occupational Risk of Infection for Healthcare Workers
Healthcare workers are at a higher risk of contracting Hepatitis B compared to other infections due to exposure to blood and bodily fluids.
Nosocomial Infections
Nosocomial (hospital-acquired) infections pose several risks:
- Risk to hospitalized patients
- Increased hospital bed occupancy
- Legal risks to healthcare workers
- Need for control measures and surveillance
Tuberculosis Characteristics
Key characteristics of tuberculosis include:
- Etiologic agents: Mycobacterium tuberculosis (primary) and occasionally Mycobacterium bovis.
- Transmission: Primarily through inhalation, rarely through ingestion or skin contact.
- Isoniazid’s mechanism of action: Inhibits the synthesis of mycolic acid, a component of the bacterial cell wall.
Staphylococcus aureus Infection Treatment
Cloxacillin is an antibiotic that is commonly used to treat infections caused by Staphylococcus aureus, especially methicillin-sensitive strains.
Nosocomial Infection Prevention
Preventing nosocomial infections involves several measures:
- Frequent handwashing
- Surveillance committees to monitor infection rates and implement control measures
- Good aseptic techniques during medical procedures
Mechanism of Action of Clotrimazole
Clotrimazole alters fungal cell membrane permeability by inhibiting ergosterol synthesis, a crucial component of the fungal cell membrane.