Viral Conjunctivitis and Trachoma Quiz

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Questions and Answers

Which of the following is a viral cause of conjunctivitis?

Adenovirus (correct)

H. pylori

Chlamydia trachomatis

Neisseria gonorrhoeae

What type of viruses are Enterovirus and Coxsackie virus A24 classified as?

Naked ss RNA viruses (correct)

Enveloped ss RNA viruses

Enveloped ds RNA viruses

Naked ds DNA viruses

Which of the following infections can transmit the virus through both direct and indirect contact?

COVID-19 (correct)

H. influenzae

Chlamydia trachomatis

Neisseria gonorrhoeae

Which of the following systemic viral infections is NOT transmitted through direct or indirect contact?

Hepatitis B Signup and view all the answers

What does auto-inoculation from a genital infection refer to?

Self-transmission of an infection to another body part Signup and view all the answers

Which immunotypes of trachomatis are primarily responsible for causing trachoma?

Types A, B, and C Signup and view all the answers

What type of infections do types D-K of trachomatis primarily cause?

Genital tract infections Signup and view all the answers

In which regions is trachoma primarily found?

Dry hot regions such as North Africa Signup and view all the answers

How can inclusion conjunctivitis occur due to trachomatis types D-K?

Through autoinoculation Signup and view all the answers

How many immunotypes of trachomatis are recognized based on specific protein antigens?

15 Signup and view all the answers

What laboratory method is NOT typically used for diagnosing trachomaitis infections in Egypt?

Serology Signup and view all the answers

Which stain would you use to detect glycogen-filled inclusions in cases of trachomaitis infections?

Iodine stain Signup and view all the answers

Which of the following statements is true regarding the diagnosis of trachomaitis infections?

Cytoplasmic IBs can be visualized using Giemsa stain. Signup and view all the answers

What is a key characteristic of serology in the context of trachomaitis infections in Egypt?

It is not used due to the high infection rate. Signup and view all the answers

Which method can be used to detect cytoplasmic inclusion bodies associated with trachomaitis infections?

Giemsa stain Signup and view all the answers

Signup and view all the answers

Study Notes

Eye Infections

Normal Eye Microbiota: Staph. epidermidis, Lactobacillus spp., and P. acnes
Eye Defense Mechanisms: Eyelashes, blinking (15-20 times/minute), secretions from lacrimal glands and goblet cells washing away bacteria and foreign matter, lysozyme and IgA in tears
Lid Infections (Etiology: Staph. aureus):
- Types: Lid margin infection (blephritis), Lid gland & follicle infection (sty)
- Clinical Presentation: Irritation, redness, burning, itching
Conjunctivitis (Etiology):
- Bacterial: Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella species, N. gonorrhoeae, and C. trachomatis
- Viral: HSV-1, Adenovirus, Enterovirus, Coxsackie virus A24, systemic viruses like measles, mumps, rubella, chickenpox, COVID-19
- Transmission: Direct and indirect contact, auto-inoculation from genital infections.
Types of Conjunctivitis: HSV, Pharyngo-conjunctival fever (PCF), trachoma, ophthalmia neonatorum

Keratitis

Etiology:
- Bacterial: Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa
- Viral: HSV-1, Adenovirus, Varicella Zoster Virus (VZV)
- Fungal: Fusarium solani
Clinical Presentation: Corneal irritation, pain, lacrimation, photophobia, gritty feeling, dendritic branching ulcer (in HSV), vesicles (in VZV)

Herpes Simplex Virus (HSV)-1 Keratitis

Structure: Enveloped ds DNA virus
Pathogenesis: Latent infection in trigeminal ganglia reactivates in immunosuppressed hosts, causing dendritic branching ulcer, repeated infections leading to scarring and blindness
Treatment: Topical and oral acyclovir

Epidemic Keratoconjunctivitis (EKC), "Adenovirus 8 & 19"

Structure: Non-enveloped ds DNA Viruses, type 8 and 19 adenoviruses causing EKC which is among the most serious adenoviral eye infections
Mode of Transmission: Close personal contact, use of non-sterile ophthalmic instruments

Herpes Zoster Ophthalmicus ("VZV")

Pathogenesis: Latent infection in trigeminal ganglia, reactivates in immunosuppressed hosts, causes unilateral painful vesicles and keratitis, conjunctivitis, and iritis
Treatment: Oral acyclovir only

General Characteristics of Important Bacterial Agents

Staphylococcus aureus: Gram-positive cocci, coagulase-positive, beta-hemolytic on blood agar, mannitol fermenter, golden yellow colonies
Streptococcus pneumoniae: Gram-positive cocci, catalase-negative, alpha-hemolytic on blood agar, optochin & bile sensitive
Haemophilus influenzae: Small gram-negative coccobacilli, requiring factors X and V for growth on laboratory media
Neisseria gonorrhoeae: Gram-negative diplococci, oxidase-positive
Pseudomonas aeruginosa: Gram-negative bacilli, aerobic, oxidase-postive, produces blue-green pigment (pyocyanin and pyoverdine) on nutrient agar

Infections of the Deeper Layers of the Eyes

Causes: Traumatic injury, blood-borne infections (opportunistic, in utero infections, CMV causes chorioretinitis in AIDS patients, ocular complications of West Nile virus)
Diagnosis: Conjunctival swab or corneal scrapings, blood and chocolate agar plates (incubated under 5% to 10% CO2), Gram stained films, biochemical tests, and PCR for viral infections.

Otitis Externa (External Ear Infections)

Causes: Pustule or furuncle (typically Staphylococcus aureus), acute diffuse (often swimmers ear, with Pseudomonas aeruginosa and other gram-negatives), malignant (necrosis with Pseudomonas aeruginosa and anaerobes).
Clinical Presentation: Often seen in patients with diabetes (malignant progression)
Pathogenesis: Damage and maceration (softening of tissues) is key in the acute diffuse form.
Diagnosis: Primarily clinical; culture of discharge, aspirate of middle ear fluid if possible.
Treatment: Antimicrobials (follow-up crucial due to risk of chronic otitis)

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Description

Test your knowledge on viral causes of conjunctivitis and the infections related to trachomatis. This quiz covers various aspects, including transmission, immunotypes, and prevalence of trachoma. Answer the questions to enhance your understanding of these ocular infections.