Atypical Bacterial Infections

Question 1

What are the different types of Mycoplasma infections?

Answer 1

• M. pneumonia
• Genital Mycoplasma
  
  • M. hommitis
  • M. genitalium
  • Ureaplasma spp.

Question 2

What are the different types of Chlamydiaceae?

Answer 2

C. trachomatis

C. pneumonia

C. Psittaci

Question 3

What is the epidemiology and clinical manifestations of m. pneumoniae?

Answer 3

Epidemiology/transmission

• Especially high in 15-19 year olds
• Epidermics occurs in confined spaces
• Transmission via:
  
  • Respiratory droplets (coughing)
  • Requires close contact
  • Slow spread because bacteria divide slowly

Clinical Manifestations

Pneumonia

• After 1-3 weeks incubation insidieous onset of symptoms
  
  • Fever
  • Sore Throat
  • Hacking Cough (nonproductive but in later stages can have white or blood-specked sputum)
  • Headache
• Skin: Steven-Johnson’s and hives
• Neurological: encephalitis
• Joints: polyarthralgia and arthritis.
• Cardiac: myocarditis, pericarditis, haemolytic anaemia
  
  • Headache

Question 4

What is the epidemiology and clinical manifestations of genital mycoplasma?

Answer 4

Epidemiology:

• Colonise the vagina and cervix of adult women
  
  • much lower rate in men
• Colonisation of infants by Ureaplasma spp./M hominis as they passage through the birth canal.

Clinical Manifestations

Ureaplasma spp./M. hominis

• Simple colonisation of the vagina and cervix of adult pregnant women is not usually associated with disease
• Presence of Ureaplasma spp and to a lesser extent M. hominis in placental membrane or amniotic fluid is associated with:
  
  • Chorioamnionitis: inflammation of the chorion and amnion that surrounds the fetus
  • Preterm birth
  • Neonatal disorders (perinatal pneumonia and sepsis in preterm infants)
• Postpartum fever
• Ureaplasma spp can split urea into ammonia causing urinary stones

M. hominis

• Pelvic inflammation disease (PID)
• Pyelonephritis
• Bacterial vaginosis
• Non-gonococcal urethritis (25% of cases)

M. genitalium

• Cervicitis
• Endometritis
• PID
• Tubal infertility

Question 5

What is the clinical manifestations of the Chlamydia trachomatis?

Answer 5

1. Trachoma (chronic keratojonjunctivitis)
2. Adult inclusion conjunctivitis
3. Neonatal conjunctivitis
4. Infant pneumonia
5. Urogenital infections
   
   1. Male
   2. Female
6. Lymphogranuloma Venereum

Question 6

What are the symptoms and manifestations of trachoma? How is it transferred?

Answer 6

Chronic Keratojunctivitis

• Leading cause of blindness in endemic areas
• Predominantly affects young children
• Initially presents as follicular conjunctivitis that involves the entire conjunctiva
• Conjunctiva becomes scarred, causing the eyelids to turn inwards
• Turned in eyelashes scratch the cornea, resulting in cornea ulceration, scarring and loss of vision over time.

Transfer via:

• Eye to eye by droplets
• Contaminated hands, clothing
• Flies
• Respiratory droplets and faeces

Question 7

What is the epidemiology and clinical manifestations of adult inclusion conjunctivitis?

Answer 7

• Occurs in people aged 18-30 years
• Genital infection usually precedes eye involvement
• Transmission is thought to occur via autoinoculation and oral-genital contact
• Characterized by mucopurulent discharge; keratitis and corneal scarring over time

Question 8

Neonatal Conjunctivitis

Answer 8

• Acquired during passage of the infant through infected birth canal
• After 5-12 days of incubation:
  
  • Eyelids swell
  • Hyperemia (increase in blood flow to the infected eye)
  • Copious purulent discharge

Question 9

Infant pneumonia

Answer 9

• Onset usually 2 to 3 weeks after birth, characterised by:
  
  • Rhinitis
  • Staccato cough
  • Afebrile throughout illness
  • Radiographic signs of infection can persist for months

Question 10

Urogenital Infections

Answer 10

In women:

• 80% are asymptomatic

In men:

• Most often symptomatic
• Urethritis with purulent discharge
• Proctitis
• Reiter’s syndrome: urethritis, conjunctivitis, polyarthritis, and mucocutaneous lesions (mucocutaneous: site where skin and mucous membrane merge)

Question 11

Lymphogranuloma Venereum (LGV)

Answer 11

First stage (1 to 4 weeks after infection) characterised by:

• Painless lesion (papulae or ulcer) at site of infection (penis, urethra, scrotum, vaginal wall, endocervix, and vulva)

Second stage (1 to 4 weeks after infection) characterised by:

• Swelling and inflammation of lymph notes
• Infected lymph nodes can be painful giving rise to fluctuant buboes that enlarge and rupture
• Fever
• Chills
• Headache, myalgias, arthralgia’s

Question 12

Chlamydophilia pneumoniae

Answer 12

Epidemiology

• Spread via respiratory secretion
• Incubation period 21 days

Clinical Manifestations

• Asymptomatic infection
• Severe sore throat with hoarseness
• Pneumonia, resembling that associated with M. pneumoniae:
  
  • Acute bronchitis: inflammation of the large bronchi
  • Otitis media: middle ear infection
  • Sinusitis: inflammation of the paranasal sinuses
  • Pharyngitis: inflammation of the throat

Question 13

Chlamydophila psittaci

Answer 13

Epidemiology

• common in birds and domestic animals
  
  • Infected birds may be asymptomatic or sick
• Infection occurs through respiratory tract (usually for dried bird excrement, urine or respiratory secretions)

Clinical Manifestations

• Abrupt or slowly evolving
  
  • Occurs after incubation period of 5-14 days
• Fever
• Headache
• Arthralgia: joint pain
• Painful myalgia (especially head and neck, muscle pain)
• Severe cough (dry and hacking) sometimes mucoid sputum
• GIT symptoms: nausea, vomiting, diarrhea
• Other systemic symptoms: carditis, hepatomegaly, splenomegaly, follicular keratoconjunctivitis
• Severe, untreated cases:
  
  • Encephalitis
  • Convulsions
  • Coma
  • Death

Question 14

Legionella spp.

Answer 14

Epidemiology

• Bacteria commonly present in natural bodies of water, as well as in air conditioning cooling towers and condensers and in water systems (e.g. shower, hot tubs)
  
  • Can survive in relatively high temperatures and in the presence of disinfectants for a long period of time

Clinical Implication

• Pontiac fever
  
  • Fever
  • Chills
  • Myalgia
  • Malaise
  • Headache
  • No evidency of pneumonia
• Legionnaires’ disease (legionellosis)
  
  • More severe and causes considerable morbidity
  • Fever
  • Confusion
  • Myalgia
  • Headache
  • Diarrhoea
  • Cough (sometimes with purulent sputum)
  • Chest examination reveals focal crackles and alveolar infiltrates (patchy areas of consolidation)