🧭 Bodyland Guide: Chlamydia Serotypes & Common Zoonoses
Think of infections like stories about who brings the germ and what scene it causes. Learn the cast, the scene, and the clue.
🧪 Chlamydia trachomatis — Serotypes at a Glance
A-C
“ABC = Africa, Blindness, Chronic”
“ABC = Africa, Blindness, Chronic”
- Scene: chronic eye infection → follicles & scarring.
- Outcome: trachoma → blindness in endemic African regions.
D-K
“D-K = everything else (urogenital + neonatal)”
“D-K = everything else (urogenital + neonatal)”
- Urethritis, cervicitis, PID, ectopic pregnancy risk.
- Neonates: conjunctivitis (1–2 wks after birth) & staccato cough pneumonia with eosinophilia.
- How: baby exposed during passage through infected birth canal.
L1-L3
Lymphogranuloma venereum (LGV)
Lymphogranuloma venereum (LGV)
- Small painless genital ulcers ⟶ painful swollen inguinal nodes (buboes), may suppurate.
- Treat: doxycycline.
Quick self-check
- Which serotypes cause trachoma blindness? → A-C
- Neonatal conjunctivitis at 1–2 weeks? → D-K acquired during birth.
- Painless ulcers → painful nodes (LGV)? → L1-L3
🐾 Zoonotic Bacteria — “Who brings it? What happens?”
Ixodes tick (deer/mice)
- Anaplasma → anaplasmosis
- Borrelia burgdorferi → Lyme (🧠/joint/heart; erythema migrans)
“IxoDeer tick: Ana + Borrelia.”
Dog tick (Dermacentor)
- Rickettsia rickettsii → RMSF (wrists/ankles → trunk, fever, headache)
Louse (body louse)
- Borrelia recurrentis → relapsing fever
- Rickettsia prowazekii → epidemic typhus
“Louse = Recurrent & Typhus.”
Cat bite/scratch
- Pasteurella multocida → cellulitis/osteomyelitis
- Bartonella henselae → cat-scratch disease, bacillary angiomatosis
Parrots & other birds
- Chlamydophila psittaci → psittacosis (atypical pneumonia)
Unpasteurized dairy
- Brucella → undulant fever (brucellosis)
Birth products/aerosols (cattle, sheep)
- Coxiella burnetii → Q fever (pneumonia, hepatitis; no rash)
“Q fever from the Quarry (barn) air.”
Rabbits, ticks, deer flies
- Francisella tularensis → tularemia
Animal urine in water (freshwater)
- Leptospira → leptospirosis; Weil disease (jaundice, renal failure)
Humans (contact); armadillo reservoir (rare)
- Mycobacterium leprae → leprosy
Reptiles & poultry; undercooked meat
- Salmonella (non-typhi) → inflammatory diarrhea
- Campylobacter → bloody diarrhea; GBS/reactive arthritis links
Fleas
- Yersinia pestis → plague
60-second recall quiz
- Parrot owner with atypical pneumonia? → Chlamydophila psittaci
- Hunter skin ulcer + lymphadenitis after rabbit exposure? → Francisella tularensis
- Fever + hepatitis after barn exposure, no rash? → Coxiella burnetii (Q fever)
- Dog-tick hiking → petechial rash wrists/ankles? → R. rickettsii
- Camping, wading through water, jaundice + renal failure? → Leptospira (Weil)