Tropical medicine for the General Practitioner - Cases From Peru Dr Clinton Colaco

Host: Michelle Odayan (My Health Academy)

Guest Speaker: Dr. Clinton Colaco (Infectious Diseases & Consultant Physician)

Watch the video version with slides at Spotify https://open.spotify.com/episode/4fOSlJ5aLu2ijIKhmlGTZg

Episode Overview

Join us as Sydney infectious diseases physician Dr. Clinton Colaco shares clinical pearls and fascinating case studies from his time completing the prestigious Gorgas Course in Clinical Tropical Medicine in Lima, Peru. While these cases originate in South America, their diagnostic lessons are highly relevant for any primary care clinician treating travelers, immigrants, or dealing with local tropical pathogens.

From navigating the diagnostic pitfalls of syphilis testing to removing botfly larvae, this episode equips general practitioners (GPs) with the essential skills to spot overlooked tropical diseases and ask the right social and travel questions.

High-Yield Chapter Markers

[00:00] Introduction

• Host Michelle Odayan introduces Dr. Clinton Colaco and his background.

[05:30] Case 1: Syphilis, HIV, & The "Prozone Effect"

• A 41-year-old male presents with a widespread psoriasiform rash and a negative RPR test. Dr. Colaco explains the prozone effect—how an excess of antigen-antibody complexes can cause false-negative serology in secondary syphilis—and how to overcome it with serum dilution.

[09:15] Case 2: Cryptococcal Meningitis & Bedside Eye Ultrasound

• A 26-year-old law student presents with severe headaches, seizures, and an astronomical lumbar puncture opening pressure of 136 cm H₂O. Learn how point-of-care ultrasound (POCUS) over the eye can detect optic nerve sheath thickening to screen for raised intracranial pressure.

[14:40] Case 3: Hydatid Lung Cysts (Echinococcus)

• A 20-year-old from the Bolivian border presents with hemoptysis and a massive fluid-filled cavity in his lung. Dr. Colaco outlines the Echinococcus lifecycle, its link to livestock and dogs, and the surgical management of hydatid disease.

[18:10] Case 4: Myiasis (Botflies in the Skin)

• A patient presents with painful, non-healing skin nodules. Using real-time bedside ultrasound, the team visualizes moving botfly larvae (Dermatobia hominis) beneath the skin, requiring occlusion with Vaseline to force the maggot to emerge for extraction.

[21:25] Cases 5 & 6: Pulmonary Tuberculosis vs. Bilateral Psoas Abscesses

• Why is Peru a hotbed for TB? Hint: it's all about overcrowded public transit. Dr. Colaco contrasts classic pulmonary tuberculosis with a rare presentation of bilateral psoas abscesses and spinal discitis in a non-compliant HIV patient.

[25:50] Case 7: Leprosy (Hansen’s Disease)

• A sibling pair presenting with severe facial disfigurement and thickened nerves. Dr. Colaco explains how to perform a quick slit skin smear to identify acid-fast bacilli and reviews the three-drug combination therapy.

[29:10] Case 8: Cutaneous Leishmaniasis

• How to approach a non-healing, crater-like ulcer. The key diagnostic takeaway: perform a punch biopsy on the active, raised border of the lesion (not the necrotic center) to successfully find amastigotes.

[32:45] Case 9: Leptospirosis Meningoencephalitis

• A patient with high viral load HIV presents with severe neurological symptoms linked to river exposure and rodent droppings. Discover the two-step diagnostic testing process (screening serology followed by the Microscopic Agglutination