Rachel Fieldhouse A TICK bite on a man’ s scrotum led doctors down a diagnostic rabbit hole that eventually resulted in the second human diagnosis of babesiosis in Australia.

The 62-year-old from the US originally presented to the ED at Royal Darwin Hospital after six days of febrile illness, including headache, fatigue, malaise and anorexia.

The man’ s symptoms had first occurred after he returned from a safari in West Arnhem Land.

In the days before the safari, he recalled a stinging sensation in his groin and had removed a suspected tick from his scrotum.

On examination he was febrile( 39 ° C) and had a 2x2mm scrotal punctum, the hospital doctors wrote in their case report in The Medical Journal of Australia.

Pathology showed pancytopenia, inflammation and intravascular haemolysis, while splenomegaly was observed on a CT scan.

He was treated with ceftriaxone

and doxycycline, adding IV artesunate after blood film investigations revealed intracellular parasitosis.

“ The differential diagnosis for this patient’ s presenting illness was expanded [ because of ] his birding trips in Costa Rica, Mexico, Panama and Belize,” the doctors said.

A six-month incubation period led them to rule out arboviral infections such as zika, chikungunya, yellow fever and West Nile virus.

But testing for malarial antigens, rickettsiosis, leptospirosis and a

PCR for mosquito-borne diseases all returned negative results.

Five days after his initial ED presentation, the man was discharged to a hotel before going on to make a full recovery.

The clinical mystery was finally solved two months later, when whole genome sequencing, microscopy and PCR testing confirmed he had a Babesia microti infection, from an Ixodes scapularis tick, also known as the black-legged or deer tick.

It turned out that between his

birding trips to South America and his holiday in Australia, the man had gone on a camping trip in Maine— one of the top four US states for babesiosis cases— at a time which coincided with the peak season for infection.

The tick-borne disease is thought to be rare in Australia, with the only other human case reported in 2012.

Med J Aust 2025; 17 Mar. Med J Aust 2012; 19 Mar.

Rachel Fieldhouse THE GP credited with saving the RACGP from financial ruin 20 years ago will be Australia’ s next Chief Medical Officer.

Professor Michael Kidd starts the job on 1 June, following Professor Paul Kelly’ s retirement back in October.

The RACGP president from 2002 to 2006, Professor Kidd led the college out of the biggest financial crisis in its history.

He was then WONCA president from 2013 to 2016, and federal Deputy Chief Medical Officer at the height of the COVID-19 pandemic, when his webinars for GPs became appointment viewing as they tried to stay on top of public health orders and the vaccine rollout.

He also founded the Journal of Medical Case Reports.

In 2023, he received an AO for distinguished service to medical administration, community health, tertiary education and primary care leadership.

At the time, he told Australian Doctor he had zero hesitation taking a high-pressure public role during the pandemic.

But he said the experience that had stuck with him the most was working during the 1980s AIDS epidemic.

“ I treated a significant number of people with HIV and then got to see one of the great miracles of modern medicine— the introduction of effective triple therapy in 1995,” he said.

“ That was an extraordinary moment to live through as a clinician.”

Professor Michael Kidd.