Prevalence of Toxoplasmic Retinochoroiditis in an Australian Adult Population: A Community-Based Study

Lisia B Ferreira; João M Furtado; Jason Charng; Maria Franchina; Janet M Matthews; Aus A L Molan; Michael Hunter; David A Mackey; Justine R Smith

doi:10.1016/j.oret.2022.04.022

Prevalence of Toxoplasmic Retinochoroiditis in an Australian Adult Population: A Community-Based Study

Ophthalmol Retina. 2022 Oct;6(10):963-968. doi: 10.1016/j.oret.2022.04.022. Epub 2022 May 11.

Authors

Lisia B Ferreira¹, João M Furtado², Jason Charng³, Maria Franchina³, Janet M Matthews¹, Aus A L Molan⁴, Michael Hunter⁵, David A Mackey³, Justine R Smith⁶

Affiliations

¹ Flinders University College of Medicine and Public Health, Adelaide, Australia.
² Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
³ Centre for Ophthalmology and Visual Science, Lions Eye Institute, Perth, Australia.
⁴ Edith Cowan University, Perth, Australia; PathWest Laboratory Medicine WA, Perth, Australia.
⁵ School of Population and Global Health, University of Western Australia, Perth, Australia.
⁶ Flinders University College of Medicine and Public Health, Adelaide, Australia; Queensland Eye Institute, Brisbane, Australia. Electronic address: justine.smith@flinders.edu.au.

PMID: 35568370
DOI: 10.1016/j.oret.2022.04.022

Abstract

Purpose: Toxoplasmic retinochoroiditis is the most common clinical manifestation of an infection with the protozoan parasite, Toxoplasma gondii. Up to 50% of the human population is estimated to be infected with T. gondii; however, the epidemiology of toxoplasmic retinochoroiditis has not been widely reported. We sought to estimate the prevalence of toxoplasmic retinochoroiditis in Australia using data that were collected as part of the Busselton Healthy Ageing Study.

Design: Cross-sectional, community-based, prospective cohort study.

Participants: 5020 Australian adults (2264 men and 2756 women; age range, 45-69 years, and median age, 58 years).

Methods: Retinal color photographs, centered on the optic disc and macula, were captured using a digital retinal camera after the dilation of the pupils. Three uveitis-subspecialized ophthalmologists assessed each pigmented retinal lesion, and complete concordance of opinion was required to assign a toxoplasmic etiology. Serum T. gondii immunoglobulin (Ig)G levels were measured for those participants with retinal lesions judged to be toxoplasmic retinochoroiditis.

Main outcome measures: Prevalence of toxoplasmic retinochoroiditis.

Results: Eight participants (0.16%) had retinal lesions that were considered to have the characteristic appearance of toxoplasmic retinochoroiditis, plus detectable serum T. gondii IgG, consistent with the diagnosis of toxoplasmic retinochoroiditis. On the assumption that 23.81% of retinal lesions occur at the posterior pole, as reported in a community-based survey conducted in Brazil (Sci Rep. 2021;11:3420), the prevalence of toxoplasmic retinochoroiditis was estimated to be 0.67% or 1 per 149 persons.

Conclusions: Toxoplasmic retinochoroiditis is common in Australian adults. Efforts to quantify and address risk factors for human infection with T. gondii are justified.

Keywords: Cohort study; Ocular toxoplasmosis; Posterior uveitis; Prevalence; Toxoplasmic retinochoroiditis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Australia / epidemiology
Chorioretinitis* / diagnosis
Chorioretinitis* / epidemiology
Cross-Sectional Studies
Female
Humans
Immunoglobulin G
Male
Middle Aged
Prevalence
Prospective Studies
Toxoplasma*
Toxoplasmosis, Ocular* / diagnosis
Toxoplasmosis, Ocular* / epidemiology

Substances

Immunoglobulin G