First Age- and Gender-Matched Case-Control Study in Australia Examining the Possible Association between Toxoplasma gondii Infection and Type 2 Diabetes Mellitus: The Busselton Health Study

Abstract

An emerging field of research is starting to examine the association of infectious pathogens with type 2 diabetes mellitus (T2DM). An understudied parasite of interest is Toxoplasma gondii. Globally, very few studies have been conducted to investigate this association. Additionally, very little data exists on the prevalence of T. gondii in the general Australian population. Our group sought to determine the prevalence, association, and risk factors between T. gondii infection and T2DM from a representative Australian human population. Through a cross-sectional, age- and gender-matched case-control study, 150 subjects with T2DM together with 150 control subjects from the Busselton Health Study cohort were investigated. Sera samples were tested for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunosorbent assays. Survey-derived data were also analyzed to evaluate associated risk factors. The IgG seroprevalence was found to be 62% and 66% for the T2DM and control groups, respectively (OR:0.84; p=0.471). IgM antibodies were detected in 5% of the T2DM patients and in 10% of the controls (OR=0.51; p=0.135). There were no significant differences between male and female IgG seroprevalence rates for both groups (OR:0.88, 0.80; p=0.723). The IgG seropositivity rate increased significantly in T2DM patients aged 45-84 years in comparison to those aged 18-44 years (p<0.05), but this was not observed in the control subjects. No risk factors were associated with T. gondii seropositivity in both groups. The first Australian study of its kind found T. gondii infection in Western Australia to be highly prevalent. The results also showed that there is no serological evidence of an association between T. gondii infection and T2DM in the studied subjects. Australian health authorities should focus on raising awareness of toxoplasma infection and target T. gondii transmission control. Further studies are needed to clarify the role of T. gondii in T2DM.

Association of Chronic Toxoplasma gondii Infection with Pro-Inflamatory Cytokine Interleukin (IL)-12 Responses in Type-2 Diabetes Mellitus Patients of Bangladesh

“…The high prevalence of toxoplasmosis in the sample population could not be concluded as an association between toxoplasmosis and T2DM in our study, as the rate of prevalence of the infection did not differ significantly between T2DM patients (39.39%) and healthy controls (39.73%). Similar results were observed in the studies on Mexican, Australian, and American populations [ 9 , 12 , 13 ]. Strain differences and geographical bias may lead to altering results from the studies conducted in Middle-East countries [ 14 – 16 ].…”

“…T. gondii infection is counted as one of the “Five Neglected Parasitic Infections” by the Centers for Disease Control [ 9 ]. The rate of this infection and the vulnerability to severe cases of the disease in humans largely depends on the strain availability in a certain geographical location as well as the host's immune responses to the parasite.…”

The Probable Association between Type 2 Diabetes Mellitus and Toxoplasma gondii Infection

“…This argument might be ascribed to genetic causes and racial susceptibility differences favoring the Middle East. 27 Single nucleotide polymorphism in proinflammatory mediators (such interleukin 1, TNF, and IFN-γ) and antiinflammatory cytokines (like Interleukin 10) might be a factor in this variance. 28,29 "The cytokine system's genetics have a significant impact on a person's chance of contracting or developing an infectious or autoimmune illness".…”

Isolated cerebral toxoplasmosis 17 years post renal transplant

“…The prevalence in Australia is not well-established, although a cross-sectional study in Western Australia found an overall seroprevalence for IgG to be 66%. 1 Felines are the only known definitive hosts. Oocysts are shed in the feces.…”

“…Toxoplasma gondii is a common parasite. The prevalence in Australia is not well‐established, although a cross‐sectional study in Western Australia found an overall seroprevalence for IgG to be 66% 1 …”