Toxoplasma gondii (T. gondii) is an obligate intracellular parasite capable of infecting warm-blooded animals, specially in humans and domestic animals (1). Infection with T. gondii in healthy individuals is often mild, while in immunocompromised patients causes a serious disease (2). Type 1 diabetes mellitus (T1DM) is an autoimmune disease, in which insufficient or no insulin is produced (3). In fact, the exact causes of T1DM are still controversial; however, it is apparent that environmental and genetic factors, as well as infectious agents are involved (3, 4). According to evidence, infection with T. gondii is more common in diabetic patients (5). Therefore, this study aimed to determine the seroprevalence rate of T. gondii infection in T1DM patients and its associated risk factors in Abadan, southwest Iran.
In this cross-section study, we included 41 patients with T1DM referred to Taleghani hospital in Abadan from December 2019 to March 2020. Written informed consent was obtained from all participants, and a questionnaire including demographic information was filled out, as earlier described (6, 7). To evaluate IgG antibody against T. gondii infection, 5 mL of blood sample was collected from each subject. The samples were centrifuged at 1700×g for four minutes and then stored at -20°C until use. To detect IgG antibodies against T. gondii infection, we used commercial ELISA kit (Torch-IgG -Trinity Biotech Company) based on the manufacturer’s guideline, as previously performed (7, 8). Data were analyzed by SPSS software (version 21), and the P value less than 0.05 was considered as statistically significant.
Overall, the seroprevalence of T. gondii infection in T1DM subjects was 68.29% (28 out of 41). The demographic characteristics and risk factors related to seroprevalence of T. gondii in T1DM patients was presented in Table 1. Out of 41 patients with T1DM (24 female vs. 17 male), 16 female participants (66.66%) and 12 male patients (70.58%) had IgG antibody against T. gondii. No statistically significant difference was observed between T1DM and T. gondii infection according to gender (P = 0.79). In terms of residence, 20 (66.66%) patients living in urban areas and eight (72.72%) patients living in rural areas were positive for IgG antibody. Among the risk factors, there was only statistically significant association between IgG seroprevalence and contact with cat (P = 0.009) (Table 1).
|Characteristic||Type 1 DM (N= 41)||P-Value|
|No. Tested||IgG Positive, No. (%)|
|0 - 10||7||4 (57.14)|
|11 - 20||10||7 (70.00)|
|21 - 30||13||9 (69.23)|
|31 - 40||11||8 (72.72)|
|Diploma or lower||29||21 (72.41)|
|University degree||12||7 (58.33)|
|Contact with cat||0.009|
|Source of drinking water||0.501|
|Unpurified water||8||6 (75.00)|
|Purified water||33||22 (66.66)|
|Consumption of raw/ undercooked meat||0.581|
In general, previous reports have shown that toxoplasmosis develops susceptibility to DM, and diabetic patients are more sensitive to be infected with T. gondii (5, 9). This study aimed to evaluate anti- T. gondii IgG antibodies among T1DM patients using ELISA method. The results of the present study demonstrated that 28 subjects (68.29%) were seropositive. In accordance with our results, Soltani et al. reported that the seroprevalence of T. gondii infection in T1DM patients was 69.4% in Khorramshahr, southwest Iran (6). In addition, Nassief Beshay et al. reported 86.37% seropositivity rate of anti- T. gondii IgG among T1DM patients (10). The probable risk factors of T. gondii infection in all participants were assessed in the current study. According to the results, there was only a statistically significant difference between contact with cats and IgG seroprevalence. This study confirmed some previous reports highlighting the importance of cats in acquiring T. gondii infection (6, 7, 11).
In conclusion, the present study revealed a relatively high seroprevalence of T. gondii infection among T1DM patients in Abadan, southwest Iran. Since the T1DM patients are among susceptible groups to acquire toxoplasmosis, they should be examined regularly for T. gondii to avoid severe infection. In addition, preventive programs, improving the knowledge of T1DM patients about infection with T. gondii, as well as effective control efforts must be performed.
Wang ZD, Liu HH, Ma ZX, Ma HY, Li ZY, Yang ZB, et al. Toxoplasma gondii Infection in Immunocompromised Patients: A Systematic Review and Meta-Analysis. Front Microbiol. 2017;8:389. doi: 10.3389/fmicb.2017.00389. [PubMed: 28337191]. [PubMed Central: PMC5343064].
Krause I, Anaya JM, Fraser A, Barzilai O, Ram M, Abad V, et al. Anti-infectious antibodies and autoimmune-associated autoantibodies in patients with type I diabetes mellitus and their close family members. Ann N Y Acad Sci. 2009;1173:633-9. doi: 10.1111/j.1749-6632.2009.04619.x. [PubMed: 19758209].
Majidiani H, Dalvand S, Daryani A, Galvan-Ramirez ML, Foroutan-Rad M. Is chronic toxoplasmosis a risk factor for diabetes mellitus? A systematic review and meta-analysis of case-control studies. Braz J Infect Dis. 2016;20(6):605-9. doi: 10.1016/j.bjid.2016.09.002. [PubMed: 27768900].
Soltani S, Tavakoli S, Sabaghan M, Kahvaz MS, Pashmforosh M, Foroutan M. The Probable Association between Chronic Toxoplasma gondii Infection and Type 1 and Type 2 Diabetes Mellitus: A Case-Control Study. Interdiscip Perspect Infect Dis. 2021;2021:2508780. doi: 10.1155/2021/2508780. [PubMed: 34122541]. [PubMed Central: PMC8169249].
Soltani S, Kahvaz MS, Soltani S, Maghsoudi F, Foroutan M. Seroprevalence and associated risk factors of Toxoplasma gondii infection in patients undergoing hemodialysis and healthy group. BMC Res Notes. 2020;13(1):551. doi: 10.1186/s13104-020-05396-5. [PubMed: 33287882]. [PubMed Central: PMC7720589].
Soltani S, Ghaffari AD, Kahvaz MS, Sabaghan M, Pashmforosh M, Foroutan M. Detection of Anti-Toxoplasma gondii IgG and IgM Antibodies and Associated Risk Factors during Pregnancy in Southwest Iran. Infect Dis Obstet Gynecol. 2021;2021:5547667. doi: 10.1155/2021/5547667. [PubMed: 34135564]. [PubMed Central: PMC8175175].
Molan A, Nosaka K, Hunter M, Wang W. The association between Toxoplasma gondii and type 2 diabetes mellitus: a systematic review and meta-analysis of human case-control studies. Bull Natl Res Cent. 2020;44(1). doi: 10.1186/s42269-019-0256-x.
Nassief Beshay EV, El-Refai SA, Helwa MA, Atia AF, Dawoud MM. Toxoplasma gondii as a possible causative pathogen of type-1 diabetes mellitus: Evidence from case-control and experimental studies. Exp Parasitol. 2018;188:93-101. doi: 10.1016/j.exppara.2018.04.007. [PubMed: 29627328].
Dubey JP, Cerqueira-Cezar CK, Murata FHA, Kwok OCH, Yang YR, Su C. All about toxoplasmosis in cats: the last decade. Vet Parasitol. 2020;283:109145. doi: 10.1016/j.vetpar.2020.109145. [PubMed: 32645556].