Background: There is a close association between problematic Internet use (PIU), sleep quality, and mental health problems. To evaluate which mental health problem is more associated with coexistence of both PIU and poor sleep quality, we hypothesized a model in which PIU influences sleep quality directly and also through the mediation of three different mental health problems. Methods: A total of 402 medical students completed the Persian versions of the Internet Addiction Test, 21-item Depression Anxiety Stress Scale, and Pittsburgh Sleep Quality Index. A maximum likelihood structural equation model was used to assess the hypothesis. For assessment of the indirect effects, bootstrapping was conducted. Results: PIU predicted poor sleep quality through indirect pathways by the mediation of mental health problems (P < 0.001). Poor sleep quality were associated with depressive symptoms (P < 0.001), anxiety (P = 0.035), and stress (P < 0.001); however, the direct pathways from stress and anxiety to poor sleep quality were not statistically significant (P > 0.05). Conclusion: Findings extend our previous knowledge about the interrelationships between PIU, sleep disturbances, and mental health problems by unveiling the key role of depressive symptoms.

Background Human toxocariasis is caused by the larval stage of Toxocara canis and Toxocara cati. This cross-sectional study was conducted to evaluate the seroprevalence and the risk factors associated with Toxocara infection in nomads of Boyer-Ahmad County in the southwest of Iran. Methods A total of 968 blood samples were collected from nomads. A structured questionnaire, containing sociodemographic data, was completed for each participant. Sera were evaluated for anti-Toxocara antibodies, using the T. canis excretory-secretory antigens prepared from the second stage larvae, in an ELISA system. Results Among the 968 participants, 220 (22.7%) were males and 748 (77.3%) were females; the mean age was 40.71 y. Anti-Toxocara IgG antibodies were detected in 14 (1.4%) of the 968 nomads. The association between Toxocara infection and gender, age, contact with dogs, residential area and level of education were not statistically significant (p&gt;0.05). Conclusions The findings of the study revealed a low prevalence rate of toxocariasis in nomadic communities in southwest Iran. Geographic location and climatic conditions as well as the lifestyle and sociodemographic features of the participants may contribute to the low prevalence rate of Toxocara infection.