Background: The impact of infectious agents, such as Toxoplasma gondii (T. gondii),
on human behavior and mental disorders, has recently attracted the attention of researchers. T. gondii
has emerged as a suitable candidate for such disorders due to its neutral nature. Therefore, the
current study aimed at investigating the possible relationship between T. gondii infection and headache.
Methods: Five databases were thoroughly searched (up to October 4, 2019) for articles on the prevalence
of T. gondii in headache sufferers. In this study, the odds ratio (OR) and corresponding
95% confidence interval (CI) were estimated using a random effect model and forest plot to gauge
effect size and effect of each study.
Results: A total number of four articles, including one cross-sectional and three case-control
studies 2517 participants, entered the meta-analysis, out of whom, 1205 subjects were afflicted
with headache or migraine (17.67% positive for toxoplasmosis) and 1312 participants were not
(18.29% for toxoplasmosis). The results of the meta-analysis indicated a common OR of 1.59
(95% CI: 1.03-2.47) by the random effect model.
Conclusion: The obtained results of several studies have linked toxoplasmosis and headache.
Therefore, more quality studies with larger sample sizes are needed to determine the detailed association
between headache and T. gondii infection for the prevention and control of toxoplasmosis
among headache sufferers.