ABSTRACT
<b>Background and Objective:</b> In recent years, respiratory tract viral infections have caused many pandemics that impact the whole world. To investigate the seropositivity of <i>Toxoplasma gondii</i>, rubella, CMV, HSV-1 and group A <i>Streptococcus</i> in recovered COVID-19 patients and correlate these findings with vitamin D levels. <b>Materials and Methods:</b> A total of 417 COVID-19 patients with diarrhoea were enrolled in this study. Vitamin D and seroprevalence for <i>Toxoplasma gondii</i>, rubella, CMV, HSV-1 and group A <i>Streptococcus</i> were evaluated and correlated. <b>Results:</b> It was found that recent infection in COVID-19 patients with HSV-1, rubella, <i>Toxoplasma</i> and CMV, respectively. IgG was detected indicating the development of adaptive immunity with all microbes. <b>Conclusion:</b> Current study detected a correlation between vitamin D levels and HSV-1 and no correlation between this infection and vitamin D deficiency with the other microbes.