Background: Several surveys have been conducted on the seroprevalence of viral infections caused by Chikungunya and West Nile viruses in humans. However, there is a paucity of studies on the seroprevalence and spread of these viruses in children. Objectives: We aimed to investigate the seropositivity of IgG antibodies against Chikungunya and West Nile viruses in a group of Iranian children aged one month to 14 years. Methods: A cross-sectional study was performed on blood samples collected from children aged one month to 14 years in Tehran who attended the outpatient clinics of a children’s hospital from March to December 2018. The serum IgG levels against Chikungunya and West Nile viruses were assessed using the ELISA technique. Results: Of 180 serum samples assessed for positivity, four (three from boys and one from girls) had positive IgG for Chikungunya and 11 (seven from boys and four from girls) had positive IgG for West Nile, causing overall seropositivity of 2.2% and 6.1% for Chikungunya and West Nile infections, respectively. Moreover, Chikungunya and West Nile viruses showed no significant association between seropositivity and sex. High seropositivity was observed predominantly in the age groups of below two years and over 10 years in Chikungunya and West Nile infections, respectively. However, the difference was not significant (P-value > 0.05). In the age group of one month to two years, all cases with positive IgG were less than six-month-old. Conclusions: The results of the seroprevalence of Chikungunya and West Nile viruses among children in Tehran showed the prevalence of these viral infections in this region. Therefore, these infections should be considered in the differential diagnosis for children with clinical symptoms of viral diseases.

: Diarrhea and vomiting with or without fever are common symptoms in children, while one of the most common clinical findings of Coronavirus disease 2019 (COVID-19) is gastrointestinal symptoms. Therefore, there is a need to develop an algorithm for dealing with a patient with gastroenteritis in the SARS-CoV-2 epidemic.

Brucellosis, with multi-organ involvement, is recognized as a zoonotic infection in Iran. This infection has multiple signs and symptoms. On the other hand, hemophagocytic lymphohistiocytosis (HLH) is described as an uncommon disorder. The secondary type of this disease may be associated with infection. However, the association between HLH and brucellosis has been rarely reported, especially in pediatric populations. Herein, we present a pediatric case of secondary HLH associated with brucellosis. Based on our findings, HLH should be considered in patients diagnosed with brucellosis with profound cytopenia and increased spleen size despite treatment.