Analysis of Reported Cases of Giardia lamblia and Cryptosporidium spp. Infection in Children from Aragón (Northeast Spain) During the Period (2012–2021)

Giardiasis and cryptosporidiosis, caused by Giardia lamblia and Cryptosporidium spp., are parasitic infections transmitted through faecal&ndash:oral routes or contaminated water. Although less common in Spain compared to developing countries, they pose a public health concern, particularly for vulnerable groups like children and immunocompromised individuals. This study aims to analyse the cases reported to the Microbiological Information System (MIS) in children between 2012 and 2021, as well as their distribution across sociodemographic variables. Proportions and infectivity rates were determined for epidemiological and sociodemographic data, and the incidence rate for giardiasis and cryptosporidiosis was calculated annually and by health sector. The variables analysed included sex, age, health sector and weather. For both diseases, there was a significant decrease in the number of cases in 2020, suggesting the importance of person-to-person transmission. Children were infected by Giardia in significantly higher proportion (p &lt: 0.001), being the majority in age groups 5&ndash:14 years, while the proportion of boys and girls infected by Cryptosporidium was almost identical (1.4% vs. 1.3%), in children aged 2&ndash:4 years. Periodically there was a significant increase in cases of cryptosporidiosis, apparently related to the presence of torrential rains. Transmission is related to increased temperature and rainfall. Person-to-person transmission in the paediatric population needs further investigation. This study provides the foundation for future research on the evolution of cases of giardiasis and cryptosporidiosis in Spanish children. The data emphasise the need for informational campaigns on hygienic measures and efforts by public health authorities to maintain water resources in optimal condition to prevent parasite spread.