Abstract
Background: Community-acquired intestinal parasitoses, including enterobiasis (Enterobius vermicularis), giardiasis (Giardia intestinalis), and hymenolepiasis (Hymenolepis nana), represent widespread parasitic diseases affecting humans worldwide, primarily in preschool and school-aged children as of result of poor personal hygiene habits and fecal-oral mode of transmission. These conditions act as important indicators for assessing societal health literacy, hygiene practices, and socioeconomic status. While mandatory parasitological screening in high-risk groups in Bulgaria increases the detection of these invasions, the post-COVID-19 resurgence reveals ongoing public health challenges. This paper reviews global literature and analyzes national surveillance data to examine the prevalence rates between 2020 and 2024.
Materials and Methods: The data were obtained from annual reports of Regional Health Inspectorates (RHI), Independent Medical Diagnostic Laboratories (IMDL), the National Center for Infectious and Parasitic Diseases (NCIPD), and the National Center of Public Health and Analyses (NCPHA) within the period of 2020 and 2024. The prevalence rate was estimated using the following equation: [(Number of diagnosed cases × 100) / Total number of examined persons] for enterobiasis; the incidence was calculated via the formula: [(Number of diagnosed cases × 100,000)/(Annual population)] for giardiasis and hymenolepiasis. Statistical methods used include descriptive statistics, Mann-Whitney U test for sex and age differences, and Kruskal-Wallis test for age groups at p < 0.05.
Results: Enterobiasis prevalence decreased during the pandemic period (2020–2022), however it increased above pre-pandemic levels by 2024 (1.73%), with highest rates in preschoolers and districts like Yambol (6.89%). The annual giardiasis incidence rose from 7.2 to 12.1 per 100,000, predominantly in children aged 0–19 years (76.8%; p=0.0079), with peaks in Yambol and Sliven. Hymenolepiasis incidence averaged 1.42 per 100,000, exhibited differences according to age groups (87.7% preschoolers; p=0.0010) and was concentrated in seven districts. The vulnerable demographic group across parasitoses was children, aligning with global patterns, though adult cases raised concerns.
Conclusions: The prevalence of community-acquired parasitic infections in Bulgaria continues to be an important problem, as post-pandemic increase in incidences indicates effective surveillance but inadequate control measures such as pharmacological treatment and case isolation. Effective health education and improved hygiene, along with medication availability, are essential in limiting the spread of these diseases, especially in children.