Cryptosporidium spp. in Argentina: epidemiology and research advances in human, animal, and environmental settings during the 21st century

Abstract

Introduction: Cryptosporidium spp. is an intestinal protozoan causing cryptosporidiosis, a diarrheal disease affecting humans and animals, with zoonotic potential. In immunocompromised individuals, infections can be severe or fatal. It is a major waterborne parasite and a leading cause of neonatal diarrhea in calves. This study systematically reviews Cryptosporidium spp. research in Argentina during the 21st century, highlighting its epidemiological significance and research gaps.

Methods: A systematic review following PRISMA guidelines was conducted using LILACS, PubMed, Scopus, and SciELO Argentina. Eligible studies (2001-2024) included human (community and hospital-based), animal (domestic, wild, and captive), and environmental (water, soil and vegetable) surveys. The review analyzed epidemiology, diagnosis, treatment, genetic diversity, distribution, and risk factors.

Results: Of 277 articles reviewed, 66 met eligibility criteria. Cryptosporidium spp. was detected in 17 of Argentina's 23 provinces, mainly in the Pampean region. Five species were identified (C. hominis, C. parvum, C. suis, C. scrofarum, and C. varanii), though genetic diversity studies remain limited. Human cryptosporidiosis primarily affects immunocompromised individuals (HIV/AIDS, transplant recipients, hematologic cancer patients). The parasite was found in feces, duodenal biopsies, blood, sputum, and cerebrospinal fluid, with complications such as cholangiopathy and pulmonary cryptosporidiosis. Infections with C. hominis and C. parvum (including co-infections) were observed, with multiple subtypes documented. In animals, C. parvum was prevalent in Pampean calves, while C. suis and C. scrofarum were found in domestic pigs. Wildlife, including non-human primates and coypu, also tested positive. Cryptosporidium was detected in recreational and drinking water samples. No Cryptosporidium spp. oocysts were detected in soil. Risk factors included socio-economic conditions and animal management practices.

Conclusion: Cryptosporidium spp. is widely distributed in Argentina, yet eco-epidemiological transmission factors remain poorly understood, hindering control strategies. Limited research on genetic diversity and distribution highlights the need for further studies, particularly in vulnerable populations and areas of close human-animal interaction, such as productive systems. The presence of Cryptosporidium spp. in water underscores the importance of improving public health policies and water treatment standards. From a One Health perspective, these findings emphasize the need for enhanced epidemiological surveillance and research to strengthen prevention and control in Argentina.

Keywords: Cryptosporidium; diagnostic techniques; human-animal and environmental health; one-health; prevalence; regional variations; risk factors; zoonotic potential.

Figure 1

PRISMA flowchart filled with final data. The strategy used for study inclusion in the final analysis is summarized (Moher et al., 2015).

Figure 2

Geospatial distribution of eligible publications across Argentina, overlaid on population density based on the 2020 national census and regional divisions defined by the National Institute of Statistics and Censuses (INDEC, 2022). Red circles indicate the total number of studies published between 2001 and 2024 in each region. Side panels disaggregate the data by study type (human, animal, laboratory, and environmental), with markers identifying specific study locations and the number of studies per category. This spatial visualization highlights geographic disparities in research efforts, with a clear concentration of studies in more densely populated central regions and limited research activity in the northwestern and Patagonian areas. These patterns underscore existing research gaps and the need for broader territorial coverage in future investigations.

Figure 3

Temporal distribution of publications on Cryptosporidium spp. in Argentina from 2001 to 2024, categorized by study setting (human, animal, laboratory, environmental) and grouped into five-year intervals. This timeline illustrates trends in research output over the 21st century, beginning with a low number of studies and showing a marked increase starting in the 2011–2015 period, with the sharpest rise observed from 2016 to 2020. The chart also highlights differences in focus by setting, with human and animal studies being more consistently represented, while environmental and laboratory studies appear more sporadically. These dynamics reflect the growing scientific interest in Cryptosporidium spp., influenced by advances in detection methods and increased awareness of its relevance in One Health frameworks.

Figure 4

Map of studies on Cryptosporidium spp. prevalence by epidemiological setting. Human: from left to right – community-based, indigenous community surveys, hospital-based studies. Animals: from left to right – domestic animals, farm animals, pets, synanthropic animals, and wild animals. Laboratory: experimental studies and genotype investigations. Environmental: vegetable and water surveys. Original icons created by the authors and by Prayudawanto, ProSymbols, Athok, Evon, Salman Azzumardi, Sandra, Adrien Coquet, Kosong Tujuh, and Pramana from the Noun Project.