Evidence map›Paper›PMID 42464509›Full record

ArticleZoonoses and public health2026

Occurrence and Diversity of Cryptosporidium spp. and Giardia duodenalis in Animals in Portugal: Novel Data and Public Health Implications.

Mariana Louro, João Lozano, Patrícia Lopes, Paulo Alves, Margarida Garret, Carolina Vale, Rui Bernardino, Francisco Petrucci-Fonseca, João Vieira, Leticia Duarte and 6 more

Abstract read
In one paragraph

Article in Zoonoses and public health, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors.

Mariana LouroCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.ORCID https://orcid.org/0000-0002-5668-745X
João LozanoCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.ORCID https://orcid.org/0000-0001-5390-6998
Patrícia LopesInstituto Nacional de Investigação Agrária e Veterinária (INIAV), Oeiras, Portugal.ORCID https://orcid.org/0000-0002-9962-2170
Paulo AlvesCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.ORCID https://orcid.org/0009-0000-7512-8285
Margarida GarretCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.
Carolina ValeCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.
Rui BernardinoLisbon Zoo, Veterinary Hospital, Lisbon, Portugal.ORCID https://orcid.org/0000-0001-6592-3920
Francisco Petrucci-FonsecaCenter for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal.
João VieiraCenter for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal.
Leticia DuarteCenter for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal.
Erica BrazioLisbons' Wildlife Rehabilitation Center (LxCRAS), City Council of Lisbon, Forest Park of Monsanto, Lisbon, Portugal.
Ana Filipa LopesLisbons' Wildlife Rehabilitation Center (LxCRAS), City Council of Lisbon, Forest Park of Monsanto, Lisbon, Portugal.ORCID https://orcid.org/0000-0002-3086-6222
Teresa Letra MateusCenter for Research and Development in Agrifood Systems and Sustainability (CISAS), Escola Superior Agrária de Ponte de Lima, Instituto Politécnico de Viana do Castelo, Ponte de Lima, Portugal.ORCID https://orcid.org/0000-0003-1236-3012
Luís Madeira de CarvalhoCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.ORCID https://orcid.org/0000-0002-7548-667X
Isabel Pereira da FonsecaCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.ORCID https://orcid.org/0000-0002-6632-1224
Jacinto GomesCentre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.ORCID https://orcid.org/0000-0003-2543-8335

Funding

Fundação para a Ciência e a Tecnologia 2020.09037.BDFundação para a Ciência e a Tecnologia 2021.09447.BDFundação para a Ciência e a Tecnologia LA/P/0059/2020Fundação para a Ciência e a Tecnologia UI/BD/152818/2022Fundação para a Ciência e a Tecnologia UID/05937/2025Fundação para a Ciência e a Tecnologia UIDB/00276/2020Fundação para a Ciência e a Tecnologia UIDB/00276/2025
6 · The paper itself

Abstract

introductionCryptosporidium spp. and Giardia duodenalis are common intestinal protozoa with zoonotic potential, affecting a broad range of domestic and wild animals. In Portugal, knowledge on their occurrence and genetic diversity remains fragmented. This study integrates new molecular results from multiple animal groups with a comprehensive review of published national data to establish an updated baseline for these parasites within a One Health framework.

methodsA total of 805 faecal samples from 91 animal species were analysed, including domestic (n = 192 samples), captive (n = 283) and wild (n = 330) hosts. Detection was performed by modified Ziehl-Neelsen and direct immunofluorescence assays; samples that were positive or doubtful after microscopic screening were further subjected to nested PCR and sequencing targeting SSU rRNA, gp60 (for C. parvum), and gdh, bg and tpi (for G. duodenalis). Newly generated sequences were compared to GenBank references and compiled with data from 29 Portuguese studies published between 2001 and 2025.

resultsOverall, Cryptosporidium spp. were detected in 11/805 samples (1.4%) and G. duodenalis in 101/805 (12.5%). Detection rates of Cryptosporidium spp. were 3.6% (7/192) in domestic, 0.0% in captive, and 1.2% (4/330) in wild animals, while Giardia spp. occurred in 18.8% (36/192), 8.5% (24/283), and 12.4% (41/330), respectively. Molecular analysis revealed C. parvum (IIaA19G2R1 in Iberian wolf, and IIcA5G3 in hedgehogs), C. canis, and C. cuniculus. Moreover, G. duodenalis assemblages were diverse, including assemblage E in ruminants, D in canids and felids, B in rabbits, lemurs, cheetahs and suricates, F in lions, and E and B co-occurring in suricates and raccoons. The compiled dataset from available Portuguese studies included 3741 animals tested for Cryptosporidium spp. and 3353 for Giardia spp., providing a descriptive overview of host and genotype diversity across the country.

conclusionsThis study provides the first integrated overview of Cryptosporidium spp. and G. duodenalis occurrences in animals across the Portuguese territory. The findings demonstrate that livestock, pets, zoo animals, and free-ranging wildlife can contribute to the circulation of these protozoan parasites, emphasizing the importance of harmonized molecular surveillance and integrated One Health strategies for early detection and control.

Indexed as

CryptosporidiosisCryptosporidiumGiardia lambliaGiardiasisAnimalsAnimals, DomesticAnimals, WildFecesGenetic VariationHumansPortugalPublic HealthZoonosesenvironmental transmissionepidemiological surveillancemolecular typingOne Healthpublic healthwildlife surveillancezoonotic protozoa

Identifiers

PMID42464509
PMCPMC13535718

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.