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An Irish perspective

Giardia and Cryptosporidium in Ireland

Explore Irish notification data and the everyday prevention of two waterborne intestinal infections.

2 minute read8 sourcesStreszczenie PL ↓

Local data, with the denominator kept honest

HPSC recorded 525 cryptosporidiosis notifications and 372 giardiasis notifications for 2025 in the national 2020–2025 table extracted on 24 August 2026. The report marks 2025 figures as provisional. These are reported notifications, not the number of all infections, and not a percentage of residents carrying parasites. The earlier quarterly publication listed 373 giardiasis notifications; the later annual extract is used here. P02 P03

YearCryptosporidiosis notificationsGiardiasis notifications
2020511163
2021845160
2022566261
2023870324
2024640362
2025525372

Changes over time can reflect exposure, testing and reporting. This chart cannot by itself explain why a year rose or fell. It also cannot quantify an individual's risk. P02

HPSC notifications: cryptosporidiosis 511, 845, 566, 870, 640, 525; giardiasis 163, 160, 261, 324, 362, 372.

Source: HPSC, Table 1; CIDR extract 24 August 2026. 2025 provisional. Notifications are not prevalence or a count of all infections. No causal trend is inferred.

[P02] · Download chart data (CSV) · Open full size ↗

Giardia cysts can pass from faecal contamination to another person's mouth. After ingestion, the organism develops in the small intestine. Some infections are asymptomatic; others cause diarrhoea, greasy stools, cramps and bloating. Laboratory confirmation and symptom context guide care. P04 P08 P26

Cryptosporidium also spreads through contaminated water, hands and environments, including contact with animals. It can cause prolonged watery diarrhoea. People with weakened immune systems can become seriously ill. Hydration matters, and treatment decisions depend on the patient and clinical setting. P23 P24

Giardia duodenalis cyst in a wet mount, differential interference contrast microscopy at 1000 times magnification.

G. duodenalis cyst, DIC microscopy, 1000×. CDC DPDx. Original diagnostic image; not AI-generated.

CDC DPDx · Public-domain CDC DPDx material; attribution retained · Original · Open full size ↗

An everyday prevention checklist

Wash hands with soap and water after the toilet, changing nappies and handling animals, and before preparing food. Do not assume clear river or lake water is safe to drink. Follow public-health advice for drinking-water incidents and recreational water. Avoid swallowing swimming water. Alcohol hand gels do not reliably inactivate Cryptosporidium. P23

Recurrent symptoms after Giardia treatment need a structured review. Demonstrating whether infection is still present is more informative than switching between untested supplements. Medicines used in US guidance should not be presented as proof of Irish availability or an Irish prescription recommendation. P27

Sources & access limits

Results remain specific to the preparation, study population and outcomes described.

  1. [P02] HPSC, Infectious Disease Notifications in Ireland 2020-2025; publikacja 24.08.2026Public-health, institutional or source documentation.
  2. [P03] HPSC, Gastroenteric and Zoonotic Diseases, Q4 2025Public-health, institutional or source documentation.
  3. [P04] CDC, DPDx - GiardiasisPublic-health, institutional or source documentation.
  4. [P08] CDC, Clinical Testing and Diagnosis for Giardia InfectionPublic-health, institutional or source documentation.
  5. [P26] CDC, Symptoms of Giardia InfectionPublic-health, institutional or source documentation.
  6. [P23] CDC, Preventing Crypto; 08.05.2025Public-health, institutional or source documentation.
  7. [P24] CDC, Treating Crypto; 04.06.2025Public-health, institutional or source documentation.
  8. [P27] CDC, Patient Care for Giardia InfectionPublic-health, institutional or source documentation.

Pomocnicze streszczenie

Najważniejsze informacje po polsku

Dane HPSC z lat 2020–2025, drogi transmisji i praktyczne ograniczanie ryzyka zakażeń wodnopochodnych.

Pełny tekst, ograniczenia badań i źródła znajdują się powyżej.