Research and analysis

Giardia data 2008 to 2017

Published 30 May 2019

1. Main points for 2017

The number of Giardia reports has increased year on year since 2013. This increase is largely attributable to the increased use of molecular or antigen-based diagnostic methods by front line diagnostic laboratories.

The region with the highest number of Giardia spp laboratory reports was the South West of England with 1,116 laboratory reports.

The South West of England had the highest rate of Giardia laboratory reports per 100,000 population in England and Wales with 20.1 laboratory reports per 100,000 population.

Reporting numbers were highest for males aged 45 to 49 in 2017.

In 2017, the peak month for Giardia reporting was September, in keeping with the average seasonal variation seen in the period 2012 to 2016.

There were 2 non-foodborne outbreaks of Giardia reported in England and Wales during 2017.

2. Giardia data, 2008 to 2017

All data presented in this report are correct as of 30 July 2018.

2.1 Annual data: 2008 to 2017

Table 1: annual laboratory reports of Giardia in England and Wales 2008 to 2017^{[footnote 1]}

Year	Number of laboratory reports	per 100,000 population
2008	3,342	6.1
2009	3,501	6.3
2010	3,858	6.9
2011	3,697	6.6
2012	3,902	6.9
2013	3,622	6.4
2014	4,039	7.0
2015	4,390	7.6
2016	4,492	7.7
2017	4,793	8.2

Figure 1: annual laboratory reports of Giardia in England and Wales (2008 to 2017)

2.2 Regional data: 2017

Table 2: regional distribution^{[footnote 2]} of laboratory reports of Giardia in England and Wales: 2017

Country	Region	Number of laboratory reports	per 100,000 population
England	East Midlands	338	7.1
England	East of England	366	5.9
England	London	456	5.2
England	North East	315	11.9
England	North West	342	4.7
England	South East	1,062	11.7
England	South West	1,116	20.1
England	Yorkshire and The Humber	310	5.7
England	West Midlands	392	6.7
Wales	Wales	96	3.1

2.3 Age and sex distribution: 2017

Figure 2: age and sex distribution of laboratory reports of Giardia reported in England and Wales 2017^{[footnote 3]}.

2.4 Seasonal variation: 2012 to 2017

Figure 3: Number of laboratory reports of Giardia in England and Wales by week in 2017, and average number of reports by week in 2012 to 2016.

2.5 Outbreak data: 2017

In 2017, there were no foodborne outbreaks of Giardia reported in England and Wales, however there were 2 non-foodborne outbreaks reported.

Table 3: non-foodborne outbreaks of Giardia reported in England and Wales 2017

Agent	Total affected	Laboratory confirmed	Hospitalised	Deaths	Setting	Food description
Giardia lamblia	4	4	0	0	Swimming pool	No food identified
Giardia lamblia	3	3	0	0	Swimming pool	No food identified

3. Data source

Public Health England (PHE) Second Generation Surveillance System (SGSS). This is a live laboratory reporting system, therefore numbers may fluctuate. Data provided in this report are new extractions from this system and provide updated figures to previously published reports.

In 2014, PHE upgraded the laboratory reporting system so direct comparisons between data reported from the previous system (LabBase2) and the new system (SGSS) may require cautious interpretation.

4. Acknowledgements

We are grateful to:

• the microbiologists, local authorities and local health protection and environmental health specialists who have contributed data and reports to national surveillance systems
• the epidemiologists and information officers who have worked on the national surveillance of gastrointestinal (GI) infectious diseases
• colleagues in the Gastrointestinal Bacterial Reference Unit (GBRU) for providing the Reference Laboratory Services and laboratory surveillance functions and expertise
• the PHE Information Management Department for maintenance and quality assurance of PHE national surveillance databases for GI diseases
• PHE Local Public Health Laboratories and Food Water and Environmental Microbiology Services for providing a surveillance function for GI pathogens and testing of food and environmental samples routinely and during outbreak investigation
• PHE National Parasitology Reference Laboratory, Department of Clinical Parasitology, University College London Hospital NHS Foundation Trust for their expertise

1. Incidence rates were calculated using the Office for National Statistics (ONS) mid-year population estimates for each respective year. ↩

2. Regional classification based on place of residence of laboratory reports and classified using Nomenclature of Territorial Units for Statistics 1 (NUTS 1) codes. Incidence rates were calculated using the Office for National Statistics (ONS) mid-year population estimates for each region. ↩

3. For laboratory reports where age and sex data were available. There were 11 laboratory reports with unknown data recorded. ↩