The incidence of acute gastrointestinal illness in Sweden.

Frida I Hansdotter,Sharon Kühlmann-Berenzon,Yvonne Andersson,Anette Hulth,Kjell-Olof Hedlund,Måns Magnusson,Kristian Sundström

doi:10.1177/1403494815576787

Abstract

Aims: The aim of this study was to estimate the self-reported domestic incidence of acute gastrointestinal illness in the Swedish population irrespective of route of transmission or type of pathogen causing the disease. Previous studies in Sweden have primarily focused on incidence of acute gastrointestinal illness related to consumption of contaminated food and drinking water. Methods: In May 2009, we sent a questionnaire to 4000 randomly selected persons aged 0–85 years, asking about the number of episodes of stomach disease during the last 12 months. To validate the data on symptoms, we compared the study results with anonymous queries submitted to a Swedish medical website. Results: The response rate was 64%. We estimated that a total number of 2744,778 acute gastrointestinal illness episodes (95% confidence intervals 2475,641–3013,915) occurred between 1 May 2008 and 30 April 2009. Comparing the number of reported episodes with web queries indicated that the low number of episodes during the first 6 months was an effect of seasonality rather than recall bias. Further, the result of the recall bias analysis suggested that the survey captured approximately 65% of the true number of episodes among the respondents. Conclusions: The estimated number of Swedish acute gastrointestinal illness cases in this study is about five times higher than previous estimates. This study provides valuable information on the incidence of gastrointestinal symptoms in Sweden, irrespective of route of transmission, indicating a high burden of acute gastrointestinal illness, especially among children, and large societal costs, primarily due to production losses.

Highlights

Acute gastrointestinal illness (AGI) is a major public health problem worldwide and an important cause of mortality and morbidity
Five questionnaires were considered to be completed incorrectly and were excluded from further analysis. We excluded another 65 questionnaires due to self-reported age differing more than ±1 years from the age obtained from Statens personadressregister (SPAR) since it was suspected that the wrong person had completed the questionnaire
In exploring possible recall bias, we found that the number of reported episodes of stomach disease was significantly associated with both the web queries ( b web =0.00016, p=0.03) and time ( b month =0.095; p=0.01).after taking into account the effect of the pattern of the web queries, it still remained that the logarithm of the number of reported episodes increased approximately by 10% per month, which we interpret as a result of better recall closer to the date of the survey.We did not find any statistically significant autocorrelation in the model (DW statistic=1.38, p=0.082)

Summary

Introduction

Acute gastrointestinal illness (AGI) is a major public health problem worldwide and an important cause of mortality and morbidity. Diarrhoea is one of the leading causes of post neonatal deaths, estimated to have caused 800,000 deaths worldwide in children under 5 years of age in 2011 [1]. AGI associated mortality is low, but morbidity remains high. A review of estimates of the incidence and prevalence of AGI from 33 studies from high income countries has shown a range from. 0.1 to 3.5 episodes per person year. Comparisons of these rates are problematic due to variation in study design, mainly prospective cohort studies and retrospective cross sectional surveys, and should be made with caution [2]. As only some cases attend health care, and are (Accepted 15 February 2015)

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Conclusion