Epidemiology and economic burden of rotavirus gastroenteritis in hospitals and paediatric clinics in Taiwan, 2005–2006

Abstract

Baseline estimates of rotavirus disease burden and epidemiology are useful for the evaluation of newly introduced rotavirus vaccination programs. Prospective, cross-sectional surveillance for acute gastroenteritis (AGE) was conducted in hospitals and outpatient paediatric clinics in Taiwan to assess the prevalence of rotavirus gastroenteritis and associated medical costs prior to rotavirus vaccine introduction. Faecal specimens were collected from 1130 children <5 years of age from December 2004 to June 2006. The year-round rate of rotavirus detection in faecal specimens was 46% for children seen in hospitals and 14% for children seen in paediatric clinics. In the winter season, the burden was higher, reaching a peak of 60% and 21% in hospitals and paediatric clinics, respectively. The rotavirus genotype distributions were 39% (G1), 34% (G9), 12% (G2), 15% (G3), and 0.3% (G5). Total medical and nonmedical costs were US $754 for a rotavirus hospitalisation and US $60 for an outpatient clinic visit. Parental work loss averaged 4.0 days per hospital visit and 1.3 days per paediatric clinic visit. These data show that rotavirus was associated with a substantial proportion of AGE medical visits and had considerable medical costs prior to rotavirus vaccine introduction.

Introduction

Rotavirus gastroenteritis is a serious diarrhoeal disease that affects every child less than 5 years of age [1]. Severe dehydration resulting from the disease requires rehydration therapy. In impoverished areas of the world, children typically do not have access to treatment facilities and, as a result, childhood mortality is high [2]. Even in areas where rehydration therapy is accessible, the disease places a heavy burden on the family [3] and public health resources [4].

In 2006, the results of clinical trials demonstrated that two new rotavirus vaccines were safe and efficacious [5], [23]. Since that time, countries around the world have begun adopting rotavirus vaccination into their immunisation schedules. To determine the effectiveness of routine rotavirus immunisation, it is important to have baseline estimates of prevaccine disease burden and epidemiology. This is particularly important given that circulating rotavirus strains can vary between different regions of the world and from year to year within the same region [6].

In Taiwan, it is estimated that among children less than 5 years of age, 1 in every 2–5 children will require medical care [7] and 1 in 15 will be hospitalised [8] for rotavirus gastroenteritis. Rotavirus infections occur throughout the year, with a winter peak that usually occurs between the months of January and March [9], [10]; however, shifts in the rotavirus season have been observed in Taiwan [9], [11]. Likewise, shifts in circulating rotavirus G serotypes have been demonstrated. For example, G9 rotavirus strains were not apparent in Taiwan prior to 2001 [12] but represented 39% of all strains in children hospitalised between 2001 and 2003 [10]. Using hospital-based surveillance data, results from the Asian Rotavirus Surveillance Network between 2001 and 2003 have shown that rotavirus gastroenteritis was responsible for 43% of diarrhoeal hospitalisations among children less than 5 years of age [10], with greater rotavirus detection rates in 2001 (48%) than in 2002 (35%). Recently, rotavirus detection rates of approximately 31% have been reported for children hospitalised for acute gastroenteritis (AGE) [13], [14]. As of August 31, 2006, two rotavirus vaccines, the pentavalent RotaTeq^® (Merck & Co, Inc., Whitehouse Station, NJ, USA) and the monovalent Rotarix^® (GlaxoSmithKline Biologicals, Rixensart, Belgium), were approved for use in Taiwan. Using published data of rotavirus vaccine importation in Taiwan [15], it is estimated that approximately 19.5% of the Taiwanese birth cohort has been vaccinated with a rotavirus vaccine regimen since licensure.

To our knowledge, there have been no prospective studies on the proportion of rotavirus infections and the associated medical and nonmedical costs of AGE from studies conducting active surveillance at both hospitals and community-based paediatric clinics in Taiwan. In order to provide background on the disease and economic burden related to rotavirus prior to vaccine licensure, this study was conducted from December 2004 through June 2006 and estimated the proportion of rotavirus infections among children hospitalised for AGE or those who sought outpatient care for AGE in paediatric clinics in Taiwan. We also determined the costs associated with rotavirus gastroenteritis for children who sought medical attention.