An eleven-year retrospective hospital-based study of epidemiological data regarding human strongyloidiasis in northeast Thailand

Abstract

Background: Human strongyloidiasis is a chronic and persistent gastrointestinal disease caused by infection with soil-transmitted helminths of the genus Strongyloides. The aim of this research was to obtain diagnostic prevalence regarding strongyloidiasis in northeast Thailand through a hospital-based study.

Methods: Patients' demographic data and the results of stool examinations conducted using the formalin ethyl acetate concentration technique were collected from the parasitology laboratory records at Srinagarind Hospital in Khon Kaen, Thailand. The relevant information from years 2004 to 2014 was collected and descriptively analyzed.

Results: Of a total of 22,338 patients, 3889 (17.4%) had stool samples that tested positive for Strongyloides larvae. The highest prevalence was 22.8% (95% CI = 19.6-26.2%) in the year 2004. This percentage progressively decreased, reaching 11.2% (95% CI = 10.2-12.4%) in 2013 and remaining stable at 12.9% (95% CI = 11.8-14.1%) in 2014. Males (2741 cases) had double the positivity rate of females (1148 cases). The prevalence of infection was highest (25.9%; 95% CI = 24.5-27.3%) among patients that were 51-60 years of age.

Conclusions: Areas endemic for strongyloidiasis should be emphasized under the national helminth control program and health education campaigns. Nationwide assessments should also be performed regarding Strongyloides infection, including risk factors, treatment, and prevention. The diagnostic laboratory data presented here identify the geographical focus of disease to be the northeastern region of the country. Further targeted surveillance using more sensitive methods will almost certainly reveal a higher individual disease burden than found in this report.

Keywords: Hospital-based study; Prevalence; Strongyloidiasis; Thailand.

Fig. 1

Diagnostic prevalence of Strongyloides stercoralis infection by FECT in 19 provinces in northeast Thailand. The map of Thailand was modified from a map in The World Factbook, published by the Central Intelligence Agency [Central Intelligence Agency [US]. The World Factbook is available at: https://www.cia.gov/library/publications/resources/the-world-factbook/geos/th.html Accesed 1 July 2017]. Remark; ANC = Amnat Charoen, BR = Buriram, CP = Chaiyaphum, KS = Kalasin, KK = Khon Kaen, LO = Loei, MS = Maha Sarakham, MDH = Mukdahan, NP = Nakhon Phanom, NR = Nakhon Ratchasima, NBL = Nong Bua Lamphu, NK = Nong Khai, RE = Roi Et, SKN = Sakon Nakhon, SK = Sisaket, SR = =Surin, UBR = Ubon Ratchathani, UDT = Udon Thani and YS = Yasothon. Classified group by quartiles

Fig. 2

Diagnostic prevalence of Strongyloides stercoralis infection classified by age group