Global prevalence of Strongyloides stercoralis in dogs: A systematic review and meta-analysis

Abstract

Strongyloides stercoralis is an intestinal parasitic helminth that mainly affects humans and dogs throughout the world. Canine strongyloidosis is generally characterized by asymptomatic infection, with fatal disease in cases of immunodeficiency. This study was conducted in order to evaluate the global prevalence of S. stercoralis in dogs. Six electronic databases were searched for this purpose. The random effects model and 95% confidence intervals (CI) were applied to determine the overall and subgroup pooled prevalence. Heterogeneity was assessed by Cochran's Q test and I2 statistic. In total, 56 datasets from 50 studies from 1,202 peer-reviewed papers were included in the current meta-analysis. 20,627 dogs were assessed in 27 countries across six World Health Organization (WHO) regions. The global prevalence of S. stercoralis infection among dogs was 6% (95% CI 4–8%; 868/20,627). According to WHO regions, the estimated prevalence ranges 2% to 11% as follows: Western Pacific (11%, 0–31%); Africa (9%, 2–19%); America (6%, 3–11%); South-East Asia (5%, 1–13%)’ Europe (3%, 2–5%); and Eastern Mediterranean (2%, 0–6%). The pooled prevalence of S. stercoralis infection in dog owners was 7% (1–18%). The prevalence of S. stercoralis infection in studies based on serological assays was significantly higher than other techniques (29%, 20–39%). Younger female dogs, less than one year old, from rural areas had higher prevalence rates than their male counterparts, with no statistically significant differences. From this review, it is concluded that the low global prevalence of S. stercoralis in dogs may be strongly associated with low sensitivity diagnostic methods applied in most studies leading to the underestimation of infection rates. Therefore, the improvement of diagnostic techniques is recommended for precise evaluation of the disease.

Is strongyloidiasis a zoonosis from dogs?

“…Strongyloides stercoralis prevalence in domestic dogs in the USA, the UK and Europe is between 2% and 5% [3]. All dog isolates genotyped thus far from these regions have been identified as belonging to the 'human and dog' type [60,61].…”

“…Parasitic nematodes of the genus Strongyloides spp. remain a major veterinary and public health challenge globally [1][2][3][4][5][6][7]. Human strongyloidiasis is in most cases caused by infection with Strongyloides stercoralis.…”

“…Within the intestine, they develop into female parasitic adults which reproduce through parthenogenesis [9]. Current global estimates indicate that approximately 600 million people [2] and 6% of dogs [3,5] are infected with S. stercoralis . Infection is more common in tropical, sub-tropical regions but the prevalence in both dogs and humans may vary widely in different geographical locations [2,3].…”

“…This review explores the evidence for and against cross-species transmission of S. stercoralis between dogs and humans and summarizes future directions for research in this area.This article is part of the Theo Murphy meeting Issue 'Strongyloides: omics to worm-free populations'. regions but the prevalence in both dogs and humans may vary widely in different geographical locations [2,3]. Marginalized and resource-poor communities, where the accessibility of adequate sanitation facilities and both human healthcare and canine veterinary care may be sparse, are disproportionately affected [10][11][12][13].Since the very early days of S. stercoralis research there has been a debate if dogs carry the same or just a similar species of Strongyloides as humans [14][15][16] and, as a consequence, if dogs are a putative source of zoonotic human infection with S. stercoralis (or vice versa).…”

“…This article is part of the Theo Murphy meeting Issue 'Strongyloides: omics to worm-free populations'. regions but the prevalence in both dogs and humans may vary widely in different geographical locations [2,3]. Marginalized and resource-poor communities, where the accessibility of adequate sanitation facilities and both human healthcare and canine veterinary care may be sparse, are disproportionately affected [10][11][12][13].…”