Experimental human infection with the dog hookworm, Ancylostoma caninum

Abstract

Objective: To investigate possible routes for human infection by the dog hookworm (Ancylostoma caninum). Design, setting and participant: Relatively small numbers of infective larvae were administered orally and percutaneously to an informed healthy volunteer (J K L) under medical supervision, at intervals between May 1998 and May 1999. Main outcome measures: Symptoms; weekly blood eosinophil counts; faecal microscopy. Results: A marked blood eosinophilia followed a single oral exposure to 100 infective larvae, while faecal examination remained negative. Eosinophil counts then declined gradually, although a rapid, spontaneous rise several months later, at the beginning of spring, possibly indicated reactivation of dormant larvae. Blood eosinophil numbers did not rise significantly after percutaneous infection with 200 larvae. A subsequent, smaller, oral inoculum of 20 larvae provoked an eosinophil response similar to that of the first experiment. Conclusions: Our findings suggest that, following ingestion, some infective larvae of A. caninum develop directly into adult worms in the human gut (as they do in dogs). While the percutaneous route might be the most common means of human exposure to canine hookworm larvae, leading generally to subclinical infection, oral infection may be more likely to provoke symptomatic eosinophilic enteritis.

Prevalence of endoparasitic infections of non descript dogs in Mathura, Uttar Pradesh

“…CLM is frequently encountered in socioeconomically disadvantaged communities that are unable to afford proper footwear and often sleep in environments heavily contaminated by faeces of stray dogs (Heukelbach et al 2002). Infections with A. caninum can also result in eosinophilic enteritis (Prociv and Croese 1996;Landmann and Prociv 2003). Study to literature revealed A. caninum to be highly prevalent with prevalence rate of 89 and 72 % in Madhya Pradesh and teagrowing communities in Assam (Traub et al 2004), respectively.…”

The mitochondrial genome of the dog hookworm Ancylostoma caninum (Nematoda, Ancylostomatidae) from Southwest China

“…Human infections typically relate to the larval migration of A. caninum under the skin and can cause cutaneous larvae migrans known as creeping eruptions (Prociv and Croese 1996). In addition, A. caninum was also sporadically reported to cause eosinophilic enteritis because its larvae can develop into pre-adult, non-patent worms in human intestines (Landmann and Prociv 2003). Recent increased molecular-based epidemiological evidence highlights that A. caninum and A. ceylanicum are emerging as important helminthic zoonosis in the Asia Pacific countries including Cambodia (Inpankaew et al 2014), Laos (Sato et al 2010), Malaysia (Ngui et al 2012), Solomon Islands (Bradbury et al 2017), Thailand (Jiraanankul et al 2011), Australia (Smout et al 2017) and China (Dai et al 2009;Liu et al 2013).…”

Dog: A Friendly Pathway to Zoonoses

“…It is one of the most common hookworms of dogs. This parasite reach adulthood in humans and cause eosinophilic enteritis (Landmann and Prociv, 2003). After contact with the human host, the parasite enters the skin and reaches heart and lungs.…”