Ancylostoma ceylanicumHookworm in the Solomon Islands

Richard S Bradbury,Richard Speare,Sze Fui Hii,Humpress Harrington,Rebecca Traub

doi:10.3201/eid2302.160822

Abstract

Although hookworm is highly prevalent in the Solomon Islands, the species involved are unknown. We initiated this study in response to finding Ancylostoma ceylanicum hookworm in a peacekeeper in Australia who had returned from the Solomon Islands. Kato-Katz fecal surveys performed in 2013 and 2014 in 2 village groups in East Malaita, Solomon Islands, identified hookworm-positive samples. These specimens were tested by cytochrome oxidase 1 (cox-1) gene multiplex PCR and sequenced. Of 66 positive specimens, 54 (81.8%) contained only Necator americanus, 11 (16.7%) contained only A. ceylanicum, and 1 (1.5%) contained both species. A. duodenale was not found. Haplotype analysis of cox-1 sequences placed all human isolates (99% bootstrap support) of A. ceylanicum within the zoonotic clade rather than the human-specific clade. This study confirms that A. ceylanicum is endemic in the East Malaita region of this Pacific Island nation. The strain of the A. ceylanicum in this region can be shared among humans, dogs, and cats.

Highlights

Hookworm is highly prevalent in the Solomon Islands, the species involved are unknown
Human infection with A. ceylanicum hookworm is highly prevalent in the East Malaita region of the Solomon Islands, comprising 18.2% of tested samples found by the Kato-Katz method to contain hookworm eggs
The presence of A. ceylanicum infection in the Eastern Malaita region of the Solomon Islands adds to the growing weight of evidence that A. ceylanicum is a widespread hookworm in humans and that this species may be present in other parts of Melanesia and the Pacific Islands

Summary

Introduction

Hookworm is highly prevalent in the Solomon Islands, the species involved are unknown. Hookworm disease, caused by blood-feeding worms of the small intestine, affects nearly 1 billion persons worldwide, with more than half of infections in the Asia-Pacific region [1]. A. ceylanicum hookworm infection was described in a soldier from Australia who had returned from the Regional Assistance Mission to the Solomon Islands, a peacekeeping mission [4]. In response to the case report of Speare et al [4], we determined the species of hookworms, and, the prevalence of human A. ceylanicum infections, in the Solomon Islands, a group of islands southeast of Papua New Guinea and northeast of Australia, located within the Melanesian archipelago.

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Results

Conclusion