An alternative explanation could be unsustained transmission via sandflies from index patients with visceral leishmaniasis who acquired their infection elsewhere. Wild vertebrates may also be reservoirs. Given the rarity of the disease it will not be on the selleck kinase inhibitor differential diagnosis of the majority of health workers in SE Asia and laboratory diagnostic techniques are rarely available—suggesting that the incidence could be underestimated. On the other hand, the relatively high incidence of HIV infection in Thailand would

have been expected to increase the incidence and clinical ‘visibility’ of this disease (Guerin et al., 2002). Human hookworm infections continue to be a major public health problem in SE Asia with approximately one quarter of the 563 million inhabitants infected (Hotez and Ehrenberg, 2010). Worldwide, enteric human hookworm infections are predominantly associated with two species, Ancylostoma duodenale and Necator americanus ( Brooker et al., 2004), and neither is considered zoonotic. However, pigs have been implicated as transport hosts of N. americanus ( Steenhard et al., 2000) and may see more have an important role in the natural history of human disease. Of the zoonotic hookworm species that cause human disease, A. ceylanicum is the only species capable of establishing a patent enteric infection in humans, canines and felines ( Anten and Zuidema, 1964,

Wijers and Smit, 1966, Yoshida

et al., 1968, Carroll and Grove, 1984 and Carroll and Grove, 1986). Historically, A. ceylanicum has received little attention despite it being known to cause human disease for at least the past 40–50 years ( Anten and Zuidema, 1964, Wijers and Smit, 1966, Carroll and Grove, 1986 and Traub et al., 2008). Zoonotic hookworm disease resulting in anaemia was first described in 1964 in Dutch marines returning from service in West New Guinea (now Indonesian West Papua) (Anten and Zuidema, 1964). Nine of eleven (82%) returning marines were found to have a patent enteric infection with A. braziliense ( Anten and Zuidema, 1964) which was later referred to as A. ceylanicum ( Wijers and Smit, 1966 and Chowdhury and Schad, 1972). Three marines Suplatast tosilate were infected with more than 100 adult worms and two of these otherwise healthy well-fed marines were anaemic ( Anten and Zuidema, 1964) which is in stark contrast to most reports where only a few adult A. ceylanicum worms have been recovered ( Kian Joe and Kok Siang, 1959, Yoshida et al., 1968 and Chowdhury and Schad, 1972). A follow-up study using A. ceylanicum worms originating in West New Guinea and passaged through dogs showed that infection in healthy volunteers produced severe clinical symptoms within 15–20 days after cutaneous exposure to L3 larvae, including severe abdominal pain and epigastric spasms ( Wijers and Smit, 1966).