A Case of Zoonotic Ancylostoma ceylanicum Infection in a Suburban Area of Selangor, Malaysia

INTRODUCTION

The animal hookworm, Ancylostoma ceylanicum, is a dominant hookworm species of dogs and cats. However, it has increasingly been found infecting humans in Southeast Asia.

PURPOSE

We report an autochthonous case of A. ceylanicum in a suburban area of Selangor, Malaysia. A 66-year-old Indian lady who is an avid gardener presented with chronic diarrhea of 4 months' duration.

METHODS

The patient was examined clinically and colonoscopy was performed. Adult parasites obtained via colonoscopy were subjected to microscopy and molecular investigations.

RESULTS

Clinical examinations were unremarkable, and blood investigation revealed normochromic normocytic anemia. Stool occult blood was positive but negative for ova, cyst and adult parasites. Colonoscopy performed showed multiple diverticulae and worm infestation from the terminal ileum to sigmoid colon. Morphological examination on the adult worms showed the specific characteristics of Ancylostoma species. Molecular investigations further confirmed the nematode as Ancylostoma ceylanicum. She was treated with albendazole 400 mg daily for 3 days with symptomatic improvements sustained 3 months later. It is suspected that the patient had ingested or contacted soil contaminated with filariform larvae while gardening.

CONCLUSION

Information on the A. ceylanicum infection in humans, especially in urban and suburban areas, is limited, necessitating further epidemiological and clinical studies.

Opening a Can of Worms: Leprosy Reactions and Complicit Soil-Transmitted Helminths

Background

> 94% of new annual leprosy cases are diagnosed in populations co-endemic for soil-transmitted helminths (STH). STH can profoundly dysregulate host immune responses towards Th2 bias, which can be restored over time after deworming. We hypothesize that STH co-infection is associated with leprosy reaction (denoted as simply “reaction” herein) occurrence within a co-endemic population.

Methods

A cohort study was performed on a cohort of Nepalese leprosy patients across treatment and diagnostic classifications who were screened by routine fecal smear microscopy and multiplex quantitative PCR (qPCR) for Ascaris lumbricoides (Al), Strongyloides stercoralis (Ss), Ancyclostoma duodenale (Ad) and Necator americanus (Na).

Results

Among 145 patients, 55% were positive for ≥ 1 STH (STH +): 34% Al +, 18% Ss +, 17% Ad + and 5% Na +. Significant inverse STH and reaction relationships were evidenced by the bulk of cases: 63% reaction-negative were STH + of total cases (p = 0.030) while 65% reaction-positive were STH − in new cases (96; p = 0.023). Strikingly, the majority of STH + were reaction-negative, even when considering each species: 59% Al +, 60% Ss +, 62% Ad + and 67% Na + of new leprosy cases.

Conclusions

Absence of STH co-infection is associated with leprosy reaction at diagnosis within a co-endemic population. This is likely due to immune reconstitution effects after deworming or interruption of chronic STH-mediated immune dysregulation.

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Fecal screening by qPCR revealed that 55% of 145 leprosy patients hosted 1 or more soil-transmitted helminth (STH) co-infections

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STH coinfection was significantly and inversely associated with leprosy reaction

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Chronic STH-induced immune bias followed by disruption of co-infection, potentially by deworming, may initiate immune reconstitution that can lead to reaction development