Ancylostomiasis

Abstract

This chapter is a concise description of the zoonotic potential of Ancylostoma species causing disease in humans. The hookworm species known to have zoonotic potential are Ancylostoma brazilense, Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma tubaeforme, Bunostomum phlebotomum and Uncinaria stenocephala. Dogs, cats, foxes, calves, etc. are the primary hosts where the Ancylostoma species completes its life cycle and man is the accidental host. Transmission of zoonotic hookworms to humans occur by penetration of skin by the filariform larvae or in rare cases by ingestion of the larvae. Infections by zoonotic hookworm in humans develops a skin disease termed as cutaneous larva migrans (CLM). In rare cases, animal hookworms may reach the intestine as a single worm and cause painful abdominal disorder called eosinophilic enteritis. Zoonotic hookworms are prevalent in tropical and subtropical regions worldwide and their transmission to human represents a significant public health concern. The burden of zoonotic hookworms in animals and humans is yet to be exactly ascertained.

Utpala Devi, (deceased), Professor Devi wrote this book while at ICMR-RMRC, Dibrugarh, India

Case Study

Umbrello and his co-workers reported a case of an Italian 2-month-old breastfeeding female infant who was hospitalised with complaint of vomiting and weight reduction. One month prior to this, she was admitted in a different hospital for the same health issues. After the examination of urine and blood, her eosinophil count was found to be 2900/μl, while ammonium concentration, ultrasound of abdomen and Rotavirus/Adenovirus faecal antigens test showed negative. During this period, she suffered from mild diarrhoea, which was cured after treating with probiotics. Thereafter, she was released with a sound health condition. Upon investigation, it showed that the mother had a travel history of 70 days to Vietnam and Thailand (Southeast Asia) during her first stage of the gestation period, where she experienced several episodes of nausea with vomiting. Blood test report of the infant showed a white blood cell count of 19,060/μl, eosinophil (5170/μl), platelets (756,000/μl) and haemoglobin (9.1 g/dl). The blood smear showed the presence of microcytic hypochromic red blood cells. Considering the haemoglobin level, iron and folic acid were supplemented orally. The other parameters such as serum protein level, bilirubin level and albumin level were in normal range. Liver function test and abdomen test showed normal. On the other hand, C-reactive protein (CRP) was also negative. Electrolytes, kidney function test and coagulase test were reported as normal. The stool looked normal, while viral antigens and bacterial culture were reported as negative. The microscopic examination of the stool revealed the presence of eggs of hookworm, which was further confirmed by real-time PCR in the parasitology laboratory of “Ospedale Sacro Cuore Don Calabria” of Negrar as A. duodenale. The absence of the parasite in the parents’ faeces proved the vertical transmission of the parasite during the gestation period. The patient was administered two doses of mebendazole (100 mg) orally twice a day for 3 consecutive days. The infant was released in a good health condition. In the follow-up visit scheduled after 1 month, the infant’s clinical condition and medical reports appeared to be normal (Umbrello G et al. 2021).

• 1. What are the various methods for speciation of Ancylostoma spp.?

• 2. Which species of Ancylostoma can cause a patent infection in humans? What are the clinical manifestations?

• 3. What are the other parasites which can cause CLM?

Research Questions

• 1. What is the worldwide burden of zoonotic diseases in cats and dogs?

• 2. What is the infection prevalence and intensity of zoonotic ancylostomiasis in human populations?

• 3. How to map A. ceylanicum in areas other than Southeast Asia and the Pacific region?