• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.391-398
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• 2017

Hookworm infections are widely prevalent in tropical and subtropical areas, especially in low income regions. In the body, hookworms parasitize the proximal small intestine, leading to chronic intestinal hemorrhage and iron deficiency anemia. Occasionally, hookworms can cause overt gastrointestinal bleeding, but this is often ignored in heavily burdened individuals from endemic infectious areas. A total of 424 patients with overt obscure gastrointestinal bleeding were diagnosed by numerous blood tests or stool examinations as well as esophagogastroduodenoscopy, colonoscopy, capsule endoscopy or double-balloon enteroscopy. All of the patients lived in hookworm endemic areas and were not screened for hookworm infection using sensitive tests before the final diagnosis. The patients recovered after albendazole treatment, blood transfusion, and iron replacement, and none of the patients experienced recurrent bleeding in the follow-up. All the 31 patients were diagnosed with hookworm infections without other concomitant bleeding lesions, a rate of 7.3% (31/424). Seventeen out of 227 patients were diagnosed with hookworm infections in the capsule endoscopy (CE), and 14 out of 197 patients were diagnosed with hookworm infections in the double balloon enteroscopy (DBE). Hookworm infections can cause overt gastrointestinal bleeding and should be screened in patients with overt obscure gastrointestinal bleeding (OGIB) in endemic infectious areas with sensitive methods. Specifically, the examination of stool specimens is clinically warranted for most patients, and the proper examination for stool eggs relies on staff's communication.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.471-476
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• 2016

To know the infection status of helminths in primary schoolchildren of southern parts of Vietnam, we performed an epidemiological study in Krong Pac district, Dak Lak Province, Vietnam. A total of 1,206 stool specimens were collected from ethnic Ede schoolchildren in 4 primary schools in 2015 and examined by the Kato-Katz technique. In addition, stool cultures were done by the Harada-Mori method to obtain hookworm larvae and then to clarify the species of hookworms infected. The results showed that the helminth infection rate was 25.0%, including 2.0% Ascaris lumbricoides, 0.33% Trichuris trichiura, and 22.8% hookworm infections. The average intensity of infection was 102.0 eggs per gram of feces (EPG) for Ascaris, 36.0 EPG for Trichuris, and 218.0 EPG for hookworms. ITS1 gene sequences of the hookworm larvae were identical with those of Necator americanus (100% homology) reported in GenBank. It has been confirmed in this study that the hookworm, N. americanus, is a dominant helminth species infected in primary schoolchildren of a southern part of Vietnam. Public health attention is needed for control of hookworm infections among schoolchildren in surveyed areas of Vietnam.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.619-625
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• 2020

Human hookworm infections caused by adult Ancylostoma spp. and Necator americanus are one of the most important tropical diseases. We performed a survey of intestinal helminths using the Kato-Katz fecal examination technique targeting 1,156 villagers residing in 2 northern provinces (Preah Vihear and Stung Treng) of Cambodia in 2018. The results revealed a high overall egg positive rate of intestinal helminths (61.9%), and the egg positive rate of hookworms was 11.6%. Nine of the hookworm egg positive cases in Preah Vihear Province were treated with 5-10 mg/kg pyrantel pamoate followed by purging with magnesium salts, and a total of 65 adult hookworms were expelled in diarrheic stools. The adult hookworms were analyzed morphologically and molecularly to confirm the species. The morphologies of the buccal cavity and dorsal rays on the costa were observed with a light microscope, and the nucleotide sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were analyzed. The majority of the hookworm adults (90.7%) were N. americanus, whereas the remaining 9.3% were Ancylostoma ceylanicum, a rare hookworm species infecting humans. The results revealed a high prevalence of hookworm infections among people in a northern part of Cambodia, suggesting the necessity of a sustained survey combined with control measures against hookworm infections.

• Journal of agricultural medicine and community health
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• v.4 no.1
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• pp.62-70
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• 1979

In order to evaluate the present status of hook-worm infection in the rural areas in Korea, stool examinations were undertaken in several selected rural villages in each year of 1970 and 1977. The methods employed were cellophane thick smear technique and brine floatation technique in 3,454 specimens collected from 7 different rural villages for the prevalence rate of hookworm infection and Stoll's dilution egg counting technique for the intensity of hookworm infection. The incidences of Ancylostoma duodenale and Necator americanus infections were determind by polyethylene tube coproculture and by the evacuated adult worms after treatment with anthelmintics to the patients who were infected by hookworms. The results are as follows : 1) In 1970, 323(18.6%) out of 1,737 specimens collected from 4 different rural areas were positive for hook worm infection and the ranges of prevalence rates in those suveyed areas were shown as 6.9 to 38.2 per cent. On the other hand, 144(8.2%) out of 1,717 specimens collected from 3 different rural areas in 1977 were shown as positive for hookworm infection and 7.5 to 10.6 per cent of prvalence rates were shown in the surveyed areas. 2) In the age group under 10 years, there was no infection of hookworm in the studied areas in 1977, however in 1970 the prevalence of the hookworm infection was shown as very low in the age group of 5~9. On the whole, the hookworm prevalence steadily increased from the age of 15 in the studied areas in 1970, however in 1977 the prevalence increased from the age of 20 to the older age groups. 3) There was not observed much differences in the intensity of hookworm infection among the studied areas in 1970 and 1977. The mean EPG in each studied areas were shown under 1,000 EPG and mean numbers of evacuated worms per infected persons were counted as 9.4 to 15. 1. 4) Both A.duodenale and N.americanus have been found in all studied areas but the incidences and st-ate of distribution of two species of hookworn were shown as different in each localities.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.417-420
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• 2017

Hookworm infections are rare causes of acute gastrointestinal bleeding. We report a middle aged man with primary nephrotic syndrome and pulmonary embolism. During the treatment with steroids and anticoagulants, the patient presented acute massive hemorrhage of the gastrointestinal tract. The results of gastroscopy showed red worms in the duodenum. Colonoscopy and CT angiogram of abdomen were unremarkable. Capsule endoscopy revealed fresh blood and multiple hookworms in the jejunum and ileum. Hookworms caused the acute intestinal bleeding. The patient responded well to albendazole. Hematochezia was markedly ameliorated after eliminating the parasites. Hence, hookworm infection should be considered in the differential diagnosis of a patient with obscure gastrointestinal bleeding. Capsule endoscopy may offer a better means of diagnosis for intestinal hookworm infections.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.533-536
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• 2016

A 26-year-old male member of the Australian Defense Force presented with a history of central abdominal pain of 4 weeks duration and peripheral eosinophilia consistent with eosinophilic enteritis. Acute hookworm disease was diagnosed as the cause. Adult worms recovered from feces after therapy with albendazole were morphologically consistent with Ancylostoma ceylanicum. As the patient had been deployed with the Regional Assistance Mission to Solomon Islands for 6 months prior to this presentation, it is very likely that the A. ceylanicum was acquired in Solomon Islands. Until now, it has been assumed that any Ancylostoma spp. recovered from humans in Solomon Islands is A. duodenale. However, this case demonstrates that human hookworm infection acquired in the Solomon Islands could be caused by A. ceylanicum.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.747-749
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• 2013

The 2 principal species of hookworms infecting humans are Necator americanus and Ancylostoma duodenale. Case studies on zoonotic hookworm infections with Ancylostoma ceylanicum and/or Ancylostoma caninum are known mainly from Asian countries. Of these 2 zoonotic species, only A. ceylanicum can develop to adulthood in humans. In the present study, we report a molecular-based survey of human hookworm infections present in southern and northeastern Thailand. Thirty larval hookworm samples were obtained from fecal agar plate cultures of 10 patients in northeastren Thailand and 20 in southern Thailand. Partial ITS1, 5.8S, and ITS2 regions of the ribosomal DNA genes were amplified using PCR. The amplicons were sequenced, aligned, and compared with other hookworm sequences in GenBank database. The results showed that, in Thailand, N. americanus is more prevalent than Ancylostoma spp. and is found in both study areas. Sporadic cases of A. ceylanicum and A. duodenale infection were seen in northeastern Thailand.

• Journal of Environmental Health Sciences
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• v.9 no.2
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• pp.11-17
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• 1983

The soil-transmitted helminthes, such as ascaris, whipworm, hookworm and trichostrongylus, have been considered as the most prevalent parasitic diseases in a matter of several decades ago in Korea. In facts, the attached eggs and/or larvae to the vegetables have been played a great role on the transmission to human because of raw eating the vegetables without the proper recipe. The aims of this study is to outline the attached helminthes egg in vegetables and to define whether the detection rates on them show a decreasing pattern or not in present. The subjected vegetables were collected from the three markets which are located at Goo-Pa Bal, Soo-Yoo Dong, Cheon-Ho Dong in suburban area, Seoul from April to May 1983. A total of 180 samples including such as 60 Korean cabbages, 60 young radishes and 60 Korean onions were examined. For the detection of helminthes eggs, the both methods of formalin-ether sedimentation and zinc-sulfate floatation were applied. The results were summarized as follows: 1) The detected eggs of ascaris, whipworm, hookworm, trichostrongylus and either filariform larvae or rhabditoidform larvae of hookworm, as well as unknown ones were found in vegetables subjected. 2) Out of 180 subjects, the overall detection rate showed 48 (26.7%). And in case of Korean onion, the rate revealed 22 heads (36.7%) among 60, 17 heads (28.3%) out of 60 Korean cabbages, 9 roots (15.0%) out of 60 young radishes respectively. 3) The ascaris eggs were detected 6 heads (10%) out of 60 Korean cabbages, while the filariform larvae of hookworm appeared in 7 heads (11.7%) among 60 Korean onions. 4) In the results of present study, the detection rates in vegetables were appeared to be the marked decreasing tendency as like 28.3%, 36.7%, 15% compared with 96%, 100%, 88% of previous investigators (Choi et al. 1967)each on Korean cabbage, Korean onion, young radish.

• Parasites, Hosts and Diseases
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• v.30 no.1
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• pp.59-62
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• 1992

An imported case of rectal hookworm infection was diagnosed by stool examination and recovery of adult worms from the rectal mucosa by sigmoidoscopy. The chief complaints of a patient were diarrhea, abdominal pain and weight loss for about 1 month after returning from his travel abroad to the Southeast Asia. Leukocytosis ($16, 750/{\mu}\ell$) and peripheral eosinophilia (33.7%) were noticed without anemia. Typical hookworm eggs were detected by stool examination, and 3 worms were collected by sigmoidoscopy from rectal mucosa of this patient. Those worms were confirmed as adult worms of Ancylostoma duodenale(♂:1, ♀: 2) based on their morphological characteristics. The symptoms were relieved after treatment with anthelmintics. This case was considered as one of the imported parasitic infections in Korea, and a rare case of hookworm infection on human rectal mucosa.

• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.121-128
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• 2007

Arthrostoma miyazakiense (Nematoda: Ancylostomatidae) is a hookworm species reported from the small intestines of raccoon dogs (Nyctereutes procyonoides) in Japan. Five Korean raccoon dogs (N. procyonoides koreensis) caught from 2002 to 2005 in Jeollanam-do (Province), a southeastern area of South Korea, contained helminth eggs belonging to 4 genera (roundworm, hookworm, whipworm, and Capillaria spp.) and cysts of Giardia sp. in their feces. Necropsy findings of 1 raccoon dog revealed a large number of adult hookworms in the duodenum. These hookworms were identified as Arthrostoma miyazakiense based on the 10 articulated plates observed in the buccal capsule and the presence of right-sided prevulval papillae. Eggs of A. miyazakiense were $60-65{\times}35-40{\mu}m$ (av, $62.5{\times}35{\mu}m$), and were morphologically indistinguishable from those of Ancyiostoma caninum. The eggs were cultured to infective 2nd stage larvae via charcoal culture, and 100 infective larvae were used to experimentally infect each of 3 mixed-bred puppies. All puppies harbored hookworm eggs in their feces on the 12th day after infection. This is the first report thus far concerning A. miyazakiense infections in raccoon dogs in Korea, and the first such report outside of Japan.