In order to determine the prevalence of Necator americanus, 182 fecal samples were collected from school children in the Taegu vicinity. These sample were subsequently cultured by the Harada-Mori technique. Necator americanus was differentiated from Ancylostoma duodenale using the bases of morphological characteristics of filariform larvae. Necator americanus was not found in the vicinity of Taegu.
parasitology-helminth-nematoda- Necator americanus ; epidemiology

This study was undertaken to evaluate the present status of hookworm infections in Korea from October 1976 through September 1978. The stool specimens of 5,632 persons(male 3,689: female 1,943) collected from primary and middle schools, foundling asylums, and the general populations of various parts in Korea were examined The methods employed were brine floatation technique for the prevalence rate of hookworm infections, Kato's cellophane thick smear technique for the other helminthic infections, and Stoll's dilution egg counting technique for the intensity of hookworm infections. Ancylostoma duodenale and Necator americanus infections were classified by polyethylene tube coproculture method and by the evacuated adult worms after administration of anthelmintics against the patients infected with hookworms. The following results were obtained in this study. The prevalence rate of hookworm infections in rural area was higher than in urban area in the ratio of 2.4:1. And in the age group of over 20, the prevalence rate in significantly higher than that in urban area in the ratio of 5.8:1. In the urban area, difference in the prevalence rate of hookworm infections between the age group of over 20 and that of under 19 was not observed. But in the rural area, the ratio of the prevalence rate between the age group of over 20 to that of under 19 was 8:1. The prevalence rate of hookworm infections in female was higher than that in male in all age group except the age group of under 9 and 20-29. The ratio of the prevalence rate between female to male was 1.5:1 in total population. The area which showed the mean E.P.G. of over 1,000 was not found and almost all of the patients who were infected with hookworms gave the mean E.P.G. between l-999. Necator americanus was newly found in Dangjin Gun, Boseong Gun, Habcheon Gun and Weonseong Gun. In these 4 newly found areas, Dangjin Gun and Boseong Gun showed the composition rate of 25.5 percent and 83.4 percent respectively.
parasitology-helminth-nematoda ; hookworm-epidemiology ; Ancylostoma duodenale ; Necator americanus

A new anthelmintic, amidantel(Bay d 8815), an acetylated p-amino-phenyl-acetamidine was tried in 140 patients with Ancylostoma duodenale and other helminth infections. In the first trial, each 16 cases in 64 patients with A. duodenale were treated with 3.0, 6.0 and 9.0 or 10.0 mg/kg body weight of amidantel including placebo control. Another 76 patients infected with hookworms and other helminths were treated with 5.0, 6.0 and 8.0 mg/kg body weight of amidantel in the second trial. In order to assess the efficacy and safety of the drug, follow-up examination by repeated and replicated examinations over three consecutive days were performed at 14 to 16 days and 28 to 30 days after treatment, And complete laboratory studies including ECG were carried out before and one day after the medication. In the results, it was confirmed that amidantel is very effective against A. duodenale as well as Ascaris lumbricoides. With regard to dosage, a single dose of 6.0 mg/kg body weight of amidantel was found to be the most effective and well tolerated than the other dosages employed. In a single dose of 6.0 mg/kg body weight the cure rates were 93.8 and 96.6 per cent for A. duodenale infection and 90.9 and 93.1 per cent for ascariasis in the first and second trials respectivley. Relatively significant activity was also observed against Necator americanus at the dosages employed, however it was not superior to other drugs currently use. No significant activity was noted against Trichuris trichiura. Side effects including headache, nausea, dizziness and abdominal discomfort were usually mild and transient. No significant changes attributable to therapy were observed in hematology, blood biochemistry and urinalysis as well as ECG.
parasitology-helminth-nematoda ; amidantel ; acetylated p-amino-phenyl-acetamidine ; chemotherapy-Ancylostoma duodenale ; Necator americanus

With the improvement of sanitation, the infection rate of hookworm is greatly reduced and the severe infected case is rarely reported. Combined morphological and molecular biological examinations, a severe hookworm infection patient was diagnosed in Department of Laboratorial Examination, Quanzhou First Affiliated Hospital of Fujian Medical University. The morphological methods such as direct fecal smear microscopy, saturated brine flotation and hookworm larvae culture methods were used to identify the eggs and larvae from stool samples of the patient. There were a large number of hookworm eggs in patient's stool samples, and the average count was 60 840 per gram by modified Kato method, which belonged to severe hookworm infection. Meanwhile, to distinguish the hookworm species, the semi-nested RT-PCR assay was employed to detect hookworm internal transcribed spacer series from eggs in patient's stool samples, and the result showed that the hookworm species was confirmed to be Necator americanus.
Ancylostomatoidea/genetics* ; Animals ; Feces ; Hookworm Infections/diagnosis* ; Humans ; Necator americanus/genetics* ; Polymerase Chain Reaction

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.
Ancylostomatoidea* ; Ascaris ; Ascaris lumbricoides ; Databases, Nucleic Acid ; Eggs ; Epidemiologic Studies ; Feces ; Helminths* ; Hookworm Infections ; Humans ; Larva ; Methods ; Necator americanus ; Ovum ; Prevalence* ; Public Health ; Trichuris ; Vietnam*

This report describes clinical and parasitological findings of an 82-yr-old female patient who lived in a local rural village and suffered from severe chronic anemia for several years. She was transferred to the National Police Hospital in Seoul for management of severe dyspnea and dizziness. At admission, she showed symptoms or signs of severe anemia. Gastroduodenoscopy observed hyperemic mucosa of the duodenum and discovered numerous moving roundworms on the mucosa. Endoscopy isolated seven of them, which were identified as Necator americanus by characteristic morphology of cutting plates in the buccal cavity. The patient was treated with albendazole and supportive measures for anemia, and her physical condition much improved. This case suggests the possibility that hookworm N. americanus is still transmitted in a remote local mountainous area in Korea.
Aged, 80 and over ; Albendazole/therapeutic use ; Anemia/*diagnosis/parasitology ; Animals ; Anthelmintics/therapeutic use ; Duodenoscopy ; Female ; Gastroscopy ; Humans ; *Necator americanus/isolation & purification ; Necatoriasis/*diagnosis/drug therapy ; Republic of Korea

OBJECTIVETo develop a quantitative PCR method for detecting hookworm infection and quantification.

METHODSA real-time PCR method was designed based on the intergenic region II of ribosomal DNA of the hookworm Necator americanus. The detection limit of this method was compared with the microscopy-based Kato-Katz method. The real-time PCR method was used to conduct an epidemiological survey of hookworm infection in southern Fujian Province of China.

RESULTSThe real-time PCR method was specific for detecting Necator americanus infection, and was more sensitive than conventional PCR or microscopy-based method. A preliminary survey for hookworm infection in villages of Fujian Province confirmed the high prevalence of hookworm infections in the resident populations. In addition, the infection rate in women was significantly higher than that of in men.

CONCLUSIONSA real-time PCR method is designed, which has increased detection sensitivity for more accurate epidemiological studies of hookworm infections, especially when intensity of the infection needs to be considered.

Animals ; China ; epidemiology ; DNA, Helminth ; genetics ; Female ; Humans ; Male ; Microscopy ; Necator americanus ; genetics ; isolation & purification ; Necatoriasis ; diagnosis ; epidemiology ; genetics ; Nucleic Acid Amplification Techniques ; Real-Time Polymerase Chain Reaction ; Sensitivity and Specificity ; Sentinel Surveillance ; Sequence Analysis, DNA ; Sex Distribution

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.
Abdomen ; Albendazole ; Ancylostoma ; Ancylostomatoidea* ; Anticoagulants ; Capsule Endoscopy ; Colonoscopy ; Diagnosis ; Diagnosis, Differential ; Duodenum ; Gastrointestinal Hemorrhage ; Gastrointestinal Tract ; Gastroscopy ; Hemorrhage* ; Hookworm Infections* ; Humans ; Ileum ; Jejunum ; Middle Aged ; Necator americanus ; Nephrotic Syndrome ; Parasites ; Pulmonary Embolism ; Steroids

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.
Albendazole ; Ancylostoma ; Ancylostomatoidea* ; Anemia, Iron-Deficiency ; Blood Transfusion ; Capsule Endoscopy ; Colonoscopy ; Diagnosis ; Double-Balloon Enteroscopy ; Eggs ; Endoscopy, Digestive System ; Follow-Up Studies ; Hematologic Tests ; Hemorrhage* ; Hookworm Infections* ; Humans ; Intestine, Small ; Iron ; Necator americanus ; Ovum

Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.
Ancylostoma/*genetics/isolation & purification ; Ancylostomiasis/*diagnosis/parasitology ; Animals ; Base Sequence ; DNA, Intergenic/genetics ; DNA, Protozoan/genetics ; DNA, Ribosomal Spacer/genetics ; Diagnosis, Differential ; Humans ; Molecular Sequence Data ; Necator americanus/*genetics/isolation & purification ; Phylogeny ; Polymerase Chain Reaction/*methods ; Sequence Alignment ; Trichostrongylosis/*diagnosis/parasitology ; Trichostrongylus/*genetics/isolation & purification