A case of severe hookworm infection / 中南大学学报(医学版)

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.

Geohelmintiasis, estado nutricional y antropometría de niños de 3 a 6 años del Centro Escolar de la ciudad de Guayaquil, Ecuador / Geohelminthiasis, nutritional status and anthropometry of children from 3 to 6 years old from the School Center of the city of Guayaquil, Ecuador

Las geohelmintiasis son nematodos que afectan al hombre a través de la ingesta de huevos parasitarios, afectando el estado nutricional antropométrico de la población infantil, motivo por el cual se planteó como objetivo determinar incidencia de las helmintiasis transmitidas por el suelo en el estado nutricional antropométrico de niños de 3 a 6 años en un centro escolar Guayaquil en Ecuador, durante el último semestre del 2018. Se aplicó la metodología descriptiva de corte transversal; donde se incluyeron 92 preescolares de 3 a 6 años. A cada niño(a) se le hizo su estudio antropométrico nutricional, unido a un estudio coprológico realizado a 45 niños. Se obtuvo el Índice de Masa Corporal (IMC) con el cual se determinó el estado nutricional (IMC/Edad/Sexo), usando los percentiles del Ministerio de Salud Pública de Ecuador. Se revisaron los IMC de los 35 niños que presentaron geohelminiasis quienes evidenciaron una ligera disminución en la ganancia de los valores de las variables antropométricas. Se encontró predominio del sexo femenino (54,35%), la edad fue 3,78 años, peso: 15,21 Kg y talla: 100,23 cm2, el IMC fue 16,62 Kg/cm2, sin diferencias entre el sexo; la especie de mayor ocurrencia fue la Trichuris. trichiura 43,47% (niñas 10/23) y 66,67% (niños 8/12). Se concluye que 29,34% de los preescolares estudiados están malnutridos, presentan geohelmintiasis, por ello es recomendable realizar intervenciones dirigidas a representantes, estudiantes y docentes, para atender paralelamente geohelmintiasis y nutrición para garantizar la calidad de vida(AU)

Geohelminthiasis are nematodes that affect man through the ingestion of parasitic eggs, affecting the anthropometric nutritional status of the infant population, which is why the objective was to determine the incidence of soil-transmitted helminthiasis in the anthropometric nutritional status in children aged 3 to 6 years of a school in Ecuador, during the last semester of 2018. A cross-sectional descriptive methodology was applied; where 92 preschoolers from 3 to 6 years old were included. Each child was given his or her nutritional anthropometric study, together with a coprological study of 45 children. There was obtained the Body Mass Index (BMI) with which there decided the nutritional state (BMI / Age / Sex), using the centiles of the Department of Public health of Ecuador. The BMI of the 35 children with geohelminiasis were reviewed and showed a slight decrease in the gain of anthropometric variables. The prevalence of female sex was found (54,35%), the age was 3,78 years, weight: 15,21 Kg and height: 100,23 cm2, the BMI was 16,62 Kg/cm2, with no differences between sex; the species of greatest occurrence was Trichuris trichiura 43,47% (girls 10/23) and 66,67% (boys 8/12). It is concluded that 29.34% of the preschools studied are malnourished, have geohelminthiasis, so it is advisable to make interventions aimed at representatives, students and teachers, to attend parallel geohelminthiasis and nutrition to ensure quality of life(AU)

Diferencias morfológicas relevantes para la identificación específica de larvas de uncinarias y Strongyloides stercoralis / Relevant morphological differences for the specific identification of larvae of hookworms and Strongyloides stercoralis

Objetivos: Describir las características morfológicas diferenciales más relevantes de los estadios larvarios de uncinarias (Ancylostoma duodenale y Necator americanus), y S. stercoralis, para su identificación específica en laboratorio clínico convencional. Material y métodos: Estudio observacional durante julio del 2015 a agosto del 2016. Se realizaron cultivos en placa de agar de muestras fecales positivas por microscopía a larvas de nematodos o huevos de uncinaria. Las larvas desarrolladas en cultivo fueron descritas morfológicamente mediante claves, se identificaron las características morfológicas diferenciales más relevantes y se ilustraron mediante microfotografías. Resultados: Las características morfológicas más relevantes para la diferenciación específica fueron la longitud de la cavidad bucal y la prominencia del poro genital en el estadio rabditiforme; y la forma del cuerpo, el extremo terminal de la cola y el diámetro del extremo anterior del intestino en relación al esófago en el estadio filariforme. Conclusiones: Las uncinarias A. duodenale y N. americanus, y S. stercoralis pueden identificarse específicamente por microscopía óptica mediante el análisis morfológico de sus estadíos larvarios desarrollados en cultivo. Debido al requerimiento de equipos e insumos de uso común en laboratorio de microbiología, se recomienda esta metodología para uso en laboratorios clínicos convencionales. (AU)

Objectives: To determine the most relevant morphologic differences of larval stages of hookworms (Ancylostoma duodenale y Necator americanus) and S. stercoralis for their specific identification in a conventional laboratory. Methods: An observational study was carried-out between July and August 2016. Positive fecal samples at microscopy to nematode larvae or to eggs of hookworms were cultured in agar plate. Larvae that developed in culture were described morphologically using passwords. We identified the most relevant differential morphologic features and illustrated them using microphotography. Results: The most relevant morphologic features that allow differentiating these nematodes were the longitude of the oral cavity and the prominence of the genital primordium for the rabditiform larva; the shape of the body, the terminal end of the tail and the diameter of the anterior extreme of the intestine in relation to the esophagus for the filariform larvae. Conclusions: Hookworms and S. stercoralis can be specifically identified by optic microscopic examination of their larval stages developed in culture. We recommend this methodology for conventional microbiology laboratories due to the requirement of simple equipment. (AU)

Hookworm Infection: A Neglected Cause of Overt Obscure Gastrointestinal Bleeding

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.

Hookworm Infection Caused Acute Intestinal Bleeding Diagnosed by Capsule: A Case Report and Literature Review

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.

Prevalence of Soil-Transmitted Helminths and Molecular Clarification of Hookworm Species in Ethnic Ede Primary Schoolchildren in Dak Lak Province, Southern Vietnam

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.

Molecular Detection of Ancylostoma duodenale, Ancylostoma ceylanicum, and Necator americanus in Humans in Northeastern and Southern Thailand

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.

Application of a real-time PCR method for detecting and monitoring hookworm Necator americanus infections in Southern China

<p><b>OBJECTIVE</b>To develop a quantitative PCR method for detecting hookworm infection and quantification.</p><p><b>METHODS</b>A 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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSIONS</b>A 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.</p>

A Case of Severe Anemia by Necator americanus Infection in Korea

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.

Ancilostomíase / Ancylostomiasis

A ancilostomíase é uma doença parasitária causada pelos helmintos Ancylostoma duodenale e Necator americanus, com importante.

A study on the prevalence of hookworm infection in four districts of West Bengal and its linkage with anaemia.

Stool samples collected from the districts of Darjeeling, Jalpaiguri, Hooghly and Calcutta in West Bengal were examined for hookworm and associated parasites. It was found that maximum prevalence of hookworm was in Hooghly district (24.8%). N. americanus appeared to be more prevalent species in all the districts studied. The load ofhookworm infection appeared to be mostly in the mild range. Ascaris lumbricoides appeared to the most common accompanying infection. In the affected population, the degree of anaemia was mostly mild.

Differential diagnosis of Trichostrongylus and hookworm eggs via PCR using ITS-1 sequence

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.

Differential diagnosis of Trichostrongylus and hookworm eggs via PCR using ITS-1 sequence

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.

Protective immunity elicited by ultraviolet-irradiated third-stage infective hookworm (Necator americanus and Ancylostoma caninum) larvae in mice and hamsters.

The protective immunity elicited by ultraviolet-irradiated third-stage infective larvae of Necator americanus (UV-NaL3) and Ancylostoma caninum (UV-AcL3) was evaluated in laboratory mice (a non-permissive model) and hamsters (a permissive model). After optimizing the time of exposure to UV-irradiation, both oral and subcutaneous vaccination routes with UV-AcL3 in mice were explored. Oral vaccination was more effective at reducing the number of challenge AcL3 entering the lungs, whereas subcutaneous vaccination was more effective at blocking muscle entry. When UV-irradiated NaL3 and non-irradiated AcL3 were used as vaccines in hamsters, both of them were effective at reducing adult hookworm burdens. However, the length of protection afforded by UV-irradiated L3 was substantially greater than that resulting from immunization with non-irradiated L3. A single dose was less effective than multiple doses. The protective immunity elicited by UV-irradiated NaL3 given once every other week for a total of three immunizations was similar to that elicited by non-irradiated AcL3 given during the same schedule. Protection was not significantly affected by administering the L3 on a weekly basis for a total of three immunizations, even though the antibody titers were reduced using this schedule. These studies will facilitate the elucidation of the mechanisms underlying larval protection.

The exsheathment of Necator americanus infective larvae.

Infective 3rd-stage larvae of Necator americanus were treated with human sweat under various conditions, and compared with human serum, 1.5% saline solution, and distilled water. The infective larvae were observed under inverted microscopy. The highest percentage (14.0%) of the exsheathed larvae was found in human sweat after 2 hours' incubation at 37 degrees C. The proportion of exsheathed larvae in human sweat was significantly different from human serum (p<0.001), 1.5% saline solution (p<0.001), and distilled water (p<0.001). This may reflect the effect of human sweat on the process of skin penetration by Necator americanus larvae.

La uncinaria americana-stile / The uncinaria american-stile

En nuestros estudios previos expusimos nuestras dudas y vacilaciones en la clasificación de ese verme intestinal Uncinaria Americana-Stiles. Hicimos la enumeración de las demás especies conocidas como anemiantes o patógenas de los mamíferos: U. trigonocéfala, U. stenocéfala, U. ceinua, etc; y dedujimos la semejanza que existía entre nuestra especia y la U. estenocéfala. Posteriormente identificamos el anquilostomo nuestro con el de Stiles, y en este trabajo resumimos sus caracteres específicos y hábitat, comparados con los del U. duodenalis, Dubini, con sus respectivas láminas. Puede decirse que la U. americana es la que por si sola causa las anemias de Venezuela. En la colección del Hospital Vargas se encuentra cerca de cincuenta mil parásitos expulsados por los enfermos y mezclados a ellos se ha encontrado 32 ejemplares de la U. duodenal

Uncinariasis: Hallazgo incidental durante CPRE / Uncinariasis: Incidental find during ERCP

Se presentan tres casos de uncinariasis como hallazgo incidental durante un procedimiento de CPRE, Colangio Pancreatografía Retrógrada Endoscópica. Los pacientes no presentaban síntomas debidos a su parasitosis. La CPRE se llevó a cabo por ictericia obstructiva, encontrando coledocolitiasis en dos de los pacientes. Se revisa la epidemiología, ciclo de vida, patofisiología y tratamiento de la uncinariasis. No debemos olvidarnos que vivimos en un clima tropical propicio al desarrollo de diferentes enfermedades parasitarias que requieren un diagnóstico y tratamiento oportuno

Hookworm infection and anemia in adult women in rural Chiapas, Mexico

OBJECTIVE: To describe associations between anemia and hookworm (Necator americanus) infection in hospitalized women in rural Chiapas, Mexico. MATERIAL AND METHODS: We retrospectively reviewed the hospital records of 68 anemic women (defined as having a hemoglobin level <10mg/dl) or with intestinal parasitism, identified through hospital discharge and transfusion records for the calendar year 1999. The medical charts of 86 cases were located, 18 of which were not confirmed as anemia cases. The hospital is located in Altamirano, Chiapas. Characteristics of subjects were compared using Student's t-test (for continuous variables) and the chi2 test (for categorical variables). A p-value <0.01 was used for statistical significance. Chart review and data analysis took place during the year 2000. RESULTS: Fifty percent of women who had stool examinations were infected with N. americanus. Necator often coexisted with other potential causes of anemia, such as pregnancy and hemorrhage. Hemoglobin levels in hookworm-infected women (mean 4.1 g/dl) were significantly lower than in uninfected women (mean 7.0 gm/dl), and Necator prevalence was significantly higher in the anemic women (50 percent) than in the overall hospital population (1.9 percent). CONCLUSIONS: Anemic women should be offered stool testing where Necator is present, and should be considered for antihelminthic treatment even if pregnant. Further investigation is recommended among women in Chiapas, and probably elsewhere in Mexico