Identification and Prevalence of Globocephalus samoensis (Nematoda: Ancylostomatidae) among Wild Boars (Sus scrofa coreanus) from Southwestern Regions of Korea

This study describes the first record of Globocephalus samoensis (Nematoda: Ancylostomatidae) recovered in wild boars from southwestern regions of Korea. Gastrointestinal tracts of 111 Korean wild boars (Sus scrofa coreanus) hunted from mountains in Suncheon-si, Gwangyang-si, and Boseong-gun between 2009 and 2012 were examined for their visceral helminths. G. samoensis, as identified by morphological characteristics of the head and tail, were recovered from the small intestine of 51 (45.9%) wild boars. Worms were found from 7 of 28 wild boars (25.0%) from Suncheon-si, 40 of 79 (50.6%) from Gwangyang-si, and all 4 (100%) from Boseong-gun. The length of adult females was 7.2+/-0.5 mm, and the thickest part of the body measured the average 0.47+/-0.03 mm, while those of males were 6.52+/-0.19 and 0.37+/-0.02 mm, respectively. The buccal cavity was equipped with a pair of large and bicuspid subventral lancets near the base of the capsule. The average length of spicules of males was 0.45+/-0.02 mm. By the present study, G. samoensis is recorded for the first time in southwestern regions of Korea. Additionally, morphological characteristics and identification keys provided in the present study will be helpful in the faunistic and taxonomic studies for strongylid nematodes in both domestic and wild pigs. The infection of G. samoensis apparently did not elicit pathologic lesions, as revealed by macroscopic observation during the autopsy of all wild boars in this study.

Instruction in behavior modification can significantly alter soil-transmitted helminth (STH) re-infection following therapeutic de-worming.

Five elementary ("prototypic") schools located in five districts in central Java were selected and the children examined for helminth infections (Ascaris, Trichuris, hookworm). They were de-wormed with a course of mebendazole and provided with 6-7 months of "behavioral remediation instruction" (BRI). In other ("control") schools, children were treated with mebendazole but were not provided BRI. The objective was to determine the effectiveness of BRI in minimizing infection/re-infection following deworming. After the 6-7 month course of BRI in the prototypic schools, all the children (in both the prototypic and control schools) were re-examined for geohelminth infection. The schools in two of the five districts were omitted from further analysis because the overall prevalence of infection was low (<10%) and the infections were dominated by hookworm which are only moderately susceptible to mebendazole. Comparisons of prototypic and control schools in the other three districts provided compelling evidence that BRI was quite effective in reducing both the frequency and intensity of infection with Ascaris and Trichuris. We suggest that instructing children and adults corrects personal habits which are conducive to infection and can be an effective and safe substitute for repeated deworming, reducing the opportunity for the emergence of drug-resistant helminthes, which should prolong the time benzimidazoles may be used for treatment of geohelminth infection.

Prevalence and distribution of soil-transmitted helminthiases among Orang Asli children living in peripheral Selangor, Malaysia.

Soil-transmitted helminthiases are a public health problem in rural communities. A cross-sectional study of the prevalence and distribution of Ascaris lumbricoides, Trichuris trichiura and hookworm was conducted in 281 Orang Asli children (aborigines) aged between 2 and 15 years, from 8 Orang Asli villages in Selangor, Malaysia. All the children were infected with soil-transmitted helminthes, with 26.3% of the children infected either with A. lumbricoides, T. trichiura or hookworm and 72.6% having mixed infection. The overall prevalences of A. lumbricoides, T. trichiura and hookworm were 61.9, 98.2 and 37.0%, respectively. Approximately 19.0, 26.0 and 3.0% of the children had severe infection of ascariasis, trichuriasis and hookworm infection, respectively. The prevalences and mean egg per gram (epg) counts for A. lumbricoides and T. trichiura were not significantly dependent on age, therefore age-dependent convexity was not seen in this study. However, the results of this study reveal an age-dependent prevalence and mean epg count in children with hookworm infection. We conclude that ascariasis, trichuriasis and hookworm infection are still prevalent and therefore a public health concern in Orang Asli communities. Severe ascariasis and trichuriasis may lead to other health and medical problems.

Anemia, malaria and hookworm infections in a Vietnamese ethnic minority.

The aim of this study was to determine the prevalence of anemia and evaluate the relationship of malaria and helminth infections on anemia status in Phan Tien village, a mountainous ethnic minority community in southern Vietnam. This longitudinal study was performed from April 1997 to 2000 by measuring the hemoglobin concentration of 2,767 people who participated in six annual surveys at the end of the rainy seasons. Ferritin concentration was measured in 2000 to evaluate the proportion of iron deficiency anemia. The relation between malaria and intestinal helminth infections with anemia was investigated. Anemia was always over 43% and mainly associated with iron deficiency (80.1%). Using generalized estimating equations, a small but significant decline of the anemia prevalence was detected (OR: 0.805; p < 0.0001). Malaria was significantly associated with anemia (OR: 2.408; p = 0.0006). There was no significant effect of the control of intestinal helminth infections on the time course of anemia (95% CI: -0.1548 to 0.1651).

Soil-transmitted helminthiases and health behaviors among schoolchildren and community members in a west-central border area of Thailand.

The prevalence of soil-transmitted helminthic infections and health behaviors related to infections in schoolchildren and villagers of a community (4 hamlets) was studied in Hauy Kayeng subdistrict, Thong Pha Phum district, in the north of Kanchanaburi Province. The intestinal helminth infection rate of the schoolchildren was 15.6%. Hookworm infection was the most prominent (9.8%), followed by Trichuris trichiura (6.2%), and Ascaris lumbricoides (2.2%). The community showed higher prevalence rates and was infected with more types of intestinal helminths than the schoolchildren. Thirty-five point two percent (35.2%) of the residents were infected with soil-transmitted helminths, 30.5% with hookworm, 3.4% with A. lumbricoides and 2.2% with T. trichiura. Almost all hookworm cases (94.3%) were light intensity infections, while only 1.3% were heavy infections. Moreover, the hookworm infection rate in the community was found to be much higher when a stool culture method was used (39.1%). With this technique, 2.3% Strongyloides stercoralis infections were detected in the community population. Examination of the health behavior of the study samples showed that approximately 75% always defecated in a toilet. Schoolchildren who always wore shoes comprised 67%, which was lower than the community, at 85%.

Intestinal helminthic infestation in children.

In this study of fecal samples from 1000 children below 6 years of age, 680 (68.0%) detected to have intestinal helminthic infection. The incidence of intestinal helminthiasis in urban group of children was 56.8% (284 out of 500 tested) while in rural group of children was 79.2% (396 out of 500 tested). Both in rural and urban population Ascaris lumbricoides was the single predominant species, whereas a combination of A. lumbricoides and Trichuris trichiura was common multiple infection. All cultures of fecal samples positive for hook worm ova revealed the prevalent species as Necator americanus in this area.

Current status of soil-transmitted helminths in Vietnam.

This paper provides a review of surveys on soil-transmitted helminths that were done in Vietnam between 1990 and 2001. Prevalence estimates could be obtained for 29 of the 61 provinces. Extrapolating from this, it is estimated that 33.9 million people in Vietnam are infected with Ascaris (prevalence 44.4%), 17.6 million with Trichuris (prevalence 23.1%), and 21.8 million with hookworm (prevalence 28.6%). Prevalence of Ascaris and Trichuris showed a declining trend from the north to the south of the country. This is probably related to differences in climatic conditions. Hookworm prevalence is more evenly distributed throughout the country, but is concentrated in peri-urban and rural agricultural areas. Vegetable cultivation in which nightsoil is used as fertilizer is a risk factor for hookworm infection, especially among adult women. Helminth control programs should be targeted at school-age children in the northern provinces. Specific interventions are needed throughout the country for women of agricultural communities that are at risk for hookworm infection. There is clearly a need for more detailed analysis of risk factors to quantify the relative contribution of climatic, environmental, and human behavioral factors in the transmission of intestinal nematode infections in Vietnam.

Hookworm infections of schoolchildren in southern Thailand.

A study of hookworm infections of schoolchildren was conducted in Nakhon Si Thammarat Province, southern Thailand. Of the 2,940 hookworms that were recovered from the children, almost all (99.9%), were Necator americanus, only three (0.1%) were identified as Ancylostoma duodenale, and all were female worms. An estimation of the worm burden of and the worm expulsion from the schoolchildren indicated there were 17 cases of light intensity hookworm infection. Fifteen cases (88.2%) expelled worms in numbers that corresponded with the worm burden that was estimated from the number of eggs per gram of feces. Two cases (11.8%) expelled more worms than predicted. In 16 moderate intensity cases, five (31.3%) expelled worms in a quantity that corresponding with the estimated worm burden. Eleven cases (68.7%) expelled fewer worms than predicted. All cases of heavy intensity infection expelled fewer worms than predicted.

Strongyloides stercoralis infection and chronological changes of other soil-transmitted helminthiases in an endemic area of southern Thailand.

A field survey was conducted in 4 primary schools in Nakhon Si Thammarat Province, southern Thailand. By Sasa modified Harada-Mori cultivation method, 1.8% of the schoolchildren were found to be infected with Strongyloides stercoralis, and 25.1% had hookworm infection. By Kato's thick smear method, the overall prevalence of soil-transmitted helminths was 46.8%, being Trichuris trichiura 28.5%, hookworm 18.0%, and Ascaris lumbricoides 5.7%. Fecal examination, performed by Kato's thick smear and culture method, indicated that the prevalence of hookworm infection was 26.9%. The prevalence in the present study was very much lower than many previous reports in the past decade. This may indicate the partial success of the parasite control project in Thailand by mass treatment, improving the sanitation and personal hygiene of the people in the endemic area. In light infection with Trichuris, albendazole administered at a dosage of 200 mg daily for 3 days showed a 48.7% cure rate. When mebendazole was given at 100 mg twice daily for 3 days, its effectiveness was 88.5%. A lower cure rate was obtained (70.0%) in moderate to heavy infection.

Epidemiology of hookworm infection in Itagua, Paraguay: a cross sectional study

A cross-sectional study in Itagua, Paraguay tested 192 people for the presence, intensity and species of hookworm infection. Fifty-nine percent of these individuals were found to be infected. Intensity of infection was determined on 92 per cent of infected individuals by quantitative egg counts. The high intensity hookworm infections, which cause the greatest morbidity, were clustered between the ages of five and 14 years. No differences were seen between genders. The species of hookworm was determined for parasites reared from 72 per cent of infected individuals. Both Necator americanus and Ancylostoma duodenale were identified, although the former species predominated. We conclude that hookworm infection continues to be a public health problem in Paraguay, particularly among children and adolescents who suffer from high intensity infections. A. duodenale continues to persist in the Western Hemisphere and has not been completely displaced by N. americanus.

Soil contamination and infections by soil-transmitted helminths in an endemic village in southern Thailand.

The aim of this study was to test the association between soil contamination and infection of the household members by soil-transmitted helminths in dry and rainy seasons. A lake-side community in southern Thailand with a population of 2,340 was studied twice, in the dry season and rainy season of 1995. Fifty households were randomly selected. Soil samples near the latrine, in the yard, at the foot-washing area and under the trees were taken and analysed for presence of helminthic eggs. All members of the selected household were interviewed and stool samples obtained. Age-adjusted odds ratios of presence of Ascaris and Trichuris eggs in the household soil for ascariasis and trichuriasis were 10.5 (95% CI 1.5-77.1) and 5.5 (95% CI 2.4-12.7) in dry season and 10.4 (95% CI 2.5-43.8) and 8.3 (95% CI 3.4-20.0) in rainy season. The levels of hookworm eggs detected in the soil were too low to test the association. Soil analysis for eggs of Ascaris and Trichuris may be used to predict infections among the household members but not that for hookworm.

Helminthic infections of urban and rural schoolchildren in Penang Island, Malaysia: implications for control.

The intestinal parasites of schoolchildren from an urban and a rural area on Penang island, Malaysia were compared. Examination of stool samples for helminth eggs showed that helminths found were Trichuris, Ascaris and hookworms. The results indicate that there is no significant difference (p<0.05) between rural and urban schoolchildren as regards to the prevalence of the three species of helminths. An extensive control program targetted at schoolchildren to monitor the helminth problem on the island is suggested.

Vitamin B1, B2 and B6 deficiency in primary school children infected with hookworm.

One thousand and seven hundred thirty-six school children from two districts in Nakhon Si Thammarat Province were screened for hookworm infection using the Kato-Katz stool examination technic. Two hundred students who have at least 2,000 eggs per g of stool were recruited into the program. The students were divided into six groups: groups 1, 2 and 3 were from Tha Sala district while groups 4, 5 and 6 were from Ronpibul district. Three milliliter blood samples were obtained from the cubital vein of each subject and were evaluated for erythrocyte transketolase activity (ETK) for vitamin B1, erythrocyte glutathione oxidoreductase activity (EGR) for vitamin B2, and erythrocyte aspartate aminotransferase activity (EAST) for vitamin B6. The school children were divided into three groups: those infected only with hookworm, those with both hookworm and Trichuris trichiura, and those whose stools show no parasite eggs. The results show that 10-20% of the school children are vitamin B1 deficient, about 40% to 80% are vitamin B2 deficient, and about 14% to 23% are vitamin B6 deficient. No correlation could be made between vitamin deficiencies and parasitic infection.

Socioeconomic and behavioral factors affecting the prevalence of geohelminths in preschool children.

The aim of this study was to examine the relationship between the prevalence of geohelminth infections in preschool children living in an urban slum area in Sri Lanka and parental education, socioeconomic status, the use of anthelmintics, and beliefs regarding these helminths. Between October 1992 and February 1993, stool samples were collected from preschool children (< or = 60 months of age) in the Mahaiyyawa area, Kandy, Sri Lanka, and examined using direct smears and a concentration technique. Stool samples which were found to be positive for helminth ova were also examined using the modified Kato-Katz technique. A pretested questionnaire was administered to the mothers or principal caretakers of the children from whom stool samples were obtained to assess parental education, socioeconomic status of the family and knowledge, attitudes and practices related to intestinal parasites, particularly geohelminths. Stool samples from 307 children were examined; 81 (26.4%) were positive for geohelminth ova. Roundworm infections predominated, and were seen in 73 of the 81 (90.1%), either alone or together with whipworm and/ or hookworm infections. All infections were of mild to moderate intensity. Questionnaires were administered to the mothers/principal caretakers of 208 children. Mothers/caretakers of 91 children (45%) claimed that the child was on regular anthelmintics. As the educational level of the mother/caretaker improved, the prevalence of geohelminth infections in the children declined (chi-square for linear trend = 8.19, p = 0.004). However, there was no significant correlation between prevalence of infections and paternal educational levels. Prevalence also tended to increase as the socioeconomic class declined (chi-square for linear trend = 4.899, p = 0.026). Another finding of note in this study was the widespread ignorance and misconceptions regarding geohelminth infections among carers.

Las helmintiasis intestinales en la República Mexicana / Intestinal helminthiases in the Mexican Republic

En la República Mexicana se han realizado escasos trabajos dirigidos a determinar la frecuencia de las helmintiasis intestinales en humanos. Sin embargo, con los pocos trabajos confiables de que se dispone, realizados de 1981 a 1992, es posible señalar que la ascariasis, tricocefalosis, uncinariasis e himenolepiasis, se encuentran presentes en forma significativa con porcentajes de infección del 11,2 por ciento, 1,7 por ciento, 0,15 por ciento y 1,8 por ciento, respectivamente. Con la información vertida en este artículo y obtenida de las encuestas realizadas en el período mencionado anteriormente, se puede señalar que las infecciones intestinales por helmintos están presentes en forma significativa en la República Mexicana. Sin lugar a dudas, esto es debido a que aún persisten los factores que contribuyen a la diseminación de las helmintiasis, tales como fecalismo, pobreza, malos hábitos higiénicos, manejo inadecuado de alimentos y bebidas, y en general deficiencias en las condiciones de saneamiento ambiental

Evaluation of hookworm control program in southern Thailand.

An intensive hookworm control program providing the rural population of southern Thailand with mass treatment with 300 mg Mebendazole and health education commenced in 1989 with a yearly budget of over US$ 1.2 million. The current research aimed to evaluate the coverage of health education and mass treatment, the effectiveness of mass treatment and the administrative process of the control program, two years after its commencement. This evaluation consisted of three studies. In the first study, 120 villages were randomly selected, from which 840 school children, 843 adults aged between 15-59 and 844 subjects aged over 60 years were interviewed to assess awareness of hookworm, latrine availability, receipt of and compliance with antihelminthics provided, and self-treatment. In the second study, 8 villages from each of the 14 provinces were randomly chosen. Stool samples from randomly selected 4,434 subjects were examined. The third study consisted of interviewing key health planners in Bangkok and 71 health officers/workers from 32 samples villages of 8 sampled provinces. Latrine availability was 80%. Percentages of subjects who had ever heard of hookworm ranged from 70 to 95 in school children, 55 to 80 in adults and 25 to 58 in the older age group. While 63 to 85% had latrines in their homes, 27% to 47% admitted defecation outside in the past month. Percentages of coverage of drug treatment ranged from 82 to 91 in school children, 68 to 80 in adults and 54 to 59 in the older age group.(ABSTRACT TRUNCATED AT 250 WORDS)

Hookworm disease: Puerto Rico's secret killer

Drs. Bailey Ashford and Pedro Gutiérrez, with the economic aid of the United States and Puerto Rican governments, were able to implement a program to reduce the incidence of hookworm infestations in Puerto Rico during the turn of the century. The program was conducted in three phases. The first phase consisted of evaluating the prevalence of infestations among the population. The second phase was concerned with treating patients and reducing further infestations. The last phase of the program was the implementation of prevention programs whose goals were to educate the population on the mechanisms of contaminations and to help implement improvements in the waste disposal systems so as to reduce the exposure to contaminated soil. The programs greatly improved the level of health of many Puerto Ricans. The incidence of hookworm infestations was reduced from 90 per cent to 15 per cent among members of the population. The program obtained world-wide recognition and serves as a model for similar programs

Some epidemiological aspects of hookworm infection among the rural population of Bali, Indonesia.

Stool examination using direct smear method, Kato-Katz thick smear technique and modified Harada Mori test tube cultivation method were done on 2,331 people among the rural population of Bali. The serum ferritin was examined by ELISA technique and hemoglobin concentration by cyanmethemoglobin technique. Overall prevalence of hookworm infection was 24.02% with heterogeneity in local prevalences. The highest prevalence was found in wet highland area (46.3%), followed by wet lowland (27.7%), dry highland (14.2%) and dry lowland (10.9%). The majority of hookworm infection cases were associated with Ascaris and Trichuris infections. Most of the hookworm infections (73.3%) were light/very light in intensity with a mean EPG of 619. The prevalence and intensity of infection were increasing with age, and the age-prevalence and age-intensity curves were slightly convex. There was no significant difference of prevalence or intensity of infection between males and females. The condition and humidity of soil found to be an important determinant for prevalence of hook-worm infection. The frequency distribution of the intensity of hookworm infection showed an over-dispersed distribution pattern with 10% of people harboring more than 63% of parasite burden as measured by EPG. The prevalence of anemia was higher, but not statistically significant, in hookworm infected persons compared with people without infection. But this study failed to show a significant correlation between intensity of infection with hemoglobin level. There was a significant correlation between serum ferritin level with intensity of infection.