Spatial-temporal clustering analysis of soil-transmitted helminth transmission risk in Jiangxi, 2016-2019 / 中国热带医学

@#Abstract: Objective　To analyze the epidemic characteristics of soil-transmitted helminth (STH) by the spatial epidemiological method in Jiangxi Province. Methods　Surveillance data of STH in Jiangxi Province from 2016 to 2019 were collected for descriptive epidemiological analysis. The space-time permutation distribution of STH infection areas was analyzed with spatial autocorrelation, hotspot analysis methods and retrospective space-time permutation scan statistics. Results　The infection rates of STH were 1.32% (947/71 766), 1.14% (803/70 547), 0.87% (604/69 507) and 0.90% (628/69 620), respectively, and the differences were statistically significant in different years (P<0.01). The rates of hookworm infection were 0.65% (466/71 766), 0.64% (450/70 547), 0.48% (336/69 507) and 0.52% (362/69 620), respectively, and the differences were statistically significant (P<0.01). The infection rates of Ascaris lumbricoides were 0.55% (393/71 766), 0.41% (287/70 547), 0.32% (221/69 507) and 0.32% (225/69 620), respectively, and the differences were statistically significant in different years (P<0.01). The infection rates of Trichuris trichiura were 0.17% (125/71 766), 0.10% (74/70 547), 0.08% (57/69 507) and 0.07% (49/69 620), respectively, and the differences were statistically significant among different years (P<0.01). The results of global spatial autocorrelation analysis showed that there was a spatial autocorrelation index Moran's I value of hookworm infection rate in 2016, Trichuris trichiura infection rate in 2016, 2018 and 2019, with statistical significance (P<0.05). The results of hotspot analysis, SaTScan and FleXScan spatial and temporal scanning analysis showed that there were high-value aggregation regions for each species in each year. Conclusion　The infection rates of STH, hookworm, Ascaris lumbricoides and Trichuris trichiura showed a decreasing trend and space-time clustering from 2016 to 2019. It should be taken into account in the formulation of control strategies.

Prevalence of soil - borne nematode infections among residents living in urban/town areas of China in 2015 / 中国血吸虫病防治杂志

Objective To understand the prevalence of soil-borne nematode infections among residents living in urban/town areas of China, so as to provide insights into the control and elimination of soil-borne nematodiasis. Methods A total of 5 epidemic areas were classified in China according to the prevalence of human Clonorchis sinensis infections captured from the 2014–2015 national survey on major human parasitic diseases in China, and the total sample size was estimated according to the binomial distribution and Poisson’s distribution. Then, the total sample size was allocated proportionally to each province (autonomous region, municipality) of China based on the percentage of residents living in urban and town areas, and the number of survey sites in each province (autonomous region, municipality) was proportionally assigned according to the percentages of residents living in urban and town areas. Then, stratified sampling was performed at county, township and community levels according to the number of sampling sites in each province (autonomous region, municipality), and the survey site (community) was defined as the smallest sampling unit. All permanent residents in the survey sites were selected as the study subjects, and their stool samples were collected for identification and counting of parasite egg using a Kato-Katz technique. The prevalence and intensity of each parasite species were calculated. Results From 2014 to 2015, among the 133 231 residents detected in 31 provinces (autonomous regions, municipalities) of China, the overall prevalence of soil-borne nematode infections was 1.23% (1 636/133 231), and the prevalence rates of hookworm, Ascaris lumbricoides and Trichuris trichiura infections were 0.77% (1 032/133 231), 0.32% (426/133 231) and 0.17% (224/133 231), respectively. The highest prevalence of soil-borne nematode infections was seen in Jiangxi (4.03%, 82/2 034) and Chongqing (4.03%, 524/13 012), followed by in Hainan (3.47%, 72/2 075). The prevalence of soilborne nematode infections was 1.07% (662/62 139) in men and 1.37% (974/71 092) in women, and the greatest prevalence was found in residents at ages of 65 to 70 years (2.56%, 219/8 569). With regard to occupations and education levels, herdsmen (2.47%, 2/81) and illiterate residents (3.33%, 226/6 795) were found to have the highest prevalence of soil-borne nematode infections, respectively. In addition, mild infections were predominantly identified in hookworm-, A. lumbricoides- and T. trichiura-infected individuals (all > 90%). Conclusions The overall prevalence of soil-borne nematodiasis remains low in urban and town areas of China; however, human infections are widespread. According to the epidemiological features, health education combined with deworming are recommended to reduce the prevalence of soil-borne nematode infections among residents living in urban and town areas of China.

Prevalencia e intensidad de infección por geohelmintos, caracterizando los factores socio culturales y ambientales que inciden en la infección de escolares, Paraguay, 2015 / Prevalence and intensity of geohelminths infection characterizing the socio-cultural and environmental factors that affect the infection of school children, Paraguay, 2015

Resumen Introducción: Actualmente Paraguay no cuenta con estudios de prevalencia de infección por geohelmintos transmitidos por contacto con el suelo en escolares de 6 a 12 años. Objetivo: Determinar la prevalencia e intensidad de infección por Ascaris lumbricoides, Trichuris trichiura y las uncinarias y las características socio culturalesambientales de la población afectada. Materiales y Métodos: Estudio descriptivo, de corte transversal, en tres zonas climáticas: semi tropical continental, semi tropical semi estépico y semi tropical húmedo. Se seleccionaron 1.404 escolares de 20 escuelas de ocho departamentos, de las tres zonas climáticas del país. Se analizaron exámenes coproparasitológicos in situ con el método Kato-Katz. Resultados: La prevalencia nacional de geohelmintiasis fue de 3,7% (IC95% = 2,8-4,8). Los factores de riesgo fueron el consumo de agua de pozo OR: 2,88 (IC95% = 1,64-2,07), piso de tierra en la vivienda OR: 2,56 (IC95% = 1,45-4,50) y falta de baño con arrastre de agua en los hogares OR: 2,29 (IC95% = 1,23-4,28). Conclusión: A pesar de que la prevalencia nacional de geohelmintiasis fue baja, se recomienda promocionar buenas prácticas higiénicas, el uso de calzado, y consumo de agua segura, así como diseñar intervenciones con los sectores pertinentes para mejorar el acceso al agua segura y a instalaciones mejoradas de saneamiento básico.

Introduction: Currently, Paraguay has no data on the prevalence of soil-transmitted geohelminth infection in schoolchildren aged 6 to 12 years. Aim: To determine the prevalence and intensity of infection by Ascaris lumbricoides, Trichuris trichiura and hookworms and the socio-cultural-environmental characteristics of the affected population. Methods: Descriptive, cross-sectional study, in three semi-tropical climatic zones: continental, semi steppe and humid. A total of 1,404 schoolchildren from 20 schools in eight departments were selected from the country's three climate zones. Copro-parasitological exams were analyzed in situ with the Kato-Katz method. Results: The national prevalence for geohelminthiasis was 3.73% (95% CI = 2.8-4.8). The risk factors found were consumption of well water OR: 2.88 (95% CI = 1.64-2.07), ground floor in housing OR: 2.56 (95% CI = 1.45-4.50) and lack of flushing water baths in households OR: 2.29 (95% CI = 1.23-4.28). Conclusion: Although the national prevalence of geohelminthiasis was low, it is recommended to promote good hygienic practices, use of footwear, and safe water consumption, as well as designing interventions with all relevant sectors to improve access to safe water and improved basic sanitation facilities.

Is it necessary to take anthelmintics every year in Korea?

Is it necessary to intake anthelmintics every year in Korea? To answer to this question, the recent nation-wide egg positive rate of the intestinal nematodes in Korea was presented. The anthelminthics which are purchasable without physician's prescription were also introduced with their pharmacological reaction and indication. The egg positive rate of Ascaris lumbricoides in 2012 was 0.025%. Those of Trichuris trichiura and Enterobius vermicularis were 0.27% and 0.004%, respectively. In 2018, purchasable anthelmintics without physician's prescription in Korea were albendazole and flubendazole only. Those two anthelmintics were derivatives of benzimidazole that may cause some side effects such as hepatitis, increase of hepatic enzymes, granulocytopenia, or pancytopenia. These anthelmintics showed excellent effect to ascariasis; while, they are not sufficient to treat trichuriaiss. For treatment of enterobiasis, repeated taking 3 times with 3 weeks interval and mass treatment of the family of egg positive person are required. In conclusion, it is not necessary to take anthelmintics every year without specific diagnosis because of negligible egg positive rate of intestinal nematodes and complicated therapeutic module for enterobiasis. There was no specific symptom of ascariasis or trchuriasis if worm burden is not high. The common symptoms of enterobiasis were pain or itching at the perianal area, sleep difficulty, or diarrhea. If intestinal nematode infection is suspected, stool examination or perianal swab should be done before prescribing anthelmintics.

Ancient Soil-Transmitted Parasite Eggs Detected from the Sixth Century Three Kingdom Period Silla Tomb

The parasitic infection patterns of the Joseon period have begun to be revealed in a series of paleoparasitological studies. However, parasitism prevailing during or before the Three Kingdom period is still relatively unexplored. In the present study, we therefore conducted parasitological examinations of soil and organic-material sediments precipitated upon human hipbone and sacrum discovered inside an ancient Mokgwakmyo tomb dating to the Silla Dynasty (57 BCE–660 CE). Within the samples, we discovered ancient Ascaris lumbricoides (eggs per gram [EPG], 46.6–48.3) and Trichuris trichiura (EPG, 32.8–62.1) eggs, the species commonly detected among Korean populations until just prior to the 1970s. These findings show that soil-transmitted parasitic infection among the Silla nobility might not have been uncommon. This is the first-ever report on the presence of ancient parasite eggs in the samples obtained from a Three Kingdom period tomb; and it also presents the earliest positive results for any of the ancient South Korean tombs paleoparasitologically examined to date.

Infections of Soil-Transmitted Helminth in Refugees from North Korea

Soil-transmitted helminthiases (STH) are now no longer public health problems in the Republic of Korea (South Korea), but their status are unavailable in the residents of North Korea (NK) despite the expectation of large scale traffic and future reunification of the Korean Peninsula. A total of 20 female refugees from NK who had been admitted to the Division of Gastroenterology, Dankook University Hospital, were subjected in this study. Among them, 15 refugees were examined by the colonoscopy and 10 ones were examined with the stool examination (formalin-ether sedimentation). Both diagnostic methods were commonly adopted in 5 patients. Eggs of Trichuris trichiura were detected in 7 out of 10 refugees in the stool examination. In the colonoscopy, T. trichiura worms were found in 6 (40.0%) out of 15 refugees. Total 9 (45.0%) peoples were confirmed to be infected with human whipworms. Additionally, 1 case of clonorchiasis was diagnosed in the stool examination and a worm of Ascaris lumbricoides was discovered from a trichuriasis case. These findings suggested that STH is highly prevalent in NO, in which living conditions are not so good in the aspect of general hygiene and medical care.

Prevalence of Intestinal Parasites and Associated Risk Factors for Infection among Rural Communities of Chachoengsao Province, Thailand

Intestinal parasitic infections remain a major public health problem in many parts of Thailand, particularly in rural areas. This study aimed to determine the prevalence of intestinal parasitic infections and associated risk factors among the people living in Huai Sai sub-district, Bang Khla district, Chachoengsao Province, central Thailand. A cross-sectional survey was carried out from June 2017 to August 2017 which included a total of 224 participants. Stool samples were examined using a simple direct smear and formalin ethyl acetate concentration technique. Association between risk factors and intestinal parasitic infections was assessed using multivariate logistic regression analysis. The overall prevalence of intestinal parasitic infections was 16.1%. Soil-transmitted helminth infections (14.3%) were more common than protozoan infections (1.8%). The most common intestinal parasites were hookworms (6.7%) followed by Strongyloides stercoralis, (5.0%), Ascaris lumbricoides (1.3%) and Trichuris trichiura (1.3%). Entamoeba histolytica/dispar (1.0%), Giardia intestinalis (0.4%), and Blastocystis hominis (0.4%) were the protozoans identified. A high prevalence of infections was found in male participants of ≥40 years who raised dogs in the households and did not wear boots while working fields. Multivariate analysis showed a significant association of intestinal parasitic infections with gender with the adjusted odds ratio (OR) of 2.4 and 95% confidence interval (CI) of 1.1–5.2 (P=0.020). The results showed a high prevalence of soil-transmitted helminth infections among adults in rural communities which were particularly apparent regarding the skin-penetrating species of nematodes. A greater focus on intervention is required by improving sanitation and personal hygiene to prevent the spread of intestinal parasitic infections.

Trichuris trichiura Infection in North Korean Defector Resulted in Chronic Abdominal Pain and Growth Retardation / 대한소화기학회지

Trichuris trichiura infection is a common helminth infection, which is transmitted via soil, with worldwide distribution, especially in rural areas of developing countries. Occasionally, sporadic cases occur in non-endemic, developed areas due to the widespread of immigration. We experienced a case of Trichuris dysentery syndrome in a young North Korean defector, who had been suffering from chronic abdominal pain for 10 years. He is relatively short and thin compared with his older brother. Unexpectedly, the diagnosis, made by a colonoscopy, revealed numerous, small, white, and gently moving worms at the cecum and ascending colon. After 3 days of albendazole (400 mg once daily) administration, clinical symptoms subsided dramatically. On the follow-up colonoscopy, which was performed two months after the completion of his treatment, complete eradication was identified. Soil-transmitted helminths, including Trichuris trichiura, are disappearing becoming less prevalent in South Korea as a result of both national driving force and environmental improvement. However, these diseases should be considered when we meet foreign patients from developing countries, like North Korea, presenting chronic abdominal pain. Moreover, proper treatment of North Korean defectors and performing cohort studies of them would help to prepare for the possible unification era in the field of gastroenterology.

Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

A First Case of Human Trichuriasis from a Roman Lead Coffin in France

A paleoparasitological study was carried out on 2 lead coffins recovered from the Roman site of Jaunay-Clan (near Poitiers, France). For the first time, this particular type of burial gave positive parasitological results, and eggs of the whipworm Trichuris trichiura were identified in 1 individual. In the present case, thanatomorphose associated with funerary practices may explain the scarcity of the recovered eggs. However, human whipworm has now been observed in 9 individuals dated to the Roman period. The very high frequency of Trichuris sp. eggs in Roman archaeological sites (up to 80%) suggests that fecal peril, hygiene, and waste management were problematic during this period. Finally, due to the fact that very few analyses have been conducted on human bodies dated to the Roman period, more analyses must be performed in the future to provide further information about diseases in the Roman world.

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.

Performance analysis of software for identification of intestinal parasites / Análise de desempenho de software para identificação de parasitas intestinais

ABSTRACTIntroduction:Intestinal parasites are among the most frequent diagnoses worldwide. An accurate clinical diagnosis of human parasitic infections depends on laboratory confirmation for specific differentiation of the infectious agent.Objectives:To create technological solutions to help parasitological diagnosis, through construction and use of specific software.Material and method:From the images obtained from the sediment, the software compares the morphometry, area, perimeter and circularity, and uses the information on specific morphological and staining characteristics of parasites and allows the potential identification of parasites.RESULTS:Our results demonstrate satisfactory performance, from a total of 204 images analyzed, 81.86% had the parasite correctly identified by the computer system, and 18.13% could not be identified, due to the large amount of fecal debris in the sample evaluated.Discussion:Currently the techniques used in Parasitology area are predominantly manual, probably being affected by variables, such as attention and experience of the professional. Therefore, the use of computerization in this sector can improve the performance of parasitological analysis.Conclusions:This work contributes to the computerization of healthcare area, and benefits both health professionals and their patients, in addition to provide a more efficient, accurate and secure diagnosis.

RESUMOIntrodução:As parasitoses intestinais figuram entre os diagnósticos mais frequentes no mundo. Um diagnóstico clínico acurado das infecções parasitárias humanas depende da confirmação laboratorial para diferenciação específica do agente infeccioso.Objetivos:Criar formas tecnológicas para auxiliar no diagnóstico parasitológico por meio da construção e da utilização de um software específico.Material e método:A partir das imagens obtidas do sedimento, o software compara a morfometria, a área, o perímetro e a circularidade, além de utilizar informações sobre características específicas de morfologia e coloração dos parasitos e permitir a identificação dos possíveis parasitas.Resultados:Nossos resultados apontam desempenho satisfatório, sendo que do total de 204 imagens analisadas, 81,86% tiveram o parasita identificado corretamente pelo sistema computacional e 18,13% não puderam ser identificados, em função da grande quantidade de detritos fecais na amostra avaliada.Discussão:Atualmente, as técnicas realizadas no setor de Parasitologia são predominantemente manuais, sendo afetadas possivelmente por variáveis como atenção e experiência do profissional. Portanto, a utilização da informatização deste setor pode melhorar a performance das análises parasitológicas.Conclusão:O presente trabalho contribui para a informatização da área da saúde e beneficia tanto os profissionais da saúde como também seus clientes, além de proporcionar um diagnóstico mais eficiente, preciso e seguro.

Epidemiology of Hookworm Infection and the Influence of Some Epidemiological Factors on their Prevalence in Some Farming Communities in Ebonyi State, Nigeria.

Aims: This study was carried out to assess aspects of the epidemiology of hookworm infection and the influence of some epidemiological factors on their prevalence in some farming communities in Afikpo South L.G.A. of Ebonyi State. Study Design: This was a laboratory-based observational study. Place and Duration of Study: This study was carried out in the Department of Applied Biology Laboratory, Ebonyi State University, Abakaliki, Nigeria between May, 2013 and November, 2013. Methodology: A total of 442 stool samples from school children and adults were collected and examined using direct smear and formol-ether concentration techniques for the presence of the parasite eggs. Results: Out of the 442 examined, 35(7.9%) samples were positive for hookworm infections. Other helminthic infections observed were Ascaris lumbricoides 192(43.4%) and Trichuris trichiura 4(0.9%). The only mixed infections were seen between hookworm and Ascaris lumbricoides which recorded 21(4.8%) prevalence. There was no significant difference in the rate of infection with hookworm between the different age groups (X2=2.68; P>0.05), though 8-14 years age group had the highest infection rate (9.8%) while those between 21-30 had the lowest (3.5%). The sex distribution showed a higher infection rate in females with prevalence of 22(9.0%) while 13(6.6%) cases were recorded among the males, however, there was no significant difference in infection rate between the sexes (X2=0.90; P>0.05). Conclusion: This study shows that the occurrence and distribution of hookworm and other geohelminth infections were still high in Afikpo South L.G.A. despite the periodic deworming exercises by the governmental and non-governmental agencies. The different epidemiological factors analyzed including farming, use of streams and open defaecation presented the highest risk factors for hookworm infections. Hence, provision of portable drinking water, adequate sanitary disposal of faeces and refuse, health education on the mode of transmission of hookworm and improved personal hygiene should be integrated into the periodic deworming exercises for optimum result.

Tricuríase: atualidades / Trichuriasis: an update

A tricuríase - parasitose causada pelo nematódeo Trichuris trichiura - é uma das principais infecções por helmintos que afeta o homem. A enfermidade produzida por T. trichiura é mais comum em indivíduos que habitam países em desenvolvimento ou que vivem em situações de pobreza. A entidade mórbida pode afetar o desenvolvimento físico, intelectual e cognitivo e aumentar a suscetibilidade a outras doenças, como malária e tuberculose. Com base nessas considerações, no presente artigo é apresentada uma revisão sobre os aspectos mais relevantes da tricuríase.

Geohelmintiasis en la Argentina: Una revisión sistemática / Soil transmitted helminthiasis in Argentina: A systematic review

Con el objetivo de analizar la prevalencia y distribución de las geohelmintiasis en la Argentina e identificar las áreas de mayor riesgo, realizamos una revisión sistemática de los estudios poblacionales publicados entre 1980 y 2011, indexados en las bases MEDLINE/ PUBMED y/o LILACS. También se incluyeron los datos de prevalencia basal del Programa Nacional de Desparasitación Masiva (PNDM, 2005). Se identificaron 310 publicaciones, de las que solo 24 artículos con información sobre 26 relevamientos, realizados en 8 provincias y un total de 5495 individuos evaluados, cumplían los criterios de inclusión. La prevalencia de geohelmintiasis varió ampliamente: Ascaris lumbricoides 0-67%, uncinarias 0-90%, Trichuris trichiura 0-24.5%, Strongyloides stercoralis 0-83%. La prevalencia acumulada estimada de los 4 geohelmintos principales varió entre 0.8 y 88.6%. Los datos basales del PNDM con información de 1943 niños de 12 provincias confirman esta heterogeneidad con rangos de prevalencia acumulada entre 0 y 42.7%. Los estudios incluidos en esta revisión muestran que la distribución de geohelmintiasis en la Argentina es heterogénea, con focos de alta prevalencia (> 20%) en el noreste y noroeste del país, los que podrían beneficiarse de una estrategia de desparasitación masiva. En muchos casos esta alta prevalencia es debida a uncinarias y estrongiloidiosis, lo que debe tenerse en cuenta para definir las estrategias diagnósticas y terapéuticas para su control. Asimismo, se resalta la escasez o ausencia de datos, con información de menos de la mitad de las provincias y menos de 8000 individuos evaluados.

A systematic review of surveys performed between 1980 and 2011 (published in MEDLINE/Pubmed and/or LILACS indexed journals, available in the baseline data from a Mass Deworming National Program (MDNP, 2005) was used to identify the prevalence, distribution and detection of risk areas for soil transmitted helminth infections (STH) in Argentina. We found 310 publications in the database using the pre-defined key-words (medical subject headings) for research purposes. Only 24 articles with 26 surveillance sites in 8 provinces and a total of 5495 surveyed individuals fulfilled the inclusion criteria. Frequency rates for STH had a wide range: Ascaris lumbricoides: 0-67%, hookworms: 0-90%, Trichuris trichiura: 0-24.6 and Strongyloides stercoralis: 0-83%. The estimated combined incidence varied from 0.8% to 88.6%. Baseline surveys from the MDNP reporting on 1943 children from 12 provinces confirmed the heterogeneity, with combined STH frequency rates ranging from 0 to 42.7%. Surveys included in this review showed that the distribution of STH in Argentina is not homogeneous, with areas of high incidence (> 20%) in the northeastern and northwestern provinces where mass deworming activities would be highly beneficial. In several surveys, the high overall incidence was mostly due to hookworms and S. stercoralis, a situation to be considered when selecting diagnostic and therapeutic control strategies. The scarcity or absence of data from various provinces and the availability of less than 8000 surveyed individuals should be considered.

V-shaped Pits in Regions of Ancient Baekje Kingdom Paleoparasitologically Confirmed as Likely Human-Waste Reservoirs

In a paleo-parasitological analysis of soil samples obtained from V-shaped pits dating to the ancient Baekje period in Korean history, we discovered Ascaris lumbricoides, Trichuris trichiura, and Clonorchis sinensis eggs. In light of the samples' seriously contaminated state, the V-shaped pits might have served as toilets, cesspits, or dung heaps. For a long period of time, researchers scouring archaeological sites in Korea have had difficulties locating such structures. In this context then, the present report is unique because similar kind of the ancient ruins must become an ideal resource for successful sampling in our forthcoming paleoparasitological studies.

Frecuencia de parásitos intestinales y evaluación de métodos para su diagnóstico en una comunidad marginal de Medellín, Colombia / Frequency of intestinal parasites and evaluation of methods for their diagnosis in a marginal community of Medellin, Colombia

Introducción: las parasitosis intestinales siguen siendo un problema de salud pública, que ha sido poco estudiado en Medellín, Colombia. Objetivo: determinar la frecuencia de parasitismo intestinal en habitantes de una comunidad marginal de Medellín y evaluar la validez, el desempeño, la eficiencia y la confiabilidad del examen directo en su diagnóstico. Materiales y métodos: estudio transversal y de evaluación de pruebas diagnósticas con fuente de información primaria. Se calcularon las proporciones con su intervalo de confianza y se hicieron pruebas de estadística no paramétrica y análisis de sensibilidad, especificidad, valores predictivos, razón de verosimilitud negativa y kappa. Resultados: la frecuencia global de parásitos, según el examen por concentración, fue 74,4%; la evaluación se hizo para parasitismo general y para las categorías protozoos, helmintos, comensales y patógenos; se hallaron sensibilidad superior al 68%, especificidad y valor predictivo positivo del 100%, valor predictivo negativo mayor de 74%, razón de verosimilitud negativa menor de 0,32, kappa superior a 0,77 y eficiencia superior al 90%. Conclusión: el problema del parasitismo intestinal amerita una pronta intervención por parte de las autoridades sanitarias dado que su frecuencia sigue siendo tan elevada como hace tres décadas y las pruebas disponibles para estudiarlo, incluyendo el examen directo de la materia fecal, tienen alto valor diagnóstico.

Background: Intestinal parasitism is still a public health problem. It has not been thoroughly studied in Medellin, Colombia. Objective: To determine the prevalence of intestinal parasites in residents of a marginal community in Medellin and to evaluate the validity, efficiency and reliability of direct examination in its diagnosis. Methods:Cross-sectional study and evaluation of diagnostic tests. Data were collected from a primary information source. Proportions with their confidence intervals were calculated; non-parametric statistical tests and analysis of sensitivity, specificity, predictive values, negative likelihood ratio and kappa were done. Results: Prevalence of parasites, according to the results of the concentration test, was 74.4%. Evaluation was done for intestinal parasites in general and for the following categories: protozoa, helminthes, commensals and pathogens. Sensitivity war over 68%, specificity and positive predictive value were 100%, negative predictive value was over 74%, negative likelihood ratio was less than 0.32, kappa was greater than 0.77 and efficiency was over 90%. Conclusion: Prevalence of intestinal parasitism is as high as it was three decades ago; its solution needs prompt and effective intervention of health authorities. The tests available for its study, including direct examination of stools, are of high diagnostic value.

Evaluación de tres técnicas coproparasitoscópicas para el diagnóstico de geohelmintos intestinales / Evaluation of three coproparasitoscopic techniques for the diagnosis of intestinal geohelminthiases

Introducción: las geohelmintiasis son un problema de salud pública; sin embargo, para su diagnóstico no se ha establecido una técnica de referencia (estándar de oro) sino que se han empleado diferentes pruebas coproparasitoscópicas con distintas tasas de sensibilidad. Objetivo: determinar la sensibilidad de la técnica coproparasitoscópica de Kato-Katz frente a la combinación del examen directo y la concentración de Ritchie para detectar geohelmintos y establecer el grado de infección. Metodología: se comparó la técnica de Kato-Katz con la combinación del coprológico directo y por concentración de Ritchie, estas dos últimas tomadas como estándar de oro, en 90 muestras de materia fecal provenientes de niños del barrio La Cruz, localizado en el Nororiente de Medellín. Resultados: la sensibilidad de la técnica de Kato-Katz para el diagnóstico de infecciones por geohelmintos fue similar a la obtenida con la combinación del coprológico directo y por concentración. Conclusión: la técnica de Kato-Katz da resultados confiables con alta sensibilidad para el diagnóstico de las geohelmintiasis intestinales más frecuentes en Colombia.

Introduction: Soil transmitted helminths (geohelminthiases) are a worldwide public health problem. However, no reference technique (gold standard) for their diagnosis has been established; contrariwise, several coproparasitoscopic tests, with variable sensibility rates, have been used. Objective: To compare the sensibility of the coproparasitoscopic Kato-Katz technique with that of the combination of direct coprologic examination and Ritchie's concentration, for the detection of geohelminths, and to determine the degree of infection. Methodology: The comparison was made in 90 stool specimens obtained from school children living in a low-income community in Medellín, Colombia. Results: Sensibility of the Kato-Katz technique was similar to the one obtained with the combination of direct microscopic examination and coprology by concentration. Conclusion: The Kato-Katz technique provides reliable results with high sensibility rate for the diagnosis of the intestinal geohelminths more frequent in Colombia.

Paleoparasitological Surveys for Detection of Helminth Eggs in Archaeological Sites of Jeolla-do and Jeju-do

A paleoparasitological survey to detect helminth eggs was performed in archaeological sites of Jeolla-do and Jeju-do, the Republic of Korea. Total 593 soil samples were collected in 12 sites of Jeolla-do and 5 sites of Jeju-do from April to November 2011, and examined by the methods of Pike and coworkers. A total of 4 helminth eggs, 2 eggs each for Trichuris trichiura and Ascaris sp., were found in soil samples from 1 site, in Hyangyang-ri, Jangheung-eup, Jangheung-gun, Jeollanam-do. The egg-recovery layer was presumed to represent a 19th century farm, which fact suggested the use of human manures. This is the third archaeological discovery of parasite eggs in Jeolla-do. Additionally, no helminth eggs in archaeological sites of Jeju-do is an interesting problem to be solved in the further investigations.

Ivermectin: pharmacology and therapeutic applications.

Ivermectin is an antiparasitic drug with a broad spectrum of activity, high efficacy as well as a wide margin of safety. It belongs to the family of avermectins. It binds to glutamate-gated chloride iron channels, which are present in invertebrate nerve and muscle cells, and causes the paralysis and death of the parasite. Ivermectin is approved by the US Food and Drug Administration, and used worldwide to treat patients with onchocerciasis and strongyloidiasis. It is also used against a wide range of endoparasites (nematodes) and ectoparasites (insects, acarine) of animals and humans.