Impact of ivermectin mass drug administration on burden of soil-transmitted helminths in onchocerciasis control and elimination programs, Yeki district, southwest Ethiopia.

Community-directed treatment with ivermectin (CDTi) is the primary strategy employed to control and eliminate human onchocerciasis in Ethiopia. After long-term mass distribution for onchocerciasis, ivermectin is expected to have additional benefits beyond the envisioned targets by reducing the burden of other co-endemic parasitic infections as to STHs. To date, studies focused on the collateral impact of CDTi on STH in Ethiopia are scanty. Two community-based cross-sectional surveys (baseline in 1997 and post-CDTi in 2017) were conducted to evaluate the impact of long-term CDTi employed to control and eliminate onchocerciasis on the burden of STH infections in Yeki district of southwest Ethiopia. Stool samples were collected and examined using Ritchie`s concentration and Kato-Katz techniques in the baseline and current study, respectively. Overall, 188(38.3%, 95% Confidence interval (CI) 34.1-42.7%) individuals were positive at least for any of the STH species from 491 study participants in the post-CDTi. The prevalence of A. lumbricoides, hookworms, and T. trichiura was 11.2% (95% CI 8.7-14.3%), 16.3% (95% CI 13.3-19.8%), and 29.9% (95% CI 26.1-34.1%), respectively. Individuals aged 5-9 years had a significantly higher prevalence of A. lumbricoides (Adjusted odds ratio (AOR) 6.5, 95% CI 1.7-25.4), T. trichuria (AOR 8, 95% CI 2.6-25.1), and any STH infection (AOR 5, 95% CI 1.7-14.7) than those of ≥ 51 years. Also, significantly higher prevalences of T. trichuria infection were observed in individuals aged 10-14 years (AOR 4.1, 95% CI 1.7-9.9), 15-20 years (AOR 3.1, 95% CI 1.2-8.1), 21-30 years (AOR 2.4, 95% CI 1.1-5.5), and 31-40 years (AOR 3.2, 95% CI 1.3-7.5) compared with those of ≥ 51 years. The prevalence of A. lumbricoides was significantly higher in males (AOR 0.5, 95% CI 0.3-0.9). Of the 491 study participants, only data from 400 individuals who had not been involved in a mass drug administration (MDA) with other STH anthelmintics were considered in the comparative analysis. Before CDTi, the prevalence of A. lumbricoides, T. trichiura, hookworm, and any STH infection was 47.1% (95% CI 41.6-52.7%), 3.3% (95% CI 1.8-5.9%), 37.9% (95% CI 32.7-43.5%), and 58.8% (95% CI 53.2-64.1%), respectively. Long-term CDTi considerably reduced the prevalences of A. lumbricoides and hookworm by 76.2% and 56.9%, respectively (p < 0.001). Nonetheless, CDTi did not affect the prevalence of T. trichiura infection and, in contrast, it was significantly higher in the current study (P < 0.001). Overall post-CDTi prevalence of any STH infection was considerably lower than reported in the baseline (p < 0.001). It is evidenced that long-term CDTi for onchocerciasis control and elimination had additional benefits by reducing the prevalence of STH infections specifically of A. lumbricoides and hookworm, but had no impact on infections with T. trichuria. Our finding of additional health benefits of large-scale ivermectin administration taking it will aid to increase positive engagement and sustain participation of communities during MDA campaigns, and strengthen governmental and non-governmental organizations (NGOs) support for the undergoing national onchocerciasis elimination program.

Impact of Semi-Annual Albendazole on Lymphatic Filariasis and Soil-Transmitted Helminth Infection: Parasitological Assessment after 14 Rounds of Community Treatment.

Between October 2012 and October 2015, we conducted a community trial to assess the impact of semi-annual (twice yearly) community treatment with albendazole on lymphatic filariasis in Seke Pembe, a village in the Republic of the Congo. Semi-annual community treatment with albendazole has been continued in the community since October 2015. We conducted an additional parasitological assessment survey in October 2019, 6 months after the 14th round of semi-annual treatment. Between October 2012 and October 2015, Wuchereria bancrofti antigenemia and microfilaremia rates in the community had decreased from 17.3% to 4.7% and from 5.3% to 0.3%, respectively. In October 2019, the antigenemia rate had decreased further to 2.8% (19 of 687). No microfilariae were found in night blood smears from persons with circulating filarial antigenemia (0 of 16), suggesting that W. bancrofti transmission has been interrupted in Seke Pembe. Semi-annual albendazole treatments also reduced significantly infection rates with soil-transmitted helminths.

Impact of Annual versus Semiannual Mass Drug Administration with Ivermectin and Albendazole on Helminth Infections in Southeastern Liberia.

We compared the impact of three rounds of annual and five rounds of semiannual mass drug administration (MDA) with albendazole plus ivermectin on helminthic infections in Liberia. Repeated annual cross-sectional community surveys were conducted between 2013 and 2019 in individuals of 5 years and older. Primary outcome was the change of infection prevalence estimates from baseline to month 36 (12 months after the last treatment). After three rounds of annual MDA, Wuchereria bancrofti circulating filarial antigen (CFA) and microfilaria (Mf) prevalence estimates decreased from 19.7% to 4.3% and from 8.6% to 0%, respectively; after semiannual MDA, CFA and Mf prevalences decreased from 37.8% to 16.8% and 17.9% to 1%, respectively. Mixed effects logistic regression models indicated that the odds of having Mf decreased by 97% (P < 0.001) at month 36 (similar odds for annual and semiannual MDA zones). A parallel analysis showed that the odds of CFA were reduced by 83% and 69% at 36 months in the annual and semiannual treatment zones, respectively (P < 0.001). Onchocerca volvulus Mf prevalence decreased slightly after multiple MDA rounds in both treatment zones. Reductions in hookworm and Trichuris trichiura prevalences and intensities were slightly greater in the annual treatment zone. Ascaris lumbricoides prevalence rates were relatively unchanged, although infection intensities decreased sharply throughout. Results show that annual and semiannual MDA were equally effective for reducing LF and soil-transmitted helminth infection parameters over a 3-year period, and reductions recorded at month 36 were sustained by routine annual MDA through month 72.

Impact of Anthelmintic Price Increases on Practice Patterns of Healthcare Providers Caring for Immigrant and Refugee Populations in the United States.

In the United States, prices of long-established, generic anthelmintic medications have markedly risen. In the past decade, albendazole and mebendazole have increased in price by > 8,000%, whereas praziquantel has increased by > 500%. To determine the effect of these price increases on the practice patterns of healthcare providers, we conducted a cross-sectional electronic survey of clinics in the United States that primarily care for immigrant and refugee patient populations. Among 32 clinics, 53.1% reported that price increases impacted how providers diagnosed and treated helminth infections. A third (34.4%) of clinics reported that price increases have left them unable to treat known helminth infections. Other ways in which price increases impacted practice patterns included prescribing anthelmintics other than albendazole, mebendazole, or praziquantel when possible (34.4%); avoiding screening asymptomatic patients for helminth infections (15.6%); advising patients to acquire medications from another country (15.6%) or the patient's home country (9.4%); reducing anthelmintic dosing regimens to fewer pills (9.4%); and advising patients to purchase medications on the Internet (6.3%). These findings suggest price increases have negatively impacted the diagnosis and treatment of helminth infections in this population, and have resulted in the inability to treat known helminth infections. These findings have significant implications for the morbidity and mortality of infected individuals, as well as for public health in the United States.

Identifying thresholds for classifying moderate-to-heavy soil-transmitted helminth intensity infections for FECPAKG2, McMaster, Mini-FLOTAC and qPCR.

The World Health Organization (WHO) has defined moderate-to-heavy intensity (M&HI) infections with soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and the two hookworms, Ancylostoma duodenale and Necator americanus) based on specific values of eggs per gram of stool, as measured by the Kato-Katz method. There are a variety of novel microscopy and DNA-based methods but it remains unclear whether applying current WHO thresholds on to these methods allows for a reliable classification of M&HI infections. We evaluated both WHO and method-specific thresholds for classifying the M&HI infections for novel microscopic (FECPAKG2, McMaster and Mini-FLOTAC) and DNA-based (qPCR) diagnostic methods. For this, we determined method-specific thresholds that best classified M&HI infections (defined by Kato-Katz and WHO thresholds; reference method) in two multi-country drug efficacy studies. Subsequently, we verified whether applying these method-specific thresholds improved the agreement in classifying M&HI infections compared to the reference method. When we applied the WHO thresholds, the new microscopic methods mainly misclassified M&HI as low intensity, and to a lesser extent low intensity infection as M&HI. For FECPAKG2, applying the method-specific thresholds significantly improved the agreement for Ascaris (moderate → substantial), Trichuris and hookworms (fair → moderate). For Mini-FLOTAC, a significantly improved agreement was observed for hookworms only (fair → moderate). For the other STHs, the agreement was almost perfect and remained unchanged. For McMaster, the method-specific thresholds revealed a fair to a substantial agreement but did not significantly improve the agreement. For qPCR, the method-specific thresholds based on genome equivalents per ml of DNA moderately agreed with the reference method for hookworm and Trichuris infections. For Ascaris, there was a substantial agreement. We defined method-specific thresholds that improved the classification of M&HI infections. Validation studies are required before they can be recommended for general use in assessing M&HI infections in programmatic settings.

Macrofilaricides: An Unmet Medical Need for Filarial Diseases.

Neglected parasitic helminth diseases such as onchocerciasis and lymphatic filariasis affect an estimated 145 million people worldwide, creating a serious health burden in endemic areas such as sub-Saharan Africa and India. Although these diseases are not usually lethal, these filarial nematodes, transmitted by blood-feeding insect vectors, cause severe debilitation and cause chronic disability to infected individuals. The adult worms can reproduce from 5 to up to 14 years, releasing millions of microfilariae, juvenile worms, over an infected individual's lifetime. The current treatments for controlling human filarial infections is focused on killing microfilariae, the earliest larval stage. Currently, there is an unmet medical need for treatments consisting of a macrofilaricidal regimen, one that targets the adult stage of the parasite, to increase the rate of elimination, allow for safe use in coendemic regions of Onchocerca volvulus and Loa loa, and to provide a rapid method to resolve reinfections. Herein, recent approaches for targeting human filarial diseases are discussed, including direct acting agents to target parasitic nematodes and antibacterial approaches to target the endosymbiotic bacteria, Wolbachia.

Helminths in organ transplantation.

With transplantation becoming an increasingly routine form of treatment for diverse populations, and with international travel becoming ever more accessible and affordable, the danger of transplantation-mediated helminth infections, exacerbated by coincident immunosuppression, must be considered. In this Review, we attempt to catalogue all clinically-relevant helminthiases that have been reported to coincide with transplantation, whether by transplantation-mediated transmission, reactivation of latent infections in an immunosuppressed context, or possible de-novo infection during the immunosuppressed peritransplant period. Helminthiasis has been reported in cases of kidney, liver, bowel, pancreas, heart, lung, and stem-cell transplant, and blood transfusion. For each helminthiasis, known risk factors, symptoms, and suggested options for screening and treatment are given. We conclude that helminths are a small but important and potentially severe source of disease after transplantation, and, with options for diagnosis and treatment, these pathogens warrant greater consideration during organ implantation. The achievement of immunological tolerance using helminth-derived products is also an exciting future prospect.

Ocular parasitoses: A comprehensive review.

Parasitic infections of the eyes are a major cause of ocular diseases across the globe. The causative agents range from simple organisms such as unicellular protozoans to complex metazoan helminths. The disease spectrum varies depending on the geographic location, prevailing hygiene, living and eating habits of the inhabitants, and the type of animals that surround them. They cause enormous ocular morbidity and mortality not because they are untreatable, but largely due to late or misdiagnosis, often from unfamiliarity with the diseases produced. We provide an up-to-date comprehensive overview of the ophthalmic parasitoses. Each section describes the causative agent, mode of transmission, geographic distribution, ocular pathologies, and their management for common parasites with brief mention of the ones that are rare.

La prevalencia de geohelmintiasis se relaciona con las condiciones socioambientales / The prevalence of geohelminthiasis is related to socio-environmental conditions

Se realizó un estudio socioambiental y parasitológico en niños de áreas urbanas, periurbanas y rurales de las provincias de Buenos Aires y Misiones. Se completó una encuesta epidemiológica y se tomaron muestras fecales seriadas, las cuales se analizaron mediante técnicas de flotación y sedimentación. Del total de muestras fecales (1893), 5.5% fueron positivas en Buenos Aires y 25.6% en Misiones. El área periurbana de Misiones presentó la mayor prevalencia de parasitosis total (34.1%) y de biparasitados y poliparasitados (45.4%). Las especies más prevalentes fueron Strongyloides stercoralis (22.1%) en el sector periurbano y Ancylostomideos (21.6%) en el área rural de Misiones. Hymenolepis nana y Ascarislumbricoides mantuvieron bajas frecuencias en ambas provincias y Trichuris trichiura sólo se encontró en el periurbano de Buenos Aires. La prevalencia de geohelmintos aumentó con la edad (p < 0.05) y se asoció en el área periurbana de ambas provincias y rural de Misiones con las condiciones socioambientales: vivienda precaria, piso de tierra, eliminación de excretas en letrinas o a cielo abierto, sin recolección domiciliaria de residuos, madre sin actividad laboral, padres sin instrucción primaria (p < 0.05). Las características biogeográficas y las condiciones socioambientales de la provincia de Misiones favorecen la persistencia de las formas parasitarias en el ambiente.(AU)

La prevalencia de geohelmintiasis se relaciona con las condiciones socioambientales / The prevalence of geohelminthiasis is related to socio-environmental conditions

Se realizó un estudio socioambiental y parasitológico en niños de áreas urbanas, periurbanas y rurales de las provincias de Buenos Aires y Misiones. Se completó una encuesta epidemiológica y se tomaron muestras fecales seriadas, las cuales se analizaron mediante técnicas de flotación y sedimentación. Del total de muestras fecales (1893), 5.5% fueron positivas en Buenos Aires y 25.6% en Misiones. El área periurbana de Misiones presentó la mayor prevalencia de parasitosis total (34.1%) y de biparasitados y poliparasitados (45.4%). Las especies más prevalentes fueron Strongyloides stercoralis (22.1%) en el sector periurbano y Ancylostomideos (21.6%) en el área rural de Misiones. Hymenolepis nana y Ascarislumbricoides mantuvieron bajas frecuencias en ambas provincias y Trichuris trichiura sólo se encontró en el periurbano de Buenos Aires. La prevalencia de geohelmintos aumentó con la edad (p < 0.05) y se asoció en el área periurbana de ambas provincias y rural de Misiones con las condiciones socioambientales: vivienda precaria, piso de tierra, eliminación de excretas en letrinas o a cielo abierto, sin recolección domiciliaria de residuos, madre sin actividad laboral, padres sin instrucción primaria (p < 0.05). Las características biogeográficas y las condiciones socioambientales de la provincia de Misiones favorecen la persistencia de las formas parasitarias en el ambiente.

Visceral helminths of wild boars (Sus scrofa leucomystax) in Japan, with special reference to a new species of the genus Morgascaridia Inglis, 1958 (Nematoda: Schneidernematidae).

Twenty-nine Japanese wild boars (Sus scrofa leucomystax), collected during the hunting seasons of 2005 and 2006 in the western part of the mainland of Japan (Honshu), were examined for their visceral helminths. Eighteen helminth parasites were prevalent in them, including 17 Nematoda species (Metastrongylus elongatus, Metastrongylus salmi, Metastrongylus asymmetricus, Metastrongylus pudendotechus, Stephanurus dentatus, Gnathostoma doloresi, Physocephalus sexulata, Ascarops strongylina, Capillaria suis, Ascaris suum, Globocephalus samoensis, Globocephalus longimucronatus, Strongyloides ransomi, Trichuris suis, Bourgelatia diducta, Oesophagostomum dentatum, and Oesophagostomum watanabei), and one Cestoda species (Pseudanoplocephala nipponensis). Muscle digestion of the diaphragm (using an artificial gastric juice) of 24 wild boars detected a single diplostomulum of probably Pharyngostomum cordatum. In addition, four female and six male adults of Morgascaridia kugii sp. n. (Nematoda: Schneidernematidae) were recovered from the large intestine of a single wild boar. Examination of an additional 20 samples of the stomach and 27 samples of the large intestine could not find this species. To date, recorded species of the genus Morgascaridia are limited to M. sellsi collected from wild boars in Uganda and Congo several decades ago, and thence, no records of the recovery are available. Morgascaridia kugii sp. n. differed from M. sellsi by smaller body dimensions, shorter distance between the precloacal sucker and the cloaca, smaller sizes of the copulatory spicules and the gubernaculum, and smaller sizes of uterine eggs.

The influence of pregnancy on intestinal parasite infection in Thai women.

The relationship between pregnancy and both the susceptibility and pathogenicity of parasite infections is disputed. This study compares the prevalence and intensity (as measured by density of eggs in stool samples) of intestinal helminth infections in pregnant and control groups of women from Khon Kaen Province in the northeast of Thailand. Stool samples were taken at the end of the first, second and third trimesters of pregnancy as well as 2 months after parturition and compared for the two groups. There were no significant changes in the prevalence of any of the common helminth species during the course of pregnancy or between the pregnant and control groups. Nor was there any evidence that the density of helminth eggs in the stool samples differed between sample times or between the pregnant and control groups. Our study therefore supports the hypothesis that pregnancy does not influence the course of human infection with helminths.

Seasonal prevalence of intestinal parasites in the United States during 2000.

One-third of 5,792 fecal specimens from 2,896 patients in 48 states and the District of Columbia tested positive for intestinal parasites during the year 2000. Multiple infections with 2-4 parasitic species constituted 10% of 916 infected cases. Blastocystis hominis infected 662 patients (23% or 72% of the 916 cases). Its prevalence appears to be increasing in recent years. Eighteen other species of intestinal parasites were identified. Cryptosporidium parvum and Entamoeba histolytica/E. dispar ranked second and third in prevalence, respectively. Prevalence of infection was lowest (22-27%) in winter, gradually increased during the spring, reached peaks of 36-43% between July and October, and gradually decreased to 32% in December. A new superior method of parasite detection using the Proto-fix-CONSED system for fixing, transport, and processing of fecal specimens is described. In single infections, pathogenic protozoa caused asymptomatic subclinical infections in 0-31 % of the cases and non-pathogenic protozoa unexpectedly caused symptoms in 73-100% of the cases. The relationship between Charcot-Leyden crystals and infection with four species of intestinal parasites is examined and the list of provoking parasitic causes is expanded.

[Travassosius rufus (Trichostrongylidae)--new for Poland nematode of beavers and comments about helminthfauna of these animals]. / Travassosius rufus (Trichostrongylidae)--nowy dla Polski nicien bobrów i uwagi o helmintofaunie tych zwierzat.

Two females of beaver from north-east Poland were necropsied. Moreover, 15 samples of feaces were examinated. Both necropsied beavers were infected with 46 and 362 specimens of trematode Stichorchis subtriquetrus (RUDOLPHI 1814). In stomach of one beaver were found 2800 specimens of nematode Travassosius rufus Khalil, 1922. It was the first registration of this species in Poland. Coproscopical examination showed eggs of S. subtriquetrus in all 15 fecal samples and eggs T. rufus in 5 samples.

[Occurrence of helminths in slaughtered sheep in Upper Bavaria. 2. Relationship between fecal egg count and worm burden]. / Untersuchungen zum Helminthenbefall von Schlachtschafen in Oberbayern 2. Mitt.: Beziehungen zwischen der Eiausscheidung und der Wurmbürde.

The relationship between the faecal egg count and the worm burden of the gastrointestinal tract of sheep was examined. Close relationships were found in strongyles, Trichostrongylidae (other than Nematodirus spp.), Nematodirus spp., Strongyloides papillosus, Chabertiidae and Trichuris spp.. Due to high percentage of false negative diagnosis from faecal examination, this relationship was in Nematodirus spp. and Trichuris spp. not as close as in the other nematodes. However, the results support the high diagnostic value of quantitative faecal examinations in sheep.

Coccidial and helminth infections in goats kept indoors in the Netherlands.

An investigation was carried out on coccidial and helminth infections in goats kept indoors on five farms in the Netherlands. The goats were individually sampled. Coccidial oocysts were identified and nematode eggs counted. Larval cultures were made and infective larvae identified to the generic or species level. The goats were divided into three groups according to their age: kids, those weaned but not served, and older goats. Oocysts were found in 26 out of 27 kids (96.3%), in 52 out of 55 weaned but not served goats (94.5%), and in 72 out of 110 older goats (65.5%). Eimeria ninakohlyakimovae was the most common species in all groups with an overall prevalence of 82%, followed by Eimeria arloingi (78%) and Eimeria aspheronica (53.3%). Other species present were Eimeria alijevi (50%), Eimeria christenseni (39.3%), Eimeria caprina (38.7%), Eimeria hirci (28.7%) and Eimeria jolchijevi (7.3%). Nematode eggs were seen on four of the five farms. It appeared that on two farms some goats, although now kept indoors, had been on pasture in the past. These goats excreted low numbers of eggs of Ostertagia and/or Trichostrongylus, Strongyloides papillosus, Haemonchus contortus, Trichuris spp. and larvae of Muellerius capillaris. In goats that were kept exclusively indoors, infections with Strongyloides papillosus were found on two farms in the older group and on one farm also in the group weaned but not served. On two farms Skrjabinema ovis was incidentally observed by the farmer in older goats. This was confirmed by faecal examinations on one farm. All kids were free of nematode infection.

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

Investigación seroepidemiológica de algunas helmintiasis tisulares mediante la reacción de hemaglutinación indirecta en la comuna de Lonquimay, Chile / Seroepidemiological research of some tissue helminthiasis using an indirect hemagglutination test in the Lonquimay county, Chile

In order to have a present perspective on the prevalence on the epidemiology of some tissue helminthiasis in Lonquimay county, southern Chile, in 1993 a seroepidemiological survey, by means an indirect hemagglutination test (IHAT) for hydatidosis, cysticerosis and trichinosis was undertaken. In 11 (1,2 for percent) and 6 (0,6 for percent) out of 945 examined persons, most of them from rural areas, the corresponding IHAT resulted positive. Addicionally, radigraphic and ecotomographical studies for thorax and abdomen respectively were performed to the 11 individuals with serology positive for hydatidosis: whereas all the thoraxic radiographies resulted negative, liver hydatic cysts were detected in five persons, who latter on were submitted to surgery. Prevalence rates of hydatidosis in Lonquimay are among the highest regional and national values