Spontaneous Sedimentation Technique Research Articles

AVALIAÇÃO PARASITOLÓGICA DE ALFACE EM FEIRAS E MERCADOS NO MUNICÍPIO DE RIO BRANCO, ACRE.

Introduction: The search for a healthy diet has grown over the last few decades, making the population opt for natural products, resulting in the intake of raw vegetables, with lettuce (Lactuca sativa L.) being one of the most consumed in the world; hygiene is necessary to reduce risks. The main contamination is due to poor sanitary conditions in the irrigation of vegetables, planting and inadequate handling of these leafy vegetables. The topic is relevant because they represent a serious public health problem. Objectives: to carry out a parasitological evaluation of lettuce (Lactuca sativa L.) sold in the municipality of Rio Branco, Acre. Methods: Lettuce samples of the species (Lactuca sativa L.) sold in 3 open-air markets were collected: Mercado Municipal Elias Mansour, Central de Abastecimento de Rio Branco (Ceasa) and Feira Livre and in different supermarkets X and Y in the municipality of Rio Branco , Ac. Methods: Lettuce samples of the species (Lactuca sativa L.) sold in 3 open-air markets were collected: Mercado Municipal Elias Mansour, Central de Abastecimento de Rio Branco (Ceasa) and Feira Livre and in different supermarkets X and Y in the municipality of Rio Branco , Ac. 5 samples were collected from each of the 5 units, totaling 25 samples per month and 250 between the months of July/2022 to November/2022 and February/2023 to June/2023. Subsequently, transported to the Parasitology Laboratory of the Uninorte University Center (UNINORTE). Leaves were established as the sampling unit for vegetables. 200g of leaf was weighed, sliced and separated for parasitological analysis and hygiene technique. To search for enteroparasites, the leaves were washed with 500 ml of distilled water containing 0.5 ml of neutral detergent. The liquid was used for the Spontaneous Sedimentation and Faust techniques. For the hygiene technique, 200g of leaves were submerged in a solution containing 1000 ml of distilled water and 10 ml of sodium hypochlorite (2%), homogenized for 10 min. Subsequently, the liquid was used to perform the spontaneous sedimentation technique. Results: To analyze diversity, the Shannon Wiener indices were used. In parasitological techniques, 51 parasitic agents were identified, with Balantidium coli (7.2%), Entamoeba coli (6.8%), Endolimax nana (4.4%), Larva of Strongyloides stercoralis (0.8%), followed by of Entamoeba histolyrica (0.4%), Arcella vulgaris (0.4%), and Enterobius vermicularis larvae (0.4%). Among the lettuce sales units, those with the highest prevalence were: Supermercado Y (27.5%), Mercado X (23.6%), Feira Livre (25.4%), CEASA (15.7%) and Elias Mansour (7.8%). Protozoa represented (94.1%) and Helminths (5.9%). Faust represented (56.8%) of the parasites found, compared to (43.2%) from the spontaneous sedimentation technique. No parasitic forms were found after the sodium hypochlorite cleaning technique. Conclusions: Lettuces sold in Rio Branco/AC contained different types of protozoa and helminths, with the most common enteroparasites being Balantidium coli and Entamoeba coli. The hygiene technique proved to be effective in eliminating these agents. Ingesting raw lettuce may present a potential risk to consumers, and it is recommended to clean it before consumption.

Prevalence of Entamoeba histolytica/dispar and Giardia lamblia infections and their associated factors among schoolchildren in the Amhara region, Northwest Ethiopia

Globally, intestinal protozoa E. histolytica/dispar and Giardia lamblia are the cause of amoebiasis and giardiasis, respectively. Despite their important medical importance and common occurrence in Ethiopia, they are minimally addressed in terms of their prevalence, sensitive diagnostic methods, and associated risk factors. Infections with E. histolytica/dispar and G. lamblia are often misdiagnosed and underreported in impoverished countries. Thus, the purpose of this study was to ascertain the prevalence of Giardia lamblia and E. histolytica/dispar infections as well as related variables among schoolchildren in the Amhara region. A cross-sectional study was conducted among 844 schoolchildren in the Amhara region from April to December 2019. A stool sample was collected from each study participant and processed via the formol ether concentration technique (FECT) and spontaneous tube sedimentation techniques (STST). Data were entered in EpiData and analysed by SPSS statistical software. The prevalence of E. histolytica and G. lamblia infections using each diagnostic method and composite reference was determined by descriptive statistics. The association of risk factors with E. histolytica/dispar and G. lamblia infections was analysed by logistic regression and variables with p < 0.05 were considered to have statistical significance. From the total, 243 (28.8%) schoolchildren were found to be infected by at least one of E. histolytica/dispar or G. lamblia. The prevalence of E. histolytica/dispar and G. lamblia infections was 201 (23.8%) and 62 (7.3%), respectively. The co-infection prevalence with both E. histolytica/dispar and G. lamblia was 22 (2.6%). The sensitivity (78.6%) and negative predictive value of STST (19.6%) were higher than FECT sensitivity (65.4%) and negative predictive value (13.1%). Children in 10–14 years of age (AOR = 1.66;95%CI: 1.16–2.38), lived in the rural (AOR = 1.97;95%CI: 1.12–3.49), used latrine improperly (AOR = 1.49;95%CI: 1.04–2.13), did not wash hands before meal (AOR = 2.10; 95%CI:1.08–4.10), and after latrine (AOR = 1.51;95%CI: 1.05–2.19), ate unwashed raw vegetables (AOR = 1.85;95%CI:1.26–2.70), and played with soil (AOR = 1.48;95%CI:1.06–2.06) were associated with E. histolytica/dispar and G. lamblia infection. These findings revealed high prevalence of E. histolytica/dispar and G. lamblia infections was high in the Amhara region. Therefore, proper implementation of water, sanitation and hygiene should be advocated at the community and school levels to mitigate the disease burden.

Comparison of the diagnostic significance of cerebrospinal fluid metagenomic next-generation sequencing copy number variation analysis and cytology in leptomeningeal malignancy

BackgroundDiagnosis and monitoring of leptomeningeal malignancy remain challenging, and are usually based on neurological, radiological, cerebrospinal fluid (CSF) and pathological findings. This study aimed to investigate the diagnostic performance of CSF metagenomic next-generation sequencing (mNGS) and chromosome copy number variations (CNVs) analysis in the detection of leptomeningeal malignancy.MethodsOf the 51 patients included in the study, 34 patients were diagnosed with leptomeningeal malignancies, and 17 patients were diagnosed with central nervous system (CNS) inflammatory diseases. The Sayk’s spontaneous cell sedimentation technique was employed for CSF cytology. And a well-designed approach utilizing the CSF mNGS-CNVs technique was explored for early diagnosis of leptomeningeal malignancy.ResultsIn the tumor group, 28 patients were positive for CSF cytology, and 24 patients were positive for CSF mNGS-CNVs. Sensitivity and specificity of CSF cytology were 82.35% (95% CI: 66.83-92.61%) and 94.12% (95% CI: 69.24-99.69%). In comparison, sensitivity and specificity of CSF mNGS-CNV were 70.59% (95% CI: 52.33-84.29%) and 100% (95% CI: 77.08-100%). There was no significant difference in diagnostic consistency between CSF cytology and mNGS-CNVs (p = 0.18, kappa = 0.650).ConclusionsCSF mNGS-CNVs tend to have higher specificity compared with traditional cytology and can be used as a complementary diagnostic method for patients with leptomeningeal malignancies.

Pattern and predictor of hookworm re-infection among schoolchildren in three districts of Amhara Region, northwest Ethiopia.

Despite integrated prevention and control measures, the prevalence of hookworm is still high in Ethiopia. The re-infection rates and predictors are poorly addressed. Therefore, this study aimed to determine the patterns of hookworm re-infection rates and predictors among schoolchildren in northwest Ethiopia. A prospective follow-up study was conducted among 86 schoolchildren from May to December 2022. Data on predictors was collected using a questionnaire. Stool samples were collected and processed via Kato-Katz, McMaster, and spontaneous tube sedimentation techniques. All hookworm-infected children were treated with albendazole and followed for six months. The re-infection rates of hookworm were checked in the 4th and 6th months. Data was entered into Epi-data version 3.1 and analysed using SPSS version 25. Descriptive statistics were used to compute the re-infection rate. The associations of predictors with hookworm re-infection rates were calculated by logistic regression. Variables with a p-value < 0.05 were considered statistically significant. Of the 86, 81 schoolchildren completed the study. The prevalence of hookworm re-infection in the 4th and 6th months was 23.5% and 33.3%, respectively. Living with family members greater than five (p = .017), poor utilization of latrine (p = .008), infrequent shoe wear (p = .039), and participating in irrigation (p = .020) were the predictors significantly associated with hookworm re-infections. The re-infection rate was high during the fourth and sixth months. Participating in irrigation, infrequent shoe wear, and poor latrine utilization were predictors of hookworm re-infection. Therefore, mass drug administration, regular shoe wearing, and health education should be advocated.

Parasite and bacterial co-infections with Leishmania spp. in dogs

Canine visceral leishmaniasis (CVL) is a major disease affecting dogs and is often associated with other illnesses. In this study, we investigated the distribution of helminths, ectoparasites and bacteria in dogs of an endemic urban area of CVL. A total of 71 dogs, uninfected or naturally infected with Leishmania spp. were studied. Splenic samples were cultured for Leishmania identification, and anti-Leishmania antibodies were measured in the serum. Helminths were diagnosed in the feces using flotation or spontaneous sedimentation techniques. Serum antibodies against six ectoparasite-transmitted pathogens were detected. Microbial growth from eyes, skin, urine, and blood samples were evaluated. To our knowledge, this is the first time that co-infections with Leishmania spp., parasites and bacteria together has been reported. Co-infections with Leishmania were observed in 89% of the animals with helminths and 95% with ectoparasites. Most of the dogs were positive for Ehrlichia spp. and Anaplasma spp. Coagulase-negative Staphylococcus was the most frequently isolated organism. It is found that Leishmania positivity dogs from endemic area in Brazil have a higher rate of co-infections with helminths, ectoparasites and bacteria. Therefore, effective treatment and public measures are needed to contain the spread of canine leishmaniasis and other infections.

Gastrointestinal parasites of domestic sheep from Patagonia throughout historical times: A paleoparasitological approach.

Sheep husbandry in Patagonia, Argentina, started at the beginning of the 20th century from European settlers. Sanitary management is minimal, which has serious implications for the sheep health. Sheep can be infested by diverse parasites, with well over 150 species of internal and external parasites reported worldwide. Gastrointestinal parasitism is one of the most common and important infections in sheep concerning the health status, and is the cause of significant morbidity and mortality, which generates considerable production losses. The present work is the first paleoparasitological study of sheep coprolites from Patagonia throughout historical times. Fifty-seven coprolites from the 'Cueva Peligro' archaeological site (Patagonia, Argentina) were analyzed using the Lutz spontaneous sedimentation technique and the modified Faust flotation technique. Ancient DNA (aDNA) study was carried out in order to identify the zoological origin of coprolites. The results obtained from Cytb analysis confirmed the identity of the host as Ovis aries (domestic sheep). A total of 39 coprolites examined were positive for parasites by at least one of the studied methods. Thirty eight samples were positive by spontaneous sedimentation and 10 samples were positive by the modified Faust technique. The parasitic fauna found was Trichuris sp. (Trichinellida: Trichuridae), Nematodirus sp., Nematodirus spathiger (Strongylida, Trichostrongyloidea), two unidentified Strongylida-type egg morphotypes, Fasciola hepatica (Trematoda: Digenea) and coccidia oocysts of Eimeria spp. (Apicomplexa: Eimeriidae). The modified Faust technique provided satisfactory results in terms of sensitivity for the detection of Eimeria spp. The use of this methodology as a routine procedure enables the processing of ancient samples, in order to increase recoveries. These results show the importance of integrating different diagnostic approaches in order to optimize parasitic findings. The recorded parasite diversity appears to have not changed over the last 120years. The study displayed the presence of different parasitic species which suggests potential exposure to parasitic diseases through the historical times, both for sheep and for other domestic and wild mammals from Patagonia. Also, suggests the presence of fasciolosis, a zoonotic disease that implies a potential risk for Patagonian populations in the past.

Prevalence of Intestinal Parasites, Risk Factors and Zoonotic Aspects in Dog and Cat Populations from Goiás, Brazil.

Gastrointestinal diseases caused by parasites are frequently diagnosed in the clinical routine of domestic animals, especially dogs and cats. In general, they trigger factors that can affect human health due to zoonoses. Therefore, this study aims to identify the main intestinal parasites obtained from the fecal samples of dogs and cats in the municipality of Jata, Brazil, and their associated risk factors. Between October 2020 and March 2022, fecal samples were collected from 359 dogs and 55 cats through spontaneous defecation and subsequently subjected to coproparasitological analyses using the Willis fluctuation and Hoffman spontaneous sedimentation techniques. The following parasitic species were identified: Ancylostoma spp., Toxocara spp., Trichuris vulpis, Dipylidium caninum; Giardia spp., Entamoeba spp., Cystoisospora spp., and Platynosomum fastosum. The risk factors associated with parasitism include age, average income of owners, access to garbage, sewage, waste, outdated deworming, and contact with animals. The results demonstrate the need to establish public policies and implement preventive and control measures to reduce the occurrence of parasites in animals and the exposure of humans to pathogenic agents.

Social and health indicators in an academic community: enteroparasites, nutritional, allergic and clinical aspects

Objective: this study aimed to associate enteroparasitic infection with nutritional, allergic, and clinical repercussions and the sociodemographic aspects in an academic community in Santo Antônio de Jesus, Bahia, Brazil. Methods: the cross-sectional research was carried out between February 2018 and March 2020, with 121 participants. Spontaneous sedimentation and Rugai techniques were used for the parasitological diagnosis of fecal samples. Allergies and clinical issues and the sociodemographic aspects were studied via a questionnaire, and the nutritional status was obtained from the assessment of body mass index and arm and abdominal circumferences. Results: there was 38.2% positivity for intestinal parasites; 65.9% for female participants; with the majority of eutrophic, between 18-27 years old; heteronormative, and single. Besides, the Endolimax nana (78.7%) and Giardia duodenalis (21.3%) were the predominant species. Statistical significance was found between obesity rates and the presence of intestinal parasites and those with allergic aspects. Nervousness, headache, and back and abdominal pains were the most common symptoms. Conclusions: this study contributes to obtaining data on epidemiological and public health surveys in the Bahian territory, providing a reference for other researchers. The statistical association of these with nutritional and allergic aspects can support future research on this population.

Performance Evaluation of Three Diagnostic Methods for Soil-Transmitted Helminth Infections among Schoolchildren in Amhara Region, Northwest Ethiopia.

Soil-transmitted helminths are parasitic nematodes found in the intestine. They are more prevalent in the tropics and subtropics, including Ethiopia. However, low-sensitive direct wet mount microscopy fails to detect soil-transmitted helminths among infected cases. Therefore, more sensitive and cost-effective diagnostic methods are urgently needed to minimize soil-transmitted helminthiasis morbidity. This study aimed to compare and evaluate the performance of diagnostic methods for soil-transmitted helminths against the "gold" standard. An institution-based cross-sectional study was conducted among 421 schoolchildren from May to July, 2022 in the Amhara Region. Study participants were selected using a systematic random sampling technique. Stool samples were processed via Kato-Katz, McMaster, and spontaneous tube sedimentation techniques. Data were entered into epi-data version 3.1 and analyzed using SPSS version 25. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated against the combined result as a "gold" standard. The strength of agreement between the diagnostic methods was determined by the Kappa value. The overall prevalence of soil-transmitted helminths was 32.8% (95% CI: 28.2-37.8%) using a combination of methods. The detection rates of Kato-Katz, McMaster, and spontaneous tube sedimentation were 28.5% (95% CI: 24.2-33.2%), 30% (95% CI: 25.6-34.8%), and 30.5% (95% CI: 26.1-35.3%), respectively. Sensitivity and negative predictive values were 87.1% (95% CI: 80.2-92.3%) and 95.1% (95% CI: 92.6-96.8%) for Kato-Katz; 91.7% (95% CI: 85.6-95.6%) and 96.5% (95% CI: 94.1-98.0%) for McMaster; and 93.2% (95% CI: 87.5-96.8%) and 97.1% (95% CI: 94.7-98.4%) for spontaneous tube sedimentation. Kappa values of Kato-Katz, McMaster, and spontaneous tube sedimentation for the diagnosis of soil-transmitted helminths were 0.901, 0.937, and 0.948, respectively. Kato-Katz, McMaster, and spontaneous tube sedimentation techniques had comparable sensitivity with almost perfect agreement for the detection of soil-transmitted helminths. Therefore, the spontaneous tube sedimentation technique can be used as an alternative diagnostic method for soil-transmitted helminth infections in endemic countries.

Ancient parasite infections from the main Pampean-Patagonian cemetery of hunter-gatherer of prehistoric times: Archaeological site Chenque I (Parque Nacional Lihué Calel, La Pampa Province, Argentina)

Paleoparasitological studies of human sediment samples from prehistoric times of Argentina are scarce. The objective of the present study is to enhance the knowledge of parasitic infections affecting hunter-gatherer populations inhabiting the Pampean region of Argentina in prehistoric times. A total of 33 samples from 12 inhumation structures of archaeological site Chenque I, the unique cementery studied in Argentina until now from a paleoparasitological point of view, were studied. Chenque I constitute the greater repository of human archaeological remains of La Pampa province. Thirty-one samples came from human burials, and 2 samples from a dog retrieved in a burial, associated with a child. By humans, 11 samples correspond to males, 13 to females, and 7 to undifferentiated individuals. A total of 5 samples corresponds to control samples and were taken under the skull. Paleoparasitological examination revealed that 8 of the 33 sediment samples resulted positive for parasite remains applying the rehydration and spontaneous sedimentation technique with or without addition of HCl (10%). The pre-treatment of samples with HCl as a preliminary step allowed a greater recovery of parasitic remains compared to standard spontaneous sedimentation procedure. The most common parasite species found was Trichuris trichiura being probably one of the parasites that commonly affect human populations inhabiting the region. The low preservation evidenced by the parasite remains recovered indicate a taphonomic interference in the data of parasite assemblages, which probably produce a bias in the recovery of other parasite species that could infect these ancient populations. Proceed in the study of new human samples to improve the knowledge of parasitic infections affecting ancient populations inhabiting the studied region is necessary.

Fungal identification in the air and water of a hemodialysis unit in Brazil.

The presence of fungi in healthcare settings, including hemodialysis units, represents a significant risk for immunocompromised patients. This study aimed to investigate the occurrence of fungi in the air and water of a hemodialysis unit located in a tertiary public hospital in Maceió, Alagoas, Brazil. Over a period of three consecutive months, monthly air samples were collected and analyzed using the spontaneous sedimentation technique on Petri dishes containing Sabouraud Dextrose Agar (SDA). Simultaneously, water samples (100 mL) were collected from four specific water distribution points and subjected plating on SDA. Fungi were phenotypically identified based on their macroscopic and microscopic characteristics. In total, 498 colony-forming units (CFUs) of fungi were isolated, with 86 CFUs originating from the air and 412 CFUs from the water. Regarding the water samples, a higher concentration of fungal CFUs was observed in the potable water from the supply network (229 CFUs). Unexpectedly, 23 CFUs were identified in the reverse osmosis samples and 11 CFUs in the storage tank, which are post-treatment points where the presence of microorganisms is not desired. The fungus Cladosporium spp. was the most prevalent in both air and water samples, followed by Penicillium spp. in the air and Rhodotorula spp. in the water. These findings underscore the need to implement effective control and monitoring measures for fungi in the hemodialysis unit to ensure patient safety.

Gastrointestinal parasite assemblages from the wild rodent capybara (Hydrochoerus hydrochaeris) inhabiting a natural protected area from Argentina

Abstract Knowledge about parasitic diseases of wildlife will help us to understand the dynamics of parasites and their effects on host populations. The capybara (Hydrochoerus hydrochaeris) is the largest living rodent in the world, and its distribution is associated with the presence of tropical and subtropical wetlands in South America. The Los Padres Lake Integral Reserve (LPLIR) is an important conservation zone in the pampean region of Argentina. One of the emblematic species found within the reserve is the capybara. The objective of this study was to determine the gastrointestinal parasites present in wild capybaras of the LPLIR and to compare different coprological methodologies. Free-ranging capybara fresh feces from 57 individuals were randomly collected from the area of LPLIR in the summer of 2022. Three different techniques were applied: spontaneous sedimentation technique (SS), INTA modified McMaster technique (MM), and Mini-FLOTAC (MF) technique. Fifty-six samples from all samples analysed (56/57, 98%) were found to be positive for gastrointestinal parasites. Two species of Strongylida, Protozoophaga obesa, Echinocoleus hydrochaeris, one unidentified nematode, one unidentified spirurid, and at least two morphotypes of Eimeria spp. oocysts were recorded. There were found significant differences in the proportion of positive samples and in richness by technique, but no significant differences were found in parasite counting. In conclusion, the choice of methodology depends on the specific objectives of the study. This is the first parasitological study of capybaras from the LPLIR and represents an exploration of parasite communities present in these wild rodents at their southernmost distribution.

Report of a protozoan of the phylum Ciliophora compatible with Balantioides coli in feces of white-lipped peccaries in Brazil

Balantioides coli is a ciliated protozoan with worldwide distribution, which parasites several species, especially the pig. In this work, it was presented the first possible case of parasitism by B. coli in white-lipped peccaries in Brazil. The 13 fecal samples were collected from white-lipped peccaries kept in the Zoológico Municipal de Curitiba, Brazil. The feces were processed using flotation and spontaneous sedimentation techniques. All of them were positive for parasites of the phylum Ciliophora similar to B. coli. As the animals did not show clinical signs of balantidiasis, they may be acting as reservoirs, which is worrying because of the proximity of white-lipped peccaries created as a means of subsistence by human population. Thus, we emphasize the importance of documenting these reports in order to understand the expansion of the parasite, mainly due to zoonotic potential of B. coli and implications for public health.

The application of the FLOTAC technique for detection of helminth eggs of medical and veterinary importance in soil samples

The FLOTAC technique was initially developed to detected infective stages of parasites in animal and human feces. Recently, its applicability has been extended by the use in pastures and vegetables for human consumption. However, its use for the detection of parasites in the soil has never been investigated. In this study, we assessed the performance of the FLOTAC and compared with centrifugal flotation (CFT) and spontaneous sedimentation (SST) techniques. A total of 50 soil samples were collected from the Metropolitan region of Recife, Northeastern Brazil. Initially, samples were standardized, and then assessed in duplicate by the FLOTAC, CFT and SST. Cohen's kappa coefficient, sensitivity, specificity, positive and negative predictive values, and accuracy of the FLOTAC, CFT and SST were assessed using the results of the combination of all three techniques as gold standard. Out of all analyses performed, in 96% (48/50), helminth eggs of parasites were detected. In particular, 96% (48/50) of samples analysed through the FLOTAC technique, 76% (38/50) for CFT and 28% (14/50) for SST were positive. Nematode eggs of the Ancylostomatidae and Ascarididae families were those mostly detected in this study. Overall, the FLOTAC presented high values of sensitivity, demonstrating that this method may also be employed for detection of parasites in soil samples. This study opens new possibilities for the use of the FLOTAC technique, highlighting its role as a potential tool for detecting environmental contamination by parasites of medical and veterinary importance.

Prevalence of Strongyloides stercoralis infection and associated clinical symptoms among schoolchildren living in different altitudes of Amhara National Regional State, northwest Ethiopia.

BackgroundStrongyloides stercoralis is a parasite that causes strongyloidiasis in humans. It is prevalent in the tropics and sub-tropics where poor sanitation is a common problem. The true prevalence of S. stercoralis in Ethiopia is underestimated due to the lack of a “Gold” standard diagnostic method. Moreover, its prevalence across altitudinal gradient in Amhara Region has not been studied.MethodsA cross-sectional study was conducted among 844 schoolchildren in Amhara Region from April to December 2019. A stool sample was collected from each study participant and processed using formol ether concentration technique (FECT), spontaneous tube sedimentation technique (STST), Baermann concentration technique (BCT), agar plate culture (APC) and real-time polymerase chain reaction (RT-PCR). Data were entered using EpiData and analyzed by SPSS version 23 statistical software. Prevalence of S. stercoralis infection was determined using a single diagnostic technique and combination of techniques. Association of clinical variables with S. stercoralis infection was assessed by logistic regression and independent variables with p<0.05 were considered statistically significant.ResultsPrevalence of soil-transmitted helminths (STHs) and S. mansoni infections was 38.0% and 20.4%, respectively. Among STHs, the prevalence of hookworm infection was 32.8%. Prevalence of S. stercoralis infection was 39.0%, 28.8%, 10.9%, 10.3%, 4.0% and 2.0% by the respective, combinations of the five methods, RT-PCR, APC, BCT, STST and FECT. The highest prevalence rates, 48.2%, 45.0% and 41.1% of S. stercoralis were recorded in the age group of 12–14 years, males and rural dwellers, respectively. Prevalence rates of S. stercoralis infection in highland, semi-highland and lowland areas were 40.4%, 41.8% and 25.9%, respectively. Having abdominal pain (AOR = 2.48; 95% CI:1.65–3.72), cough (AOR = 1.63;95%CI:1.09–2.42), urticaria (AOR = 2.49;95%CI:1.50–4.01) and being malnourished (AOR = 1.44;95%:1.10–2.01) were significantly associated with strongyloidiasis.ConclusionPrevalence of S. stercoralis infection was high and varied across different altitudes in Amhara Region. Some clinical syndromes were found to be significantly associated with S. stercoralis infection. Therefore, proper diagnosis and preventive strategies against S. stercoralis infection are highly recommended to be devised and implemented in Amhara Region.

Evaluation of five diagnostic methods for Strongyloides stercoralis infection in Amhara National Regional State, northwest Ethiopia

BackgroundStrongyloides stercoralis is an intestinal parasite that can cause chronic infection, hyperinfection and/or a dissemination syndrome in humans. The use of techniques targeting ova fails to detect S. stercoralis, as only larvae of the parasite are excreted in faeces. Due to the absence of “Gold” standard diagnostic method for S. stercoralis, there is a paucity of reported data worldwide.ObjectiveThis study aimed to evaluate the performance of diagnostic methods of S. stercoralis infection by taking the composite reference as a “Gold” standard.MethodsA cross-sectional study was conducted among 844 schoolchildren in Amhara Region, Ethiopia, from April to December 2019. Stool samples were collected and processed with formol-ether concentration technique (FECT), spontaneous tube sedimentation technique (STST), Baermann concentration technique (BCT), agar plate culture (APC) and real-time polymerase chain reaction (RT-PCR). Sensitivity, specificity, positive predictive value, and negative predictive value of each diagnostic method were computed against the composite reference. The agreements of diagnostic methods were evaluated by Kappa value at 95% CI.ResultsThe composite detection rate of S. stercoralis by the five diagnostic methods was 39.0% (329/844). The detection rate of the parasite from stool samples by FECT, STST, BCT, APC and RT-PCR was 2.0% (17/844), 4.0% (34/844), 10.2% (86/844), 10.9% (92/844) and 28.8% (243/844), respectively. The highest detection rate (37.8%; 319/844) of S. stercoralis was recorded by a combination of BCT, APC, and RT-PCR followed by a combination of STST, BCT, APC and RT-PCR (37.3%; 315/844). The sensitivity of FECT, STST, BCT, APC and RT-PCR against the composite reference was 5.2%, 10.3%, 26.4%, 28.0% and 73.9%, respectively. The diagnostic agreements of RT-PCR, APC, BCT, STST and FECT with the composite reference in detection of S. stercoralis were substantial (0.775), fair (0.321), fair (0.305), slight (0.123), and slight (0.062), respectively.ConclusionRT-PCR detected the highest number of S. stercoralis infections. A combination of RT-PCR with APC and/or BCT better detected S. stercoralis from stool samples compared to other combinations or single diagnostic methods. Therefore, RT-PCR and combination of RT-PCR with APC and/or BCT diagnostic methods should be advocated for detection of S. stercoralis infection.

Prevalence of Intestinal Parasites and Schistosoma mansoni and Associated Factors among Fishermen at Lake Tana, Northwest Ethiopia.

Background Intestinal parasites and Schistosoma mansoni infections adversely affect the health of humans in the world especially in sub-Saharan African countries including Ethiopia. Fishermen who spend most of their time in water bodies are supposed to be at high risk of schistosomiasis and other water-born parasites. However, the magnitude of these parasitic infections and their determinant factors are not well addressed. Methods A cross-sectional study was conducted at Lake Tana among 388 fishermen from March to May 2021. Questionnaire data was collected through face to face interview. Stool sample from each participant was processed by the Kato-Katz and spontaneous tube sedimentation techniques. Data were analyzed using SPSS version 26. Results One hundred sixty four (42.3%) and 88 (22.7%) participants were infected by intestinal parasites and Schistosoma mansoni, respectively. One hundred twenty two (31.4%) and 42 (10.8%) participants were infected by soil-transmitted helminths and intestinal protozoa, respectively. Attending only primary school (AOR = 2.02, p = 0.014) or being illiterate (AOR = 2.54, p = 0.004) and not washing hands before meal (AOR = 2.23, p = 0.007) were significantly associated with intestinal parasitic infections. Illiterate educational status (AOR = 2.37, p = 0.022), fishing by bargee (AOR = 2.43, p = 0.005), fishing ≥4 days per week (AOR = 2.27, p = 0.029), swimming habit (AOR = 3.03, p = 0.030), and participation in irrigation (AOR = 3.09, p ≤ 0.001) predispose fishermen to S. mansoni infection. Conclusion Intestinal parasites and S. mansoni infections are highly prevalent among fishermen at Lake Tana basin. Low education level and frequent water contact predispose fishermen for intestinal parasites and S. mansoni. Therefore, health education to fishermen on intestinal parasites and S. mansoni infection and regular deworming should be advocated.

Storage tanks for household water usage in Brazil: Microbiological and chemical quality, and maintenance of sanitary conditions

Introduction: Storage tanks for household water usage guarantees convenience and safety forconsumers in relation to water intermittency. Neglecting a minimal care for storage tanks can turnthem into a source of water unfit for consumption. Objective: Evaluate the physical, chemical, andmicrobiological quality of water in household tanks to highlight the need for individual actions toguarantee the quality of water consumed at home. Methods: Residents of 217 homes answereda questionnaire to gather information about the water storage tank conditions and maintenance.Chlorine dosing, pH and temperature measurements were performed in situ and metal analyseswere made using an inductively coupled plasma mass spectrometry (ICP-MS). The presence ofparasites was evaluated using the spontaneous sedimentation technique and presence of bacteriafrom the coliform groups (total and fecal) were made using the multiple-tube technique with thechromogenic substrate. Results: Results showed that 115 participants knew the correct storage tankmaintenance period and 109 participants did not perform the storage tank maintenance at therecommended frequency. Mean values of chlorine, pH, and temperature were 1.34 mg/L, 6.5, and25.4 ºC, respectively. Average concentrations of metals were below the maximum values allowed.Parasites and bacteria were not detected. Tests indicated the water samples were in accordancewith the potable water quality standards endorsed or recommended by the Brazilian legislation.Conclusion: Results did not show microbiological contamination in study samples. Nevertheless, it isnecessary to keep the population regularly informed about the importance to maintain storage watertanks clean. Currently, there is a growing concern with the development of individual actions aimedat human health and prevention of water-related diseases concerning its access and use. Therefore,we need health education programs to guide community participation into the promotion of a betterquality of life.

DIBOTHRIOCEPHALUS LATUS: A CASE REPORT IN SOUTHERN BRAZIL / DIBOTHRIOCEPHALUS LATUS: UM RELATO DE CASO NO SUL DO BRASIL

Diphyllobothriosis, an infection caused by an adult parasite of the genus Dibothriocephalus , is associated with the intake of raw or undercooked fish. This disease is worldwide in distribution and present sporadic outbreaks. A few cases of Dibothriocephalus infections have been reported in Brazil. This report aims at presenting the case of a male patient from Southern Brazil (Rio Grande do Sul) who was suffering from chronic diarrhea, tested positive for fecal occult blood and upon anamnesis reported eating sushi recently. A parasitological stool test was conducted using the spontaneous sedimentation technique and the microscopic analysis revealed the presence of typical structures of Dibothriocephalus latus . Due to the association between the consumption of raw fish such as salmon and diphyllobothriosis, it is extremely important to consider this infection among the symptomatic population who eats raw or undercooked fishes.

Agar Plate Culture: An Alternative Sensitive Routine Laboratory Detection Method for Strongyloides stercoralis and Hookworm Parasites.

Background:Human infection with Strongyloides stercoralis and hookworm parasites is usually under reported due to less sensitive diagnostic methods. Agar plate culture (APC) is the most sensitive technique for parasites having larval stage. However, using APC in routine diagnosis is uncommon. This study aimed to determine the detection rate and sensitivity of APC in comparison with formal ether concentration technique (FECT) and spontaneous tube sedimentation techniques (STSTs) for S. stercoralis and hookworm larvae.Methods:Stool samples collected from 844 schoolchildren in Amhara Regional State, northwestern Ethiopia in 2019, transported to nearby health institutions and processed by APC, FECT and STSTs. The prevalence of S. stercoralis and hookworm was computed by descriptive statistics and Chi-square. The diagnostic agreement among the three techniques was evaluated using Kappa value.Results:The overall prevalence of S. stercoralis and hookworm infections by combining the three methods was 13.2% (111/844) and 33.8% (277/844), respectively. Using APC alone, the prevalence of S. stercoralis and hookworm were found to be 10.9% (92/844) and 24.5% (207/844), respectively. Agar plate culture was 5.4 and 2.7 times respectively more sensitive than FECT and STST, with slight and fair agreement in the detection of S. stercoralis. Hookworm diagnostic agreement was moderate between APC and FECT, and APC and STST. The Kappa value between STST and FECT diagnostic methods was substantial.Conclusion:APC has a better detection rate of S stercoralis and hookworm larvae. Therefore, APC can be used as an alternative routine diagnostic method to S. stercoralis and hookworm co-endemic countries.