Stool Concentration Technique Research Articles

Evaluation of Stool Concentration Techniques in the Detection of some Parasites among Almajiri School Children in Sokoto Metropolis

Infection with intestinal parasites is one of the main health issues in poor nations. It is estimated to affect 3.5 billion people worldwide, and 450 million people are thought to be ill as a result of such illnesses, with children making up the majority of those who are ill. By using several stool concentration techniques, this study was aimed at identifying parasite ova in the stool of Almajiri school children in Sokoto. The Formol-ether concentration technique, which is regarded as the gold-standard, Sheather's sugar floating technique, and saline floatation technique were employed to detect parasite ova in stool samples taken from Almajiri school children. A total of 137 stool samples were collected from Almajiri school children and each sample was examined by these concentration techniques. A prevalence of 37.9% of intestinal helminthiasis was observed by Formol-ether concentration technique. The sensitivity and specificity of Formol-Ether concentration technique were 96.2% and 97.8% respectively, followed by Sheather’s sugar floating technique 88.5% and 93.8% and the lowest sensitivity and specificity of 76.9% and 90% respectively were obtained in the saline floatation technique. There was a high prevalence of intestinal helminthiasis among Al-majiri school children, sheather’s sugar floatation technique was as sensitive as the Formol-ether concentration technique and more sensitive than the Saline floatation technique. Therefore, Sheather’s sugar floatation technique is recommended as a better alternative in the diagnosis of intestinal helminthiasis.

Frequency of giardia lamblia infection in children presented with acute diarrhea to tertiary care hospital

Background: Giardia lamblia was the most common parasite-caused gastrointestinal ailment in the United States by the late 1980s, and it is now a significant global public health issue. Giardiasis is an infectious condition that may have both short-term and long-term effects. Objective: To assess the frequency of giardia lamblia infection in children presented with acute diarrhea to tertiary care hospital. Methodology: The current Descriptive Cross Sectional study was carried out at the Department of Paediatrics, Hayatabad Medical Complex, Peshawar from 21 July, 2019 to 22 January, 2020. The overall Sample Size in the current study was 114. After performing the stool concentration technique using the formol-ether concentration method, trophozoites and cysts of Giardia lamblia were detected using direct microscopy of the smear in saline (0.90% w/v NaCl solution) and Lugols iodine. Data was entered in SPSS version 23.0. Results: In the current study, totally 114 patients were enrolled. Mean and SDs for age was 4.13+1.566. Mean and SDs for weight was 13.21+2.598. Mean and SDs for BMI was 24.93+0.890. Mean and SDs for duration of disease was 7.02+1.540. 43 (37.7%) patients were females and 71 (62.3%) patients were males.

High Prevalence of Intestinal Capillariasis in Chronic Diarrhea Patients in Thailand: Serological Screening Using a Rapid Lateral-Flow Immunochromatographic Assay.

Intestinal capillariasis is an emerging fish-borne helminthic disease caused by the round worm Capillaria philippinensis. Chronic infection may lead to death if the disease is misdiagnosed and inappropriate treatment is given. We used a rapid lateral-flow immunochromatographic test for screening of intestinal capillariasis in patients with chronic diarrhea. We screened 292 chronic diarrhea patients who had visited hospitals in Thailand. Sixty-six (22.6%) cases were positive according to the kit. All positive patients received mebendazole at 200 mg twice per day for 30 consecutive days or albendazole at 200 mg twice per day for 10 consecutive days. Later, stool concentration techniques, used to examine stool samples from all serologically positive individuals on three consecutive days, revealed C. philippinensis eggs, larvae, and/or adults. The kit is useful for screening and rapid diagnosis of intestinal capillariasis in chronic diarrhea patients in an endemic area for prevention of serious disease and facilitates treatment.

Helminth Infections in Children.

Helminth Infections in Children.

Elimination of STH morbidity in Zimbabwe: Results of 6 years of deworming intervention for school-age children.

This paper reports the prevalence and intensity of soil-transmitted helminth (STH) infections measured in Zimbabwe before and after a control intervention based on annual deworming of school-age children (SAC) conducted from 2012 to 2018.In 2010, epidemiological data were collected from 13 195 SAC in 255 randomly selected schools in all districts nationwide using, as diagnostic methods, the Kato–Katz and the formal ether stool concentration technique. At follow up, conducted in 2017, only Kato–Katz was performed; specimens were collected from 13 352 children in 336 schools. The data were evaluated using a geospatial approach. The national prevalence of STH infection in SAC was estimated at 5.8% at baseline, with 0.8% of infections of moderate and heavy intensity. Preventive chemotherapy (PC) targeted all 2.5 million children of school age enrolled in Zimbabwe, with coverage ranging from 49% to 85%. At follow up, national prevalence of STH in SAC was estimated at 0.8%; infections of moderate and heavy intensity almost disappeared (0.1% prevalence). As a result, Zimbabwe can suspend deworming activities in 54 districts and reduce the frequency of PC in the remaining six districts. The total amount of albendazole tablets needed will be approximately 100 000 a year.

Diagnostic Performance of Mini Parasep® Solvent-Free Foecal Parasite Concentrator for the Diagnosis of Intestinal Parasitic Infections

AbstractIntroduction: Various stool concentration techniques have been used to increase the microscopic detection of parasites. We assessed the enclosed, single-vial, Mini Parasep® technique in comparison to the currently used coprodiagnosis procedures. Materials and Methods: A total of 150 stool samples were collected. Samples concentrated by formol–ether method (FEM) and Mini Parasep® SF foecal concentrator and unconcentrated samples were subjected to wet mount, iodine mount microscopy and smear examination by modified acid-fast staining. Results: Direct wet mount detected 72 positive samples (48.6%), whereas 77 (51.3%) and 80 (53.3%) samples were detected by FEM and Mini Parasep® SF methods, respectively. The sensitivity of detection of parasites was 98.7%, 95% and 90.1% with Mini Parasep®, FEM and direct microscopy, respectively. A clearer background with less foecal debris and a better yield of Hymenolepis nana, Trichuris trichiura, Entamoeba coli and Giardia lamblia were noted with Mini Parasep®. Conclusion: Mini Parasep® SF technique is simple, rapid and less cumbersome than conventional diagnostics, making it suitable for routine use. In addition, it offers higher sensitivity and better background clearance than both direct stool examination and FEM.

The Prevalance of Blastocystosis among Patients with Gastrointestinal and Dermatologic Complaints and Effects of Blastocystis spp. Density on Symptomatology.

Blastocystosis has been linked with non-specific symptoms, such as diarrhea, abdominal pain, and distention. In this study, we evaluated the relationship between Blastocystis spp. with urticaria and intestinal symptoms. The results of the stool examinations of the patients who were referred to Ege University Medical Faculty Hospital's Medical Parasitology Department Direct Diagnosis Laboratory with gastrointestinal (GIS) and/or dermatologic symptoms between January 2011 and July 2016 were retrospectively scanned. Of the evaluated 37108 stool samples, 2573 (6.93 %) were identified to be positive for Blastocystis spp. The patients with gastrointestinal complaints comprised 68.4% of Blastocystis spp. positive samples (1.761 samples) while 30.1% of patients had dermatologic symptoms (urticaria) (776 samples). Blastocystis spp. density in the non-amplified (without using any stool concentration technique) stool samples of the patients with GIS and dermatological symptoms was as follows: 2.47%, 1.35% rare, 21.73%, 22.17% few, 49.65%, 54.29% medium, 26.27%, and 22.17% dense, respectively. 75.92% and 76.46% of the patients with GIS and dermatological complaints had medium to dense parasite densities in their stool samples respectively. This suggests a positive correlation between parasite density and GIS and dermatologic symptomatology.

Management of severe strongyloidiasis attended at reference centers in Spain.

IntroductionStrongyloides stercoralis is a globally distributed nematode that causes diverse clinical symptoms in humans. Spain, once considered an endemic country, has experienced a recent increase in imported cases. The introduction of serology helps diagnosis and is currently replacing microbiological techniques in some settings, but its sensitivity is variable and can be low in immunocompromised patients. Diagnosis can only be confirmed by identification of larvae. Often, this “gold standard” can only be achieved in severe cases, such as disseminated S.stercoralis infection, or S.stercoralis hyperinfection syndrome, where parasite load is high. In addition, these clinical presentations are not well-defined. Our aim is to describe severe cases of S.stercoralis, their epidemiological profile, and their clinical details.MethodsAn observational retrospective study of disseminated S.stercoralis infection, or hyperinfection syndrome. Inclusion criteria: aged over 18, with a diagnosis of disseminated S.stercoralis infection, or hyperinfection syndrome, confirmed by visualization of larvae. Patients were identified through revision of clinical records for the period 2000–2015, in collaboration with eight reference centers throughout Spain.ResultsFrom the period 2000–2015, eighteen cases were identified, 66.7% of which were male, with a median age of 40 (range 21–70). Most of them were foreigners (94.4%), mainly from Latin America (82.3%) or Western Africa (17.6%). Only one autochthonous case was identified, from 2006. Immunosuppressive conditions were present in fourteen (77%) patients, mainly due steroids use and to retroviral coinfections (four HIV, two HTLV). Transplant preceded the clinical presentation in four of them. Other comorbidities were coinfection with HBV, Trypanosoma cruzi, Mycobacterium leprae or Aspergillus spp. All presented with digestive disorders, with 55.6% also presenting malaise. 44.4% of cases had fever, 27.8% skin complaints, and 16.7% respiratory or neurological disorders. One patient presented anemia, and one other nephrotic syndrome. Diagnosis was confirmed by identification of larvae in fresh stool samples (n = 16; 88.9%), concentration techniques (n = 6; 33.3%), larval culture (n = 5; 29.4%), or digestive biopsies (n = 8; 44%). S.stercoralis forms were identified during necropsy in one case. In addition, ten (55%) had a positive serology. All the cases were treated with ivermectin, six (33%) also received albendazole and one case received thiabendazole followed by ivermectin. All needed inpatient management, involving a mean hospitalization stay of 25 days (range 1–164). Two cases received intensive care and eventually died.ConclusionsOnly eighteen cases of disseminated S.stercoralis infection/hyperinfection syndrome were identified from the 15-year period, most of which were considered to have been imported cases. Among those, immunosuppression was frequent, and mortality due to S.stercoralis was lower than previously described.

A comparative study of formalin-ethyl acetate sedimentation technique and Mini Parasep® solvent-free method in the rapid diagnosis of intestinal parasites.

Background:Stool microscopy and concentration techniques are the two most important and necessary aspects of diagnostic parasitology. In an era when there is increased disease burden due to intestinal parasites, an early and appropriate diagnosis is warranted. Direct microscopy is usually labor intensive and tedious.Materials and Methods:Thirty-two fresh fecal specimens from patients presenting with eosinophilia and/or anemia (hemoglobin levels <10 g%), HIV-positive patients, and in patients clinically suspected of harboring parasites, were collected for the study. All the positive samples were processed by both the standard methodology, i.e., formalin-ethyl acetate sedimentation technique and Mini Parasep® SF method, by the standard operating procedure of our laboratory and the manufacturer's instruction. Stool pellet concentrates were subjected to saline/iodine wet mount, modified acid fast staining for intestinal coccidian parasites and trichrome staining for Blastocystis hominis. The average number of organisms counted in 0.5 ml of pellet was used for comparison of the two techniques.Results:The morphology of eggs was maintained in both the techniques; however, the wet mount prepared from the sedimentation technique had more background fecal debris in comparison to the Parasep® technique. The parasite yield was equal for both the techniques while Mini parasep had the advantage of less distortion of parasite morphology.Conclusion:We found that Parasep® offered a better parasitic yield, a better workflow capacity, and a reduced turnaround time, which would further benefit resource-restrained laboratories and those with a high sample turnover.

Helminth prevalence among adults in rural Kenya: a stool survey for soil-transmitted helminths and schistosomiasis in Nyanza province.

Soil-transmitted helminth (STH) prevalence in children is high in rural southwestern Kenya, but adult prevalence data are scarce. A 2010 study of a village in Nyanza province found a pediatric STH prevalence of 44% using a direct stool-smear method. Adult STH prevalence and associated predictors was measured in the same village. Adults (≥18 years) presenting at the out-patient department of the small hospital or community outreach events completed a short questionnaire and provided stool samples. Light microscopy for ova and larvae was conducted using a stool concentration technique to improve sensitivity. Multivariable regression models were used to identify predictors of STH prevalence. Among 344 adults, STH prevalence was 15.7% (54/344). Hookworm was most common (13.1%; 45/344), followed by Ascaris lumbricoides (6.1%; 21/344) and Trichuris trichiura (0.6%; 2/344). Twelve participants (3.5%; 12/344) had multiple STHs and three (0.9%; 3/344) had Schistosoma mansoni. Female sex, older age and lower education level were significant STH predictors. Adult STH prevalence was lower than previous studies of children from the same village. Adults with the identified risk factors had a prevalence of ≥20%, which may warrant periodic, targeted deworming of adults with these risk factors given the low cost and low toxicity of anthelmintic drugs.

Influence of selected stool concentration techniques on the effectiveness of PCR examination in Giardia intestinalis diagnostics.

Giardia intestinalis is a widespread parasitic protozoa which has great significance as a public health threat. Molecular diagnostics of stool sample can be unreliable because of the presence of inhibitors of enzymatic reactions. The aim of this study was to determine the effectiveness of selected pre-treatment methods of fecal samples for further PCR-based diagnostics of G. intestinalis, and the effect of each component of pre-treatment solutions on PCR reactions. Seven stool concentration techniques were compared. The results showed that the most efficient concentration method for stool sample preparation for detection of G. intestinalis by PCR is centrifugal flotation with Percoll (with saturated NaNO3 as the flotation solution). This method is relatively inexpensive, less labor-intensive, and suitable for epidemiological monitoring and clinical investigations.

English

IntroductionMaharashtra is a very large state of 300,000 km2, with a total population of around 97 million. The capital city of Maharashtra, Mumbai, is the most populous city in India, with around 14 million inhabitants. The HIV prevalence at antenatal clinics in Maharashtra was 0.5% in 2007. The state has the highest reported rates of HIV prevalence among female sex workers (18%). Similarly high rates were found among injecting drug users (24%) and homosexual men (12%). Pune is the second largest city in Maharashtra, with a growing population of more than 40 lakhs (4 million). It ranks among the top five HIV prevalent cities in the state. There are very few studies that have been carried out to compare the prevalence of intestinal parasitic infestation in HIV-reactive and non-reactive individuals in Maharashtra. Materials and MethodsStudy PeriodThe present study was carried out from 1st December 2008 to 31st August 2010 in Pad. Dr. D.Y. Patil Medical College Hospital and Research Center, Pimpri, Pune. Results and ObservationsIn this study, stool samples of 490 individuals were processed, out of which 110 were HIV-positive and 380 were HIV-negative. Evaluation of 4 different stool concentration techniques was done in comparison with the direct wet mount microscopic examination. Out of all the stool samples examined, 100 of them were also processed using concentration techniques (by all methods). It was seen that using routine examination, only 6% of the stool samples revealed a positive finding, whereas using concentration techniques a maximum of 17% of the same samples were positive. ConclusionFurther, as demonstrated in our study, we can conclude that stool concentration techniques should be adopted, since in case of low parasite load, often the diagnosis is missed by carrying out only direct wet mount examination. Finally, to prevent intestinal parasitic infections, patients should be educated regarding maintenance of personal hygiene. Keywordsintestinal parasites, Ascaris lumbricoides, H. nana, T. solium, T. saginata

Opportunistic protozoa in HIV seropositive cases and best stool concentration technique for detection

Parasitic gastrointestinal diseases increase morbidity and mortality in HIV patients. This study is aimed at the occurrence of Cryptosporidium, Isospora, Cyclospora and Microsporidium in the stool samples of HIV positive cases since the diarrhea is the second most common presentation of HIV positive cases who requires hospitalization.

A diagnostic approach to detect murine Shistosoma mansoni infection using a polymerase chain reaction

Background: Traditional diagnosis of Schistosoma mansoni infection involves direct microscopic detection of eggs in feces. The use of some stool concentration techniques may increase the diagnostic yield. However, it seems that the sensitivity of parasitological methods diminishes when prevalence and intensity of infection are low, making these methods less appropriate for low-endemic areas and in post treatment situations. In 2001, a new antischistosomal drug, Mirazid® was introduced into the Egyptian market by Pharco Pharmaceutical Company (Alexandria, Egypt). Extensive advertising efforts have encouraged physicians in private clinics to use Mirazid. The chemistry of myrrh is not fully studied. Reports on its anti-schistosomal effect in human or experimental animals seem to be controversial. Methods: Our present study is a laboratory trial aimed at using conventional PCR technique for studying the schistosomicidal effect of Mirazid® in the murine model, and comparing the results with the parasitological results (ova and worm count). Results: Microscopic results showed that there was no eggs passing till the 41st day of infection by examining fecal samples of all infected mice by Kato-Katz technique. Only on the 42nd day, the first batch of eggs appeared in stool samples. Comparable results were found in the number of S. mansoni worms recovered from sacrificed mice of infected groups. By using PCR for detection of S. mansoni specific DNA sequences in murine fecal samples of infected control group, all fecal samples showed positive results by using feces from the 45th day after infection. On the other hand, all fecal samples of uninfected control group showed negative results. Regarding results of the Mirazid® treated group, six fecal samples (60%) showed positive results for feces from the 77th day after infection. Interestingly, the four mice diagnosed negative by PCR were among the eight mice that diagnosed negative by the microscopic technique. Conclusion: The used PCR technique was more sensitive than the Kato-Katz thick smears. Mirazid® showed some schistosomicidal effects against murine S. mansoni. However, it was not efficient enough to cure any of the mice. Thus, re-evaluation of myrrh as a schistosomicidal drug must be considered because of its recommendation by some Egyptian physicians motivated by its natural origin. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive

Comparison of 2 centrifugation procedures in the formalin-ethyl acetate stool concentration technique for the detection of Cryptosporidium oocysts

A comparison between the standard formalin-ethyl acetate (FEA) stool concentration procedure (centrifugation at 400 g for 2 min) and a modification proposed to increase the recovery of Cryptosporidium oocysts (500 g for 10 min) was performed on 73 formalin-preserved stool specimens known to be positive for Cryptosporidium. False-negative results were obtained with both methods, but the increase in centrifugation time and force resulted in the detection of a higher number of oocysts and positive samples. The modified procedure had a sensitivity significantly higher than the standard method (99% compared to 86%, P=0.0045).

The diagnosis of strongyloidiasis with special reference to the value of the filarial complement fixation test as a screening test

In 72 patients from Africa, Asia, America and Australasia with strongyloidiasis the diagnosis rested in the main on stool concentration techniques, without which light or moderate infection is likely to be missed. Infections may persist for at least 20 years. Eosinophilia was inconstant, but the filarial complement fixation test was poskive in 75%. Successful treatment with thiabendazole caused the test to fall in titre or to revert to negative. Follow up stool examinations confirmed the widespread reports of the efficiency of thiabendazole in this infection. It is important to diagnose this condition. Apart from symptoms directly due to the parasite, the long term use of steroids may lead to superinfection and death, and there is a probable though rare association between strongyloidiasis and septicaemic states dependent on the auto-infective cycle. The filarial complement fixation test may be valuable in pointing to the diagnosis of light to moderate infections; positive tests in the absence of any evidence of filariasis should lead to a careful search for the larvae of Strongyloides stercoralis in the stool, and failing that in the duodenal aspirate.