scholarly journals Comparison of Polyvinyl Alcohol Fixative with Three Less Hazardous Fixatives for Detection and Identification of Intestinal Parasites

2000 ◽  
Vol 38 (4) ◽  
pp. 1592-1598 ◽  
Author(s):  
B. Jensen ◽  
W. Kepley ◽  
J. Guarner ◽  
K. Anderson ◽  
D. Anderson ◽  
...  

Polyvinyl alcohol (PVA) containing the fixative mercuric chloride is considered the “gold standard” for the fixation of ova and parasites in the preparation of permanently stained smears of stool specimens. However, mercuric chloride is potentially hazardous to laboratory personnel and presents disposal problems. We compared three new alternative, nontoxic fixatives with PVA, analyzing ease of sample preparation and quality of smears. Sixty-eight fresh stool specimens were divided into aliquots and placed in each of four different fixatives: PARASAFE (PS) (Scientific Devices Laboratory, Inc., Des Plaines, Ill.), ECOFIX (EC) (Meridian Diagnostics, Inc., Cincinnati, Ohio), Proto-Fix (PF) (Alpha-Tec Systems, Inc., Vancouver, Wash.), and low-viscosity PVA fixative (PVA) (Meridian). Specimens were processed and stained according to each manufacturer's directions. Parasites were found in 31 of 68 slide preparations with PVA, 31 with PF, 30 with EC, and 30 with PS. Blastocystis hominis andIodamoeba bütschlii were preserved in a readily identifiable state by all methods of fixation. However, some parasites were more easily identified with some of the fixatives because of differences in parasite distortion. For example, Entamoeba histolytica (Entamoeba dispar) was detected in 13 stools fixed with PF, 7 with PVA, and 6 with EC but none with PS. Likewise, Chilomastix mesnili was identified in 13 specimens fixed with PF, 8 with EC, and 5 with PVA but only 1 with PS, while Entamoeba coli was seen much less frequently with PS than with the other three fixatives. A dirty background was observed in 41% of specimens prepared with PS, whereas background quality was acceptable with other fixatives. Sample preparation was most rapid with PS, although the EC method involved the fewest steps. In conclusion, PVA and PF produced the least parasite distortion, while PS proved unsatisfactory for the identification of E. histolytica,E. coli, and C. mesnili. Both PF and EC appear to be acceptable, environmentally safe substitutes for PVA.

2007 ◽  
Vol 40 (3) ◽  
pp. 346-348 ◽  
Author(s):  
Filipe Anibal Carvalho-Costa ◽  
Alessandra Queiroga Gonçalves ◽  
Sandra Laranjeira Lassance ◽  
Carla Pontes de Albuquerque ◽  
José Paulo Gagliardi Leite ◽  
...  

The objective of the present study was to estimate the frequency of infection by Cryptosporidium spp and other intestinal parasites in dehydrated children with gastroenteritis who were admitted to a pediatric hospital. Stool examinations from 218 children were performed. Cryptosporidium spp was identified in eighteen out of 193 stool samples (9.3%) subjected to safranin-methylene blue staining. Giardia lamblia was detected in ten out of 213 (4.7%) samples examined via the direct or Ritchie methods. Other parasites identified were Ascaris lumbricoides (4.2%), Blastocystis hominis (1.4%), Entamoeba coli (0.9%), Entamoeba histolytica/Entamoeba dispar (0.5%), Endolimax nana (0.5%), Trichuris trichiura (0.5%) and Enterobius vermicularis (0.5%).


1998 ◽  
Vol 36 (7) ◽  
pp. 1974-1976 ◽  
Author(s):  
Lynne S. Garcia ◽  
Robyn Y. Shimizu

As a result of disposal problems related to the use of mercury compounds, many laboratories have switched from mercuric chloride-based Schaudinn’s and polyvinyl alcohol (PVA) stool preservatives to other, non-mercury-based preservatives. A comparison of organism recoveries and morphologies of the intestinal protozoa was undertaken with PVA containing the EcoFix zinc-based Schaudinn’s preservative (Meridian Diagnostics, Inc.); both Wheatley’s modification of Gomori’s trichrome stain (WT) and EcoStain (ES) were used to stain 51 human fecal specimens. Morphology, clarity of nuclear and cytoplasmic detail, overall color differences, and the ease or difficulty in detecting intestinal protozoa in fecal debris were assessed for the two permanent stained smears. Overall, organism morphology of the intestinal protozoa stained with WT and that of protozoa stained with ES were not equal in nuclear and cytoplasmic detail or range of color. However, the same organisms were identified in stained fecal smears with either WT or ES, with the exception of situations in which organism numbers were characterized as rare. Included were 67 protozoan challenges (number of organisms): Entamoeba histolytica-Entamoeba dispar (5), Entamoeba coli (9),Entamoeba hartmanni (6), Endolimax nana (12),Iodamoeba bütschlii (8), Blastocystis hominis (19), Giardia lamblia (6), Dientamoeba fragilis (2), yeast (2), and leukocytes (2). Five specimens were negative for parasites but contained fecal debris that was compared for morphologic detail and color range. The ES produces a more gray-green monotone with very little pink or red tone; contrast among the various colors is less than that seen with WT. Stain intensity for all organisms was acceptable, and there were no problems with stain deposition. The quality of the protozoan morphology with ES was often comparable to that with WT (36 of 67 [53.7%]) and, in some cases, better (24 of 67 [35.8%]). Organisms on the WT-stained smear exhibited better morphology in a few instances (4 of 67 [6%]), and in three instances, there were discrepant organism numbers.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Julián Dib ◽  
Juana Oquilla ◽  
Silvia G. Lazarte ◽  
Silvia N. Gonzalez

Prevalence of intestinal parasites was investigated in rural primary school children in Famaillá city, Tucumán province, Argentina. Stool specimens from 149 school children were collected. The prevalence rate of intestinal parasite infections was 86.6%. No significant differences were observed in the distribution by age or by sex. Blastocystis hominis was the most commonly found protozoan parasite (54.4%), followed by Entamoeba coli (35.6%), Giardia lamblia (24.8%), and others (16.7%). Enterobius vermicularis was the most prevalent intestinal helminth (27.5%), followed by Ascaris lumbricoides (20.8%), Trichuris trichiura (12.8%), and others (5.4%). Most of the patients had polyparasitism (62.4%), and protozoan infections prevailed over helminthic infections. These results show high rates of parasitism in the school children of Famaillá, which would be associated with socioeconomic factors and poor environmental sanitation conditions in this area.


1999 ◽  
Vol 37 (3) ◽  
pp. 835-837 ◽  
Author(s):  
James A. Kellogg ◽  
Carol J. Elder

Of 12,321 stool samples analyzed over a 6-year interval, 870 (7.1%) were positive for a total of 1,019 parasites, of which 1,011 (99.2%) were found in trichrome-stained smears of unconcentrated specimens while only 479 (47.0%) were detected in iodine-stained smears of concentrated samples. Stool specimens were next analyzed by trichrome staining of both unconcentrated and concentrated specimens preserved in either mercury-polyvinyl alcohol (PVA) or cupric PVA. Of 2,198 specimens, 171 (7.8%) were positive for a total of 208 parasites, 192 (92.3%) and 204 (98.1%) of which were found in the unconcentrated and concentrated specimens, respectively (P < 0.05). In our patient population, examination of a single trichrome-stained smear of a concentrated stool specimen is a cost-effective alternative to routinely analyzing both concentrated and unconcentrated specimens for parasites.


2019 ◽  
Vol 19 (3) ◽  
pp. 284-287
Author(s):  
S. Viesy ◽  
J. Abdi ◽  
Z. Rezaei

Background: Intestinal parasitic infections are the one of the most common health problems in developing countries. Objective: A number of patients die annually due to complications caused by these parasites.Therefore, the aim of this study was to investigate the rate and type of parasitic infections, determine the factors affecting them in Ilam city and also provide strategies to prevent them.In this descriptive cross-sectional study conducted in one of the Ilam labs in 2016, 417 stool specimens were randomly collected. All specimens were examined using direct and ethanol formaldehyde.Suspect specimens were examined using Trichrom staining. Demographic information was also recorded in a questionnaire, and finally the results were analyzed using statistical software SPSS 20.The data were then compared with Chi-square test. Results: Out of the 417 patients examined, 59 (14.1%) were infected with intestinal parasites. The type of parasitic infection in 9.4% was Blastocystis hominis, 3.6% Entamoeba coli, 0.5% Entamoeba histolytica, 0.5% Giardia and 0.2% Trichomonas hominis. Conclusion: Despite the improvement of public health, parasitic infections are still considered as one of the health problems in the city of Ilam. Therefore, proper planning, public health education, raising the level of health in the area and the provision of safe drinking water are some of the ways to reduce parasitic infections in the region.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Corinne Légeret ◽  
Céline Rüttimann ◽  
Hans Fankhauser ◽  
Henrik Köhler

Abstract Background A wide variation of causes can lead to gastrointestinal symptoms in children- an infection with parasites is one of them. The expansion of international travel might lead to an increase in testing children for a correspondent infection. Currently there are no guidelines available, which patients should be tested for a possible parasitical infection. The aim of the study was to characterize Swiss children suffering from intestinal parasites, in order to provide more knowledge for the clinician who should be tested. Methods This is a retrospective study of Swiss pediatric patients, whose stools have been tested for parasites and helminths. Results A total of 1855 stool samples, belonging to 572 different children with an average age of 7.9 years, were tested within a 10-year period. The prevalence of a positive result was 4.2%, of which all were positive for Blastocystis, and 12.5% had a co-infection with Endolimax nana. Conclusion Immigrants, immune compromised children with diarrhea and pediatric patients with bloody or protracted diarrhea should have 2 different stool specimens examined for a possible parasitical infection.


PEDIATRICS ◽  
1980 ◽  
Vol 66 (1) ◽  
pp. 132-134
Author(s):  
James Seidel

Polyvinyl alcohol preservative (PVA) is used routinely in the laboratory for collection of specimens for examination for ova and parasites.1-4 PVA, presently used at Harbor-UCLA Medical Center, contains: 4.5% mercuric chloride, 5% polyvinyl alcohol, 30% denatured alcohol, 4.5% acetic acid, and 1.5% glycerin in an aqueous solution. The kit, as shown in the Figure, contains three bottles with 10-ml aliquots of PVA, wooden sticks for mixing the specimen, and written instructions for collection of the specimens. The bottles are clearly labeled as poison in English and Spanish, and specific verbal as well as written instructions are given to patients and their families when the ova and parasite kits are dispensed.


Author(s):  
Mohammad Reza Mahmoudi ◽  
Behnaz Rahmati

Introduction: Patients with cancer and hemodialysis are prone to opportunistic infections. The present research aims to examine the frequency of Toxoplasmosis and intestinal parasites in these patients. Methods: In the present cross-sectional study, seventy stool and blood samples from immunocompromised patients (46 hemodialysis and 24 cancer patients) from Guilan Province were collected in 2017-2018. Different tests including direct smear examination and formalin-ether was conducted for the intestinal protozoan parasites. To detect coccidian parasites (e.g. Cryptosporidium spp.) Ziehl Neelsen staining was applied. The anti T.gondii antibodies were detected via ELISA method. Results: Totally 6.52% and 4.16% cases of hemodialysis and cancer patients were positive for intestinal parasite infection respectively. Blastocystis hominis was only intestinal parasite that were detected in these patients. IgG anti-Toxoplasma antibody detected in 35 (76.8%) hemodialysis and 15 (62.5%) cancer patients. IgM antibody were found in 1 elderly hemodialysis patient. Mix infection (Toxoplasmosis and Blastocystis) was observed in 6.52% and 4.16% in hemodialysis and cancer patients respectively. Conclusion: It is recommended to evaluate these patients for intestinal parasitic infections during hemodialysis or chemotherapy sessions. Data showed the high percentage of elderly patients were susceptible to reactivation of chronic Toxoplasmosis. Therefore, in order to refer them for early therapy or other interventions, it is important that elderly hemodialysis and cancer patients with toxoplasma infection be diagnosed and identified.  


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