Comparison of methods of sampling for Toxocara species and fecal coliforms in an outdoor day care environment

OBJECTIVE: To compare three sampling methods and to pretest methods for the determination of fecal coliform (FC) counts and Toxocara species from sand in the day care outdoor environment. DESIGN: The sand samples were obtained from the play area and the sandbox of a day care centre and examined for the presence of FC and Toxocara species, the common roundworm of dogs and cats. The sampling methods included random selection and two types of judgement methods. The latter included one method where domestic animals were judged to be likely to defecate and the other where children would be likely to be playing. In addition, to obtain a global estimate of contamination, the entire areas of both the sandbox and the play area were sampled on the last day. SETTING: Outdoor day care environment. MAIN RESULTS: The most representative levels of bacterial contamination and Toxocara species originated from the combined sample of the entire surface areas rather than from any separate random or judgement method of sampling. FCs were found in all sampled areas of the sandbox (median 910 FCs/g of sand) and of the play area (median 350 FCs/g of sand). Toxocara species were recovered from a number of areas in both the sandbox and the play area. CONCLUSIONS: Research on environmental microbial contamination of outdoor day care settings would benefit from the application of standardized and validated sampling and laboratory methods

Effects of different schedules and availability of answers on learning

This study was motivated by the author's belief both as a teacher and researcher that the method of presenting answers to students who are in the process of learning is important to their learning. The two main variables studied were the availability of answers and the proportion of answers. A basic 3x2 factorial design was used with two levels of availability: 1) available 2) non-available and three levels of proportion of answers 1) 80% of the answers given 2) 20% incorrect answers given 3) all the answers given. Two topics, solving equations of the first degree and simplifying exponential expressions were used as the subject material. Four grade eleven classes were given instruction and then pretested on the particular topic. Then the six treatments were randomly assigned in a stratified way and the students proceeded to the exercises pertaining to the particular topic. A posttest was administered after a particular topic was completed. Then the students were re-assigned topics while maintaining their same treatment. The students followed the same procedure as above of lecture, pretest, exercises and posttest. An analysis of co-variance was calculated on each of the groups according to topic, order of unit, and particular group. The pretest was covaried on the posttest. Students were also asked to rank-order their preference for answer sheets or treatments. The results indicated that the availability factor had no statistically significant effect on the student's performance on any topic although the students favored the non-available answers. The results also showed that the students who were given 80% of the answers and those who were given 2 0% incorrect answers, performed better than the group who was given all the answers. This was statistically significant with the group who followed the sequence solving equations of the first degree then simplifying exponential expressions and only pertained to the simplifying of exponential expressions. The results were discussed in terms of the particular topics involved and the variables that were under study. Suggestions for further studies were made in terms of the results of this study.Education, Faculty ofCurriculum and Pedagogy (EDCP), Department ofGraduat

Parasite contamination of sand and soil from daycare sandboxes and play areas

Objectives: To determine if there was parasite contamination in the sand and soil in daycare sandboxes and play areas, with the goal of developing practice guidelines for their management

Comparison of methods of sampling for Toxocara species and fecal coliforms in an outdoor day care environment

OBJECTIVE: To compare three sampling methods and to pretest methods for the determination of fecal coliform (FC) counts and Toxocara species from sand in the day care outdoor environment

Detection of Pathogenic Protozoa in the Diagnostic Laboratory: Result Reproducibility, Specimen Pooling, and Competency Assessment▿

Stool microscopy as performed in clinical parasitology laboratories is a complex procedure with subjective interpretation. Quality assurance (QA) programs often emphasize proficiency testing as an assessment tool. We describe a result reproducibility assessment tool, which can form part of a broader QA program, and which is based on the blinded resubmission of selected clinical samples, using concordance between the reports of the initial and resubmitted specimen as an indicator. Specimens preserved in sodium acetate-acetic acid-formalin can be stored for several months for use in such a program. The presence of multiple protozoa in one specimen does not affect concordance. Some dilution of specimens occurs in this process, and this may explain poor concordance when specimens with low protozoal concentrations are resubmitted. Evaluation of this tool in a large parasitology laboratory revealed concordance rates for pathogenic protozoa (Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Dientamoeba fragilis) of about 80%, which may be considered for use as a benchmark value. We also used this tool to demonstrate that when pairs of specimens from one patient are pooled to create a single specimen, concordance between the results of the individual and pooled specimens is high

Comparison of Blood Smear, Antigen Detection, and Nested-PCR Methods for Screening Refugees from Regions Where Malaria Is Endemic after a Malaria Outbreak in Quebec, Canada

The importation of malaria into a region where it is not endemic raises many concerns, including the timely delivery of appropriate care, safety of the blood supply, and the risk of autochthonous transmission. There is presently no consensus on the best way to screen mobile populations for malaria. Between August 2000 and March 2001, 535 refugees arrived in Quebec, Canada, from Tanzanian camps. Within 4 weeks of resettlement of the first group of 224, the McGill University Centre for Tropical Diseases noted an outbreak of malaria across the province (15 cases over a 3-week period). This group (group 1) was traced and screened for malaria between 3 and 4 months after arrival in Canada. Subsequent groups of 106 and 205 refugees were screened immediately upon arrival in Canada (group 2) and immediately prior to their departure from refugee camps (group 3), respectively. A single EDTA-blood sample was obtained from 521 refugees for testing by thick and thin blood smears (groups 1 and 2), antigen detection (ICT Malaria Pf and OptiMAL; group 1 only), and nested PCR (all groups). Overall, 98 of 521 refugees were found to be infected (18.8%). The vast majority of infections (81 of 98) were caused by Plasmodium falciparum alone. Using PCR as the “gold standard,” both microscopy (sensitivity, 50%; specificity, 100%) and antigen detection (ICT sensitivity, 37.5%; ICT specificity, 100%; OptiMAL sensitivity, 29.1%; OptiMAL specificity, 95.6%) performed poorly. None of the PCR-positive subjects were symptomatic at the time of testing, and only two had recently had symptoms compatible with malaria (with or without diagnosis and treatment). Active surveillance of migrants from regions of intense malaria transmission can reduce the risk of morbidity in the migrant population and mitigate against transmission to the host population. Our data demonstrate that PCR is, by far, the most powerful tool for such surveillance

Malaria Epidemics and Surveillance Systems in Canada

In the past decade, fluctuations in numbers of imported malaria cases have been seen in Canada. In 1997–1998, malaria case numbers more than doubled before returning to normal. This increase was seen in no other industrialized country. The Canadian federal malaria surveillance system collects insufficient data to interpret these fluctuations. Using local (sentinel), provincial, federal, and international malaria surveillance data, we evaluate and interpret these fluctuations. Several epidemics are described. With an ever-increasing immigrant and refugee population of tropical origin, improved surveillance will be necessary to guide public health prevention policy and practice. The Canadian experience is likely to be generalizable to other industrialized countries where malaria is a reportable disease within a passive surveillance system

Laboratory Diagnosis for Giardia Lamblia Infection: A Comparison of Microscopy, Coprodiagnosis and Serology

OBJECTIVE: To evaluate newer techniques such as coproantigen detection and serology in the diagnosis of symptomatic Giardia lamblia infection