الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Intestinal parasitic infections (IPIs) are major health problems in many developing countries, especially in tropical and sub-tropical regions and particularly among pre-school and school children. Globally, over 568 million school-age children live in intestinal helminth prevalent areas. Those living in poverty are more vulnerable to infection. Worldwide, about 2 billion people are infected with STHs which cause undernutrition, anemia, intestinal obstruction, mental and physical growth retardation, abdominal colic, cholestasis, cholecystitis, pancreatitis and even mortality.
Diagnostic testing is an important part of parasitic control programs. There are various methods for detecting intestinal parasitic infections in humans, but when the programs involve a large population it is important that the technique chosen is suitable not only for its sensitivity and specificity but also its usability and low cost. The mini-FLOTAC is a novel direct technique for the diagnosis of helminthic and protozoal intestinal infections. The aim of the present study was to validate mini-FLOTAC technique versus formol ether concentration technique (FECT) and Kato-Katz techniques for the diagnosis of intestinal parasitosis and the estimation of the intensity of infections among school children (from grade 1 to grade 6) at Mohamed Farid Primary School, in one of the rural villages Banger El-Sokkar, in Borg El-Arab area, Alexandria Governorate.
An interviewing questionnaire was designed to collect data from all school children including: sociodemographic data, house environment data in addition to medical history.
Stool samples were collected from 250 students for diagnosing parasitic infections. Each sample was examined by the three techniques; Mini-FLOTAC, FECT and Kato-Katz (3 slides).
from the present work, the following results were obtained:
1- Considering pooled data of the three techniques used, the total prevalence of IPIs among the studied sample was 36.4%. The prevalence of protozoa was 34.8% while helminths prevalence was 1.6%.
2- Children aged from six to less than eight years had the lowest rate of infection (21.6%), but the highest rate was among children aged from ten to twelve (67.6%).The difference in the rates of infection between the different age groups was statistically significant.
3- Male children presented with a higher percentage of intestinal parasitic infection than females (40.3% vs 32.5% respectively). However, the difference was not statistically significant (p<0.05).
4- The highest percentage of the intestinal parasitic infection was between children whose fathers were merchants (43.3%).5- The highest percentage of infection was detected among children who used a pit latrine (39.0%).
6- Children who had animal shelter inside their houses presented with statistically significant higher percentage of infection (55.9%) compared to those who had no shelter (24.8%, p<0.001).
7- Children living in separate houses had a higher rate of parasitic infection (37%) than those living in shared houses (34.9%). Also, children who lived in two rooms had a higher percentage of parasitic infection (40.8%) compared to those living in three rooms and more (32.2%).
8- The majority of schoolchildren (65.2%) did not have any previous parasitic infections, and about 44% of them were found to harbor parasites in the present study. On the other hand, a percentage of 21.8% was recorded for children with a history of previous parasitic infections. The difference was statistically significant.
9- Children who did not give history of diarrhea during the last two weeks prior to the sample collection presented with a significantly higher IPIs rate compared to children who had history of diarrhea (74.1% vs 17% respectively, p˂0.001.
10- By using FECT, only 25.2% of examined samples were found positive for IPIs (p<0.001). The detected parasites were different species of protozoa mainly: E.histolytica/E.dispar, B. hominis and G.lamblia with percentages of 12%, 10% and 9.2% respectively. No Helminths were detected. Also the examination of the three kato katz slides didn‘t reveal any helminths.
11- When using the Mini-FLOTAC technique with the two flotation solutions FS2 and FS7, the percentage of the total positive samples with intestinal parasites was 35.6%. The different species of protozoa detected were also; E.histolytica/E.dispar, B.hominis and G.lamblia but with higher percentages: 18%, 11.2% and 10.8% respectively. A.lumbricoides was the only helminth detected with a rate of 1.6%.
12- The mean counts of cysts of E.histolytica/E.dispar, G.lamblia and B.hominis were 5.3, 8.4 and 7.4 cysts per HPF respectively by using Mini-FLOTAC technique. Lower counts were obtained when using FECT (4.6, 7.1, and 6.3 respectively) but the difference in mean counts between the two techniques was not statically significant.
13- As regards A.lumbricoides infection, the eggs were detected only when using Mini-FLOTAC technique. Its intensity of infection was computed to be 1520 + 992.37 eggs/g stool.
14- An almost perfect agreement was detected between the Mini-FLOTAC and the gold standard technique (pooled data of the all coproscopic techniques); Cohen‘s Kappa coefficient (K) was 0.983. Meanwhile, the agreement between the FECT and the gold standard technique was substantial (K=0.741).
15- Compared to the gold standard results, Mini-FLOTAC sensitivity was 97.8%, its specificity was 100%, the PPV was 100%, the NPV was 98.76% with an overall diagnostic accuracy of 99.2% and the AUC was 0.989. As regards FECT, the sensitivity was 69.23%, its specificity was 100%, the PPV was 100%, and the NPV was 85.03%. The overall diagnostic accuracy was 88.8% and AUC was 0.846.6.2 Conclusions: Protozoal infection among studied sample was 34.8% whereas helminthic infection rate was only 1.6%.
Ascaris lumbricoides was the only helminth detected while E.histolytica/dispar, G.lamblia and B. hominis were the main protozoa diagnosed.
A significant difference was detected between the performance of Mini- FLOTAC, Formalin-ether Concentration and Kato-Katz techniques in the detection and estimation of prevalence of IPIs.
In terms of degree of agreement, an almost perfect agreement was observed between Mini FLOTAC and the gold standard while only a substantial agreement was obtained between them and FECT.
Mini FLOTAC technique was proved to be a highly sensitive, specific, affordable and of low-cost technique.
The Mini-FLOTAC technique can be a better alternative to the Kato-Katz technique for diagnosis of intestinal helminths and estimation of prevalence.
6.3 Recommendations
from this Study, the following could be recommended:
i. Sustainability of control program against IPIs targeting school children is still mandatory emphasizing protozoal diagnosis and treatment.
ii. Health education of school children about the importance of washing hands especially after going to toilet and after dealing with animals.
iii. The use of more than one diagnostic technique to detect IPIs especially in low intensity settings and when evaluating a control program.
iv. The use of Mini FLOTAC as an alternative to Kato- Katz and FECT especially in resources limited settings, low intensity settings, drug efficacy evaluation and control programs.
v. A further evaluation of Mini-FLOTAC performance in moderate or high intensity settings especially for S. mansoni infection is needed.
vi. Further research is needed to assess the possibility of including a staining step in the process of Mini-FLOTAC technique by using a temporary stain as iodine to facilitate the diagnosis of protozoal cysts.