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  Background & Objectives: Cryptosporidium is a coccidian protozoan parasite. This organism is one of the main causes of severe, long-time and life-threatening diarrhea in immunocompromised persons. It is also among the most prevalent diarrheal agents in children. Cryptosporidial epidemics occur after consumption of water which is contaminated by oosit species of cryptosporidium. Water is usually contaminated by animal feces or by drainage of waste water into drinking water resources.

  Methods: In this study, from ten regions 200 water samples were collected, filtered by 1.2 micron papers and then positive samples were identified in terms of cryptosporidium using PCR method. Finally the related species were detected by RFLP method.

  Results: Nested-PCR showed 8 samples were positive for cryptosporidium that according to RFLP of PCR products 5 samples belonged to cryptosporidium andersony, 2 samples belonged to cryptosporidium parvum bovine genotype and 1 sample belonged to cryptosporidium pig genotype.

  Conclusion: Since Cryptoridium andersony and cryptosporidium parvum bovine genotype are the common species in animals and cryptospovidium swiss is seen in wild animals (pigs and boars), it so we conclude that animal reservoirs have the main role in the contamination of related water resources in this region.

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Background & Objective: Iodine deficiency is one of the most important life-threatening factors from the beginning and encounter irreversible damage to human. This study aimed to investigate stability of Iodine in iodized salt in different situations such as light and humidity and comparing it with standard amounts.
Methods: In this cross-sectional descriptive-analytical study, 12 samples of iodized salts which have been distributed in Damghan, were accidentally selected. Samples were examined in the chemistry laboratory of Faculty of Health (Damghan University of Medical Sciences) using titration method recommended by British pharmacopeh. 10 mg of each iodized salts were kept at presence of light, darkness, humidity, and non- humidity situation and then titration method was performed. The samples were kept for two weeks and examined weekly. Data were analyzed with T paired and ANOVA tests using SPSS software.
Results: Findings of this study showed that reduction of Iodine was seen for all samples. The amount of reduction were 2.2, 1.5, 4.1 and 2.1 mg/l for purified salts at light, darkness, humidity, and non- humidity situation, respectively. The amount of reduction were 3.4, 2.1, 5.35 and 2.6 mg/l for non-purified salts at light, darkness, humidity, and non- humidity situation, respectively. In spite of reduction in Iodine, concentration of it was at standard amount (30-50 PPM).
Conclusion: Results showed that stability of iodine was more when salt was exposed to darkness in comparison with light situation (p< 0.09). Meanwhile, the stability of purified salts was more than the non- purified salts (p< 0.28). Also, stability of iodine was less at humidity in comparison with non- humid situation (p< 0.006). The purified salts which was exposed to humidity was much stable compared to the non- purified salts (p< 0.28). It also, demonstrated that the amount of iodine stability was more for salts which was exposed to light in comparison with humidity (p< 0.05).

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Background & objectives: One of the difficulties of community of dentists, especially dentists dealing with children, is the pain and fear of dental treatment. The purpose of this study was to investigate the effectiveness of systematic desensitization and distraction on reducing fear and pain in children with dental problems.

Methods: This is a quasi-experimental study designed with pretest-posttest multi groups according to control group. For this purpose, 45 children with dental problems referred to the dental clinic of Ardabil was selected and divided into three groups of 15 people: systematic desensitization (n=15), distraction (n=15) and control group (n=15). All of three groups answered to dental fears survey and numeric scale of pain as pre-test. Then, the therapeutic method of systematic desensitization and distraction was performed on two experimental groups. After completion of the treatments, three groups answered to dental fear survey and numeric scale of pain. Multivariate analysis of covariance was used for the analysis of the data.

Results: The results showed a significant difference in the score of post-test between three groups in pain (F=197.27; p<0.001) anddental fear (F=178.36; p<0.001). LSD post hoc test results showed that systematic desensitization method was more effective in reduction of pain and the distraction method was more affective in reduction of dental fear.

Conclusion: The results of this study indicate that psychological interventions of distracting and systematic desensitization can be used to reduce fear and pain at pediatric clinics.

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Background & objectives: There is evidence that COVID-19 may have some long-term effects on the patients' blood biochemical and hematological factors. The purpose of this study was to investigate and compare the changes in biochemical and hematological factors in adults with and without past history of COVID-19.
Methods: The present study is a cross-sectional study including 72 cases with a past history of COVID-19 (PCR+ test) and 52 controls without a history of COVID-19. All participants were from two prospective cohort studies, namely Yazd Health Study (YaHS) and Shahedieh Cohort Study. Biochemical parameters such as blood glucose, lipid profiles, liver, kidney and hematological factors of cases and controls were extracted from the databases and analyzed.
Results: The mean red blood cell count in patients with COVID-19 was significantly higher than in non-COVID-19 patients (p<0.05), and mean corpuscular volume (MCV) was significantly lower in patients with COVID-19 (p>0.001). However, no significant difference was found between the two groups in terms of lipid and kidney profiles and liver enzymes.
Conclusion: No significant difference was found between the two groups of patients exposed to COVID-19 and patients not exposed to COVID-19 in terms of liver enzymes, lipid and kidney profiles, which probably indicate that COVID-19 has no long-term effect on these variables. However, a significant difference was observed between the two groups (p<0.05) regarding the number of red blood cells and MCV.