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  Abstract

  Background and Aim: Allergy is one of the unusual body reactions with the intermediate of immune system. Today, allergy to foods and fresh fruits is one of the world's health problems in developing countries and its incidence has raised like other allergic disorders. The aim of this study is to investigate the allergic reactions, that is, frequency to alimentary allergens, among native population and university students in Gonabad.

  Materials and Methods : This is a descriptive and cross-sectional study. We studied 339 patients of native population and of university students who were only residing in Gonabad city to continue their study. Simple random sampling was used for data collection. We used the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire to collect data. T-test and Chi-square were applied for data analysis.

  Results: The results showed that from 339 patients, 57.2% were native population of Gonabad, 35.4% native population of Khorasan Razavi province, and 7.4% non-native population. The frequency of males was 152 (44.8%) with 25.1 of age average and that of females was 187 (55.2%) with 21.1 age average. The frequency of each allergen was as follows: melon (34.2%), saffron (17.4%), eggplant (%16.8), milk (16.2%), garlic (10.9%), grape (8.8%), cantaloupe (8%), soya (8%), kiwi (7.4%), egg (7.1%), banana (5.3%), sesame (2.1%) and hazelnut (1.5%). 

  Conclusion: In our study, the patients' most common allergens were melon, saffron, garlic, grape, cantaloupe, kiwi and eggplant. In most of the cases, food allergies were more frequent in females than in males.

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Background and Aim: Allergic diseases are among the most important health problems in childhood. In this study, we decided to compare the prevalence of asthma, allergic rhinitis, and eczema in rural and urban children in Gonabad. Materials and Methods: A cross-sectional study was conducted in the city of Gonabad in 1390. 1626 urban and rural children aged 12-18 years participated in this study using multi-stage sampling. International Study of Asthma and Allergies in Childhood questionnaire (ISAAC) was used to evaluate the prevalence of allergic symptoms in children. Statistical analysis was performed using SPSS software version 16. The Chi-Square tests were used for comparison of qualitative variables between the two groups. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated to show the strength of association. A two-tailed analysis was considered statistically significant (p<0.05). Results: Of the 1626 students, 876 (53.8%) were boys and 751 (46.2%) were girls. Mean age of children was 14.5±1.8. 1219 (74.9%) of students were living in urban and 407 (25.1%) were living in rural areas. 617 (38%) of students had at least one allergic symptom at some time in their life and there was no statistical difference between rural and urban ones (p-value=0.141). However, a 12-month prevalence of rhinitis symptoms was significantly higher in urban children than that in rural ones (p-value=0.020). Conclusion: The prevalence of allergic rhinitis was higher in urban children than that in rural ones which may be related to urbanization risk factors.

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Aims: Hepatitis B infection is one of the common diseases and the most prevalent communicable virus transferred by blood to the healthcare personnel. Active immunity, through vaccination, is the most effective way to prevent hepatitis B infection. The current study aimed to determine the protective antibody titer against HBs antigen in Gonabad University of Medical Sciences students, Gonabad City, Iran, 2018.
Methods & Materials: The present cross-sectional study was conducted on 416 students of Gonabad University of Medical Sciences. The HBsAb level was determined in blood samples by an Enzyme-Linked Immunosorbent Assay (ELISA) kit made in Iran. Data were analyzed using descriptive statistics like frequency distribution tables and inferential statistics as independent 2-sample t-test and Chi-square test to determine the relationship between variables. The significance level was considered P<0.05.
Findings: HBsAb level of 217 cases (51.8%) was below 10 IU/mL, 96 (61.3%) had an HBsAb level between 10 and 100 IU/mL, and in 106 (36.5%) cases, HBsAb level was above 100 IU/mL. There was no statistically significant difference between the means of HBsAb in terms of gender, age, and body mass index (P<0.05).
Conclusion: In general, more than 50% of the study participants had mild immunity against hepatitis B viruses. Therefore, in these people, it is recommended to check the antibody titer periodically to ensure immunity against hepatitis B.

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Aims Chemokine receptor type 5 is recognized as the main co-receptor in HIV infection. Many studies have shown that the deletion of 32-base pairs (bp) of both alleles of CCR5 leads to the reduction or elimination of the expression of this gene in immune cells and the natural resistance to HIV infection. This study aims to determine the frequency of delta 32 mutations in healthy people, referring to the health center of Gonabad City, Iran, to focus on finding new treatment methods for the treatment of HIV. 
Methods & Materials In this descriptive cross-sectional study, after obtaining ethical approval and informed consent, blood samples were collected from 293 healthy people along with ethylenediaminetetraacetic acid anticoagulant. Genomic DNA extraction was carried out by the kit, and the investigation of delta 32 (∆32) mutation of the CCR5 gene was investigated via the polymerase chain reaction method. 
Findings Our results showed that out of 293 people who referred to the health center, 269 people (91.8%) had a healthy gene without mutation (188 bp), 15 people (5.1%) had heterozygous mutations (188 bp and 156 bp), and 9 people (3.07%) had a homozygous mutation on both alleles of CCR5 (156 bp). 
Conclusion Based on the results, the homozygous mutation rate of Gonabad Region, Iran, in the studied community is higher compared to similar studies, and more epidemiological and molecular studies are needed for better conclusions.