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Background and purpose: Âmong rheumatic inflammatory diseases, rheumatoid arthritis has the highest rate of prevalence (1% in majority of the societies and as well as in Ïran). This is a chronic disease, followed by multiple- system involvement of unknown etiology. Major sing is inflammation of sinovial joints. Ïn addition to pain, inflammation, restriction and joints deformity the patients experience mental disorder, stress, anxiety and depression resulting from disease condition is associated with disease which provid defective cycle between mental and physical signs, as a result, the disease is activated by stress and nervous stimulants. Therefore control of the disease is difficult sometimes, hence, in this study, medication was followed along with benson relaxation in order to control the disease activity.
Materials and methods: This clinical trial study was performed in rheumatology research clinic of Ïmam khomeini hospital in Tehran during 2000-2001. Fifty patients were selected as non probable samples from the society under investigation, and on the basis of age and sex, randomly were divided in two case (26 patients) and Çontrol (26patients) groups. Patients of the case group individually were trained for benson relaxation with tape. This interferance was followed for 8 weeks. Ïn order to evalute benson relaxation effects, clinical symptoms, laboratory findings, anxiety, depression and feeling of well being before and after interferance were measured.
Results : Statistical tests showed no significant difference in variable of pre and post intervention in two groups. Mean variables of anxiety, depression and feeling of well being in two groups in post intervention were as follow: P=0.0001, P= 0.0001 and P=0.001 respectively which indicated significant difference. Most variable of clinical symptoms and laboratory findings showed decline in disease progress. But no significant statistical difference was observed.
Çonclusion: Hypothesis of this study emphasizing that, benson relaxation declines disease progress, was confirmed for anxiety, depression and feeling of well being. Referring to the other variables related to clinical symptoms and laboratory findings, and in order to obtain more accurate statistical results, study with more sample size and performing of interferance in more than 8 weeks period is necessary.

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Background and purpose : Çongenital anomalies are common causes of mortality & morbidity in children. Ïts treatment and rehabilitation imposes high economic burden on the society. The oceurence of the defects in newborns with congenital, environmental or both factors is 3-5% . The purpose of this study was to evaluate the incidence of Gross congenital neural tube defect in newborns at obstetric center of the Vally-e-Âsr Hospital in Zanjan. Detection of correlation between N.T. D & the parameters such as the place of Mother’s residence, duration of pregnancy and past history of N.T.D in family were among the secondary objective.
Materials and methods : This was a cross-sectional prospective study done on all newborns that were visited at least once by physician and data were recorded in special form.
Results : From a total of 2250 newborns,14 had N.T.D. ( birth). The most common (N.T.D) was spina bifida-cystica (Meningomylo cele & then Meningocele) and mothers in this group were resident in villages (78 %) and 71% of newborns in this groups were term anomaly group, 98% of mothers had history of NTD and also 42% with history of abortion.
Çonclusion : Çontrary to prevalence of NTD in the Ü.S. ( ), in our study the Gross anomaly of NTD was higher ( birth ). There are significant statistical differences between the prevalence of NTD and low socio- economic and residence status of mothers.

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Background and purpose: Tody, most societies face significant decrease in consuming milk products in children and this process would cause problems in providing the calcium needed by children, particularly since the osteoporosis is definitely connected to a lack of receiving sufficient calcium in children and adolescence age. Therefore, the goal of this study is to study the knowledge and pattern of milk consumption in 7-12 year old children of Sari and their mothers.
Materials and Methods: The research samples consisted 638 male and female student at 7-12 in elementary schools (urban and rural), chosen at random from 16 schools. Necessary data were obtained through separate and different questionnaires on the output of milk consumption and its products through direct interviews. The data of the study were analyzed using t-Test, ANOVA, Duncan follow up, Chi-square and correlation coefficient.
Results: In this study, 44% of children and 37.7% of mothers consumed milk and 50.1% of children and 19.4% mothers sometimes consumed milk. 5.5% of children and 19.4% of mothers did not consume milk. Mostly, the reason for non-consuming milk among children and mothers was: not having access to milk (27.9% and 17.7%). The awareness towards the advantages of milk was desirable in 67% children and 48.7% of mothers. It was almost desirable in 21.1% children and 4.5% of mothers and undesirable in 1.4% of children and 1.1% of mothers. The amount of milk consumption for 62% of urban children and 49% of rural children was only one unit, and, in sum, the amount of milk consumption for 59% of boys and 55% of girls was less than the recommended figures. The mean average of criteria deviation in the amount of milk consumption for children showed a significant difference from their educational levels (p=0.001) and insignificant difference from their sex. In addition, the pattern of milk consumption of children had significant relationship with the sex, education level and education of father however, it had significant relationship with the education level of mothers and the jobs of mother and father. Children's knowledge about the advantages of milk had a significant relationship with the education level of mothers, fathers and jobs of mothers (P<0.004) however, it had a insignificant relationship with their sex.
Conclusion: In this study, the amount of milk consumption in half of the population subjects of the study was less than the standard recommended amount therefore, to improve children's health status and prevent the destructive effects of osteoporosis in adulthood, there should be necessary actions to increase milk consumption among children.

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Background and purpose: The Beijing genotype is one of the most important strains of Mycobacterium tuberculosis involving outbreaks of tuberculosis in various parts of the world. Unsought regarding Beijing genotype in Iran, is the reason this study is undertaken in order to evaluate the frequency of this genotype in Mashhad.
Materials and Methods:This descriptive study was carried out on 113 M.tuberculosis Specimens isolated from patient with pulmonary tuberculosis in hygienic centers, located at Ghaem and Imam Reza hospitals in the City of Mashhad. In this study, Beijing genotypes were detected with PCR-based method, and spoligotyping. Results were processed with descriptive statistics and CI was evaluated.
Results:Beijing genotype was detected in 8 specimens of all the 113 isolated M.tuberculosis strains (7.1%, CI 95%, 2.36-11.84). Out of 8 isolated specimens, 5 isolates belonged to Afghan patients and 3 specimens were isolated from Iranian patients. Out of 8 patients that were infected with Beijing genotype, 2 patients were male and 6 patients were female.
Conclusion:Although the rate of Beijing family is low in Iran, in comparison to other Asian countries, however, one needs to adopt a suitable policy in order to prevent its spread.

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Background and Purpose: Different studies have shown that caregivers of patients suffering from chronic physical or mental disorder endure a considerable burden. Authors decided to evaluate such burden on two groups of caregivers, (schizophrenic and ESRD patients), since few studies have been carried out regarding this subject in Iran.
Materials and Methods:In an experimental, cross sectional, comparative, two-tier cohort study, 60 caregivers (30 of Schizophrenic and 30 of those suffering from End Stage Renal Disease), were selected as convenient groups. Demographic questionnaires and FBIS were completed for both groups and results were reviewed by SPSS software based on t test.
Results:Caregivers of Schizophrenic patients endured a heavier burden in comparison with those suffering from ESRD by a meaningful difference, (0.05%). The results achieved from subgroups also showed that caregivers of both groups bear almost similar economic burden. In subgroup of objective burden, the caregivers of schizophrenic patients endured more burdens in comparison with patients suffering from ESRD, with once again a meaningful difference. Moreover, in subgroup of subjective burden, the caregivers of Schizophrenic patients endured more burdens comparing to patients suffering from ESRD, however the difference was not meaningful.
Conclusion:This study revealed that the caregivers of Schizophrenic patients experience more burdens, both objective and subjective, in comparison with patients suffering from ESRD.

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Background and purpose: Matrix metalloproteinase are a family of proteolytic enzymes that have specific functions in digestion of cells cohesive extra cellular matrix and also, increasing metastasis behavior of acute human tumors. It has been reported that MMPs in two forms, namely proenzyme and active enzyme in biological samples. It is distinguished that among this family, (MMP-9) Matrix Metalloproteinase-9 has function in both initiation and invasion steps of breast cancer. In our previous study, we reported a correlation between C/T polymorphism at promoter region of this gene and metastasis step of breast cancer. Considering few findings regarding the relationship between the active form of this enzyme and occurrence of cancer, and also the correlation between active form and allelic genotype of persons, in this study we decided to do a parallel study on measurement of active plasma MMP-9 and its relationship with allelic genotype of breast cancer patients.
Materials and methods: After analysis of data, we found that concentration of active MMP-9 has a significant difference in breast cancer patients in comparison with control group, as the concentration of active form of this enzyme was less in control group than the breast cancer patients group (0.7 ng and 1.7 ng respectively). Thus, the level of active MMP-9 showed a significant increase in persons with CT and TT genotypes in comparison with CC genotype (1.5 folds).
Results: The present data suggest the concentration of active MMP-9 in breast cancer patients has significantly increased in comparison with the control group and the increased in plasma level of this enzyme is related with the existence of T allele at this gene promoter and also in progression of breast cancer in these patients. We can use the active plasma level of this enzyme or the existence of T allele as a diagnostic tool for discriminating subgroups of breast cancer patients and also, for diagnosis of susceptible breast cancer women for metastasis to other tissues.
Conclusion: The present data suggest that the concentration of active MMP-9 in breast cancer patients has a significant increasing comparison with the control group and the increasing in plasma level of this enzyme is related with the existence of T allele at this gene promoter and also progression of breast cancer in this persons, we can use the active plasma level of this enzyme or the existence of T allele as a diagnostic value for discriminating subgroups of breast cancer patients and diagnosis of susceptible breast cancer women for metastasis to the other tissues.

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Background and purpose: Religious attitude and mental health are the categories that have advocated many researches in the world .Although mental health related studies were performed in Iranian students, there is little evidence in the religious attitude field. The aim of the current study was to survey the mental health and religious attitude in the students of the Mazandaran University of Medical Sciences.
Materials and methods: This descriptive study was undertaken on 222 students of Mazandaran University of Medical Sciences (86 male and 136 female) whom were selected randomly. Data collection instruments were a 25-question religious attitude questionnaire (Golris-Brahni), and a 28-question mental health questionnaire (G.H.Q-28).
Results:The finding showed that the mean scores on religious attitude in female students was at high levels (µ=76.4) and in male students (µ =72.2) at good levels with statistical significant differences. The average value of mental health in girl (µ = 20.4) and boys (µ = 23.8) with significant difference.
Conclusion: The results showed that religious attitude and mental health scores are higher in girl students compared with those in boy students. The findings also support the idea that there is an association between religious attitude and mental health. Based on current findings, it is important to pay attention to the socio-cultural status of the students to improve their mental health.

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Background and purpose: Çoncept of locus of Çontrol, as a personality variable, is now an important theoretical and applied research field, studied in connection with several phenomena. This study evaluates if locus of Çontrol variable can be a predictor for academic performance toward the next semesters and if previous academic performance can affect the locus of control score.
Materials and methods: This is a descriptive study and the subjects were students of Mazandaran Üniversity of Medical Sciences. Â stratified random sampling and control of educational levels and schools were conducted. We used Rotter 29 item locus of control inventory and demographic questionnaire as measurement tools and researchers attended the selected classes in the third educational semester onward. Questionnaires were distributed and completed forms were collected at the same session.
Results: This study showed that, although students who have internal locus of control had higher academic achievement, there was no significant relationship between locus of control and the average score of the second and third semesters. There were no statistical differences between the demographical variables of the parents and the locus of control.
Çonclusion: Âlthough people with internal locus of control are more successful in their lives, this does not necessarily mean they are successful in any kind of activities, including education. Âcademic achievement is suggested to be multifactorial.

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Background and purpose: Nausea and vomiting are common complaints in early gestation. The most severe form of this disorder is hyperemesis gravidarum (HG), which occurs in 1–2% of pregnancies. Some researches showed that special type of HCG influence TSH receptor increase iodine removal. This process could result in chemical hypothyroid. This study investigated the relationship between beta human chorionic gonadotrophin (BHCG) and throyid function with HG among pregnant women admitted to Sari Imam Khomeini Hospital. Materials and methods: This case-control study was performed in 42 patients admitted to for nausea and vomiting whose gestational age was 8-18 weeks. The study was carried out during June 2011 to December 2011. In this rsearch 45 pregnant women enrolled in a control group who were matched for demographic features. The data including demographic features and levels of TSH, T3, FT4 and BHCG was recorded in both groups. It was then analyzed using t-test and chi square test in SPSS. Results: The mean ages of the participants in control group and experimental group were 25.33±5.9 and 23.17±4.28, respectively. Significant differences were seen in levels of TSH, FT4, T3, and BHCG between the two groups. Conclusion: The serum level of BHCG, FT4, and T3 was higher in patients with nausea and vomiting but the level of TSH was lower. There was chemical hypothyroid among the patients but none of the patients had clinical manifestations of hyperthyroidism.

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Due to the predisposing conditions in patients with cystic fibrosis (CF) caused by defective mucociliary clearance facilitates of colonization and invasion with bacteria and fungal species has dramatically increased. In different studies many opportunistic fungi such as Candida and Aspergillus species have been frequently isolated from the respiratory tract of patient suffering from cystic fibrosis. Molecular biotyping studies have revealed that some fungal genotypes are capable of chronically colonizing in the airways. Although colonization of Candida species was more common, other fungi such as Aspergillus species, Scedosporium apiospermum, and Exophiala dermatitidis frequently recovered from respiratory secretions of CF patients. Due to the predisposing conditions of fungi agent colonization in these patients, identification and preliminary diagnosis of infectious agents for early treatment and preventing the invasion is highly recommended. On the other hand, regarding the differences in epidemiology, virulence, and susceptibility profile in isolated species of fungi from cystic fibrosis patients, identification and discrimination of ethological agents are crucially important and further studies is highly suggested.

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Background and purpose: Due to the beneficial physiological effects of conjugated linoleic acid (ÇLÂ), there has been a growing tendency to produce it as a functional lipid in recent years. Different ÇLÂ isomers have different physiological effects hence, production of certain ÇLÂ isomers with high purity is of great importance. ÇLÂ can be produced through both chemical and enzymatic methods however, unlike chemical catalysts, enzymes make it possible to produce pure ÇLÂ isomers. Ïn this study, linoleic acid isomerase from Propionibacterium acnes was expressed in Ë. coli and the possibility of the production of ÇLÂ was studied.
Materials and methods: The vector containing linoleic acid isomerase, pGËX-6P-PÂÏ, was transformed in Ë. coli . Transformants were selected based on their resistance to ampicillin and restriction digestion analysis. To express the recombinant linoleic acid isomerase, transformants were induced using isopropyl-beta-thiogalactopyranoside (ÏPTG). The expression of recombinant protein was confirmed by SDS-polyacrylamide gel electrophoresis and Western blotting using anti-linoleic acid isomerase antibody. Then, the possibility of the production of ÇLÂ from Linoleic acid by using Ë-coli transformant was investigated.
Results: Recombinant linoleic acid isomerase was intracellularly produced as a glutathione S-transferase (GST) tagged protein by transformed Ë-coli. The fusion of GST to the N-terminus of linoleic acid isomerase increased its molecular weight from 49 to 75 kDa. GST-tagged enzyme acted like linoleic acid isomerase and the transformed bacterium could convert considerable amounts of linoleic acid to ÇLÂ.
Çonclusion: The findings indicated that transformed Ë. coli can be used for ÇLÂ production in biocatalytic processes.

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Background and purpose: Finding an efficient vaccine against HÏV infection is still a major concern and a great challenge. Ïn our previous study, HÏV-1 virions with capability of a single replication were produced. Ïn the present study their immunological evaluation has been carried out to study their induction of cellular and humoral responses in mice model.
Materials and methods: Ïn this study, first and second virion generations were produced in human HËK293T cells, and were injected to three different mice groups in three doses with or without adjuvants. Âfter the last injection, immune responses were evaluated in serum and spleen cells of mice using ËLÏSÂ.
Results: Âlthough all animals vaccinated with different immunogen regimens did develop cellular responses, in the main group injected with novel adjuvants, the highest levels of specific antibody, ÏFN-γ, ÏL-4 an also most ÏFN-γ excreting cells were evident, which is suggestive of a strong cellular response in these cells.
Çonclusion: Ân effective vaccine against HÏV requires induction of strong humoral and cellular responses. Hence, these results demonstrate the high immune system stimulating capabilities of virion injection regime accompanied by M720 and ÇpG adjuvants, which provides the potential for an efficient HÏV vaccine.

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Background and purpose: Due to the difficulty of diagnosis, esophageal and gastric cancers have a special position in Mazandaran Province. Ïn this province, gastric cancer is considered to be one the most important causes of mortality therefore, this study was conducted to investigate the survival of patients with gastric cancer in Mazandaran.
Materials and methods: Ïn this historical Çohort study all gastric cancer patients referring to an academic center clinic from 2007 to 2010 were enrolled. Â parametric model was fitted to the data. Parametric survival models, Kaplan-Meier and life table were applied for estimating the survival probability and investigating the effect of different variables.
Results: The mean age of the participants was 64 years and 68.3% of the patients were men. Âmong the patients, 48.4% were in the most advanced stage i.e.: stage 4. The survival probability of more than 2 years was calculated 27.7% in the patients, using Kaplan Mayer method. Çox hazard proportional model revealed that variables like the stage of the disease, metastasis and surgery status, and age influenced the survival probability of patients.
Çonclusion: Low survival time of the participants of the study may be due to the late diagnosis and lack of medical facilities.

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Background and purpose: Polycystic ovary syndrome (PCOS) can reduce body control and makes feeling of worthlessness, insecure, negative body image and consequently, makes a degree of despair, pessimism and low self-esteem. This study aimed to determining body esteem components in women with PCOS. Materials and methods: This study was done on 100 women with PCOS who were selected by consecutive sampling in Tehran, 2013. Data were collected by body esteem questionnaire and then analyzed using t student test. P < 0.05 was considered as a statistically significant level. Results: Total mean score and standard deviation (SD) of body esteem in PCOS women was 31.64 ± 3.51 and mean and SD of body esteem components was 2.57 ± 0.55 in sexual attractiveness, 7.54 ± 1.50 in being comfort with body, 11.11 ± 1.99 in own body comparison with healthy body, and 7.85 ± 1.64 in own and others ideas about sexual attractiveness. In case of all components scores and total score, there were no differences between fewer than 30 and 30 and over age's groups. Conclusion: Although it seems total score of body esteem in PCOS women is moderate and there are no differences between two age groups (under 30 and 30 years and more) regarding to body esteem, researches recommend further studies.

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Background and purpose: Kawasaki disease (KD) is an acute vasculitis in children. Studies indicated different relationships between eosinophilia and coronary artery disease (CAD). This study was done to assess the possible relationship between eosinophilia and coronary artery disease. Materials and methods: This descriptive study was carried out during 13 years on 61 children with Kawasaki disease who were admitted to Sina Referral Hospital. They were assessed regarding eosinophilia and coronary artery diseases. Data was evaluated by Fisher exact and t-test. Results: The research population included 61 patients of whom 33 (54%) were male and 28 (46%) were female with the mean age of 36.56 ± 23 months. Among the patients 85% were >5 years of age and eosinophilia was found in 28 cases (45.9%) and five patients (14.8%) were diagnosed with coronary artery disease. This disease was observed in 25% suffering from eosinophilia and in 6% of the cases without eosinophilia. However, there was no association among gender, eosinophilia and coronary artery disease. Also, no significant difference was found between age groups. Conclusion: Eosinophilia was not a risk factor or protective factor for CAD. However, the exact relationship could be determined if further multicentre studies are carried out.

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Background and purpose: After anemia thrombocytopenia is the most common disorder in pregnancy which is encountered in 10% of pregnancies. Thrombocytopenia in pregnant women may lead to maternal and neonatal morbidity. This condition could involve some complications in pregnancy, so diagnosing its causes is important for treatment. This study was performed to determine the incidence, causes and complications of thrombocytopenia in pregnancy. Materials and methods: In this prospective study, all pregnant women with gestational age of ≥ 24weeks and also those in pregnancy termination stage who referred to two teaching hospitals in Babol, during 2008-2009 were selected. Among this population those with platelet count less than 150,000/ µL were chosen. Causes of thrombocytopenia, method of delivery, maternal and neonatal complications in these patients were recorded. Platelet count less than 100,000/ µL was considered severe thrombocytopenia. Results: During the study period, 4589 pregnant women were examined and thrombocytopenia was reported in 239 cases. The incidence of thrombocytopenia in pregnancy was 5.2%. The causes of thrombocytopenia were gestational thrombocytopenia in 222 patients (92.9%), ITP in 11 patients (4.6%), preeclampsia in five patients (2.1%) and HELLP syndrome in one patient (0.4%). Six pregnancies (2.5 %) resulted in IUFD and bleeding occurred only in one patient with ITP during and after delivery. No neonatal complication was seen in newborns of women with thrombocytopenia. Conclusion: The results showed that gestational thrombocytopenia was the most common cause of thrombocytopenia in pregnancy which revealed no complication for patients and their fetuses. However, differential diagnosis should be made to avoid diagnosis of HELLP syndrome or preeclampsia that require urgent termination of pregnancy to prevent further complications.

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Background and purpose: Common cold is the most prevalent viral infection in children that is associated with high health care expenditure every year. Echinacea is commonly used to prevent viral respiratory infections. The goal of this study was to assess Echinacea effect in improving the symptoms of acute upper respiratory tract infection (URI) in children. Materials and methods: This clinical trial was performed in 100 children aged 5 to 11 years with URI referring to Pediatric Hospital in Bandar-abbas, 2009. A complete history and physical examination were conducted. Patients were randomly assigned into two groups to receive either Echinacea or placebo. Echinacea group received 5 ml Echinacea (root extract) per 12 hours during 10 days while the control group was given only analgesics and saline. The patients were followed for 10 days to identify the reduction in duration and severity of symptoms and side effects. This was done by parents or physical examination. The data was analyzed by SPSS ver. 16 using descriptive, Chi-square test and t-test. Results: The mean age of the studied patients was 7.56 ± 1.78 years. No significant differences were found between Echinacea and control group regarding the mean duration of fever, cough, rhinorrhea and nasal congestion. Also, no adverse reactions were seen among the two groups. Conclusion: The results of our study showed that Echinacea extract was not effective in decreasing the duration of symptoms of common cold. But, further well-designed randomized trials should be undertaken to elucidate the effects of Echinacea on treatment of common cold.

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Background and purpose: Febrile seizure is the most common convulsive disorder which occurs in 2% - 4% of children. This study determined demographic and etiologic first attack of febrile seizure in children admitted BooALISina hospital Sari, iran. Materials and methods: In this cross-sectional study, all children (6 months to 6 years old) that were admitted with the diagnosis of febrile seizure in pediatric department of Boo Ali Sina hospital mazandaran medical sciences, Sari, Iran in March to October 2011 were studied. The obtained data was analyzed by means of SPSS software (version 16) applying chi-square at the significant level of α = 0.05. Results: Among 250 children studied, 134 males and 126 females, and the peak incidence of fever and convulsions in the age range 1-2 years. The most common underlying causes were respiratory infections (56.8), followed by gastroenteritis (22.4). In% 91.3 of cases of seizures occurred within the first 24 hours after onset of fever. And the most common form of seizures generalized tonic clonic and simple Febrile convulsion. There was no significant correlation between age, sex and the type of seizure. 5%>p and the seasonal incidence of fever and convulsions common in winter (% 68.4). no significant relation between the Febrile seizure and electrolyte Disturbances (Na, k, BS, Ca) .Anemia was found in (%56.8) of patients. Conclusion: Positive family history and genetic background one of the important factors in the incidence of febrile seizure at ages 1-2 years and the over use of drugs in the prevention of febrile seizures is ineffective. Routine blood chemistry analysis is not necessary in children with febrile seizures and only should be ordered based on the patient’s condition or medical history.

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The acute disseminated encephalomyelitis is a rare, monophasic or multi-phasic dismyelinating disease, which affects the central nervous system and that appears shortly after either a exanthematous, non-exanthematous or vaccination. It attacks mainly children and young adults. The prognosis is usually favorable but sequelae are possible. The common therapeutic approach is the use of corticosteroids. Intravenous immunoglobulin (IVIg) has been proposed for relapses, and plasmapheresis for fulminant cases the cause of ADEM is unknown. The diagnosis is based on clinical picture, supported by radiology and laboratory tests. This 24-month-old boy was admitted with fever, vomiting and intermittent irritability preceded by a herpetic gingivostomatitis 10 days earlier. Growth and development were normal. Brain MRI at that time revealed multiple asymmetric, hyperintense and patchy white matter lesions of variable size on T2-weighted images. CSF examination revealed no cells, normal protein and glucose levels, normal IgG index and no oligoclonal bands. Gram’s and Wright’s stains and screening for viral antibodies were negative. Electroencephalography (EEG) was normal. He was started on Intrvenous immunoglobulin (400 mg/kg) intravenously for 5 days. At the end of the treatment he was afebrile with good general condition.

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Background and purpose: Influenza is a respiratory infection that annually affects 5-15% of the global population. Influenza A/H1N1 is the most virulent human pathogens that results in a more severe disease and was first reported in 2009. The aim of this study was to investigate the epidemiology of influenza A/H1N1 in patients referring to several hospitals in North of Iran during 2009-2011. Materials and methods: This descriptive cross-sectional study was done on patients with symptoms of influenza using Real-Time PCR analysis. Results: The patients included 572 (41.97%) male and 791 (58.03%) female. The prevalence of influenza A/H1N1 was seen more in patients aged 21-30 (25%) years. In this study, 205 patients (15.4%) were diagnosed with influenza A/H1N1 including 94 (54.85%) male and 111 (54.15%) female. Influenza A/H1N1-associated death was seen in five patients (2.44%). Conclusion: Influenza A viruses are constantly evolving by mutation or by reassortment. The influenza virus evolves rapidly, and new strains quickly replace the older once, therefore, new vaccines should be developed for immunization against new strains of influenza.