Journal of Shahid Sadoughi University of Medical Sciences
Year:2003 | Volume:11 | Issue:1(Supplement on Health)|Papers Count:15

In observational studies or non-randomized clinical trials, treated and control groups may differ in their outcomes even if the treatment or exposure has no effect. This may happen if the groups were not comparable before the start of treatment. The groups may not be comparable in two respects; they may differ with respect to variables that have been measured in which case there is an overt bias, or that they may differ in ways that have not been measured, in this case there is a hidden bias . Overt biases are controled though adjustments such as maching or grouping. Hidden bias is more difficult to address because the relevant variables are not available. In this paper we used sensitivity analysis that have been represented and first we introduced software for difficult calculations of sensitivity analysis. This applied for a true observational study.

In all of the sciences, statistical modeling has been used for determination of relevances between variables and prediction. Model selection is dependent on the nature of variables and its underlying preliminary assumptions. New methods for model building are artificial Neural Networks. Because of their intelligent structure and flexibility, they are competitors for traditional statistical modeling. Neural networks are advanced in theory and application. We have introduced artificial neural networks and used them in order to predict unwanted pregnancy and showed that they are capable of more accurate predictions as compared to other model building methods by ROC analysis.By using woman’s age, number of live daughters and sons as predictors and based on the ROC analysis, we have computed an area under ROC curves for logistic, probate regression, discriminant analysis model, 3:2:1 and 3:3:1 percepterons; 0.758, 0.757, 0.630, 0.768, 0.823 respectively. It seems that prediction of unwanted pregnancy using artificial  neural networks are more accurate than traditional statistical models.

Cutaneous leishmaniasis is one of the most prevalent parasitic diseases in Iran. In recent years, this disease has remained the topmost public health problem in Yazd, especially in Ardakan. Studies over the two last years show a new focus of Zoonotic Cutaneous Leishmaniasis (ZCL) with Leishmania major as the agent, Rhombomys opimus and Meriones libycus as the reservoir hosts and Phlebotomus papatasi as the vector.Because of very high prevalence of the disease in this area, the public health heads of  Yazd  decided to take steps to control the disease. The control program was conducted via indoor residual spraying with WP 50% Propoxour in 2g/m2, and also poisoning of reservoir host rodents with Klerat in a radius of 2000 m around the infected area. Investigation of ZCL status by house to house visit in the treated villages, examination the patients and completion of the related questionnaire in early 2001 showed a great decline in the incidence rate of the disease in the controlled area. In Ahmadabad, the incidence rate of ZCL fell from 228.1 per 1000 in 1999 to 107.4 per1000 in 2000. In Torkabad, this rate reduced from 229.8 per 1000 to 35.8 per 1000. This decrease was significant (P<0.0001 in Ahmadabad & P<0.00001 in Torkabad). Due to relative similarity of weather conditions before and after the control program, we concluded that it had an effective role in reduction of the number of disease cases. Due to the exophilic behavior of the vector and the fact that people of this area go to sleep outdoors (in the yard and on the roof) during the high risk months, it is suggested that the rodent control has an important role to play in case reduction. Indoor residual spraying can be mentioned as a less effective method alongside rodent control for containing zoonotic cutaneous leishmaniasis (ZCL)

The average educational level of a population is an important indicator of the development of that society and is closely linked with the economic growth as well as the quality of socio-cultural life.The main aim of this semi-experimental study was to assess the effects of health education on knowledge and behaviors of traders in the food industry. (n = 420).After education, the mean level of knowledge increased from 26.5 to 52.4 and also the mean level of behavior increased in various aspects (p=0.000).The mean level of knowledge changed significantly before and after education. The bakers were the least knowledgeable group before intervention and therefore the most significant change in level was also observed in this group In our survey, the mean level of knowledge increases with increasing education and is low in elderly and those with longer history of work

Intestinal parasitic infections are one of the most important sanitation problems in developing countries. The majority of these infections are usually chronic and asymptomatic. The major route of infection is by direct contact with the source of infection. One of the main sources are workers in pizza and sandwich selling houses. In this study, 3 successive specimens were obtained from all of the 197 workers of 76 sandwich and pizza centers in Yazd during one week and the specimens were examined by three different methods; wet mount, floatation and formalin – ethyl method. Our data showed 39% of the population under study were healthy, while 61% were infected with at least one pathogenic and/ or non pathogenic parasite, the statistics of which were as follows: 26.3%. Entamoeba coli, 20.8% Endolimax nana, 12.2% Giardia lambdia, 8.6% Iodamoeba butschlii, 4% schilomastix mesnili, 3.6%. Hymenlepis nana 2.5%. Trichocephalus, 1% Ascariasis, 1% Enterobius and 6% with other species.In regards to relation of “years of work” and “rate of infectivity”, 39.1% were working since 1 year of which 63.3% were infected, 35.5% were working since 2 years of which 60% were positive, 18.7% had a three year record of which 56.7% were infected and 6.6% had a record of 4 years or more of which 62% were infected. In conclusion, our data indicated that there is significant relation ship between the parasitic infections and years of work (P ≤0.01).

Nosocomial infections or those infections, which a patient acquires during his hospital stay from the hospital environment have always been an important health problem. Such infections are usually resistant to the routine antibiotics and can even lead to death of the patient.The rate of incidence of these infections is directly related to the hygienic conditions of the hospitals. Taking into consideration the fact that Prevention is the best cure, appropriate proper use of antiseptics and disinfectants is the best approach towards these infections.The aim of this study was to determine and compare the appropriate concentrations of 3 solutions; savlon, betadine and dettol for their optimal fungicidal action. The test organisms were three fungi ; aspergilus nijer, candida albicans and mucour. The study was carried out according to the standard method (NFT67-1500) issued by the French Institute of Standards and the methods recommended by AOAC for the evaluation of the fungicidal effects of antiseptics and disinfectants. After the preparation of the fungal suspensions from spores of the test organisms, the neutralization effect of each chemical was determined.The results showed that 7.5% savlon, 4.5%dettol and 10% betadine were the best effective concentrations for killing the three test organisms in this study.Although the above-mentioned chemicals are fungicidal in the recommended concentrations, the most reasonable and appropriate way is preventing the entry of fungi or other microorganisms in hospital environments. It is therefore necessary to prevent the introduction of infective agents into hospital environments by applying suitable health measures.

Measles is an important childhood disease and is very contagious. Approximately 90% of susceptible family contacts acquire the disease. Measles has been reported in vaccinated school aged children. Since 1976, yearly epidemic of measles has been reported in this age group in Sistan and Baluchestan province of Iran.The aim of this study was to determine the level of measles antibodies in students of Zahedan. This study was a cross –sectional survey in a time period of 6 months(Oct  to June 2000)  in Zahedan schools.A total of 349 cases were enrolled in this study.Titer of antibody against measles was measured using hemagglutination inhibition method (HI).These studies revealed that 78.6% (274 cases) were immune to measles while 21.4% of the total were susceptible to the disease.We concluded that for correction of immunity defect in this population, we need to have another immunization program for 4-6 year olds.

According to World Health Organization (W.H.O) estimates about 68 million males, females and children had been infected by the HIV virus up to Dec.2002. Meanwhile, it is estimated that the number of surviving cases was 42 million individuals.W.H.O and UNAIDS have declared that now a days AIDS is a health dilemma for the youth. Meanwhile, one the most applicable preventive approaches in this regard is promoting knowledge and awareness in young people, especially attitude towards AIDS during puberty.This cross sectional study was conducted in order to determine the level of awareness and attitude of high school students studying in government schools in the city of Tehran towards AIDS as well as the relationship between these two variables and the individual characteristics of students.Using a classification method, 5 of the 20 educational districts of Tehran were selected randomly.Then, two high schools were selected from each district randomly (one boys high school & one girls high school) thus students studying in 10 high schools; about 590 girls and boys were included in the study.Information was collected via a special questionnaire containing 19 questions.Relation assay among research variables was carried out using SPSS software and DOS program .Research findings were as follows: Awareness and knowledge of 50.3 % was low,  36.9% ranked moderate and 12.7% was high. Attitude ranking based on Leekert scoring was as follows:13.7% low, 62.6% moderate, and 23.7% high.Statistical test (X2) showed 95% confidence level; there was a statistically significant difference between awareness variable and individual characteristics (sex, age, educational discipline and district of education ) . Meanwhile, there was a statistical significant difference between attitude and sex, discipline, and district of education, however there was no statistically  significant relationship between attitude and age of students .

 Increase in population and water demand is the reason why conventional rapid sand filters are not able to meet the water consumption demands.  Anthracite as a filter bed medium  (low density & large particles) is able to provide increased filtration rate. As anthracite is more expensive than sand, it is not possible to use it in many developing countries.  Two series of tests were conducted: 1- Anthracite characteristics determination: Determination of “carbon, ash, sulfur, moisture and volatile matter content, rate of solubility in acid and base, relative density, hardness and crushing rate during the backwash. 2- Pilot plant tests: Measurement of turbidity, residual chlorine, total organic carbon,  coliform content and surface over flow rate were preformed at the school of public health , Isfahan. For statistical analysis, the two statistical tests;T-test and co variance were used. The mean of “turbidities removal” in local and imported anthracite were 85.96 and 80.5 percent respectively (no significant value P>0.05) .The mean of “residual chlorine removal” in local and imported anthracite were 59.6 and 61/2percent respectively, (no significant value P>0.05). The mean of “total organic carbons removal” in local and imported anthracite were 47.2 and 63.4 percent respectively (significant value P<0.05). The mean time for receiving 1m height in filter pilot were 29min 30sec and 33min 42sec in the local and imported anthracite respectively (no significant value P>0.05).The local anthracite structural characteristics do not meet relevant standards, which is due to insufficient thermal processing.Reduction of residual chlorine and total organic carbon content in dual media filters is very complex and more studies are needed. “Surface over flow rate” results and also higher turbidity removal (5.5%) shows that imported anthracite has a more convenient grading than the local type. The study results show that local anthracite does not have a good grading for water treatment and needs revision on the grading.

Phthalic acid is a toxic organic compound, which can enter the environment through various industries.Biological removal of this pollutant before wastewater disposal therefore plays an important role for environmental protection and human health. Due to ability of SBR system to remove domestic and industrial wastewater contaminants, this system has been studied.In this research, SBR system with two different hydraulic retention times (24hrs and 48hrs) was used for biological elimination of phthalic acid. In this study, the volume of the reactor was about 7liters and total COD feed was adjusted to 1000mg/l, by using Glucose.Concentrations of inlet phthalic acid were 10,20,35,50,75,100,150,200 and 500mg/l respectively. COD, BOD5 and phthalic acid concentrations (using HPLC-UV with wave length of 200nm) were measured in the effluent.Obtained results showed that in both the retention times,more than 95%phthalic acid was removed. However, removal of phthalic acid in the one using 48hrs-retention time is more than that of 24hrs retention time. If the concentration of inlet phthalic acid is less than 200mg/l, hydraulic retention time equal to 24hrs is recommended. For concentrations of phthalic acid more than 200mg/l, use of 48hrs retention time is suggested.According to this study, recommended allowable volumetric loading rates for 24hrs and 48hrs are 200g/m3.d and 500g/m3.d respectively. The concentration of phthalic acid in the sludge was 200mg/kg.

Stabilization ponds have become popular means of wastewater treatment for small communities and certain industries such as slaughterhouses, dairies and meat processing plants. The main objective of this study was to investigate the efficacy of stabilization ponds for treating slaughterhouse wastewater.The efficiency of the slaughterhouse wastewater treatment plant of Bisotoon, Kermanshah was studied over a period of six months from September 2000 to March 2001. The general conditions and operation of the plant were studied and some of the wastewater treatment indices such as pH,TSS, BOD5 ,COD,coliform and fecal coliform bacteria  in both the inflowing and outflowing sewers  were  determined.The average levels of TSS, BOD5, COD, total coliform and fecal coliform bacteria in the effluent were 280.67 mg/l, 353.17 mg/l, 580.5 mg/l, 1.51´107 MPN/100ml and 2.10´105 MPN/100ml respectively. The results were significantly different from the standard limits recommended by the Iranian Environmental Protection Agency.The results showed that the effluent could not be used for irrigation or discharged to surface water according to the recommendations by the Iranian environmental protection agency. Also, comparison of the average number of fecal coliform bacteria in the effluent with the standard levels in the microbiological quality guideline of World Health Organization (WHO) showed that the effluent was not acceptable for use in irrigation.

Edontobuthus is one of the most dangerous scorpion species in Iran. Its toxin can cause severe problems and can be fatal in humans or animals. With regards to serum biochemical alterations, which may occur in any organ system, study of biochemical changes following injection of scorpion venom can explain the chemical alterations due to venom injection. Since experimental research work is not allowed on humans in Iran, this research was conducted in animals, so that the findings can be applied later in humans.  Regarding  this point that the odontobuthus scorpion is not present everywhere in the world and a few studies have been done on this kind of arthropod , this study was carried out for the first time in Iran in  the year1381. Sixteen healthy native dogs aged about 2 years with average body weight of 18.5 kg from both sexes were selected for this study. Dogs were divided randomly into four groups (four dogs in each group). Blood samples were collected for laboratory examination before injection of venom. In the control group, 1 ml saline solution was injected and  0.1, 0.05 and 0.01 mg/kg body weight of venom powder were dissolved in 1ml saline solution and injected intradermally in the abdominal region or hind limb of each dog in the second, third and fourth group respectively. Blood samples were collected at regular time intervals ( 5, 15, 30, 60, 90, 120,180, 360 minutes and 24 hours after injection of venom) and laboratory investigations (Total serum proteins, total bilirubin, uric acid, cholesterol, amylase and serum electrolytes such as Ca2+, Mg2+, Na+, K+, P and Cl-) were performed on the blood serum samples. Significant increase in amylase was observed in the venom injected group as compared to the control (p<0.05). This increase could be related to acute pancreatitis and increase in acetylcholine secretion. Significant decrease in sodium, chloride and potassium levels were observed after scorpion venom injection (p<0.05), which may be due to the cholinergic effects of the venom and vomiting. No significant change (p>0.05) in levels of  serum total proteins, total bilirubin, uric acid, cholesterol, calcium, phosphorus or magnesium was observed.