Department of Community. Medicine. University of Baghdad Al Kindy College of Medicine. Midyear Exam - Fourth Stage الرقم:

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1 Medicine University of Baghdad Al Kindy College of Medicine Department of Community Midyear Exam - Fourth Stage Please read carefully each question, it guides you to correct answer. Neatness and organization are important; they help us to easily evaluate your answers. Be clear and be brief. Answer the question that is asked you do not need to give reasons unless you are specifically asked. Answer all the 9 questions (3 papers, not including the front page). Calculators may be used for exams, and any necessary statistical tables will be provided. Good luck! التوقيع الدرجة كتابة الدرجة رقما رقم السؤال س ١ س ٢ س ٣ س ٤ س ٥ س 6 س 7 س 8 س 9 المجموع الكلي (من ١٠٠%) المجموع الكلي (من %25) االسم الكامل: الرقم:

2 Q1: Answer the following questions (10 marks) 1- A researcher enrolled 100 subjects into a study on January 1, All of the subjects were at risk for developing Influenza A. On September 1, 2000, 10 subjects developed Influenza A. On December 1, 2000, 8 more subjects developed Influenza A. None of the remaining subjects developed Influenza A and none of these subjects left the study. The incidence of Influenza A from December 1, 2000 to December 31, 2001 per 1000 is , while the prevalence is / X1000= /100X1000= Researchers select 100 patients with colon cancer and 300 patients without colon cancer. Of the 100 patients with colon cancer, 10 smoke cigars while 30 of the 300 patients without colon cancer smoke cigars. This study design is The association between colon cancer and cigar smoking can be assessed by measuring its value is which interpret as Case control OR 1 no association 3- Disease occurrence in excess of normal expectancy is called Epidemic 4- Pap screening (checking for early signs of cervical cancer before clinical symptoms arise) a form of prevention Primary 5- The stage of disease when signs and symptoms are not yet apparent in an individual is Subclinical 6- In a screening, decreasing the cut-off point for a positive test will increase of the test. sensitivity Q2) Using the following demographic data to calculate the vital statistics requested. Total midyear population= 25,000, Population size, 65 years of age or older 750, Number of live births =300, Total deaths (all cause) 250, Deaths in infants under 1 year of age=3, Deaths in persons 65 and over =125 (10 marks) (a) Crude birth rate per 1,000 (300 / 25000) 1000 = 12 (b) Crude death rate per 1,000. (250 / 25000) 1000 = 10 (c) Infant mortality rate per (3 / 300) 1000 = 10 (d) Age-specific death rate in those over 65 years of age per (125 / 750) 1000 = (e) Percentage of population 65 years of age or older (750/25000) x 100= 3

3 Q3) A screening test for hepatitis B virus with a sensitivity of 80% and a specificity of 96% was used in 100,000 symptom-free individuals from a population in which the prevalence of hepatitis B is a) Set up a 2-by-2 table. b) Of all positive test results, what proportion will be false positives? c) Of all the negative test results, what proportion were false negatives? d) What is the PV+ of this test? e) In plain language, interpret this result illustrating how we can increase the yield of this test. (10 marks) a) HBV + - Total Total b) 3980/4380 X 100 = c) 100/95620 X 100 = 0.1 d) 400/4380 X 100 = 9.13 e) by applying the test to high risk population Q4) A study was undertaken to test the effects of Ciprofloxacin suspension treatment in children with shigella dysentery comparing to traditional Mrtronidazole suspension. 140 children (divided into 2 equal groups), aged 2-15 years, with dysentery of 72h or less duration were enrolled in the study. Patients stayed in hospital and were followed up for 10 days. Clinical success was defined as the absence of frank dysentery on day 3, and on day 5 no watery stool. The treatments were assigned at random to each group.traetment was effective in 60% of ciprofloxacin group comparing to 20% of metronidazole group. Given this scenario, answer the following questions: a) What is the research question? b) What are the exposure and the outcome? c) What is the design of this study? Draw 2X2 table d) Is Ciprofloxacin suspension is effective comparing to metronidazole? e) How can the investigator control known and unknown confounders in this study? (10 marks) a) Is Ciprofloxacin suspension is effective comparing to traditional metronidazole in treatment of children with shigella dysentery? b) Exposure Ciprofloxacin suspension and metronidazole Outcome absence of frank dysentery on day 3 C) Randomized clinical trail heal No Ciprofloxacin Metronidazole D) We calculate RR=0.6/0.2=3 e) By randomization

4 Q5: Discuss the special problems associated with breast feeding: 1- Cracked nipples: painful condition which may suckle by the infant, condition result from wrong positioning of the baby's mouth. When the condition occurs, he milk must be expressed manually and fed to the baby for 2 days until the nipple healed. 2- Breast milk congestion: condition that can happen at any time during lactation due to incomplete emptying of the breast, part or the whole breast is tender and swollen and infection may occur in the congested segment which results in high fever and malaise. It is important to continue emptying the breast either manually or by the infant, warm sponges may help, breast should be supported and pain killer is given until condition subsides. 3- Nipple confusion: if the mother uses bottle alternating with breast feeding, the baby will be confused and prefer the bottle because sucking is easier. 4- Scheduled feeding: some mothers think that giving breast feeding on a specific time table is better. This may cause suppression of lactation because the more is sucking lead to more milk production. Night feeds are very important in increasing milk production. 5- Oral contraceptive drugs especially those containing estrogen can reduce location. Smoking also reduces milk production. 6- Prematurity and risk infant: the premature and low birth weight infant may be too weak to suckle properly; ill or febrile infant could have the same problem. Cleft lip and palate also make suckling difficult or even impossible. In such conditions, breast milk can express and fed by spoon or nasogastric tube. 7- Twins: most mothers are able to fully breast fed her babies but if there is any failure in weight gain, supplementary milk can be given after breast feeding. Q6: Enumerate child health services that should be provided in PHC center. What do we mean by children at risk? Give five examples, and what can we do concerning the schedule of their visits to PHC center? Can be summarized by GOBI FFF: Children at Risk : Certain risk factors have an influence on child's nutritional state, those children need more care and more frequent follow up visit LBW Twins or multiple births Many children in a family, brothers or sisters undernourished Short spacing {short intervals between births} Poor growth in early life Early stopping of breast feeding {i.e. before 6 mothers} Introduction of complementary food either too early or too late Many episodes of infection Poverty- 3 or more children in family died Children with only one parent Illiterate mother.

5 Q7: Answer the following questions (10 marks) A) Pregnant women should be advised to seek immediate medical care if they experience certain symptoms or sign, mention 5 Alarming Symptoms & Signs. (5 marks) 1 Vaginal bleeding. Sever edema. Passage of fluid from the vagina. Abnormal gain or loss of weight. Decrease or cessation of fetal movement. Sever, persistent or recurrent headache. Visual disturbance (blurred vision) Epigastric pain Fever Lower abdominal pain Respiratory discomfort or dyspnea. Convulsion B) Complete the following table with required information: Causative factor Mode of Transmission Incubating Period Communicable period Measles virus. air-borne 6~18days two to four days prior, a paramyxovirus until two to five days Measles following the onset of the rash Rubella polio Tetanus Diphtheria Rubella virus RNA virus Poliovirus RNA virus Clostridiumtetani Corynebacterium diphtheriae air-borne days 7 days before to 5-7 days after the onset of rash Susceptibles All age person young unimmunize adults Oral-oral 7 14 days about 2 weeks infancy and childhood contaminated 3-21 DAYS not contagious disease of active age wounds (5-40 years) Respiratory Skin and fomites 2-5 days several weeks non immunized or under immunized children below 15 years of age Q8) Answer the following questions (10 marks) A) what are the WHO classification of pandemic? (5 marks)

6 B) Differentiate between i) Communicable disease and infectious disease (5 marks) ii) Eradication and eliminating Communicable diseases: is an illness due to a specific infectious (biological) agent or its toxic products capable of being directly or indirectly transmitted from man to man, from animal to man, from animal to animal, or from the environment (through air, water, food, etc..) to man. Infectious disease : caused by pathgens. 3. Eradication and Elimination: Termination of all transmission of infection by the extermination of the infectious agent through surveillance and containment. Eradication is an absolute process, an all or none phenomenon, restricted to termination of infection from the whole world. Q9) For each of the following statements, choose the most appropriate answer: (20 marks) 1- The incidence of bronchogenic carcinoma was found to be three times higher for men than for women, but the prevalence rates were almost the same. This can be explained by: a) Disease duration is shorter in women b) The incidence rate is higher for women c) Disease duration is shorter in men d) Disease duration is longer in women e) Disease recovery is higher in women 2- Phenylkenouria is a disease with a genetic (absence of phenylalanine hydroxylase) and environmental (presence of dietary phenylketones) disease. Suppose phenylketones were entirely absent from the environment, the prevalence of phenylkenouria in the population would be: Low not affected zero as usual not determined 3- Sleeping under mosquito net to prevent malaria is a form of prevention a) primary b) secondary c) tertiary d) non specific e) primordial

7 4- The developing fetus is influenced mostly by diet between: a) 24 &50 days after conception b) 17 & 56 days after conception. c) 7 & 56 days after conception. d) 22 & 70 days of conception. e) non f the above 5- Regarding hepatitis C infection, all are true EXCEPT: a) Jaundice is not seen in majority of infections b) Less than 30% of infections progress to chronic infections c) Presence of both plasma viraemia and antibodies to HCV is seen in chronic infection d) Increased intake of alcohol is recognized factor for progression to chronic liver cell disease e) is generally considered to be among the most serious of these viruses 6- Regarding hepatitis B vaccine all are true EXCEPT a) Should be given to infants, children, and adults at increased risk of infection b) Hepatitis B immunoglobulin provides long term protection c) Highly effective and save vaccine d Presence of anti-hbs antibodies indicate immunity e) Booster doses are recommended 7- Routine periodic examination for children should be done: a) at birth, linked with immunization schedule. b) every 2 weeks in the first year. c) every 3 months during the 1st year d) every 2 months during 4-5 years. e) none of the above 8- Regarding National Immunization Schedule in Iraq, all are true EXCEPT: a) End of 1 st week after birth, BCG+OPV0+HBV1 b) End of 2nd month, DPT1+OPV1+HBV2 c) End of 4th month, DPT2+OPV2 d) End of 6th month, OPV3+HBV3 e) End of 9th month, Measles 9- All of the following statements about prospective cohort study are false EXCEPT: a) It can be used to study the exposure to factors that are rare. (T) b) It is relatively cheap to perform because it follows a defined group of individuals. c) It is unusual to have losses to follow-up because it follows a defined group of individuals. d) It requires a very small sample size. e) The temporal relationship between exposure and outcome can't be assessed. All of the following should be considered when assessing causality EXCEPT: a) Consistency with other knowledge. b) Strength of association. c) Disease prevalence. T d) Biologic plausibility. e) Alternative explanation.