بسم الله الرحمن الرحيم

1. بسم الله الرحمن الرحيم Epidemiology of Brucellosis Shahid Beheshti University of medical sciences 2007 By: Hatami H. MD. MPH

2. الف ـ مقدمه و معرفي بيماري ب ـ اپيدميولوژي توصيفي و وقوع(OCCURRENCE) • 1- تعريف و اهميت بهداشتي • 2 – عامل يا عوامل اتيولوژيك ج ـ پيشگيري و كنترل

3. 1- تعريف و اهميت بهداشتي • Human zoonotic disease • A systemic infectious disease with acute or insidious onset • Is a very costly zoonoses with highly variable clinical features • Infected animals readily infect one another and shed the organisms into their environment

4. ZOONOSIS A disease, primarily of animals, that can be transmitted to humans as a result of direct or indirect contact with the infected animal population

5. ZOONOSIS • Brucellosis • Plague • Listeriosis • Anthrax • Tularemia • Erysipeloid

6. ZOONOTIC DISEASES اهميت بهداشتي • More than 300 diseases can be transmitted from animals to humans • Humans are usually accidental and dead end hosts • Only a limited number of zoonotic diseases can be transmitted person-to-person • Importance of emerging zoonoses and bioterrorism • Laboratory hazards via sharps injuries or inhalation of aerosols

7. Brucella are Ideal Biological Warfare Agents اهميت بهداشتي • They are highly infectious • They can be easily aerosolized • They are stable in production, storage, & delivery • They are sensitive to sunlight • They cause high morbidity, but low mortality • There are no human vaccines against brucellosis • There is high economic loss to animal agriculture

8. Public health impact اهميت بهداشتي • Disruption of pregnancy • Loss of stock • Decrease milk • Infect human

9. 2- عامل يا عوامل اتيولوژيك • Fastidious & aerobic • Facultative intracellular • Gram negative non motile cocobacilli

10. Etiologic agents

12. Isolated species in Iran

13. Pathogenesis • Skin abrasion, conjunctivae, inhalation or ingestion • Engulfed by neutrophils and monocytes (resistant to killing) • Localize regional lymph nodes • Infect phagocytic cells in the RE system and form granulomas

14. ب ـ اپيدميولوژي توصيفي و وقوع بروسلوز 1 – دوره نهفتگي(Incubation period) 2 – سير طبيعي(Natural course) 3 – انتشار جغرافيائي(Geographical distribution) 4 – روند زماني(Timeline trend) 5 – تاثير سن، جنس، شغل و موقعيت اجتماعي 6 – تاثير عوامل مساعد كننده(Predisposing factors) 7 – حساسيت و مقاومت(Susceptibility & Resistance) 8 – ميزان حمله هاي ثانويه(Secondary attack rate) 9 – نحوه انتقال و دوره قابليت سرايت (Mode of transmission & period of communicability)

15. 1 ـ دوره نهفتگي • 5-60 days (1-2 month)

16. 2 ـ سير طبيعي • Subclinical and unrecognized infections are more frequent than clinical one • Is usually a self-limiting disease • 50% of cases recover their health in one year

17. 2 ـ سير طبيعي (ادامه) • Untreated clinical illness may become chronic • The death rate of untreated brucellosis is about 2% • Death is usually due to bacterial endocarditis

18. 2 ـ سير طبيعي (مرور) • ميزان موارد بدون علامت (ساب كلينيكال) • ميزان موارد حاد • ميزان موارد مزمن • ميزان موارد بهبودي خودبخودي • سير بعدي بيماري با درمان و بدون درمان • ميزان مرتاليتي و مربيديتي

19. 3 ـ انتشار جغرافيائي • Occurs worldwide • Endemic areas - Africa, Asia • True incidence not known

20. 3 ـ انتشار جغرافيائي وضعيت بيماري در ايران

21. 4 ـ روند زماني • پاندمي ها ؟(Pandemics) • اپيدمي ها ؟(Epidemics) • طغيان ها ؟ (Outbreaks) • تناوب زماني ؟ (Duration) • الگوي فصلي ؟(Seasonality)

22. Seasonal distribution in Iran

23. 5 ـ تاثير سن، جنس ، شغل و موقعيت اجتماعي • تاثير سن بر ميزان بروز و شيوع ، موارد با علامت و بدون علامت و شديد و خفيف و احتمال مزمن شدن و ميزان مرگ و مير • All ages and genders affected • تاثير جنس بر عوامل مذكور • شغل و موقعيت اجتماعي ؟

24. Effect of Gender • Men aged 15-45 years are affected twice as often as women of the same age • The man is more likely than the woman to be exposed to the heaviest concentration of organisms

25. Effect of Gender • In Iran both sexes are nearly always equally contacted with contaminated animals and dairy products • There is not a significant predominance of male to female brucellosis in Iran

26. Sex distribution in Iran Male 56% Female 44%

27. Age distribution • Children are affected very much less than adults • The odd low incidence in children is unexplained • It may be that gastric acidity is less often deficient than in adult • Occupational exposure is much more important

28. توزيع سني 56000 بيمار ايراني در سال 1370 0-4 5-9 10-14 20-24 30-34 40-44 50-54 + 60

29. Occupational hazards • Farmers • Shepherds, goatherds • Veterinarians • Abattoir workers • Laboratory workers • Butchers

30. موقعيت اجتماعي و شغلي 56000 مورد بروسلوز گزارش شده در ايران در سال 1370 %

31. 6 ـ تاثير عوامل مساعد كننده • عوامل فرهنگي و عقيدتي • زمينه هائي نظير ضعف ايمني ، ابتلاء به بيماريهاي سركوبگر ايمني ، مصرف داروهاي مضعف سيستم ايمني • استرس هاي مختلف • فقر و بي خانماني

32. 7 ـ حساسيت و مقاومت در مقابل بيماري • مقاومت طبيعي • مصونيت اكتسابي بعد از ابتلاء • مصونيت اكتسابي بعد از واكسيناسيون • - در انسان ؟ • - در حيوانات ؟

33. Susceptibility and resistance • Children are more resistant than adults • Immunity to reinfection follows initial infection in the majority of the individuals

34. 8 ـ ميزان حملات ثانويه اين بيماري نوعي زئونوز است و طي تماس‌هاي معمولي، از انسان به انسان منتقل نمي‌شود.

35. 9 ـ منابع و مخازن ، نحوه انتقال بيماري و دوره قابليت سرايتبروسلوز • تعريف منبع ؟(Source) • تعريف مخزن ؟(Reservoir) • راه هاي انتقال • مستقيم • غير مستقيم • دوره قابليت سرايت ؟(P. of communicability)

36. Brucellosis in animals • Transmitted by contact with infected tissue or milk (oral, aerosol or abrasion) • Predilection for erythritol rich organs (breast, uterus, epididymis, ect.) • Abortions, mastitis and sterility

37. Transmission of brucellosis • Farmers / Ranchers • Veterinarians (food animal practice) • Brucellosis eradication personnel • Meat inspection personnel • Abattoir workers • Laboratory personnel

38. Transmission of brucellosis Brucellosis as a Food Borne Disease • Is not or is not occupation related • Often no history of animalcontact • May occur outside brucellosis enzootic areas • Often occurs in outbreaks • May involve women & children • May involve travelers to brucellosis enzootic areas

39. Reservoirs • Natural Human Species HostPathogen • Brucella abortus Cattle * • Brucella suis Swine * • Brucella melitensis Goats/Sheep * • Brucella ovis Sheep • Brucella canis Dogs * • Brucella neotomae Desert wood rat7

40. Occurrence in Wildlife

41. Reservoir • Mammalian parasite • Host specificity is not exclusive • Horse is occasionally infected • Serum from camels have proved positive • Have been isolated from foxes, buffaloes, elk, moose, deer, polecats • Rabbits have been infected • Infection of hares have proved

42. Reservoir • Flies, mosquitoes, ticks and other insects can be infected with all species • Ticks have transmitted to guinea pigs by biting • Dogs and cats are fairly resistant • Has not been found in monkeys

43. Infection of Cattle • In many parts of the world, cattle are heavily infected • Br. Abortus is most commonly involved • They may readily infect with Br. Melitensis and Br. suis

44. Infection of Cattle • Br. Melitensis do not cause serious symptoms in cattle • Br. Abortus may lead to death of the fetus and abortion • The aborted fetus, the placenta and the discharge from vagina are all heavily contaminated

45. Infection of Cattle • Brucella tend to lodge in mammary gland and supramammary lymph nodes • They may shed in the milk for years • The organisms tend to settle in the testicles, epididymis and seminal vesicles • Organisms may be present in the semen and may transmit sexually • Transmission by artificial insemination • In cattle is a serious economic and public health problem

46. Infection of Goats • Is always due to Br. Melitensis • Abortion is not a prominent symptoms • Reduced fertility in the herd • Br. Melitensis is passed in enormous numbers in the milk • for 6-7 month

47. Infection of Sheep • Is always due to Br. Melitensis • Is occasionally due to Br. Abortus or Br. Suis • Affecting fertility and meat and wool production

48. Infection of Swine • Br. Suis is the most common brucella in swine • Swine may infect with brucella abortus and melitensis • The semen may be teeming with brucella and the boar may disseminate infection throughout the herd

49. Transmission between animals • Milk • Meat • Trans placentally • Sexually (& artificial insemination) • Respiratory • Urine

50. Mode of transmission • Ingestion • Inhalation • Abrasion skin • Mucous membranes • Conjunctive • Sexual • Blood transfusion • Organ transplant