brucellosis by azhar

Brucellosis, a bacterial disease caused by members of the genus Brucella, is an important zoonosis and a significant cause of reproductive losses in animals.

1. BRUCELLOSIS Prepared By Mr. Shaikh Azharoddin Mumtaj Under the guidance of Asst. Prof. Mr. Sandip V. Phoke SHRI R.D. BHAKT COLLEGE OF PHARMACY, JALNA

2. Contents Introduction Review Literature Geographic distribution Transmission Pathogenesis Clinical feature Diagnosis Treatment, prevention and control

3. Introduction Brucella is first isolated by the Dr. David Bruce while serving in Malta in 1887 . Brucellosis , a bacterial disease caused by members of the genus Brucella , is an important zoonosis and a significant cause of reproductive losses in animals. Brucellosis is usually caused by Brucella abortus in cattle, B. melitensis or B. ovis in small ruminants, B. suis in pigs and B. canis in dogs. Abortions , placentitis, epididymitis and orchitis are the most common consequences, although other syndromes are also reported. The main impact is economic; deaths are rare except in the fetus and neonate. Some Brucella species are also maintained in wildlife populations.

4. Review Literature MJ CORBEL, SS ELBERG AND O COSIVI The executive editors have drawn on the expertise of contributors who are acknowledged experts in their field and who understand the difficulties of dealing with this disease under the suboptimal conditions which still apply in many of the areas in which brucellosis remains an important economic and public health problem. We are grateful for their outstanding contributions and for the constructive comments of the many other experts who have advised on the text. Further, we wish to thank both the Swiss and the Italian Ministry of Foreign Affairs for their financial support. SATISH GUPTE* AND TANVEER KAUR Brucellosis is a worldwide zoonosis with a high degree of morbidity in humans. The disease may be overlooked and misdiagnosed because of the difficult diagnosis and the absence and lack of experience with laboratory testing . As the clinical picture of human brucellosis is fairly non-specific, a definitive diagnosis requires isolation of the causative organism, or the demonstration of the high levels of specific antibodies, or organism specific DNA in samples. Isolation of organism is time-consuming and hazardous, so must be performed by highly skilled personnel. So serological methods are preferred. Advanced serological methods like ELISA, Brucellacapt are more sensitive techniques. Combination of culture and serological test should be used to avoid misdiagnosis. Molecular assays come with high sensitivities and specificities and may reduce diagnostic delays in clinical laboratories. Several PCR based assays have been studied for standardizing them for brucellosis diagnosis. Another rapid, sensitive and inexpensive molecular technique, LAMP has been developed by designing primers specific for Brucella abortus genes. This technique can prove helpful in resource limited settings in developing countries. Highthroughput MLVA-16 genotyping techniques are also being studied and developed for brucella typing for tracing the source of brucellosis infection. This test can be useful for brucella diagnosis and surveillance studies. This review article describes procedures, advantages or limitations of some useful conventional diagnostic techniques to more sophisticated molecular techniques for brucellosis diagnosis.

5. Definition

6. Brucellosis Brucellosis is a zoonosis primarily of domestic animals, causing a chronic debilitating septicemic disease leading to abortion. The disease is prevalent worldwide and is particularly common in the Mediterranean and Middle Eastern countries, and in parts of Africa and South America. Malta Fever, Undulant Fever, Mediterranean Fever, Gastric Fever.

7. Objective Students should be able to

8. The Organism

9. Brucella spp. Gram negative, intracellular coccobacilli bacteria. Non-motile, non-capsulated, non-spore forming.

10. Geographic Distribution

11. Geographic Distribution Brucellosis is found worldwide but it is well controlled in most developed countries. Clinical disease is still common in the Middle East, Asia, Africa, South and Central America, the Mediterranean Basin and the Caribbean. Brucella species vary in their geographic distribution. B. abortus is found worldwide in cattle-raising regions except in Japan, Canada, some European countries, Australia, New Zealand and Israel, where it has been eradicated.

12. Transmission

13. Transmission B. abortus, B. melitensis , B. suis and B. canis are usually transmitted between animals by contact with the placenta, fetus, fetal fluids and vaginal discharges from an infected animal. Animals are infectious after either an abortion or full term parturition. Although ruminants are usually asymptomatic after their first abortion, they can become chronic carriers, and continue to shed Brucella in milk and uterine discharges during subsequent pregnancies. Most or all Brucella species are also found in semen.

14. Pathogenesis

15. Pathogenesis Ingestion: Raw milk & unpasteurized dairy products. Rarely through undercooked meat. Inhalation: Inoculation: Person-to-person transmission is very rare. of placental or uterine discharges, blood and urine.

16. Pathogenesis Animal tissues and products, such as placenta, uterus and milk, that are rich in erythritol (a growth factor for brucellae) can be heavily contaminated and highly infectious. Spread in the body occurs via lymphatic, replication within lymph nodes, and then wide hematogenous spread to organs and tissues. Intracellular parasitism: brucellae have a particular tendency to persist intracellularly, notably in the reticuloendothelial system.

17. Who is at Risk? Occupational Disease: Cattle ranchers/dairy farmers. Veterinarians. Abattoir workers. Meat inspectors. Lab workers. Hunters. Travelers. Consumers of unpasteurized dairy products.

18. Clinical features

19. Clinical features Incubation period: 1-3 weeks, occasionally several months. Can affect any organ or organ system. Fever may be intermittent or undulant. Fever, often persists for months or years. Non specific symptoms: sweating, anorexia, constipation, rigor and weakness. Depression. Osteoarticular complications e.g. arthritis, osteomyelitis.

20. Clinical features Splenomegaly, lymphadenopathy and hepatomegaly. Orchitis and epididymitis. A septicemic disease, abortion can occur. Classification: Acute (< 1 year) and Chronic (>1 year). Low case fatality rate mostly due to infective endocarditis.

21. Diagnosis

22. Diagnosis 1- Clinical features. 2- Serology: brucella agglutinins in the blood. 3- Blood or tissue culture. 4- Polymerase Chain Reaction (PCR).

23. Diagnosis in Humans Serology: brucella agglutination test. Four-fold or greater rise in titer. Samples 2 weeks apart. BAT detects antibody to B. abortus, B. melitensis and B. suis but NOT to B. canis. Therefore, specific serologic tests for B. Canis must be requested. Rose Bengal Test is useful for screening. False positive: cross reactivity with antibodies of F. tularensis, E. coli and V. cholerae.

24. Diagnosis in Humans

25. Diagnosis in Humans False negative: in prozone phenomenon. Prozone phenomenon may occur secondarily to hyperantigenemia, which might result in a false-negative results. High levels of antigen may prevent the formation of antigen-antibody complexes. To solve this problem, routine dilution of the serum beyond 1:320 would help to prevent such a problem. 2-ME-test (mercaptoethanol): more specific, positive in chronic Brucellosis.

26. Diagnosis in Humans ELISA test: High IgM in acute infection. High IgG in chronic infection. Culture of blood, bone marrow and tissue fluids. Blood culture: + ve in about 50 -70% of cases. Bone marrow culture is the standard criterion, since the reticuloendothelial system holds a high concentration of the organism. Sensitivity 80-90%. Blood or bone cultures should be incubated for at least 6 weeks.

27. Diagnosis in Humans PCR is a rapid and accurate method for diagnosis of Brucella species. CBC: Non specific, (leucopenia, lymphocytosis , anemia). Moderate elevation of ESR.

28. Treatment, Prevention & Control

29. Treatment of Choice Combination therapy has the best efficacy. Doxycycline for six weeks in combination with streptomycin for 2-3 weeks or rifampicin for 6 weeks. CNS cases treat 6-9 months. Same for endocarditis cases plus surgical replacement of valves.

30. Prevention and Control Education about risk of transmission. Farmer, veterinarian, abattoir worker, etc. Wear proper attire if dealing with infected animals/tissues. Gloves, masks, goggles. Avoid consumption of raw dairy products.

31. Prevention and Control Immunize animals in areas of high prevalence. Effective attenuated live bacterial vaccines exist against B. abortus (strain 19) and B. melitensis (Rev-I), but as yet none exists for B. suis or B. canis. No human vaccine.

32. Thank you