طرق التشخيص المعملي

1. طرق التشخيص المعملي

2. التشخيص المباشر : نظرا لان الاصابة بطفيل الملاريا تكون عادة مصحوبة بارتفاع في درجات الحرارة مثل العديد من الامراض البكتيرية والفيروسية لذا فانه من الصعب التفرقة بينها وبين الاصابات . وللتأكد من اصابة المريض بطفيل الملاريا يجب فحص عينة دم للمريض للتحقق من وجود الاطوار المختلفة للطفيل بما يؤكد الاصابة بالمرض.

3. - يتم جمع عينة دم للمريض بطريقة المسحة السميكة او الرقيقة بعد صبغها بصبغة جيمسا (يفضل فحص العينة السميكة لامكان احتوائها علي كمية اكبر من طبقات الدم (20-40 طبقة). من المهم دقة التمييز بين الطفيل وباقي محتويات الدم مثل الصفائح الدموية والشوائب العالقة.

4. فيلم الدم السميك

5.  1- التشخيص الغير مباشر (التشخيص السيرولوجي) منذ بداية الستينات وجدت العديد من الطرق التي اعتمدت علي التحقق من وجود الاجسام المضادة للطفيل بسائل الدم (المصل) وهو ما يعرف بالتشخيص المصلي او السيرولوجي ومن هذه الطرق:فحص المناعي الوميضي (Immunofluorescnce)

6. الفحص المناعي الوميضي (Immunofluorescnce)

7. التجلط المناعي الدموي الغير مباشر (Indirect Haemoagglutination) وهذه الطرق تفيد في اعمال المسح الاولي الشامل ، وقد تستعملها بعض الدول في موانيها ومطاراتها.

8. Case presentations

9. Diagnosis

10. Malaria. Thin blood film showing gametocyte of P. vivax with stippling (Schuffner's dots) in the cytoplasm. Giemsa stain.

11. Malaria. Thin blood film showing trophozoites (ring forms) of P. falciparum. Note two parasites within the same red cell and double chromatin knobs. Giemsa stain.

12. Malaria. Thin blood film showing early trophozoite (ring form) of P. vivax.

13. Malaria. Thin blood film showing band forms (trophozoites) of P. malariae. This is a characteristic feature of P. malariae. Giemsa stain.

14. Malaria. Thin blood film showing trophozoite of P. ovale. Note pronounced stippling of red cell and coarse pigment within parasite. Giemsa stain.

15. Malaria. Thin blood film showing several ring forms and a schizont of P. falciparum. This is only seen in severe cases. Giemsa stain.

16. Malaria. Thin blood film showing fully developed schizont of P. vivax with merozoites ready to burst out. Giemsa stain.

17. Malaria. Thin blood film showing banana-shaped gametocyte of P. falciparum. Note the central mass of pigment. Giemsa stain.

18. Malaria. Thin blood film showing gametocyte of P. vivax with stippling (Schuffner's dots) in the cytoplasm. Giemsa stain.

19. Malaria. Child with mild jaundice, pallor and bilateral conjunctival haemorrhages associated with P. falciparum infection.

20. Malaria. Tropical splenomegaly in a patient with evidence of hypersplenism living in a P. falciparum endemic area.

21. Malaria. Very heavy parasitaemia in a patient with severe P. falciparum infection. Despite chemotherapy and exchange transfusion the patient died of cerebral malaria.

22. Babesiosis. Peripheral blood film showing red cell infestation with the typical small coccoid and dumb-bell shaped Babesia organisms.

23. This is a thin film from a 27 year old female backpacker, with a recent history of trekking through Northern Thailand and high fever.

24. Salient features are: Numerous fine ring forms Double chromatin dots Marginal forms Red cells are not enlarged. This is a typical Plasmodium falciparum presentation.

25. A thin film from a 22 year old male holidaying in Lombok (Indonesia) one month previously. Intermittent fevers since returning.

26. Salient features are: Developing and thick (signet) ring forms Enlarged red cells This is a typical Plasmodium vivax presentation.

27. Recent travel in Africa. Pyrexia of unknown origin.

28. Salient features are: Developing form of plasmodium "Comet-like" red cells Enlarged red cell This is a typical Plasmodium ovale presentation.

29. Female patient, arrived from Brazil two weeks previously. Flu like symptoms since arrival.

30. Salient features are: Broad band form of plasmodium Red cells not enlarged This is a typical Plasmodium malariae presentation.

31. This is a thick film prepared from a 32 year old male recently returned from Vietnam.

32. Salient features are: Numerous ring form of Plasmodium can be seen as indicated by the arrows. Note size of neutrophils (for comparison The only definitive diagnosis that can be made from this film is that Malaria is present. Thin films would have to be examined for species identification.

33. This is a thick film prepared from a recent arrival from India who presented with a high temperature

34. Salient features are: No parasites seen in this field This film would need to be examined for 10 minutes before being called negative. Repeat films should be prepared and examined on at least 2 further occasions, ideally as the temperature peaks, before the presence of Malaria can be excluded.