Method for detection of malaria and other parasite infections

1. A method of detecting a parasite infection using a blood sample comprising the steps of:

(a) mixing said blood sample with a lytic reagent system to lyse red blood cells, and to form a sample mixture;

(b) performing a differential analysis of white blood cells of said sample mixture on a blood analyzer, and obtaining a cell volume distribution of a white blood cell subpopulation from a cell volume measurement used in said differential analysis;

(c) obtaining a cell volume parameter from said cell volume distribution of said white blood cell subpopulation;

(d) evaluating said cell volume parameter against a predetermined criterion, and reporting an indication of said parasite infection if said cell volume parameter meets said predetermined criterion.

2. The method of claim 1 , wherein said white blood cell subpopulation is monocytes.

3. The method of claim 1 , wherein said white blood cell subpopulation is lymphocytes.

4. The method of claim 1 , wherein said white blood cell subpopulation is neutrophils.

5. The method of claim 1 , wherein said cell volume parameter is a standard deviation of said cell volume distribution.

6. The method of claim 1 , wherein said cell volume parameter is a mean of said cell volume distribution.

7. The method of claim 1 , wherein said cell volume measurement is an impedance measurement.

8. The method of claim 1 , wherein said cell volume measurement is a low angle light scatter measurement, or an axial light loss measurement.

9. The method of claim 1 , wherein said parasite infection is Plasmodium infection.

10. The method of claim 1 , wherein said parasite infection is Toxoplarma gondii infection, Leishmania infection, or Babesia infection.

11. A method of detecting a parasite infection using a blood sample comprising the steps of:

(a) mixing said blood sample with a lytic reagent system to lyse red blood cells, and to form a sample mixture;

(b) performing a differential analysis of white blood cells of said sample mixture on a blood analyzer; and obtaining a first cell volume distribution of a first white blood cell subpopulation and a second cell volume distribution of a second white blood cell subpopulation from a cell volume measurement used in said differential analysis;

(c) obtaining a first cell volume parameter from said first cell volume distribution of said first white blood cell subpopulation and obtaining a second cell volume parameter from said second cell volume distribution of said second white blood cell subpopulation;

(d) obtaining a discriminant as a function of said first and second cell volume parameters; and

(e) evaluating said discriminant against a predetermined criterion, and reporting an indication of said parasite infection if said discriminant meets said predetermined criterion.

12. The method of claim 11 , wherein said first and second cell volume parameters are standard deviations of said first and second cell volume distributions, respectively; and said discriminant is a function of said standard deviations of said first and second cell volume distributions.

13. The method of claim 11 , wherein said first white blood cell subpopulation is monocytes.

14. The method of claim 11 , wherein said second white blood cell subpopulation is lymphocytes.

15. The method of claim 11 , wherein said cell volume measurement is an impedance measurement.

16. The method of claim 11 , wherein said cell volume measurement is a low angle light scatter measurement, or an axial light loss measurement.

17. The method of claim 11 , wherein said parasite infection is Plasmodium infection.

18. The method of claim 11 , wherein said parasite infection is Toxoplarma gondii infection, Leishmania infection, or Babesia infection.

19. A method of detecting a parasite infection using a blood sample comprising the steps of:

(a) mixing said blood sample with a lytic reagent system to lyse red blood cells, and to form a sample mixture;

(b) performing a differential analysis of white blood cells of said sample mixture on a blood analyzer, and obtaining a first cell distribution of a first white blood cell subpopulation from an impedance measurement used in said differential analysis;

(c) obtaining a first cell distribution parameter from said first cell distribution of said white blood cell subpopulation;

(d) evaluating said first cell distribution parameter against a first predetermined criterion, and reporting an indication of said parasite infection if said first cell distribution parameter meets said predetermined criterion.

20. The method of claim 19 , wherein said impedance measurement is a direct current impedance measurement, or a radio frequency impedance measurement.

21. The method of claim 19 , wherein said cell distribution parameter is a standard deviation of said first cell distribution.

22. The method of claim 19 , wherein said cell distribution parameter is a mean of said first cell distribution.

23. The method of claim 19 , wherein said parasite infection is Plasmodium infection.

24. The method of claim 19 , wherein said parasite infection is Toxoplarma gondii infection, Leishmania infection, or Babesia infection.

25. The method of claim 19 , wherein said white blood cell subpopulation is monocytes, lymphocytes, or neutrophils.

26. The method of claim 19 further comprising the steps of:

obtaining a second cell distribution of a second white blood cell subpopulation from said impedance measurement;

obtaining a second cell distribution parameter from said second cell distribution of said second white blood cell subpopulation;

obtaining a discriminant as a function of said first and second cell distribution parameters; and

evaluating said discriminant against a second predetermined criterion, and reporting an indication of said parasite infection if said discriminant meets said second predetermined criterion.