Diagnostic tests for various diseases

3. Introduction
Diagnostic tests for
Malaria
Typhoid
Cholera
TB
Leprosy
Diphtheria
Bacillary Dysentry
food poisoning
Tetanus
Hepatitis
Gonnorrhoea
Syphilis
HIV

4. A diagnostic test is a
procedure performed to confirm or
determine the presence of disease in an
individual who is suspected to have a disease
Some methods of diagnosis
 questions asked by the doctor to the
patient while examining him
 Physical examination
 Radiologic tests
ex:- X-Rays, CT-Scan,Mammography
 blood tests

5.  Urine tests
 Stool tests
 Sputum tests
 Molecular diagnostics
 Echocardiography
 Complete blood count
Diagnostic tests for Malaria
Microscopy
Blood smear{thick and thin} is prepared
and observed under microscope using giemsa
stain

7. Antigen testing
 detects the presence of malarial antigens in
the sample of persons blood
 also called dipstick test

8. Molecular tests {PCR}
amplifies the parasitic DNA

9. Antibody test
detects the antibodies in the blood for
malarial antigens
QBC test {quantitative buffy coat}
This method is based on acridine orange
staining of centrifuged blood samples

10. Body fluid or tissue culture
 culture may be of blood, stool, urine, or
bone marrow.
 culture is later tested for s.typhi under
microscope

11. Clot culture
The blood clot is lysed with the Enzyme
streptokinase and then cultured and examined
under microscope

12. Widal test
It is done on serum of the patient
Principle
Bacterial suspension which carry antigens{o
and H antigens of parasite} will agglutinate on
exposure to antibodies which are produced
against salmonella organisms .
Procedure
Preparation of widal antigens
H-culture
Bacteria cultured for 24 hours .to this
formalin{0.1%} is added
o-culture
organisms are cultured on phenol agar

13. These antigens are treated with chloroform
{preservative} and appropriate dyes are added for
easy identification of antigens
Widal test can be done in two methods
slide test
tube method

14. Typhidot {kit}
 This test uses strips which contains nitro
cellulose strips which contains outer membrane
protein{omp} antigen
 detects the antibodies{IgG and IgM}
produced against omp antigen

15. Culture of stool specimen is done on cary blair
Media or thiosulphate citrate bile salt agar
media

16. Physical examination
Dr checks for swelling of lymph nodes and
listen to the sounds of heart.

17. Mantoux test
 Ppd tuberculin is injected just below the skin
and between dermis layers
 If a hard raised red bump is observed then the
person is tested positive for TB

18. Imaging test
CAT scan or X-ray is done

19. Sputum is also tested for Mycobacterium
tuberculosis

20. Lepromanin skin test
 This test is performed by injecting a
small sample of inactivated M.leprea under
the skin in fore arm
 patient is examined after 3 days of
injection to see if they had any reaction
 Redness swelling and other skin changes
indicates positive test for leprosy
Skin biopsy blood tests and PCR are other tests
for leprosy

21. Schick test
minute amount of diphtheria toxin is
injected into the skin .redness at that site
indicates positive reaction

22. Stool culture on MC conkeys Agar and further
by grams staining

23. Blood culture and stool culture for the
examination of parasites

24.  Symtoms like muscle spasms stiffness and
pain are examined
 In this disease serum muscle enzymes like
creatinine kinase may be elevated
 Higher antitoxin levels are considered
protective

25.  Liver function tests
 albumin
 ALP
 Bilirubin
 Blood tests made to find out antibodies
against antigens
 Liver biopsy

26. Swab test, blood tests and urine tests

27. Microscopy and PCR

28. ELISA and Western blot