Diagnostic Bacteriology

1-Proper sampling

2-Diagnostic Tests

Direct Staining e.g Zheil Nelssen for Tuberculosis, Direct Gram for Meningoccoci in CSF(life saving)

-Culture of appropriate sample

-Direct antigen detections by ELISA, Latex

-Serology detection for specific IgM, IgG

.Diagnostic titer

.Rising titer four fold or more for IgG

.Positive IgM.

-PCR for detection of nucleic acid

1-Pyrexia of unknown origin (PUO)



Definition: Pyurexia without obvious clinical cause for 10 days or more.Chronic PUO>3weeks

Aetiology

Infections

Non specific

Urinary tract infections

Infective endocarditis

Abscesses in viscera e.g liver.pelvic, etc.

Osteomyelitis

Ear, sinus, dental infections

Specific

-Bacterial: TB, Brucellosis , typhoid fever, leptospirosis

-Viral: viral hepatitis, glandular fever, yellow fever, CMV, HIV.

-Richetssial: typhus, Q fever.

Chlamydia , pertussis, cat scratch fever.

Fungal: Candidiasis, histoplasmosis, asperigyllosis, Cryptococcus.

Protozoa: malaria, amoebiasis, trypanosomiasis, leishmaniasis.

Helminthes; Fasciola, filariasis.

Non Infective:

-Hematological causes