diagnosing infectious diseases

7/31/2019 Diagnosing Infectious Diseases

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Introduction

The proper diagnosis of an infectious diseaserequires:

1. Taking a complete patient history

2. Conducting a thorough physical examination ofthe patient

3. Carefully evaluating the patients signs andsymptoms and

4. Implementing the proper selection, collection,transport, and processing of appropriate clinicalspecimen


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Types of Clinical Specimen Submitted to the Clinical

Microbiology Laboratory

TYPE OF SPECIMEN TYPE(S) OF INFECTIOUS DISEASETHAT THE SPECIMEN IS USED TODIAGNOSE

Blood B, F, P, V

Bone Marrow B

Bronchial and bronchoalveolar washes V

Cerebrospinal fluid (CSF) B, F, P, V

Cervical and vaginal swabs B

Conjunctival swab or scraping B, V

Feces and rectal swabs B, P, V


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Hair clippings F

Nail (fingernail and toenail) clippings F

Nasal swabs B

Pus from a wound or abscess BScotch tape prep P

Skin scrapings F

Skin snip P

Sputum B, F, P

Synovial (joint) fluid B

Throat swabs B, V

Tissue (biopsy and autopsy) specimens B, F, P, V

Urethral discharge material B

Urine B, P, V

Urogenital secretions (e.g., vaginaldischarge material, prostatic secretions)

B, P

Vesicle fluid or scraping V

* B, BACTERIAL INFECTIONS ; F,FUNGAL INFECTIONS * P, PARASITIC INFECTIONS; V,VIRAL INFECTIONS


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A close working relationship among the membersof the healthcare team is essential for the properdiagnosis of infectious diseases.

When an attending physician suspects that a patienthas a particular infectious disease, appropriate clinicalspecimens must be obtained and certain diagnostictests may be requested. The doctor, nurse, medical technologist, or other

qualified healthcare professional must select theappropriate specimen, collect it properly, and thenproperly transport it to the laboratory where it isprocessed.


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According to the Clinical and Laboratory

Standards Institute (CLSI), All specimens should

be collected or transferred into a leakproof

primary container with a secure closure. Care

should be taken by the person collecting the

specimen not to contaminate the outside of theprimary container . Within the institution, the

primary container should be placed into a second

container, which will contain the specimen if theprimary container breaks or leaks in transit to the

laboratory.


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Importance of High- Quality

Clinical Specimens> High-quality clinical specimens are required to achieveaccurate, clinically relevant laboratory results (i.e.,results that provide information about the patientsinfectious disease).

The three components of specimen quality are:1. Proper specimen collection (i.e., the correct type ofspecimen must be submitted)

2. Proper specimen collection and

3. Proper transport of the specimen to the laboratory.> The laboratory must provide written guidelines regarding

specimen selection, collection, and transport in the form ofa book.


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However, the person who collects the specimen isultimately responsible for its quality.

When clinical specimens are improperly collected andhandled,

1. the etiologic (causative) agent may not be found

or may be destroyed2. overgrowth by indigenous microflora may mask

the pathogen , and

3. contaminants may interfere with the

identification of pathogens and the diagnosis of theinfectious disease


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THE

END!!!!!!!

diagnosing infectious diseases

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