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Chapter 5: Infectious and Parasitic Diseases

THIS CHAPTER IS ABOUT Diseases that are recognized as

communicable or transmissible and some diseases of unknown but possibly infectious origin.

The infectious and parasitic diseases are classified by body site and organism.

HOW IS THIS DIAGNOSED? There are laboratory tests that are used in

the Diagnosis and Treatment of Infectious Diseases. This tells you the type of bacteria involved.

Smear and stain examinationso Gram staino Gram positive and Gram negative organismso Acid-fast stains are used when bacteria does not

stain well with the Gram Stain.o Other staining methods listed on page 71.

AFTER THE LAB TEST A DR MAY ORDER… Cultures The rate of growth, atmospheric needs (anaerobic vs

aerobic) and nutritional requirements of the bacterium are clues to it’s identity.

Broths, and agar are most commonly used as growth media.

Grouping of the bacteria growth is called a colony. Other id’s are odor, pigment, shape, size and

consistency of the colony. Sensitivity tests will tell what antibiotic will treat

the infection.

SEROLOGIC STUDIES Serologic Studies

o These blood tests are used to provide a specific diagnosis when attempts to identify an infectious agent are unsuccessful or impractical or when culture techniques are unavailable

Infectious diseases diagnosed by serologic studies are:

Syphilis, rubella, mycoplasma pnueumoniae, Lyme disease and mononucleosis.

When a good sputum specimen is collected the gram stain is rapid, simple, and a inexpensive technique to diagnose bacterial pneumonia.

What’s the ICD code for bacterial pneumonia?

MICROORGANISMS THAT CAUSE INFECTIONS Bacteria- can be gram positive (+) or gram negative (-) Parasites- these organisms that live in or on another

living organism Fungi- Cause infectious diseases including poisonings,

allergies, cutaneous, or mucous membrane infectionso Fungi Does not spread from person to person

Virus- infectious microorganism that is much smaller than a bacterium and survives only within a living host cell because it doesn’t have it’s own RNA/DNA

The entire health record must be reviewed to identify the body site, severity, specific organism or parasite, etiology of the infection, and associated signs & symptoms

COMMON BACTERIA

ALSO DEPENDS ON SHAPE. THEY MAY BE IN CLUSTERS OR CHAINS

RODS –COCCI -

Gram (+) the organism stain purpleo Streptococcus o Staphylococcuso Clostridium o Anthraxo Listeriao Lactobacilluso Peptococcus

Gram (–) the organism stain redo Salomonellao Proteuso Shigellao Neisseriao Enterobacteriaceaeo Serratia

GRAM STAINING WILL TELL THE SHAPE OF THE BACTERIUM. RODS VS COCCI

SHAPE ORGANISM Cocci in chains Cocci in clusters Straight rods Brick shaped rods

Streptococci Staphylococci Salmonella Clostridium perfringens

COMMON PARASITES AND FUNGI

PARASITES FUNGI Worms are parasites and

include tapeworms, flukes, roundworms, pinworms, hookworms, and whipworms.

Candidiasis infection is most common fungi.

o Disease may be localized to the mouth, throat, skin, scalp, vagina, fingers, nails, bronchi, lungs, or GI tract.

COMMON VIRAL INFECTIONS Adenoviridae Arbovirus Aseptic meningitis Cytomegalovirus Epstein-Barr virus Hepatitis viruses Herpes simplex

virus HIV

Influenza virus Measles Mumps Papilloma viruses Paralytic

poliomyelitis Respiratory syncytial

virus Varicella zoster Rabies

CODING THE BUGS, SEQUENCING RULES Multiple coding is often necessary to

completely describe an infectious condition and the organism that caused it.

Infectious agents are assigned as secondary to describe the causing organism when the organism is not specified in the code title.

Example: UTI due to E. coli 599.0, UTI 041.4, E. coli

V09 Code V09 is used as an additional code

for infectious conditions to indicate the presence of drug resistance in the infectious organism.

Code assignment should not be based on the laboratory or sensitivity report alone.

The physician should document this in the record.

SOME BACTERIA Streptococcus (group A) responsible for URI’s

spread by droplets or direct contact. Streptococcus pneumoniae found in the mouth of

10%-40% of people. This bug can also cause lobar pneumonia in adults and sinusitis & otitis media in children and meningitis in elderly people.

S. aureus cause infections involving the skin and subcutaneous tissues, the eye, or ear. Can also cause pneumonia, endocarditis, food poisoning, toxic shock syndrome. Can be transmitted by direct spread or through the bloodstream.

TUBERCULOSIS (TB) TB is highly contagious, an acute or

chronic infection caused by Mycobacterium tuberculosis.

It occurs primarily in the lungs, but it can occur in other sites.

A fifth digit is required to identify the method used to establish the diagnosis.

STREPTOCOCCAL (STREP) SORE THROAT ICD-9-CM classifies strep throat to code

034.0. No additional code is necessary to

identify the organism because it is already included in the title of code 034.0.

Find 034.0 in your ICD-9 book now.

SEPTICEMIA Septicemia is a bloodstream infection

caused by the entry of pathogens into the blood.

Blood cultures are usually positive but can be negative in a patient with the disease.

Septicemia codes include the underlying disease.

Coding guidelines exist for septicemia, septic shock, and SIRS. (what’s SIRS?)

SEPSIS, SEE PAGE 77 The terms septic shock, severe sepsis,

sepsis and septicemia may be used interchangeably by physicians but they are clinically distinct conditions.

The term sepsis is indexed to code 995.91 and severe sepsis is indexed to code 995.92

Septic shock meets the definition of severe sepsis

CODING SEPSIS The “code first” note at subcategory 995.9

provides instruction that the underlying cause of the sepsis should be coded first.

In the absence of a specified underlying condition, the default first code should be 038.9.

If documentation is unclear whether the sepsis was present on admission, ask the provider.

The term sepsis or SIRS must be documented to assign a code from subcategory 995.9.

MENINGITIS Bacterial meningitis is an inflammation

of the meninges and is classified to category 320.

However, Meningococcal meningitis is coded with 036.0.

CHILDHOOD COMMUNICABLE DISEASES Chicken pox (052) or

varicella is a common acute and highly contagious infection caused by the herpes virus varicella zoster. Category is subdivided to identify the presence or absence of complications.

Measles (055) is one of the most common illnesses known. Category is subdivided to identify the presence or absence of complications.

Rubella (056), or German measles, is an acute, mildly contagious viral disease.

Category 056 is further subdivided to identify complications.

When rubella is documented as congenital, code 771.0 should be assigned.

HERPES- CONTAGIOUS STUFF! Herpes zoster (053), or shingles, is a severe

infection caused by the varicella zoster virus. Herpes simplex type 1 & 2 is the gift that

keeps on giving! Herpes simplex 1 is transmitted by oral &

respiratory secretions, affecting skin & mucous membranes with cold sores and fever blisters.

Herpes simplex 2 affects primarily the genital area and is transmitted by sexual contact.

HEPATITIS Viral hepatitis (070) is an inflammation of the

liver caused by a virus. The five forms of hepatitis include:

o Type A- contagious, transmitted by oral-fecal routeo Type B- transmitted by direct exchange

contaminated blood, human secretions, feces.o Type C- transmitted through blood transfusions.

The blood donors do not know they have it. o Type D- found only in patients with acute/chronic

episode of hepatitis Bo Type E- transmitted enterally (what’s this?)

CANDIDIASIS Candidiasis (112) is a fungal infection caused by

the Candida species moniliasis. The category is further subdivided to identify the

specific site affected. This is usually a mild & superficial. Occurs in nail, skin, mucous membranes, vagina, esophagus, and GI tract. Sometimes can enter the bloodstream and invade kidneys, lungs, brain or other major organs.

Neonatal candida monilia infection is excluded from this category and is assigned to 771.7.

STD’S Contagious, spread by sexual contact

or intercourse. Include:

o Syphilis (090–097)o Gonorrhea (098)o Chlamydia (099.5) with fifth digits

identifying specific sites

INFECTIOUS GASTROENTERITIS Caused by a variety of organisms including

bacteria, viruses, and parasites. Some of the symptoms include: severe

nausea, vomiting, anorexia, abdominal cramps, fever, malaise, muscle aches, hypokalemia, acidosis.

Several categories are used to classify including 003.0, Salmonella gastroenteritis; 005, Other food poisoning; and 008, Intestinal infections due to other organisms.

NONINFECTIOUS GASTROENTERITIS Gastroenteritis not specified as

infectious is assigned to either 558.1, 558.2, 558.3, or 558.9.

Under code 558.3 (Allergic gastroenteritis and colitis), there is a note to “use additional code” to identify the type of food allergy (V15.01–V15.05).

HIV Presence of HIV in blood indicates HIV infection. HIV1 infection involves five phases, see pg 80 Health records with diagnostic statements of

“suspected,” “likely,” “possible,” or “questionable” HIV should be returned to the physician for clarification.

Patients who are seen for an HIV-related illness will be coded with at least two codes—one for the HIV disease and one for the manifestation.

EXAMPLE Delivery of a male infant in mother with AIDS

o 647.61, Other specified infectious and parasitic disease in the mother

o 042, HIV diseaseo V27.0, Outcome of delivery

If a patient with symptomatic HIV disease or AIDS is admitted for an unrelated disease, such as traumatic injury, the code for the unrelated condition is listed first, followed by the code for the HIV infection.

EXAMPLE Patient was seen by the physician who

diagnosed acute appendicitis; patient also has AIDS.o 540.9, Acute appendicitiso 042, HIV disease

CODING HIV V08, Asymptomatic human

immunodeficiency virus infection, indicates that the patient has a virus in the blood but has no symptoms of an HIV-related disease.

042, HIV disease, indicates that the patient has an HIV-related disease.

795.71, Nonspecific serologic evidence of HIV is used for patients with inconclusive HIV test results

CODING HIV Code V08 is used as long as the patient

is asymptomatic. Code 042 is used once the patient

exhibits HIV-related illnesses even when the patient may be asymptomatic for a period of time (never go back to V08).

Code 795.71 is used for very limited situations when an HIV test is inconclusive.

HIV TESTING & COUNSELING V73.89, Screening test for HIV V69.8, High risk group V65.44, HIV counseling

V CODES There are several V codes applicable to

infectious and parasitic diseases. These are found on page 83