Staphylococcus (staph) is a bacterium that commonly lives on the skin and in the nose of healthy people. Although staph bacteria are typically harmless, infections caused by staph are the leading cause of nosocomial infections in the United States. Staph bacteria are most commonly spread by direct contact with contaminated open sores or body fluids and rarely spread through air.

Staphylococcus infection is classified to ICD-9-CM code 041.1x. A fifth-digit subclassification is needed to identify the type of Staphylococcus as follows:

• 041.10, Staphylococcus, unspecified;

• 041.11, Staphylococcus aureus; and

• 041.19, Other Staphylococcus.

Category 041 is for bacterial infection in conditions classified elsewhere and of unspecified site. This category of codes is intended to be used as an additional or secondary code to identify the bacterial agent in diseases classified elsewhere and is not ordinarily sequenced as the principal diagnosis.

The disease caused by the bacteria (eg, cellulitis) should be sequenced first. A code from category 041 can be used alone, if necessary, to classify bacterial infections of unspecified nature or site. In the rare circumstance that the physician documents bacterial infection as the principal diagnosis with no underlying condition and the clinical situation, therapy provided, and response to therapy support the physician’s clinical judgment, a code from category 041 may be sequenced as the principal diagnosis (AHA Coding Clinic for ICD-9-CM, 1991, second quarter, page 9). If the code includes the disease and the causative organism, then it is appropriate to assign only one code without an additional code from category 041.

Conditions Caused by Staph Infection
If the staph bacteria get into the body through a break in the skin, such as abrasions, cuts, wounds, surgical incisions, or indwelling catheters, they may cause the following conditions:

• pimples (709.8 + 041.1x);

• boils/carbuncle (680.x + 041.1x) — pockets of infection and pus under the skin;

• cellulitis (categories 681-682 + 041.1x);

• pneumonia (482.40 - 482.49);

• meningitis (320.3);

• endocarditis (421.0 + 041.1x);

• septicemia (038.10 - 038.19);

• osteomyelitis (730.xx + 041.1x); and

• bacteremia (790.7 + 041.1x).

Patients who are more susceptible to staph infections include the following:

• newborns;

• women who are breast-feeding;

• immunocomprised patients caused by radiation therapy, chemotherapy, or other medications;

• intravenous drug users;

• patients with surgical incisions or skin disorders; and

• patients with a serious illness such as cancer, diabetes, or lung disease.

Staphylococcus Aureus
Staphylococcus aureus appears as a Gram-positive coccus, coagulase-positive and can be divided into two subspecies: S. aureus aureus and S. aureus anaerobius. Most strains of staph aureus are now resistant to penicillin.

Methicillin-resistant Staphylococcus aureus (MRSA) is a term used to denote a strain of organisms resistant to flucloxacillin, oxacillin, and methicillin. MRSA is classified to code V09.0, which should be assigned as a secondary diagnosis after the code(s) for the infection.

MRSA is generally sensitive to vancomycin and teicoplanin. However, recently some staph strains, called vancomycin-resistant Staphylococcal aureus, are even resistant to vancomycin and classified to code V09.80.

Other strains of Staphylococcus include the following:

• Staphylococcus epidermidis is an organism that most often contaminates devices that provide direct access to the bloodstream because they are capable of clinging to the tubing.

• Staphylococcus saprophyticus commonly causes urinary tract infections in sexually active women.

Coding and sequencing for staphylococcus infections are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Health Information Systems (800-367-2447), a supplier of coding and classification systems to nearly 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payors as the result of the misuse of this coding information

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