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CERTAIN INFECTIOUS AND PARASITIC DISEASES (A00-B99)

Includes: diseases generally

recognized as communicable or

transmissible

Use additional code to identify

resistance to antimicrobial drugs (Z16)

New section called infections

with predominantly sexual mode of transmission

(A50-A64)

New sections for Viral Hepatitis (B15-B19) and

Other Viral Disease (B25-

B34)

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Changes in Chapter 1

• Septicemia has been replaced with the term sepsis

• Severe Sepsis is the term in ICD-10 that is used for SIRS due to an infectious process

• Sepsis due to Streptococcus (streptococcal Septicemia) – documentation must specify due to Group A, Group B, or Streptococcus Pneumoniae

• Streptococcal sore throat has been moved to the respiratory chapter

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Chapter 1

When coding sepsis or AIDS, it is important to review the Coding Guidelines and the notes at the category level of ICD-10-CM

Categories B90-B94 are to be used to indicate conditions in categories A00-B89 as the cause of sequelae, which are themselves classified elsewhere.

I.C.1.a.1. HIV Infections Code Only Confirmed Cases

Code only confirmed cases of HIV

“Confirmation” does not require documentation of positive serology, the provider’s diagnostic statement that the patient is HIV positive is sufficient

Asymptomatic HIV-Z21 is to be applied when the patient without documentation of symptoms is listed as being “HIV Positive”. Do not use this code if the terms AIDS is used or if the patient is treated for any HIV-related illness.

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I.C.1.a.2. HIV - Selection and Sequencing of HIV Codes

(a) Patient admitted for HIV-related condition● If a patient is admitted for an HIV-related condition, the

principal diagnosis should be B20, Human immunodeficiency virus [HIV] disease followed by additional diagnosis codes for all reported HIV-related conditions.

(b) Patient with HIV disease admitted for unrelated condition● If a patient with HIV disease is admitted for an unrelated

condition, the code for the unrelated condition should be the principal diagnosis. Other diagnoses would be B20 followed by additional diagnosis codes for all reported HIV-related conditions.

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I.C.1.a.2. HIV - Selection and Sequencing of HIV Codes -2

(c) Whether the patient is newly diagnosed● Whether the patient is newly diagnosed or has had previous

admissions/encounters for HIV conditions is irrelevant to the sequencing decision.

(d) Asymptomatic human immunodeficiency virus● Z21, Asymptomatic human immunodeficiency virus [HIV]

infection status, is applied when the patient without any documentation of symptoms is listed “HIV positive,” “known HIV,” “HIV test positive”. Do not use this code if the term “AIDS” is used or if the patient is treated for any HIV-related illness or is described as having any condition(s) resulting from his/her HIV positive status; use B20 in these cases.

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I.C.1.a.2. HIV - Selection and Sequencing of HIV Codes -3

(e) Patients with inconclusive HIV serology● Patients with inconclusive HIV serology, but no definitive

diagnosis or manifestations of the illness, may be assigned code R75, Inconclusive laboratory evidence of human immunodeficiency virus [HIV].

(f) Previously diagnosed HIV-related illness● Patients with any known prior diagnosis of an HIV-related

illness should be coded to B20. Once a patient develops an HIV-related illness, the patient should always be assigned code B20. Patients previously diagnosed with any HIV illness (B20) should never be assigned to R75 or Z21, Asymptomatic human immunodeficiency virus [HIV] infection status.

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I.C.1.b. Infectious Agents

Certain infections are classified in chapters other than Chapter 1 and no organism is identified as part of the infection code

An additional code from Chapter 1 should be used to identify the organism:● B95 Streptococcus, Staphylococcus, and Enterococcus● B96, Other bacterial agents● B97 Viral agents

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I.C.1.b. Infectious Agents -2

An instructional note will be found at the infection code advising that an additional organism code is required

Use an additional code

(B95 – B97) to identify

infectious agent

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I.C.1.b. Infectious Agents -3

Code first condition resulting from (sequela) the infectious or parasitic disease

Bacterial and viral infectious agents (B95-B97) are provided for use as supplementary or additional codes to identify the infectious agent(s) in diseases classified elsewhere● Index

Infection, infected, infective; bacterial as cause of disease classified elsewhere; Streptococcus group A – B95.5

Streptococcus, streptococcal; group A, as cause of disease classified elsewhere – B95.5

Examples UTI with hematuria due

to E.coli● N30.91, Cystitis unspecified

with hematuria● B96.2, Escherichia coli [E.

coli] as the cause of diseases classified elsewhere

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Pneumonia due to streptococcus group B with sepsis● J15.3, Pneumonia due to

streptococcus, group B● A41.9 Sepsis, unspecified

organism Septicemia NOS

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Chapter 1 Coding Case #1

This 80-year-old female patient was seen with fever, malaise, and left flank pain. A urinalysis was performed and showed bacteria more than 100,000/ml. This was followed by a culture, showing E. coli growth as the cause of the UTI. What diagnosis codes are assigned?

Answer #1

N39.0 Infection, infected, infective (opportunistic), urinary (tract)

B96.20 Infection, infected, infective opportunistic), bacterial NOS, as cause of disease classified elsewhere, Escherichia coli [E. coli] (see also Escherichia coli)

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Rationale: The symptoms associated with the UTI should not be coded. The “use additional code” note under N39.0 instructs the coder to an additional code (B95-B97) to identify the infectious agent.

I.C.1.c. Infections Resistant to Antibiotics

Infections Resistant to Antibiotics● Identify all infections documented as antibiotic resistant

Assign code Z16● Infection with drug-resistant microorganisms following the

infection code

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Coding Note: ICD-10-CM has created a range of

codes to identify infections with a predominantly sexual mode of transmission (A50-A64). It is important to note

that human immunodeficiency virus (HIV) disease is excluded from this

range of codes.

I.C.1.d. Sepsis, Severe Sepsis, and Septic Shock

Coding of (a) Sepsis ● Assign the appropriate code for the underlying systemic

infection. Use A41.9 for unspecified organism● R65.2, Severe sepsis, should not be assigned unless severe

sepsis or acute organ dysfunction is documented

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Exercise #1

This 87-year-old nursing home patient is being treated with IV antibiotics for E. coli sepsis. What diagnosis codes are assigned?

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Answer #1

A41.51 Sepsis (generalized), Escherichia coli (E. Coli). Review Tabular for complete code assignment.

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Rationale: Without documentation of severe sepsis or an associated organ dysfunction, only one code from category A41 is necessary for correct code assignment.

Urosepsis Guidelines

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I.C.1.d. Sepsis, Severe Sepsis, and Septic Shock -2

Coding of (b) Severe Sepsis● Requires at least two codes:

1st underlying systemic infection 2nd code from subcategory R65.2 for severe sepsis

● If the causal organism is not document, assign A41.9, Sepsis unspecified

● Assign additional codes for the associated acute organ dysfunction

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I.C.1.d.2. Septic Shock

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Exercise #1

This 25-year-old woman was transferred from an outside facility for treatment of septic shock and acute meningococcal sepsis. The outside facility was unable to manage her severe illness. What diagnosis codes are assigned?

Answer #1

A39.2 Sepsis (generalized), meningococcal, acuteR65.21 Shock, septic (due to severe sepsis)

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Rationale: The combination code of severe sepsis with septic shock is assigned as a secondary diagnosis although severe sepsis is not.

d. Sepsis, Severe Sepsis, and Septic Shock

3. Sequencing of Severe Sepsis● If severe sepsis is present on admission, and meets the

definition of principal diagnosis, the underlying systemic infection should be assigned as principal diagnosis followed by the appropriate code from subcategory R65.2 as required by the sequencing rules in the Tabular List. A code from subcategory R65.2 can never be assigned as a principal diagnosis.

● When severe sepsis develops during an encounter (it was not present on admission) the underlying systemic infection and the appropriate code from subcategory R65.2 should be assigned as secondary diagnoses.

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d. Sepsis, Severe Sepsis, and Septic Shock -2

4. Sepsis and severe sepsis with localized infection● If the reason for admission is both sepsis or severe sepsis and a

localized infection, such as pneumonia or cellulitis, a code(s) for the underlying systemic infection should be assigned first and the code for the localized infection should be assigned as a secondary diagnosis.

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Severe Sepsis Coding Example

ICD-9-CM

• Severe sepsis due to hemophilus influenza with septic shock and acute renal failure

• 038.41 (Hemophilus influenza septicemia)

• 995.92 (Severe sepsis)• 785.52 (Septic shock)• 584.9 (Acute renal failure)

ICD-10-CM

• Severe sepsis due to hemophilus influenza with septic shock and acute renal failure

• A41.3 (Hemophilus influenza sepsis)

• R65.21 (Severe sepsis with septic shock)

• N17.9 (Acute renal failure)

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d. Sepsis, Severe Sepsis, and Septic Shock -3

5. Sepsis due to a postprocedural infection● (a) Documentation of Causal relationship – As with all

postprocedural complications, code assignment is based on the provider’s documentation of the relationship between the infection and the procedure.

● (b) Sepsis due to a postprocedural infection – The postprocedural infection code (such as T80.2, Infections following infusion, transfusion and therapeutic injection, or T81.4, Infection following a procedure) should be coded first, followed by the code for the specific infection. If severe sepsis is documented, the appropriate code from subcategory R65.2 should also be assigned with the additional code(s) for any acute organ dysfunction.

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d. Sepsis, Severe Sepsis, and Septic Shock -4

5. Sepsis due to a postprocedural infection● (c) Postprocedural infection and postprocedural septic shock –

In cases where a postprocedural infection has occurred and has resulted in severe sepsis and postprocedural septic shock, the code for the precipitating complication such as code T81.4, Infection following a procedure or O86.0, Infection of obstetrical surgical wound should be coded first followed by code R65.21, Severe sepsis with septic shock and a code for the systemic infection.

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d. Sepsis, Severe Sepsis, and Septic Shock -5

6. Sepsis and severe sepsis associated with noninfectious process (condition)● If sepsis or severe sepsis is documented as associated with a

noninfectious condition, such as a burn or serious injury, the code for the noninfectious condition should be sequenced first, followed by the code for the resulting infection

● If the infection meets the definition of principal diagnosis it should be sequenced before the noninfectious condition.

● Only one code from category R65 should be assigned. Therefore, when a non-infectious condition leads to an infection resulting in severe sepsis, assign the appropriate code from subcategory R65.2, Severe sepsis. Do not additionally assign a code from subcategory R65.1 SIRS of noninfectious origin.

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Coding Note: In ICD-10-CM, when coding an infection due

to an indwelling urinary catheter, the coding

professional is instructed to use an additional code to

identify the infection. Additionally, if the infectious

agent is also known, this should be assigned as an

additional diagnosis.

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e. Methicillin Resistant Staphylococcus Aureus (MRSA) Conditions

1. Selection and sequencing of MRSA codes● (a) Combination codes for MRSA infection – When an

infection due to MRSA has a combination code that includes the causal organism assign the appropriate combination code Do not code B95.62 MRSA infection as the cause of diseases elsewhere

or Z16.11 Resistance to penicillin as additional codes

● (b) Other codes for MRSA infection- When there is a current infection and that infection does not have a combination code that includes the causal organism, assign the appropriate code to identify the condition along with code B95.62 Do not also assign Z16.11, Resistance to penicillin

e. Methicillin Resistant Staphylococcus Aureus (MRSA) Conditions -2

1. Selection and sequencing of MRSA codes● c) Methicillin susceptible Staphylococcus aureus (MSSA) and

MRSA colonization- means that MSSA or MSRA is present on or in the body without necessarily causing illness. Assign code Z22.322, Carrier or suspected carrier of MRSA or Z22.321,

Carrier or suspected carrier of MSSA

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Q&A

Chapter 1: Certain Infectious

and Parasitic Diseases

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Exercise #1

True or false? In ICD-10-CM, code B20 is used to report a diagnosis of symptomatic HIV disease.a. Trueb. False

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Answer #1

Answer: a. True

Rationale: Code B20, Human immunodeficiency virus disease, is used to report a diagnosis of symptomatic HIV disease. Code Z21, Asymptomatic human immunodeficiency virus infection is used to report a patient who has tested HIV positive but has not yet developed symptoms from the HIV disease.

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Exercise #2

True or false? Bacteremia and septicemia NOS are coded to R65.2.a. Trueb. False

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Answer #2

Answer: b. False

Rationale: Bacteremia is coded to R78.81 and septicemia to A41.9. A code from subcategory R65.2 should not be assigned unless severe sepsis or an associated acute organ dysfunction is documented.

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Exercise #3

A patient with a diagnosis of interstitial cystitis due to E. coli with hematuria is coded:a. N30.11, N02.9b. N30.10, N02.9, B96.20c. N30.11, B96.20d. N30.91, B96.20

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Answer #3

Answer: c. N30.11, B96.20

Rationale: The code for interstitial cystitis is N30.11 and the code for the E. coli is B96.20. A note appears in the Tabular under N30 that instructs the coding professional to use an additional code to identify infectious agent (B95-B97).

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Exercise #4

True or false? When assigning the principal diagnosis for a patient with AIDS, the AIDS code would always be sequenced before any other conditions.

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Answer #4

Answer: False

Rationale: When a patient is admitted with an HIV-related condition, the principal diagnosis should be B20, Human immunodeficiency virus [HIV] disease, followed by additional diagnosis codes for all reported HIV-related conditions (ICD-10-CM Coding Guideline I.C.1.a.2.a). When a patient with HIV disease is admitted for an unrelated condition, for example, trauma, the code for the unrelated condition should be the principal diagnosis with B20 listed as an additional code (ICD-10-CM Coding Guideline I.C.1.a.2.b).

 

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Exercise #5

True or False? Patients with a prior diagnosis of an HIV-related illness should be assigned the code for AIDS (B20) on every subsequent admission.

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Answer #5

Answer: True

Rationale: Patients with any known prior diagnosis of an HIV-related illness should be coded to B20. Once a patient has developed an HIV-related illness, the patient should always be assigned code B20 on every subsequent admission or encounter. Patients previously diagnosed with any HIV illness (B20) should never be assigned to R75 or Z21, Asymptomatic human immunodeficiency virus [HIV] infection status (ICD-10-CM Coding Guideline I.C.1.a.2.f).

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Exercise #6

True or false? When coding severe sepsis, a minimum of three codes is required.

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Answer #6

Answer: False

Rationale: The coding of severe sepsis requires a minimum of two codes: first a code for the underlying systemic infection, followed by a code from subcategory R65.2, Severe sepsis. If the causal organism is not documented, assign code A41.9, Sepsis, unspecified organism, for the infection (ICD-10-CM Coding Guideline I.C.1.d.1.b). Additional codes for the other acute organ dysfunctions should also be assigned. This condition usually will result in a total of three codes, except in the case of combination codes, such as severe sepsis with septic shock.