Currentmedical mutual - ohioPolicy AHS - G2158 - Testing for Vector-Borne Infections, 1 = Initial Presentation

Testing for Vector-Borne Infections

Clinical coverage policy describing which laboratory tests for vector-borne infections are covered or not covered, with indications, limitations, and specimen/timing requirements for ordering providers and laboratory billing for Medical Mutual - Ohio.

Policy Summary

Payermedical mutual - ohio

PolicyTesting for Vector-Borne Infections

Policy CodePolicy AHS - G2158 - Testing for Vector-Borne Infections, 1 = Initial Presentation

Change TypeCoverage language and coding updates

Effective DateFeb 1, 2026

Next Review Date

Key ActionWhen ordering serologic tests that require paired acute and convalescent specimens (e.g., babesiosis, rickettsial disease), document timing and ensure samples are collected at least two weeks apart to support coverage.

SourceLink

POLICY UPDATE CHANGES

Added 'IgG or IgM indirect immunofluorescence antibody (IFA) assay for Babesia (initial testing and confirmatory testing should occur a minimum of two weeks apart)' to CC1.

Removed CC2 entry that specifically named 'PCR testing'.

Replaced 'serum sample' with 'blood sample' in CC4.

Replaced 'PCR testing' with 'NAAT testing' in CC2, CC5, and CC11.

CC13 and CC14 were edited for clarity and consistency.

Off-cycle coding modification added CPT codes 87164 and 87166 effective 2025-01-01.

Updated background, guidelines, and evidence-based scientific references.

~20vector-borne pathogens referenced

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Coverage Criteria by Disease / Test

General Coverage Logic / Indications

Testing for specific vector-borne infections MEETS or DOES NOT MEET COVERAGE CRITERIA as specified below for individuals with clinical suspicion or defined risk factors:

ALL of the following

Verify member benefits and applicable Medicare/Medicaid specifications prior to ordering; coverage is dependent on individual benefit coverage and regulatory rules
Verify member benefits and regulatory sections

Tests must be ordered for individuals with clinical suspicion or defined exposure risk; routine asymptomatic screening without clinical signs or exposure does not meet coverage

Babesiosis

For individuals suspected of having babesiosis:

ANY of the following

Giemsa- or Wright-stained blood smear
initial diagnostic modality
Nucleic acid amplification testing (NAAT) for Babesia
meets coverage
ANY of the following
- IgG indirect immunofluorescence antibody (IFA) assay
  serology may be used
- IgM indirect IFA assay
  serology may be used

ALL of the following

Acute and confirmatory serologic testing should occur a minimum of two weeks apart
timing requirement for paired serology

Confirmatory laboratory evidence may include identification of intraerythrocytic Babesia on Giemsa/Wright-stained smear, detection of Babesia spp. DNA in whole blood by NAAT within 60 days of illness onset, or a four-fold rise in IgG titer by IFA in paired sera

CDC confirmatory criteria

Relapsing Fever (Borrelia spp.)

For individuals suspected of relapsing fever:

HTRF (Hard Tick Relapsing Fever)

Serologic assays to detect Borrelia antibodies
meets coverage
NAAT testing to detect Borrelia miyamotoi
meets coverage

LBRF (Louse-borne Relapsing Fever)

Peripheral blood smear microscopy
meets coverage
NAAT testing to detect Borrelia recurrentis
meets coverage

Chikungunya

For individuals suspected of chikungunya:

ANY of the following

Viral culture for diagnosis
meets coverage
NAAT for chikungunya in blood sample
meets coverage
IFA assay for IgM antibodies during both acute and convalescent phases
meets coverage; paired testing implied

Because viremia is highest during the first week, molecular or culture methods are most useful early in illness; serology (IgM) becomes informative later

Colorado Tick Fever (CTF)

For individuals suspected of CTF:

ANY of the following

Virus-specific IFA-stained blood smears
meets coverage
IFA for CTF-specific antibodies
meets coverage
RT-PCR for CTF
meets coverage

RT-PCR/NAAT is more sensitive early in disease; antibody tests may not be positive until 10–14 days after symptom onset

Dengue Virus (DENV)

For detection of dengue virus:

ANY of the following

NAAT for dengue (preferred within 7 days of symptom onset)
meets coverage
IgM antibody capture ELISA (MAC-ELISA)
meets coverage
NS1 ELISA
meets coverage
Confirmatory plaque reduction neutralization test (PRNT) for DENV
meets coverage

ALL of the following

Ehrlichiosis and Anaplasmosis

For individuals suspected of ehrlichiosis and/or anaplasmosis:

ANY of the following

NAAT of whole blood
meets coverage
IFA assay for IgG antibodies
meets coverage
Microscopy for morulae detection (blood smear/buffy coat)
meets coverage

ALL of the following

IFA assay for IgM antibodies DOES NOT MEET COVERAGE CRITERIA
DOES NOT MEET COVERAGE CRITERIA

Malaria

For individuals suspected of malaria:

ANY of the following

Rapid immunochromatographic diagnostic test (RDT) (e.g., BinaxNOW)
meets coverage for diagnosis and rapid screening
Smear microscopy (thick and thin) to diagnose, speciate, stage, and quantify parasitemia (can be repeated up to three times within three days if initial microscopy is negative)
meets coverage; can be repeated up to three times within three days if initial microscopy is negative in suspected cases

ALL of the following

NAAT to confirm Plasmodium species in diagnosed malaria
meets coverage
IFA for Plasmodium antibodies DOES NOT MEET COVERAGE CRITERIA

Rickettsial Disease

For individuals suspected of rickettsial disease:

ANY of the following

Rickettsial DNA by PCR (preferred specimens: skin biopsy/eschar or whole blood depending on species)
meets coverage
Four-fold rise in IgG specific antibody by IFA assay on paired tests collected two weeks apart (limited to two units)
meets coverage; paired tests two weeks apart, limited to two units

ALL of the following

Standard blood culture DOES NOT MEET COVERAGE CRITERIA
DOES NOT MEET COVERAGE CRITERIA
IFA assay for IgM antibodies DOES NOT MEET COVERAGE CRITERIA

West Nile Virus (WNV)

For individuals suspected of WNV disease:

ANY of the following

IFA for WNV-specific IgG or IgM antibodies in serum or CSF
meets coverage
Confirmatory plaque reduction neutralization test (PRNT) for WNV
meets coverage

ANY of the following

Nucleic acid detection (NAAT/PCR) for WNV in immunocompromised individuals
meets coverage
NAAT for WNV in immunocompetent individuals DOES NOT MEET COVERAGE CRITERIA
DOES NOT MEET COVERAGE CRITERIA

Yellow Fever Virus (YFV)

For individuals suspected of YFV infection:

ANY of the following

NAAT for YFV
meets coverage
Serologic assays to detect virus-specific IgM and IgG antibodies
meets coverage
Confirmatory PRNT for YFV
meets coverage

Perform NAAT/isolation early since virus/RNA may not be detectable later; contact public health for testing logistics as YF is nationally notifiable

Zika Virus

Coverage for Zika virus testing (NAAT and IgM) is conditional on pregnancy status, exposure, symptoms, timing, and infant findings:

Covered indications for Zika NAAT

Pregnant symptomatic individuals
- Symptomatic pregnant individuals up to 12 weeks after symptom onset who lived in or traveled to areas with current/past Zika transmission or had sex with someone who lived/traveled to such areas
  NAAT meets coverage up to 12 weeks after onset
Symptomatic non-pregnant individuals with travel
- Symptomatic non-pregnant individuals living in or recently traveling to an area with an active CDC Zika Travel Health Notice when symptoms presented within the last 7 days
  NAAT meets coverage

Additional covered Zika IgM/PRNT scenarios

Asymptomatic / Screening

Testing in absence of clinical signs or exposure during general exam:

ALL of the following

Testing in asymptomatic individuals for babesiosis, chikungunya, CTF, DENV, ehrlichiosis/anaplasmosis, malaria, rickettsial disease, TBRF, WNV, YFV, or Zika during a general exam without abnormal findings DOES NOT MEET COVERAGE CRITERIA
DOES NOT MEET COVERAGE CRITERIA

Exceptions require documented clinical indication, exposure history, or public health justification

Tickborne rickettsial diseases - CDC diagnostic recommendations

Diagnostic methods recommended by the CDC and summary guidance for various tickborne rickettsial illnesses:

For Rocky Mountain spotted fever and other rickettsial diseases

IFA (IgG) assays on paired acute and convalescent sera (collect acute sample during first week and convalescent 2–4 weeks later); a ≥4-fold rise in titer is confirmatory
IFA is insensitive during first week; serial titers required
PCR of whole blood, skin/eschar or rash biopsy may be used; PCR on whole blood has low sensitivity for R. rickettsii except in severe disease
PCR helpful early for ehrlichiosis/anaplasmosis
Microscopy (morulae detection) for ehrlichiosis/anaplasmosis (buffy coat or smear) can be indicative
Microscopy morulae detection guidance

Relapsing fevers (soft tick, hard tick, louse-borne) - CDC diagnostic recommendations

CDC guidance for STRF/HTRF/LBRF diagnosis:

ANY of the following

Direct visualization of spirochetes by dark-field or stained peripheral blood smear in symptomatic untreated patients (high spirochetemia)
Most readily detected early in symptomatic patients
PCR of whole blood — more sensitive than microscopy and useful during asymptomatic periods or after treatment; preferred specimen = whole blood
Preferred specimen: whole blood
Serologic testing available from some labs; most sensitive when specimen collected ≥14 days after symptom onset
Serology timing and specimen preference

Interpret serology with exposure history due to possible cross-reactivity with Lyme disease

Babesiosis - CDC confirmatory laboratory criteria

Confirmatory laboratory evidence (any one of the following):

ANY of the following

Identification of intraerythrocytic Babesia organisms by light microscopy of Giemsa/Wright-stained blood smear
May require multiple smears; consider reference lab confirmation
Detection of Babesia spp. DNA in whole blood by NAAT/PCR or genomic sequencing on specimen taken within 60 days of illness onset
NAAT useful for donated blood screening and asymptomatic detection
Serologic evidence of a four-fold change in IgG titer to B. microti by IFA in paired serum samples (acute and convalescent)
Paired samples: one within 2 weeks of onset and second 2–10 weeks after acute specimen

Any one of the above meets CDC confirmatory laboratory criteria

Malaria - CDC diagnostic recommendations

CDC guidance on diagnostic test roles and sequencing:

ALL of the following

Microscopic examination of stained blood films (thin and thick smears) is gold standard — provides species ID, stage, and parasitemia quantification; results should be available as soon as possible (within 24 hours)
Microscopy gold standard
Adjunct or confirmatory tests
- Rapid diagnostic tests (RDTs, e.g., BinaxNOW) useful when microscopy not readily available but have limitations (lower sensitivity, species discrimination, persistence post-treatment)
  BinaxNOW FDA-cleared for labs; low sensitivity in non-endemic areas and can misclassify P. falciparum
- PCR/NAAT is more sensitive than microscopy and useful to confirm species and detect mixed infections, but not usually timely for acute management
  Encouraged for confirmation after initial diagnosis

Dengue - CDC diagnostic recommendations

Testing depends on phase of illness:

ANY of the following

Acute phase (0–7 days): NAAT (RT-PCR) plus IgM OR NS1 antigen plus IgM on serum preferred; negative NAAT/NS1 does not rule out infection
Serum preferred; NAAT/NS1 timing
Convalescent phase (>7 days): IgM ELISA primary test; NAAT/NS1 less sensitive after day 7
IgG not recommended for acute dengue diagnosis
PRNT may be inconclusive in previously flavivirus-exposed patients; use PRNT to distinguish dengue when IgM positive in co-circulating flavivirus areas
PRNT use when flavivirus co-circulation exists

Interpret results in clinical and epidemiologic context; collect appropriate specimens and timing based on CDC guidance

Zika - CDC diagnostic recommendations

Testing recommendations vary by pregnancy status, symptoms, travel exposure, and specimen type:

ANY of the following

For pregnant symptomatic with exposure: collect specimens ASAP up to 12 weeks after symptoms; perform dengue and Zika NAAT and IgM on serum and Zika NAAT on urine; repeat NAAT or perform PRNT as specified
Pregnancy-specific algorithms and specimen types (urine, amniotic fluid) noted
If amniocentesis performed, NAAT on amniotic fluid may be done and interpreted with limitations; infant testing and follow-up per CDC guidance including NAAT and IgM on infant serum/urine and CSF when obtained
Specimen types including urine and amniotic fluid notes; infant testing and follow-up guidance

Testing and interpretation in pregnancy require careful application of CDC algorithm and consideration of cross-reactivity; routine testing of asymptomatic pregnant women is generally not recommended without exposure

Chikungunya - CDC diagnostic recommendations

Laboratory diagnosis overview:

ANY of the following

Perform viral culture or NAAT on serum during first week of illness when viremia is high
Viral culture/NAAT early
Serologic IgM testing can cross-react with related alphaviruses; interpret with epidemiologic context
Cross-reactivity and timing considerations

Use molecular assays early; be aware of serologic cross-reactivity and persistence when interpreting results

West Nile virus (WNV) - CDC diagnostic recommendations

Testing strategy and limitations:

ANY of the following

Front-line screening is WNV IgM assay (serum/CSF); positive screening should be followed by PRNT to confirm and differentiate from other flaviviruses
IgM screening followed by PRNT
RT-PCR or viral isolation may be helpful early or in immunocompromised patients, but viremia is usually absent by neuroinvasive illness
PCR limitations

Negative PCR does not rule out infection; use serology and confirmatory PRNT when indicated

Yellow fever virus (YFV) - CDC diagnostic recommendations

Testing recommendations:

ANY of the following

Perform viral isolation or NAAT early in suspected YFV cases; virus/RNA often not detectable later
NAAT/isolation early
Use PRNT to confirm due to cross-reactivity of flavivirus serology; contact public health for testing logistics as YF is nationally notifiable
PRNT and public health contact

Coordinate testing with state/local health departments or CDC; specimen handling and availability may require reference/public health labs

Testing recommendations and diagnostic logic (excerpted guidance)

Testing and interpretation depend on organism, timing (acute vs convalescent), specimen type and clinical context. Key decision rules included in source guidelines:

ANY of the following

Relapsing fever (Borrelia spp.): primary test = Wright's, Giemsa, or Diff-Quik stains of peripheral thin and/or thick blood smears; optimum specimens = blood or bone marrow
Lyme disease (Borrelia burgdorferi): testing not routinely recommended for early localized erythema migrans; two-tier testing for disseminated/late disease (initial EIA followed by supplemental immunoblot only if EIA positive/equivocal); specimen = serum
Borrelia miyamotoi: primary acute test = NAAT; serology (EIA to GlpQ) available; optimum specimen = blood
Babesia microti: primary tests = Giemsa/Wright-stained thin and thick blood smears (Giemsa preferred) and NAAT for acute infection; optimum specimen = whole blood (EDTA preferred)

Revision summary impacting coverage criteria (CC1-CC14)

Summarizes changes made to coverage criteria referenced elsewhere in the policy (applies to CC1, CC2, CC4, CC5, CC11, CC13, CC14):

ALL of the following

CC1 now includes IgG or IgM indirect immunofluorescence antibody (IFA) assay for Babesia as an acceptable testing method; initial and confirmatory testing should occur a minimum of two weeks apart
Initial testing and confirmatory testing should occur a minimum of two weeks apart.
CC2, CC5, and CC11: wording 'PCR testing' replaced with 'NAAT testing' to standardize terminology and operationalize orders/claims
Operational implication: claims/documentation referencing PCR should use NAAT terminology.
CC4: 'serum sample' terminology replaced with 'blood sample' to standardize specimen language
Specimen terminology standardized to 'blood sample'.

Applicable Procedure Codes and CPT Updates

Applicable CPT/HCPCS Procedure Codesmixed

No codes listed

Clinical/diagnostic focus (no explicit billing codes in this part)mixed

No codes listed

Applicable CPT/HCPCS and proprietary codes (listed)mixed

86280	Hemagglutination inhibition test (HAI)
86382	Neutralization test, viral
86619	Antibody; Borrelia (relapsing fever)
86666	Antibody; Ehrlichia
86750	Antibody; Plasmodium (malaria)
86753	Antibody; protozoa, not elsewhere specified
86757	Antibody; Rickettsia
86788	Antibody; West Nile virus, IgM
86789	Antibody; West Nile virus
86790	Antibody; virus, not elsewhere specified

1–10 of 25

1/3

CPT codes added (off-cycle coding modification)CPTCovered

87164	Infectious agent detection by immunofluorescent assay technique, direct or indirect, each reagent; organism not otherwise specified (added to policy effective 2025-01-01)
87166	Infectious agent detection by immunofluorescent assay technique, direct or indirect, each reagent; organism not otherwise specified, additional code (added to policy effective 2025-01-01)

What Providers Must Do (Documentation, Billing, Test Selection)

Documentation Required

Paired serology documentation

When ordering serologic testing that requires acute and convalescent specimens (for example, babesiosis and rickettsial disease), document the dates of specimen collection and that samples were collected at least two weeks apart; note that some serologic confirmations are limited to two units/tests. Include the specimen type (e.g., serum) in the record.

Document dates for acute and convalescent specimens (minimum two weeks apart).
Indicate specimen type (e.g., serum) and test method (e.g., IFA).
Note limits where applicable (e.g., rickettsial paired IFA limited to two units).

Documentation Required

Travel/exposure and pregnancy status for Zika

To support coverage for Zika testing, document travel history, exposure risk, pregnancy status, and the date of symptom onset relative to testing; these data determine whether NAAT, IgM, and PRNT are covered per the policy.

Travel or residence in areas with current/past Zika transmission or CDC Zika Travel Health Notice.

Numeric and Time-Based Requirements

Key thresholds and timing

Paired serology timingAcute and convalescent/confirmatory tests should be a minimum of two weeks apart (where specified)

Malaria microscopy repeatSmear microscopy can be repeated up to three times within three days if initial microscopy is negative in suspected cases

Dengue hemoconcentration (DHF criterion)≥20 percent rise in hematocrit above baseline indicates hemoconcentration

Tickborne rickettsial diseases - serology confirmation≥ fourfold rise in IgG antibody titer between acute and convalescent sera

Babesiosis - serology confirmationFour-fold change in IgG titer (e.g., 1:64 to 1:256) in paired sera

Babesiosis - NAAT timingPositive NAAT from whole blood within 60 days of illness onset

Clinical and Diagnostic Background

This policy addresses laboratory evaluation of vector-borne pathogens including arthropod‑borne viruses (arboviruses such as Zika, West Nile virus, chikungunya, dengue, yellow fever, and Colorado tick fever), protozoan parasites (notably Plasmodium causing malaria and Babesia causing babesiosis), and bacterial agents (including Rickettsia, Ehrlichia, Anaplasma, and non‑Lyme Borrelia species). These infections have distinct clinical presentations (e.g., febrile syndromes, neuroinvasive disease with WNV, congenital concerns with Zika, hemolytic anemia with babesiosis, relapsing fevers with Borrelia spp., and rash/eschar with many rickettsial infections) that guide test selection and interpretation.

A range of diagnostic modalities are discussed and used in practice: microscopy and stained blood smears (Giemsa/Wright; thick and thin smears) for malaria, babesiosis, and direct visualization of spirochetes; dark‑field microscopy for motile spirochetes in relapsing fever; culture/isolation for select agents (often limited to specialized labs and of limited routine utility); nucleic acid amplification testing (NAAT/PCR/RT‑PCR) for early detection and species confirmation (e.g., NAAT for Babesia, Plasmodium speciation, Rickettsia and Ehrlichia/Anaplasma where appropriate, and molecular diagnosis of arboviruses early in illness); and serology including indirect immunofluorescence antibody (IFA) and ELISA approaches for IgM/IgG detection. For flaviviruses and other cross‑reactive agents, plaque‑reduction neutralization testing (PRNT) is recommended as a confirmatory method to distinguish closely related viruses when serology is positive.

Test selection must account for timing and specimen type: molecular assays and viral isolation are most useful during the period of viremia (typically the first week for many arboviruses), NAAT on whole blood/EDTA is preferred for some agents (e.g., Babesia, Borrelia miyamotoi, Anaplasma/Ehrlichia), NS1 antigen or NAAT are preferred early for dengue (RNA detectable ≤7 days; NS1 detectable day 1–10), and serology (IgM/IgG IFA or ELISA) often requires paired acute and convalescent samples to demonstrate a fourfold rise in titer for confirmatory diagnosis of rickettsial diseases, babesiosis, and others. Rapid diagnostic tests (RDTs) may be useful adjuncts (for example malaria RDTs) but have limitations in sensitivity, species discrimination, and persistence after treatment.

Defined Terms and Abbreviations

Definitions

NAATNucleic acid amplification testing (e.g., PCR, RT-PCR, qPCR)

IFAIndirect immunofluorescence antibody assay; serologic test for IgG/IgM

PRNTPlaque reduction neutralization test; confirmatory serologic test for flaviviruses

MAC-ELISAIgM antibody capture enzyme-linked immunosorbent assay

RDTRapid diagnostic test (immunochromatographic) for antigen/antibody detection

EIAEnzyme immunoassay (antibody screening test)

Policy Changes and Material Updates

2025-09-04Policy revision (clinical & editorial)Latest

Reviewed and updated background, guidelines, and references; added IgG or IgM IFA assay for Babesia with requirement that initial and confirmatory tests occur a minimum of two weeks apart; replaced specific references to 'PCR testing' with the broader term 'NAAT testing' in CC2, CC5, and CC11; replaced 'serum sample' with 'blood sample' in CC4; edited CC13 and CC14 for clarity and consistency.

2024-12-04Coding modification (off-cycle)

Off-cycle coding modification added CPT codes 87164 and 87166 (effective date 2025-01-01).

Policy Summary

Payermedical mutual - ohio

PolicyTesting for Vector-Borne Infections

Policy CodePolicy AHS - G2158 - Testing for Vector-Borne Infections, 1 = Initial Presentation

Change TypeCoverage language and coding updates

Effective DateFeb 1, 2026

Next Review Date

SourceLink

On This Page

Denial Risk

Avoid non-covered tests

Tests explicitly listed as not meeting coverage criteria may be denied if billed: examples include culture for Borrelia, IgG ELISA or hemagglutination for dengue, IFA IgM for rickettsial/ehrlichial/anaplasmal diseases, NAAT for WNV in immunocompetent individuals, and routine testing in asymptomatic individuals without abnormal findings.

Culture testing for Borrelia DOES NOT MEET COVERAGE CRITERIA (likely denied).
IgG ELISA or hemagglutination testing for dengue DOES NOT MEET COVERAGE CRITERIA.
IFA IgM for rickettsial/ehrlichial/anaplasmal diseases DOES NOT MEET COVERAGE CRITERIA.
NAAT for WNV in immunocompetent individuals DOES NOT MEET COVERAGE CRITERIA.
Asymptomatic screening without abnormal findings DOES NOT MEET COVERAGE CRITERIA.

Documentation Required

Submit paired sera for serologic confirmation when required

When serologic confirmation requires paired acute and convalescent sera (e.g., tickborne rickettsial diseases, babesiosis), collect and submit acute specimens during the first week when possible and convalescent specimens 2–4 weeks (or 2–10 weeks for babesiosis) later to demonstrate a ≥4-fold rise in titer per CDC guidance.

For rickettsial diseases: acute specimen in first week and convalescent 2–4 weeks later to show ≥4-fold rise.
For babesiosis: acute within 2 weeks of onset and second 2–10 weeks after acute specimen to document four-fold change.
Document specimen collection dates and clinical onset date in the record.

Documentation Required

Order appropriate specimen types and tests based on disease stage

Order tests and specimen types based on illness stage and CDC/IDSA guidance: use NAAT/RT-PCR or NS1 antigen early for dengue/Zika, microscopy for malaria and babesiosis during acute illness, and NAAT for relapsing fever when indicated.

Dengue/Zika acute phase (0–7 days): NAAT or NS1 antigen ± IgM as appropriate.
Malaria/babesiosis acute: Giemsa/Wright-stained blood smears (microscopy) ± NAAT for confirmation.
Relapsing fever: microscopy (dark-field or stained smear) early or NAAT for detection.

Prior Authorization

Refer to public health labs for specialized testing

For specialized assays (culture, IHC, PRNT, reference NAATs), coordinate specimen referral with state/public health or reference laboratories because these tests may not be available in routine hospital labs.

Contact state/local health departments or CDC for testing logistics for certain agents (e.g., YFV, CTF).
Arrange referral to reference or public health labs for PRNT and specialized PCRs and document the rationale and referral details.

Denial Risk

Interpreting single serologic results

Claims relying on a single serologic result or improperly timed serology can be questioned or denied; when serology is used for confirmation, ensure paired titers or supporting NAAT/PCR are documented per CDC guidance.

Single or inappropriately timed serologic tests can lead to misinterpretation and may not meet coverage criteria.
Document paired serology showing seroconversion or fourfold rise when required, or supportive NAAT/PCR results.

Documentation Required

Specimen selection and timing

Select specimen types and record timing per organism-specific guidance (e.g., whole blood/EDTA for Babesia NAAT, urine for Zika NAAT adjunct, CSF for neuroinvasive arbovirus testing) and document symptom onset or exposure dates to justify test choice.

Babesia: whole blood (EDTA preferred) for NAAT/PCR; document illness onset.
Zika: perform NAAT on serum and urine where indicated; document exposure and symptom onset.
Neuroinvasive arboviruses (WNV): test CSF for IgM/PRNT when clinically indicated and document timing.

Prior Authorization

Reference lab / specialized testing pathway

When confirmatory or reference testing is needed (e.g., PRNT, specialized NAATs), arrange testing at a public health or reference laboratory, document the clinical rationale and referral, and include prior test results that prompted referral.

Document why local testing was insufficient and reference clinical findings prompting referral.
Include prior laboratory results and specimen collection dates when submitting to reference labs.

Documentation Required

Use paired sera when possible

When diagnosis depends on seroconversion or a titer rise (for example, RMSF, WNV, many arboviruses), obtain and document acute and convalescent specimens 2–4 weeks apart to demonstrate a fourfold rise in IgG titer per CDC/ASM guidance.

Collect acute specimen early (first week when possible) and convalescent specimen 2–4 weeks later.
Document dates and titer results to demonstrate ≥4-fold rise for confirmatory diagnosis.

Documentation Required

Babesia IFA testing timing requirement

For Babesia IFA testing, perform initial IgG or IgM IFA and a confirmatory IFA at least two weeks after the initial test; document both test dates, specimen types, and include CPT codes 87164 and 87166 where applicable.

Initial and confirmatory IFA testing must occur a minimum of two weeks apart.
Document specimen type and collection dates for both tests.
Use CPT codes 87164 and 87166 as listed in the policy when applicable.

Documentation Required

Use NAAT terminology in orders and claims

Use the term 'NAAT' in clinical documentation, test orders, and claims for items referenced in CC2, CC5, and CC11 (replacing prior 'PCR' wording) to align with the policy revisions.

Replace 'PCR' with 'NAAT' in orders, progress notes, and billing/claims for the affected coverage criteria.
Ensure laboratory requests and claim submissions use NAAT terminology to match policy language.

Clinical context and public health guidance shape testing pathways: examples include using NAAT and IgM testing for symptomatic pregnant persons with possible Zika exposure (with urine and serum NAAT as indicated and PRNT confirmation when needed), preferential use of NAAT/NS1 plus IgM in acute dengue, microscopy as the frontline and immediate test for malaria and babesiosis (with PCR/NAAT as confirmatory or for low parasitemia), and reliance on serologic IFA with paired sera for spotted fever group rickettsioses. Culture and specialized assays (IHC, PRNT, specialized PCRs) are often available only at public health or reference laboratories and should be coordinated accordingly.

Testing for Vector-Borne Infections

Coverage Criteria by Disease / Test

Applicable Procedure Codes and CPT Updates

What Providers Must Do (Documentation, Billing, Test Selection)

Numeric and Time-Based Requirements

Clinical and Diagnostic Background

Defined Terms and Abbreviations

Other Policies to Read

Policy Changes and Material Updates