Statement of Principles concerning scrub typhus (Reasonable Hypothesis) (No. 77 of 2018)

The Statement rests on a small set of interlocking legal and medical concepts that determine its application.

Scrub typhus: The instrument gives scrub typhus a clinical, organism‑based definition: an illness caused by Orientia tsutsugamushi (section 7(2)). The Statement notes the usual vector and typical symptoms in explanatory notes to the definition, and it records that while scrub typhus carries ICD‑10‑AM code A75.3, the operative meaning for the instrument is the clinical definition in section 7(2) rather than the code (sections 7(2) and 7(3)-(4)).

Death from scrub typhus: The instrument treats death as included where a terminal event or condition was contributed to by the person’s scrub typhus (section 7(5)). The Schedule defines "terminal event" to include listed proximate or ultimate causes such as pneumonia, respiratory failure, cardiac arrest, circulatory failure and cessation of brain function (Schedule 1).

Relevant service: The instrument applies only where the claim is one to which the specified provisions of the VEA or MRCA apply (section 5). The Schedule defines "relevant service" by reference to particular categories under the VEA and MRCA, for example operational, peacekeeping, hazardous, warlike and non‑warlike service (Schedule 1).

Factors for a reasonable hypothesis: The core legal mechanism is the list in section 9. A claimant must establish at least one of the listed factors before a reasonable hypothesis of a connection to service can be said to be raised. The factors are: (1) being exposed to Orientia tsutsugamushi within the 28 days before clinical onset; and (2) inability to obtain appropriate clinical management for scrub typhus (section 9). The Schedule expands "being exposed" to include four modes: infected trombiculid mite bite, being in an area endemic for scrub typhus, percutaneous exposure to contaminated blood, or receiving contaminated blood products or a contaminated stem cell transplant (Schedule 1).

Relationship to service: The instrument requires that any factor relied on be related to the person’s relevant service (section 10(1)). Section 10(2) narrows the second factor (inability to obtain appropriate clinical management) so that it applies only to material contribution to, or aggravation of, scrub typhus where the disease was suffered or contracted before or during, but did not arise out of, the person’s relevant service.

Cross‑reference to other Statements of Principles: If a factor refers to an injury or disease already covered by another Statement of Principles, that other Statement’s factors apply in the manner it provides (section 11).

ICD‑10‑AM and classification: The instrument recognises the ICD‑10‑AM code but displaces it for the instrument’s operative meaning (section 7(3)-(4)). The Schedule cites the text and the issuing body for the ICD edition referenced.

These concepts combine to make the Statement an applied causation test: determine whether one of the enumerated exposure or treatment‑access circumstances exists, ensure it is related to the listed forms of relevant service, and then apply any cross‑referenced Statements of Principles as necessary.

Primary affected persons are claimants who are veterans or members covered under the VEA and MRCA and who make claims that involve scrub typhus or death from scrub typhus. The instrument expressly applies to claims to which section 120A of the VEA or section 338 of the MRCA applies (section 5). The Schedule’s definition of "relevant service" identifies the categories of service that can anchor the relationship requirement: operational service, peacekeeping service, hazardous service and British nuclear test defence service under the VEA, and warlike and non‑warlike service under the MRCA (Schedule 1).

Decisionmakers are affected because the Statement sets the threshold for raising a "reasonable hypothesis" in claim adjudication. The Repatriation Medical Authority made the Statement (section 3 and the seal), and its view about the medical‑scientific evidence is recorded in section 8. The instrument therefore guides the Repatriation Commission or other decision‑makers who apply VEA/MRCA criteria in particular cases by prescribing the factors that must be present for causation to be considered plausible.

Medical practitioners and experts are affected in their evidentiary role. The Statement dictates the kinds of factual circumstances that will be significant in claims decisions: evidence about exposure within 28 days of clinical onset, the presence of residence or deployment in an area endemic for scrub typhus (Schedule 1), modes of exposure such as unexplained percutaneous blood exposure or receipt of contaminated blood products, and clinical management gaps (section 9 and Schedule 1). That shapes the content of medical reports and opinions that decision‑makers will rely on.

Organisations or providers of blood, blood products and stem cell transplants are indirectly implicated because receiving contaminated products is listed as a form of exposure (Schedule 1). The instrument does not regulate those organisations; it treats such receipt as a factual circumstance that can raise a reasonable hypothesis.

Administrative actors in veterans’ services, including claims officers and legal representatives, are affected because the Statement changes the evidentiary checklist for scrub typhus claims by replacing the earlier Statement of Principles No. 72 of 2009 (section 4).

The instrument does not itself create monetary entitlements, criminal offences, or administrative penalties. It operates as the medical‑causation framework used in adjudicating claims under the specified provisions of the VEA and MRCA.

The Statement is not drafted as a statute that imposes obligations on the public in the manner of criminal law or licensing schemes. Instead, its operative function is to set the factors that must exist before a reasonable hypothesis can be raised connecting scrub typhus (or death from it) with relevant service (section 9). The Statement therefore establishes evidentiary duties in the claims context rather than regulatory duties in the ordinary sense.

For claimants, the practical duty is to establish at least one of the factors in section 9 and to show that the factor is related to their relevant service as defined in the Schedule (sections 9 and 10; Schedule 1). The Statement does not specify procedural steps for meeting that duty, but it sets the substantive threshold: evidence of exposure to Orientia tsutsugamushi within 28 days before clinical onset, or evidence of inability to obtain appropriate clinical management, with the relationship to relevant service demonstrated (section 9; section 10(1)). Where the inability to obtain appropriate clinical management is relied on, section 10(2) narrows its application to material contribution or aggravation where the disease was suffered or contracted before or during, but did not arise out of, the person’s relevant service.

For decision‑makers, the Statement sets a prescribed formulation for causation assessment. The Repatriation Medical Authority has stated its view that there is sound medical‑scientific evidence that scrub typhus and death from it can be related to relevant service (section 8). The Statement supplies the factors which, if established and connected to relevant service, permit a reasonable hypothesis to be treated as raised. The instrument does not itself direct how decision‑makers must resolve disputed facts, what standards of proof to apply beyond the "reasonable hypothesis" concept, or how to weigh competing medical opinion. Those procedural and adjudicative duties may be set elsewhere in the VEA or MRCA; the Statement supplies the substantive medico‑legal framework to be applied where relevant.

Medical practitioners and experts have a role, not a statutory duty under this instrument, to provide evidence that addresses the enumerated factors and definitions. The Schedule’s definitions provide precision for typical evidentiary points. For example, "being exposed" is defined expansively to include presence in an area endemic for scrub typhus, percutaneous exposure to contaminated blood, or receipt of contaminated blood products or a stem cell transplant (Schedule 1). The Statement therefore shapes the content of medical evidence that claimants or decision‑makers will treat as material.

The instrument does not create express rights such as entitlements to compensation or review rights. It does not contain its own enforcement or penalty provisions. Its legal effect is to inform the causation assessment in claims under the cited statutory provisions.

The Statement contains no penalty provisions and does not establish a separate enforcement regime. It is a medical‑causation instrument made under subsection 196B(2) of the VEA (section 3) and is intended to be used in the adjudication of claims under the VEA and the MRCA (section 5). The text supplies substantive criteria for raising a reasonable hypothesis of connection between scrub typhus and relevant service (section 9) but does not, within its terms, prescribe sanctions, fines, criminal penalties or administrative enforcement measures.

Because the Statement is an evidentiary tool in the VEA/MRCA claims framework, compliance outcomes and any remedial or adverse consequences flow from how the VEA or MRCA decision‑making and review machinery apply the Statement. The instrument itself does not say how decisions that apply the Statement are to be enforced, appealed or reviewed. Any enforcement, judicial review, merits review, or administrative consequences therefore belong to the statutory regimes under which claims are decided, not to this Statement as drafted. The Statement does not purport to confer compensation, nor does it purport to direct payment; it defines when a reasonable hypothesis may be raised in the context of those other statutes.

The absence of penalty or enforcement language within the Statement means that the instrument functions as binding medical guidance to the extent the VEA/MRCA regime requires decision‑makers to have regard to Statements of Principles under subsection 196B(2) of the VEA. The instrument itself does not articulate the decision‑maker’s sanctioning powers or the procedural consequences of successful or unsuccessful claims. Practitioners should therefore consult the VEA and MRCA for the procedural and enforcement frameworks that will determine the final outcomes once the Statement has been applied to the facts of a claim.

The instrument is expressly made under subsection 196B(2) of the Veterans' Entitlements Act 1986 (section 3). It applies to claims that fall under section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 (section 5). Those cross‑references locate the Statement within the statutory architecture for veterans’ entitlements and military compensation. The Statement itself does not reproduce the adjudicative, review or payment provisions of those Acts. It supplies the medical‑causation content to be used under them.

The Statement recognises and interacts with external medical classification systems. It notes that scrub typhus attracts ICD‑10‑AM code A75.3 but states that for the purposes of this instrument the meaning of scrub typhus is the clinical definition in section 7(2), not the code per se (sections 7(3)-(4)). The instrument cites the relevant edition and issuing body of the ICD‑10‑AM, indicating an intention to align with recognised diagnostic classification while preserving its own operative definition.

Section 11 provides for interaction with other Statements of Principles. If a factor in section 9 refers to an injury or disease that is itself covered by another Statement of Principles, then the factors in that other Statement apply in accordance with its terms. This mechanism creates a networked interaction among Statements of Principles so that cross‑referenced medical conditions are governed by the provisions of their own Statements as they stand from time to time (section 11).

The Schedule defines "relevant service" by reference to particular categories under the VEA and MRCA (Schedule 1). That definition binds the instrument’s relationship requirement to the statutory categories that exist in those Acts, thereby tying the causation test to the statutory conception of service without altering those Acts.

The Statement repeals an earlier Statement of Principles (No. 72 of 2009) (section 4). That repeal is an internal legal housekeeping measure that replaces one medical‑causation schema with another for scrub typhus within the VEA/MRCA framework.

Outside the immediate VEA/MRCA framework, the Statement treats receipt of contaminated blood, blood products or stem cell transplants as modes of exposure (Schedule 1). The instrument does not regulate blood services, infection control, or public health law, but it recognises those clinical pathways as relevant factual circumstances in claims. Any interaction with public health or civil liability regimes is not addressed in the instrument.

The instrument itself records a brief amendment history in the form of a repeal and a new commencement. It was dated 24 August 2018 and commenced on 24 September 2018 (front matter and section 2). It expressly repealed the previous Statement of Principles concerning scrub typhus No. 72 of 2009 (section 4). The instrument therefore replaces the 2009 Statement as the operative Statement of Principles for scrub typhus under subsection 196B(2) of the VEA.

There are no other amendments recorded within the text. The instrument does not include transitional provisions or grandfathering clauses about claims made prior to commencement. The repealing clause is unqualified: the earlier Statement is repealed (section 4). The instrument applies to claims to which section 120A of the VEA or section 338 of the MRCA applies (section 5), but it does not specify retroactivity or applicability to pending decisions. Any transitional handling would therefore be governed by the general approach of the VEA/MRCA decision‑making bodies or administrative practice, none of which is specified in this instrument.

The Schedule and the body of the Statement are silent on later amendment mechanisms; however, the making provision (section 3) identifies subsection 196B(2) of the VEA as the statutory source of authority. Future changes to the Statement would therefore follow the process established by that statutory authority. The instrument does not list subordinate instruments amending it, nor does it set out a review timetable.

Practitioners seeking to track changes should note the explicit repeal of the 2009 Statement and the dates on the instrument to establish which Statement governs a particular claim. The instrument’s text is the definitive current Statement from its commencement date; any prior versions ceased to be operative when repealed.

The instrument does not record any litigation history. Its text contains no references to judicial decisions, appeals or precedents concerning its interpretation. It records only the Repatriation Medical Authority’s view that there is sound medical‑scientific evidence indicating a relationship between scrub typhus and relevant service (section 8), but it does not cite cases or adversarial determinations.

Because the Statement functions as a medico‑legal evidentiary instrument within the VEA/MRCA regime, disputes about its application may arise in the claims decision process or be the subject of administrative or judicial review. The instrument itself, however, contains no account of litigation, no reported decisions, and no annotations concerning contested points.

Practitioners who require jurisprudential treatment of how Statements of Principles are applied in adjudication will need to consult decisions under the VEA and MRCA or administrative law outcomes that interpret such Statements. Those materials are not contained in this instrument and hence are not described here. The absence of litigation references in the instrument does not mean none exists in administrative or judicial fora; it means the instrument does not provide that material.

Because the instrument cross‑references other Statements of Principles (section 11), litigation concerning those other Statements could affect how the factor network operates in specific cases. Any case law construing the meaning of terms such as "reasonable hypothesis", "material contribution", "aggravation" or the application of specific exposure definitions would be relevant to claims applying this Statement, but such cases are outside the scope of this instrument’s text.

Several points in the instrument are likely to catch claimants, clinicians and decision‑makers if they are not read closely.

"Being exposed" is broad. The Schedule defines "being exposed to Orientia tsutsugamushi" to include simply being in an area endemic for scrub typhus (Schedule 1). That means presence in listed geographic areas counts as an exposure mode without the need to prove a specific known bite. The Schedule defines the endemic areas expressly to include Africa, the Middle East, South America, Islands of the Pacific and the so‑called "tsutsugamushi triangle" extending to northern Australia (Schedule 1). Practitioners should note that "being in an area endemic" is a listed form of exposure and that the presence alone is a factor under section 9(1).

Short temporal window. The first factor in section 9 requires exposure within 28 days before the clinical onset of scrub typhus. Where a claimant cannot link exposure to that 28‑day window, the first factor will not be satisfied. That temporal limitation is strict as expressed and will be decisive in many cases where travel or exposure history is remote from symptom onset.

Scope of inability to obtain treatment. The second factor in section 9 is "inability to obtain appropriate clinical management for scrub typhus". Section 10(2) carves this back. That factor applies only to material contribution to, or aggravation of, scrub typhus where the disease was suffered or contracted before or during the person’s relevant service but did not arise out of the person’s relevant service. In plain terms, the inability to obtain appropriate clinical care functions as an aggravation or material contribution mechanism, not as a standalone cause for cases where scrub typhus arises out of the service itself. Users must therefore be precise about the chronology: was the disease contracted before/during the service and then materially worsened by lack of care, or did it arise out of the service in the first place? Section 10(2) addresses only the former.

Death and terminal event linkage. Death from scrub typhus is treated as death from a terminal event or condition that was contributed to by scrub typhus (section 7(5)). The Schedule lists terminal events such as pneumonia and respiratory failure (Schedule 1). A claimant must establish a contribution link between scrub typhus and the terminal event to bring death within the Statement. The instrument does not define the standard for "contributed to", so claimants and decision‑makers will need to translate that concept into the evidential standards used in adjudication.

ICD code not determinative. Although the instrument notes the ICD‑10‑AM code A75.3, it emphasises that the operative meaning is the clinical definition in section 7(2) (section 7(3)). Practitioners should not rely solely on diagnostic coding; the clinical definition and the Statement’s factors govern.

Cross‑reference traps. Section 11 makes clear that when a factor refers to an injury or disease covered by another Statement of Principles, the other Statement’s factors apply. That can complicate cases involving comorbidity or overlapping conditions because the relevant factors from multiple Statements may need to be satisfied in accordance with their own terms.

No procedural detail. The Statement supplies substantive factors but contains no procedural guidance on evidence standards, admissibility, or how decision‑makers must weigh competing medical opinions. Those procedural matters are left to the VEA/MRCA frameworks and administrative practice, which claimants and advisers must consult separately.

Repeal without transitional text. The instrument repealed the 2009 Statement but includes no transitional provisions in the text. It therefore replaces the prior framework as of the commencement date without detail about pending claims, which may create administrative ambiguity that advisers should anticipate.

Compliance here means preparing or deciding claims in a manner that addresses the instrument’s substantive requirements. The Statement sets a concise evidentiary checklist; meeting it requires aligning factual and medical evidence to the sections and Schedule definitions.

1. Identify the applicable claim regime. Confirm the claim is one to which section 120A of the VEA or section 338 of the MRCA applies, because the Statement only applies in that statutory context (section 5). The Statement does not itself create entitlement; it informs causation assessment under those Acts.

2. Establish the disease definition. Ensure the clinical diagnosis corresponds to the instrument’s operative definition: scrub typhus is illness caused by Orientia tsutsugamushi (section 7(2)). Do not rely solely on ICD coding; section 7(3)-(4) makes the clinical definition the operative meaning.

3. Address the minimum factors. The claimant must demonstrate at least one factor in section 9:

   • For section 9(1): assemble evidence that the claimant was exposed to Orientia tsutsugamushi within 28 days before clinical onset. The Schedule defines exposure broadly (Schedule 1). Evidence may need to show timing of symptom onset and navigable link to an exposure event within 28 days.
   • For section 9(2): where reliance is placed on inability to obtain appropriate clinical management, be prepared to show that this inability materially contributed to or aggravated scrub typhus and that the disease was suffered or contracted before or during, but did not arise out of, the relevant service (section 10(2)).

4. Demonstrate relation to relevant service. Any factor relied upon must be related to the person’s relevant service as defined in the Schedule (section 10(1) and Schedule 1). Tie the exposure or management failure to the service period or circumstances included in the Schedule’s definition (operational, peacekeeping, hazardous, nuclear test defence, warlike, non‑warlike).

5. If factors refer to other Statements, apply those Statements. Where a factor in section 9 refers to an injury or disease covered by another Statement, retrieve and apply the factors of that Statement in accordance with its terms (section 11).

6. Address death cases carefully. For a death claim, establish that the terminal event listed in the Schedule was contributed to by scrub typhus (section 7(5) and Schedule 1). The Statement does not define the quantification of "contributed to", so medical evidence should articulate causal contribution between scrub typhus and the terminal event.

7. Prepare medical evidence against the defined meanings. Use the Schedule’s definitions to frame questions for treating clinicians or experts. For example, where "being in an area endemic" is relied on, identify the relevant named regions in the Schedule and dates of presence there; for percutaneous or transfusion exposures, document the factual pathway and timing.

8. Time sensitivity. Pay attention to the 28‑day window in section 9(1) and to the chronology required by section 10(2). Records of symptom onset, travel/deployment dates and any medical encounters are therefore central.

9. Anticipate cross‑condition complexity. If the claimed exposure involves other diseases or injuries that are the subject of their own Statements of Principles, gather the corresponding Statements early because their factors will govern the application (section 11).

10. Administrative practice and proof standards. The Statement provides the substantive factors only. Practitioners should align their evidentiary presentation with the decision‑making procedures, standards and review rights available under the VEA and MRCA. The Statement does not provide those procedural details.

Checklist (referencing instrument):

• Confirm claim type and statutory basis (section 5).
• Confirm clinical diagnosis matches section 7(2).
• Demonstrate exposure within 28 days before onset (section 9(1); Schedule 1 for exposure modes and endemic areas).
• Or demonstrate inability to obtain appropriate clinical management and that this materially contributed or aggravated the condition in the specified circumstances (section 9(2); section 10(2)).
• Show relationship between the factor and the person’s relevant service (section 10(1); Schedule 1 definition of relevant service).
• If other Statements are implicated, apply them as required (section 11).

Following this approach aligns evidence to the Statement’s language and reduces the risk that a claim fails because the wrong factor or temporal relation was relied upon.