Statement of Principles concerning Ross River virus infection (Reasonable Hypothesis) (No. 94 of 2019)

“Reasonable hypothesis” is the standard of proof for claims under sections 120A of the VEA and 338 of the MRCA where a SoP exists. It is lower than the civil standard of balance of probabilities; the hypothesis need only be possible, not probable, and must be grounded in the factor set out in the SoP. The instrument defines “Ross River virus infection” as a symptomatic clinical illness caused by infection with Ross River virus. Asymptomatic infection is expressly excluded. The ICD-10-AM code B33.1 is noted but is only a reference point; the definition in subsection 7(2) governs. Two pathways to establish the factor of exposure are provided. First, “being exposed to the Ross River virus” means being bitten by a mosquito infected with the virus, or receiving a blood transfusion, blood product, stem cell transplant, or organ transplant from an infected person. Second, the factor of being in a “country or geographic area that has experienced Ross River virus transmission” between three and 21 days before clinical onset is satisfied if the person was in any of the eleven listed jurisdictions: American Samoa, Australia, Cook Islands, East Timor, Fiji, French Polynesia, Indonesia east of the Weber line, New Caledonia, Papua New Guinea, Solomon Islands, or Wallis and Futuna. The Weber line is defined in a note as the hypothetical boundary along the Australo-Papuan Shelf, which imposes a geographical precision that may require expert evidence for claims involving Indonesia. The third factor , “inability to obtain appropriate clinical management” , applies only to material contribution to or aggravation of Ross River virus infection where the infection was suffered or contracted before or during (but did not arise out of) the person’s relevant service (section 10(2)). This is a significant limitation: it cannot be used where the infection first occurred after the relevant service period. The dictionary defines “relevant service” as operational, peacekeeping, hazardous, or British nuclear test defence service under the VEA, or warlike or non-warlike service under the MRCA. “Terminal event” is defined as including pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function, and for death claims the infection must have contributed to that terminal event. The SoP also contains a cascading provision in section 11: if any factor refers to an injury or disease that itself has a SoP, then the factors in that other SoP apply. This creates a complex interaction where a Ross River virus claim may require satisfaction of multiple SoP technicalities.

The instrument directly affects veterans of the Australian Defence Force and members of the Peacekeeping Forces and the Forces (as defined under the VEA), as well as current and former members covered by the MRCA who have rendered relevant service. These individuals are the only persons who can benefit from the reasonable hypothesis pathway. Their dependants and families are affected indirectly through death claims. The instrument also binds decision-makers in the Department of Veterans’ Affairs and the Military Rehabilitation and Compensation Commission, who must apply the SoP when assessing claims. The Repatriation Medical Authority itself is affected insofar as it must maintain the instrument and may amend or replace it as new medical evidence emerges. Medical practitioners who provide evidence of diagnosis, incubation timing, and exposure are affected because their clinical records and opinions become critical to satisfying the factor. Australian taxpayers, as the ultimate source of compensation funding, are indirectly affected because the lower threshold likely increases the number of successful claims and the associated fiscal cost. The instrument does not affect civilians or former defence members who served in non-relevant service categories (such as peacetime service not captured by the defined terms). The list of geographic areas also directly affects claimants who served in the listed countries; those who served in other areas with Ross River virus transmission (for example, some Pacific islands not listed) cannot rely on factor (2) and must instead prove actual mosquito bite under factor (1). This creates a differential treatment based on a fixed list that may not reflect all actual risk zones. Compliance professionals advising the Department must train decision-makers on the dictionary definitions and the limited scope of factor (3). Legal representatives for claimants must ensure that evidence of service location and clinical onset dates is gathered, and that any reliance on a geographic area is backed by official records. The instrument does not impose duties on employers or third parties, making its compliance burden relatively low for external stakeholders but concentrated in the public sector.

The instrument confers a right on eligible claimants to have their claim assessed using the reasonable hypothesis standard if at least one of the three factors in section 9 exists and is related to relevant service under section 10. There is no duty on the claimant to prove causation on the balance of probabilities; it is enough to raise a reasonable hypothesis consistent with the factor. The decision-maker has a duty to apply the SoP as a mandatory relevant consideration when determining whether a reasonable hypothesis exists. Failure to apply the SoP would be a jurisdictional error and could lead to a set-aside of the decision on review. The factor of inability to obtain appropriate clinical management carries a specific duty on the claimant to show that the infection was suffered or contracted before or during (but did not arise out of) relevant service, and that the inability materially contributed to or aggravated the infection. This imposes an evidentiary burden to produce evidence of what clinical management was appropriate and unavailable. The instrument does not create any private rights of action; it operates exclusively within the administrative claims framework. The RMA, in making the SoP, had a duty under section 196B(2) to be satisfied that there is sound medical-scientific evidence indicating that the condition can be related to relevant service. That duty is self-declared in section 8 and is not open to direct challenge by claimants, though the validity of the SoP may be challenged if the RMA’s view is not based on such evidence. The instrument also preserves the operation of other SoPs through section 11: if a factor in the Ross River virus SoP refers to an injury or disease that has its own SoP, the factors in that other SoP must also be satisfied. This means a claimant may have multiple evidentiary hurdles to clear if the Ross River virus infection led to a secondary condition. The instrument does not confer any discretion to depart from the factors; once a factor is present, a reasonable hypothesis is raised. Conversely, if no factor is present, the claim must fail. This binary structure reduces decision-maker discretion but also limits the ability to consider atypical cases not captured by the three factors.

This instrument does not create any penalties because it is a Statement of Principles for claims determination, not a prohibitory or regulatory instrument. There is no enforcement mechanism against claimants; failure to satisfy the factors simply results in the claim being rejected under the standard of proof provisions of the VEA or MRCA. False or misleading statements made in connection with a claim may attract penalties under other provisions of the VEA (for example, section 56 of the VEA regarding false statements), but those penalties arise from the parent Act, not from this instrument. The SoP itself is not a source of punitive consequences. Decision-makers who fail to apply the SoP are not penalised directly by the instrument, but their decisions may be set aside by the Administrative Appeals Tribunal or the Federal Court, with potential costs implications for the Commonwealth. The instrument is enforceable in the sense that it must be followed , a decision made without considering the SoP is legally invalid. The RMA does not have enforcement powers over the SoP; it is a legislative instrument that self-executes upon its terms. The only indirect enforcement pressure is the threat of judicial review if the SoP is not properly applied. This low enforcement profile is typical of SoPs, which are designed to structure discretion rather than command behaviour. From a free-market perspective, the absence of penalties means there is no chilling effect on private conduct; the primary cost is borne by the public purse through increased claim acceptance rates, not by regulated entities.

The instrument is made under subsection 196B(2) of the VEA and is a legislative instrument registered under the Legislation Act 2003. It directly interacts with sections 120A of the VEA and 338 of the MRCA, which adopt the SoP as the benchmark for the reasonable hypothesis standard. It repeals the earlier SoP concerning Ross River virus infection (No. 90 of 2010), so any claim determined after 22 October 2019 must use the current instrument. The instrument interacts with other SoPs through section 11: if a factor in this SoP refers to an injury or disease that is itself the subject of a SoP, then the factors of that other SoP must be applied in accordance with its terms as in force from time to time. For example, if a veteran’s Ross River virus infection leads to chronic fatigue syndrome, and there is a SoP for chronic fatigue syndrome, the claimant would need to satisfy both the Ross River virus factor and the chronic fatigue syndrome factor. This cascading effect increases compliance costs for claimants with complex conditions. The instrument does not interact with the Safety, Rehabilitation and Compensation Act 1988 (SRCA) or state workers’ compensation schemes, because it is confined to veterans’ and defence members’ entitlements under the VEA and MRCA. However, a defence member who also has civilian workers’ compensation coverage may be able to choose which scheme to claim under, and the SoP would only apply to the VEA/MRCA pathway. The instrument’s dictionary defines “relevant service” in a way that excludes peacetime service under the VEA that is not operational, peacekeeping, hazardous, or British nuclear test defence service; those excluded service types fall under a different standard of proof (reasonable satisfaction) and are governed by a different SoP regime (subsection 196B(3) or (4)). The instrument also expressly notes that the ICD-10-AM code is only for administrative reference, so it does not interact with the National Health Reform Agreement or hospital funding codes. There is no direct interaction with the Biosecurity Act 2015 or public health laws, though the RMA’s reliance on medical-scientific evidence may indirectly reflect research on virus transmission.

The compilation note shows that this is Compilation No. 1, effective 22 October 2019. It incorporates an amendment made by the Amendment Statement of Principles concerning Ross River virus infection (Reasonable Hypothesis) (No. 103 of 2019) (F2019L01370), registered on 23 October 2019 but commenced on 22 October 2019, thus backdated by one day. This amendment only altered section 2 (commencement) from the original date of 18 November 2019 to 22 October 2019. The reason for this amendment is not stated in the source, but it effectively brought the SoP into force almost a month earlier than originally planned. The original SoP (No. 94 of 2019) was registered on 21 October 2019. The instrument repealed the previous SoP (No. 90 of 2010) upon its own commencement. There have been no other amendments. Future amendments may occur if the RMA revises the factors based on new medical evidence or if the list of countries or definitions are updated. The amendment history in endnote 4 confirms only one provision (section 2) was amended. This simple amendment history suggests the instrument is stable and has not required correction of substantive content. The change of commencement date could have been to align with the broader scheme of SoP determinations or to respond to an urgent need for updated factors. Regardless, it demonstrates the RMA’s willingness to use amending instruments to adjust dates, which can cause confusion for claimants who may rely on the original commencement date. Practitioners should always check the compilation date and endnotes to ensure they are using the correct version.

The instrument itself does not provide any litigation history. As a legislative instrument, the SoP may have been considered in judicial or tribunal decisions concerning claims for Ross River virus infection, but the source includes no case references. Statements of Principles are routinely challenged in the Administrative Appeals Tribunal (AAT) and the Federal Court on grounds that the RMA failed to consider relevant medical-scientific evidence, or that the factors are too narrow or not supported by sound medical evidence. However, no such challenges are recorded in this instrument. The SoP’s predecessor (No. 90 of 2010) may have been litigated, but that history is not disclosed. Because the instrument is a determination by an expert body, it is generally given significant deference on review; the AAT and courts cannot substitute their own medical opinion unless the RMA’s decision was irrational or procedurally flawed. Any litigation would likely focus on whether the factors accurately reflect the current state of medical knowledge. Claimants who cannot satisfy the factors may argue that the SoP is ultra vires or that the RMA’s view was not based on “sound medical-scientific evidence”. The absence of cited cases means this SoP has not yet been the subject of reported court proceedings as at the compilation date. Practitioners should monitor future litigation, as a successful challenge could force the RMA to expand the factors or the geographic list. Given the increasing incidence of Ross River virus and climate change, the SoP may face updated medical evidence that could lead to amendment or challenge.

The first hidden trap is the narrow application of factor (3): inability to obtain appropriate clinical management. Section 10(2) provides that this factor applies only to material contribution to or aggravation of Ross River virus infection where the person suffered or contracted the infection before or during (but did not arise out of) relevant service. This means that if a veteran develops Ross River virus infection for the first time after the period of relevant service, factor (3) cannot be used. It is only available for pre-existing or concurrent infections that became worse due to lack of clinical management during service. Many claimants may overlook this limitation and assume any inability to access treatment will suffice.

Second, the geographic list in the dictionary for factor (2) is exhaustive. If a claimant served in a country or area that has experienced Ross River virus transmission but which is not listed (e.g., parts of Indonesia west of the Weber line, or other Pacific islands), they cannot rely on that factor. They must instead prove actual mosquito bite under factor (1), which requires evidence that the mosquito was infected. Proving infection of a specific mosquito is practically very difficult. The Weber line definition adds an extra layer of complexity for claims involving Indonesia; a claimant would need to prove whether their location was east or west of that hypothetical boundary.

Third, the incubation window of between three and 21 days before clinical onset is strict. If clinical onset cannot be precisely dated, the factor may not be satisfied even if exposure was likely. The same window applies for both factor (1) and factor (2). A claimant whose symptoms began outside this range relative to exposure or presence in an endemic area will fail.

Fourth, the definition of “being exposed to the Ross River virus” includes a transplanted organ or blood product from an infected person. But that pathway requires proof that the donor was infected. This is rarely known.

Fifth, the cascading provision in section 11 means that if a claimant’s Ross River virus infection leads to another condition that has its own SoP (such as post-viral arthritis), the claimant may need to satisfy multiple SoPs. This multiplies the evidentiary burden.

Sixth, the instrument only covers “symptomatic” clinical illness. Asymptomatic infection, even if detected by serology, is not compensable. This excludes claims where the virus is detected incidentally.

Seventh, the instrument does not include a “smoking” factor or any generic life-style factor; only vector exposure and clinical management failures are recognised. Claimants cannot rely on other theories of causation such as stress or non-mosquito transmission.

Eighth, the note in section 7 stating typical symptoms includes fever with arthralgia, rash, myalgia and lethargy, but the definition is not limited to those symptoms. However, if a claimant presents with atypical symptoms, diagnosis may be disputed and the claim may require specialist evidence.

Finally, the instrument uses “reasonable hypothesis” but still requires that the factor “must exist”. This means the decision-maker must be satisfied on the evidence that the factor is present, even though the ultimate standard is lower. A lack of documentary evidence of location or timing can be fatal.

For a claimant or their legal representative, compliance means gathering and presenting evidence that strictly matches one of the three factors. If relying on factor (1) (actual exposure), obtain contemporaneous medical records of mosquito bites, or evidence of a blood transfusion or organ transplant within the incubation period. This is often impossible, so most claimants will rely on factor (2) (presence in a listed geographic area). For factor (2), obtain service records showing the claimant was in one of the eleven listed countries or areas between three and 21 days before the onset of symptoms. The onset date must be clinically determined, ideally by a medical practitioner with experience in arboviral diseases. Claimants who served in Australia itself are covered, as Australia is listed. For factor (3) (inability to obtain appropriate clinical management), the claimant must first show that the Ross River virus infection was suffered or contracted before or during (but did not arise out of) relevant service. That means the infection must have been present before the relevant service or must have been contracted during service but from a non-service cause. Then, the claimant must demonstrate that appropriate clinical management was unavailable and that this inability materially contributed to or aggravated the infection. This requires medical evidence comparing the management that was reasonably required with what was actually available at the time and place of service.

For decision-makers, compliance means checking the claim against the dictionary definitions. Confirm that the claimed disease meets the definition in subsection 7(2) (symptomatic clinical illness caused by Ross River virus). Verify the incubation window. Ensure that the geographic location falls within the exhaustive list. For factor (3), rigorously apply the limitation in section 10(2). Document the reasoning. If the claim relies on a terminal event, confirm that the infection contributed to that event.

Record-keeping: claimants should retain all service medical records, post-discharge medical reports, and any documentation showing dates and places of service. Decision-makers must keep a clear audit trail showing which factor was satisfied and how it relates to relevant service. The compliance burden is moderate; the main costs are in obtaining expert medical evidence to establish the clinical onset date and, for factor (1), to prove the mosquito was infected. The geographic factor is the most straightforward. The instrument does not require complex statistical analysis or epidemiological studies, as the reasonable hypothesis standard does not demand proof of probability. However, the specificity of the dictionary terms means that sloppy record-keeping can derail a claim. The overarching incentive is for claimants to be proactive in documenting their service locations and any illness symptoms. For the Department, compliance training must emphasise the distinction between factor (3) and the other factors, and the exclusive geographic list. Periodic review of the list may be needed as Ross River virus spreads to new areas, but that is the RMA’s responsibility, not the decision-maker’s.