Statement of Principles concerning chickenpox (Balance of Probabilities) (No. 30 of 2023)

The instrument defines several key concepts that are essential to its operation. “Chickenpox” itself is not simply any varicella infection: it requires manifestation with a vesicular eruption involving skin or mucous membranes, and explicitly excludes herpes simplex, shingles, postherpetic neuralgia, Mpox and smallpox. This exclusion is important because shingles (reactivation of varicella-zoster) and chickenpox are caused by the same virus but are treated differently for compensation purposes; shingles has its own SoP. The ICD-10-AM code B01 is referenced only for administrative identification; the legal meaning is as per subsection 7(2). “Death from chickenpox” includes death contributed to by a “terminal event” such as pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function. This broadening of death coverage means a veteran whose chickenpox contributed to a listed terminal event may still satisfy the SoP even if chickenpox was not the immediate cause of death.

“Being exposed to the varicella-zoster virus” is defined in detail: close contact with an infectious person, contact with contaminated articles within the previous two days, or inhaling droplet nuclei. “Being in close contact” requires direct physical contact or direct contact with vesicle fluids. “Droplet nuclei” are dried residues from coughing or sneezing. The exposure window for standard cases is 10 to 21 days before clinical onset; for those who are in an “immunocompromised state as specified” or have received varicella-zoster immunoglobulin prophylaxis, the window extends to 10 to 28 days. This distinction accommodates longer incubation periods in immunocompromised individuals. “Immunocompromised state as specified” is limited to five conditions: HIV infection, immunosuppressive drug treatment, haematological malignancy, chronic renal failure (as defined by a low glomerular filtration rate for three months, need for renal replacement therapy, or chronic dialysis), or having undergone solid organ, stem cell or bone marrow transplantation. This definition is narrow; other causes of immune compromise (e.g. diabetes, autoimmune disease not treated with immunosuppressants) are not included.

“Vaccine strain chickenpox” is chickenpox attributed to the vaccine strain by isolating it from lesions, and the factor for that is exposure to live attenuated varicella vaccine between 5 and 45 days before clinical onset. This factor is separate from the wild-type exposure factor. Another factor is “being prevented from accessing appropriate varicella-zoster vaccination in accordance with contemporary medical standards of the time, between 1 year and 10 years before the clinical onset”. This factor is notable because it requires a showing that vaccination was medically indicated and available but the person could not access it due to service circumstances. The instrument does not define “contemporary medical standards of the time” or “prevented”, leaving scope for interpretation. For clinical worsening (aggravation) of chickenpox that existed before or during service but did not arise out of service, the factors are: being in an immunocompromised state as specified at the time of worsening, being pregnant at the time of worsening, or inability to obtain appropriate clinical management for chickenpox. These apply only to material contribution or aggravation, not to the initial onset. Finally, section 11 provides that if a factor in section 9 refers to an injury or disease covered by another SoP (e.g., chronic renal failure is defined by reference to the SoP for that condition), then the factors in that other SoP apply as in force from time to time. This creates an interlocking regime where eligibility for one condition may depend on proving another condition under its own SoP.

This SoP directly affects three groups: veterans (including members of the Forces) who have rendered relevant service as defined; members covered by the MRCA; and the decision-makers who assess claims for compensation, treatment or other benefits under the VEA or MRCA. The class of service covered is limited. “Relevant service” under the VEA means eligible war service (other than operational service) and defence service (other than hazardous service and British nuclear test defence service). Under the MRCA, it means peacetime service. This is a deliberate narrowing: operational service (combat or warlike service) and hazardous service (including British nuclear test defence service) are excluded. For those categories, different SoPs exist - likely the “Reasonable Hypothesis” version (No. 29 of 2023, depending on the numbering). This means a veteran who served in a combat zone and contracts chickenpox must satisfy a different standard of proof (reasonable hypothesis rather than balance of probabilities). The SoP therefore primarily affects veterans who served in peacetime or non-hazardous roles. The practical effect is to make it more difficult for those veterans to obtain compensation for chickenpox unless they can prove one of the factors.

Indirectly, the SoP affects the families and dependants of veterans who die from chickenpox, since the definition of death includes cases contributed to by a terminal event. It also affects health practitioners who provide evidence in support of claims; they must understand the defined exposure windows and immunocompromised state criteria. The Department of Veterans’ Affairs and the Military Rehabilitation and Compensation Commission are bound to apply the SoP when making decisions on claims. For claimants, the SoP imposes a burden to produce evidence of exposure, vaccination history, vaccination availability, immune status, or inability to obtain care. This may be particularly challenging for older veterans whose service records may not document varicella exposure or vaccination. The SoP also affects the relative economic burden: it limits the circumstances in which the taxpayer funds compensation, but also may lead to disputes over whether a factor existed, increasing administrative and legal costs. The instrument does not apply to members of the Australian Defence Force still serving who may claim under the Safety, Rehabilitation and Compensation Act (since the SoP is under VEA/MRCA). It also does not apply to civilian claimants.

The dictionary definitions further narrow the pool. For example, “chronic renal failure” is defined stringently; many veterans with moderate kidney impairment would not qualify. “Immunocompromised state as specified” excludes those with common conditions such as diabetes or corticosteroid use short of immunosuppressive drug therapy. This means that a veteran who develops severe chickenpox due to poorly controlled diabetes cannot rely on factor 9(4) (clinical worsening due to immunocompromised state). The SoP thus allocates risk to the claimant: if the medical condition is not listed, the claim fails. That is a conscious design choice by the Repatriation Medical Authority, based on the available medical-scientific evidence as stated in section 8. However, it leaves little room for individual circumstances that do not fit the specified categories.

The instrument imposes no duties on the public; it is a rule of decision-making for the executive. However, it creates a duty on the Repatriation Medical Authority to base its determination on “sound medical-scientific evidence” (section 8). For veterans and members, the SoP confers a right to have a claim for chickenpox assessed according to the factors in section 9, provided the claim falls under section 120B of the VEA or section 339 of the MRCA. The right is conditional: if the claimant proves at least one factor exists and that the factor is related to relevant service, then the decision-maker must accept the condition as service-related, other things being equal. If no factor exists or the evidence is insufficient, the claim must be refused. The SoP does not create a right to compensation in itself; it is a tool for determining causation.

For decision-makers, the duty is to apply the SoP strictly. They must not accept a causal connection based on medical opinion alone if none of the enumerated factors is satisfied, unless the case involves operational service (where a different standard applies). The SoP also requires that factors 9(4) to 9(6) (immunocompromised state at time of worsening, pregnancy at time of worsening, inability to obtain appropriate clinical management) are only relevant when the person’s chickenpox was suffered or contracted before or during service but did not arise out of service (section 10(2)). This means that if a veteran had chickenpox before service and it worsened after service due to an immunocompromised state that itself is related to service, the worsening may be accepted. If the chickenpox arose out of service (e.g., due to exposure during service), the clinical worsening factors are not needed; the initial connection is made under factors 9(1) to 9(3).

The right to rely on vaccination prevention: factor 9(3) is “being prevented from accessing appropriate varicella-zoster vaccination in accordance with contemporary medical standards of the time, between 1 year and 10 years before the clinical onset”. This places a duty on the decision-maker to consider what vaccination was appropriate given medical standards at that time and whether the person was prevented due to service. It implicitly requires evidence of vaccine availability and the person’s inability to get it. The term “prevented” is not defined; it could include operational constraints, lack of medical services at a posting, or clinical contraindications. This factor creates a retrospective inquiry into medical standards over a wide window (1 to 10 years). Similarly, factor 9(6) (“inability to obtain appropriate clinical management for chickenpox”) for clinical worsening is open-ended. The decision-maker must determine what appropriate management was and whether the person could not obtain it. These factors shift the inquiry from causation to systemic barriers, which may be difficult to prove for service that occurred decades ago.

The SoP also interacts with other SoPs through section 11. If a factor refers to a disease covered by another SoP (e.g., “haematological malignancy” in the definition of immunocompromised state), then the factors in that other SoP must be satisfied to prove the existence of that disease. This creates a cascade of evidentiary requirements. For a claimant, the right to rely on, say, leukaemia as an immunocompromising condition depends on proving leukaemia under its own SoP. This can multiply the evidentiary burden. The instrument gives claimants the right to use any one of the factors; they are not required to satisfy all. But they must prove that factor relates to relevant service.

This instrument does not contain penalties. It is a Statement of Principles under the VEA, not a criminal or civil penalty provision. Enforcement is not a concept applicable to the SoP itself. However, there are consequences for incorrect application. If a decision-maker fails to apply the SoP correctly, a claimant may seek merits review by the Veterans’ Review Board or the Administrative Appeals Tribunal, and ultimately judicial review in the Federal Court. The SoP is a legislative instrument, so it is binding on decision-makers. Failure to follow it may lead to a decision being set aside and remitted. There is no separate penalty for the decision-maker; the remedy is correction of the decision.

For claimants, the penalty for failing to prove a factor is simply rejection of the claim. There is no criminal liability. However, the SoP could be relevant in the context of fraudulent claims: if a claimant knowingly makes a false statement about, say, being exposed to varicella-zoster virus, they may be liable under general provisions of the VEA regarding false statements or fraud (section 56 of the VEA provides for offences, but these are not in the SoP). Similarly, the Criminal Code 1995 may apply to providing false or misleading information to the Commonwealth. The SoP itself says nothing about enforcement. Its role is purely evidentiary and definitional.

The Repatriation Medical Authority is not subject to penalties for issuing a SoP that is later found to be inconsistent with the VEA or based on flawed evidence, though judicial review could result in the SoP being declared invalid. No such challenge is mentioned in the source. The SoP contains a note about the ICD-10-AM code, but non-compliance with coding has no penalty. In summary, the enforcement significance of this SoP is indirect: it determines the outcome of claims, and errors in its application are corrected through standard administrative law mechanisms.

The instrument operates within the framework of the Veterans’ Entitlements Act 1986 and the Military Rehabilitation and Compensation Act 2004. It is made under subsection 196B(3) of the VEA, which allows the Repatriation Medical Authority to determine a SoP for the balance of probabilities standard. It expressly applies to claims under section 120B of the VEA (balance of probabilities for non-operational service) and section 339 of the MRCA (which imports the same standard). For claims concerning operational service, section 120A of the VEA requires a reasonable hypothesis SoP, not this instrument. Therefore, if a veteran has operational service, this SoP is irrelevant; the relevant SoP would be the “Reasonable Hypothesis” version (likely No. 29 of 2023, if consecutively numbered). This bifurcation is fundamental: the same disease can have two SoPs, one for each standard of proof.

The SoP also interacts with other SoPs through section 11. If a factor in section 9 refers to an injury or disease covered by another SoP, then the factors in that other SoP apply as in force from time to time. For example, “haematological malignancy” is a condition that would have its own SoP. To prove factor 9(4) (immunocompromised state due to haematological malignancy), the claimant must satisfy the factors in that SoP to prove the malignancy. This creates a system of cross-referencing that prevents claimants from short-circuiting the requirements by simply asserting a condition exists. Similarly, “chronic renal failure” is defined in this SoP but is not itself a disease that necessarily has its own SoP; the definition is self-contained. However, if chronic renal failure were also covered by a SoP (e.g., for other purposes), the definitions might conflict but this SoP states its own definition.

The interaction with the Safety, Rehabilitation and Compensation Act 1988 (SRCA) is not addressed. The SRCA covers employees of the Commonwealth, including peacetime defence members, but claims under the SRCA are not governed by these SoPs. The MRCA covers defence members from 2004 onward, and the SoP applies to MRCA claims relating to peacetime service. However, the MRCA also covers hazardous service and operational service, but the SoP only applies to peacetime service as defined. For operational service under the MRCA, a reasonable hypothesis SoP would be used. The interaction between the MRCA and VEA for dual eligibility is not resolved by this instrument.

The instrument also references the ICD-10-AM classification system, which is used for administrative indexing. The note in subsection 7(3) says that while chickenpox attracts code B01, the legal meaning is governed by subsection 7(2). This prevents mechanical reliance on coding by decision-makers. The ICD-10-AM edition cited (Tenth Edition, 2017) is frozen for consistency; changes to future editions will not automatically update the SoP unless amended. The SoP does not interact with state or territory workers’ compensation laws, as it is confined to Commonwealth veteran and defence compensation.

The instrument repeals the Statement of Principles concerning chickenpox No. 88 of 2015 (made under subsection 196B(3) of the VEA). This is the only amendment history disclosed in the source. There is no explanatory memorandum or revision statement provided. The source does not outline what changes were made from the 2015 version. However, the repeal and replacement suggests that the Repatriation Medical Authority reviewed the medical-scientific evidence and determined that new factors or definitions were warranted. The commencement date is 23 May 2023, so the instrument has been in force since then. There is no indication of any subsequent amendments, but as a legislative instrument it can be amended by subsequent SoPs. The Authority regularly updates SoPs, so practitioners should check for later versions. The instrument number (30 of 2023) implies that it is the thirtieth SoP made in 2023 under the VEA. No further history is available from the source.

The source contains no references to litigation, court cases, or tribunal decisions. The instrument itself has not been judicially considered as stated in the source. However, it is common for SoPs to be challenged in the Administrative Appeals Tribunal and the Federal Court on grounds such as unreasonableness, jurisdictional error, or misinterpretation. Given that this SoP is recent (2023), there may be cases pending but not cited. The absence of litigation history in the source does not mean none exists; it means the instrument does not mention any. The author cannot invent cases. Therefore, the safest statement is that the source provides no litigation history. Practitioners should conduct independent case law searches for decisions interpreting this SoP, particularly regarding the factors for vaccine prevention and clinical management inability.

Several provisions can trap both claimants and decision-makers if not read carefully.

First, the definition of “relevant service” is narrow. It excludes operational service, hazardous service and British nuclear test defence service. A claimant who served in a war zone may mistakenly apply this SoP; their claim would be considered under the reasonable hypothesis standard using a different SoP. The instrument does not cover such cases at all. Decision-makers must verify the type of service before applying this SoP. Similarly, for MRCA members, only peacetime service is covered; hazardous service and operational service under the MRCA are excluded.

Second, the exposure windows in factor 9(1) differ depending on immune status. For a standard person, the exposure must be 10-21 days before clinical onset. For someone who is immunocompromised as specified or who received varicella-zoster immunoglobulin prophylaxis, the window is 10-28 days. But note: the “immunocompromised state as specified” definition is exhaustive. A person with temporary immune suppression from chemotherapy that does not meet the definition (e.g., if not taking an immunosuppressive drug, or if not one of the listed conditions) cannot use the longer window. The claimant must prove they fit the definition at the time of exposure, not just later. Also, receiving normal human immunoglobulin after exposure does not extend the window unless it is varicella-zoster immunoglobulin. This is a fine distinction.

Third, factor 9(2) applies only to “vaccine strain chickenpox” which requires isolation of the vaccine strain from lesions. This is a laboratory test rarely performed. If a person develops chickenpox after vaccination but no strain typing is done, they cannot use this factor. They would need to rely on the wild-type exposure factor, which requires proving exposure to an infectious person. This may be impossible if the only known contact was the vaccine. This effectively limits the factor to cases where the vaccine strain is confirmed.

Fourth, factor 9(3) is “being prevented from accessing appropriate varicella-zoster vaccination in accordance with contemporary medical standards of the time, between 1 year and 10 years before the clinical onset”. This requires two separate proofs: that contemporaneous medical standards recommended vaccination for that person, and that service circumstances prevented access. The standard is “contemporary medical standards of the time” - which could change over the decade. For example, varicella vaccine was introduced in Australia in 2000 under the National Immunisation Program; before that, it was not standard. The window is 1 to 10 years, so for a person who developed chickenpox in 2023, vaccination would need to have been appropriate between 2013 and 2022. But if the person served in the 1980s, they may not have been in service during the relevant window. The factor does not require that the prevention occurred during service, only that the prevention was due to service? Actually section 10(1) requires the factor to be related to relevant service. So if a veteran left service in 2005 and developed chickenpox in 2023, the prevention of vaccination (if it occurred after service) would not be related to service unless service somehow caused the prevention. This is a high bar.

Fifth, factors 9(4) to 9(6) apply only to clinical worsening of chickenpox that already existed before or during service but did not arise out of service. This is an important limitation. If the chickenpox arose out of service (e.g., due to exposure during service), the clinical worsening factors are irrelevant; the initial onset factors apply. But if the chickenpox was pre-existing, the claim for aggravation requires showing that the worsening occurred due to an immunocompromised state as specified, pregnancy, or inability to obtain clinical management. The immunocompromised state must be present at the time of worsening. And the worsening must be a material contribution or aggravation. The definitions of “clinical worsening” are not further elaborated; presumably it requires a significant increase in severity.

Sixth, the dictionary definition of “chronic renal failure” is strict: a GFR <15 for 3 months, or need for dialysis/transplantation, or undergoing chronic dialysis. Many veteran kidney patients with moderate impairment (eGFR 30-44) do not meet this. They cannot be considered immunocompromised under this definition. Similarly, “haematological malignancy” is not defined; it would depend on the SoP for that condition. The definition of “immunocompromised state as specified” excludes common causes of immunosuppression like diabetes, advanced age, or corticosteroid use unless it is “immunosuppressive drug therapy”. It is unclear whether short courses of high-dose steroids qualify. This narrowness can lead to unexpected claim denials.

Seventh, the instrument’s note under subsection 7(2) states that chickenpox can involve lungs, brain, and other organs, and produce disseminated intravascular coagulation. These complications do not automatically make the chickenpox itself more severe; they are merely noted. But if a death occurs from pneumonia complicating chickenpox, the definition of death from chickenpox (including terminal events) may capture it. That definition includes pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function. However, the claimant must show that chickenpox contributed to the terminal event. If the veteran died of pneumonia unrelated to the varicella (e.g., bacterial pneumonia), the connection may be weak.

Eighth, section 11 incorporates other SoPs. If a factor refers to a disease that has its own SoP, the claimant must satisfy that SoP. This means that proving an immunocompromised state due to HIV infection requires the claimant to satisfy the HIV SoP. If that SoP was also replaced or revised, the current version applies. This can create a moving target.

Compliance with this instrument is not about following its rules in the usual regulatory sense; it is about using it correctly in claims processing or preparation. For a claimant seeking to establish chickenpox as service-related under the balance of probabilities standard, the first step is to confirm that they have relevant service as defined (eligible war service other than operational, defence service other than hazardous/British nuclear test defence service, or peacetime MRCA service). If they have operational service, they must use the reasonable hypothesis SoP instead. Next, the treating doctor should diagnose chickenpox according to the SoP definition: varicella-zoster infection with vesicular eruption, excluding herpes simplex, shingles, Mpox, and smallpox. Confirmation may require PCR or serology, especially if the presentation is atypical.

For the initial onset factors (9(1) to (3)), the claimant needs to gather evidence of:

• For factor (1): evidence of close contact with an infectious person (or contaminated articles, or droplet nuclei) within the incubation period. This could include service records showing quarters, leave travel, or exposure to a known case. Timing must be 10-21 days (or 10-28 days if immunocompromised as specified or received varicella-zoster immunoglobulin). Documentation of the contact and the date of symptom onset is critical. If the claimant was immunocompromised at the time, they must prove that status via medical records showing HIV, immunosuppressive drug therapy, haematological malignancy, chronic renal failure (as defined), or transplantation. The medical records should specify the dates and details.
• For factor (2): isolate the vaccine strain from lesions, which usually requires a PCR test that differentiates vaccine from wild-type. The vaccine must have been administered 5-45 days before onset. Records of vaccination are needed. If the vaccine was not recorded or the strain typing not performed, this factor cannot be used.
• For factor (3): prove that the claimant was prevented from accessing appropriate varicella vaccination between 1 and 10 years before onset. This requires evidence of contemporary medical standards (e.g., National Immunisation Program schedules) showing that vaccination was indicated for the claimant (age, occupation, health status). Then evidence of service-related prevention: the claimant was on a remote posting with no access to vaccination, was deployed overseas, was denied leave, or had a medical contraindication that was itself service-related. This is highly fact-specific. Seek records from Defence Health, personnel files, and clinical notes.

For clinical worsening (factors 9(4)-(6)), the claimant must show that the chickenpox existed before or during service (but did not arise out of service). Then show that at the time of worsening, the claimant was in an immunocompromised state as specified, or pregnant, or unable to obtain appropriate clinical management. Evidence of the immunocompromised state or pregnancy should be contemporaneous. For “inability to obtain appropriate clinical management”, provide evidence that appropriate treatment (e.g., antiviral therapy, hospitalisation) was not available or not provided due to service circumstances. This might include evidence of delayed evacuation, lack of medical supplies, or failure of service medical staff to diagnose early.

All factors must be related to the person’s relevant service under section 10. This means the factor itself must arise from service, not merely exist coincidentally. For example, being exposed to varicella while on leave at home may not be related to service unless the leave was compelled by service. The decision-maker must assess the causal nexus.

For decision-makers, compliance means correctly identifying the type of service, verifying that the standard is balance of probabilities, and checking that the claimant has provided evidence for at least one factor. The factor must be exactly met; the definitions are legal, not clinical. For instance, a doctor’s note that the claimant was “immunocompromised from chemotherapy” does not automatically satisfy the definition unless the chemotherapy is an “immunosuppressive drug” and the condition causing the chemotherapy is not itself excluded. The decision-maker should cross-reference other SoPs if the factor depends on another condition. The instrument should be applied as a whole, including the note about ICD-10-AM not overriding the legal definition. The decision must contain reasoned analysis linking the evidence to each element of the chosen factor. If the factor cannot be proved, the claim must be refused unless the claimant has operational service or a different standard applies.