KELLY v ROADS & TRAFFIC AUTHORITY

THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40643/99 CC 6368/96

MASON P GILES JA DAVIES AJA

JUDGMENT 1 MASON P: The appellant failed in his application for worker's compensation for incapacity stemming from contracting an unusual strain of pneumonia called Chlamydia Pneumoniae. There was an award for the respondent employer which is now challenged "in point of law" (Compensation Court Act 1984 s32). 2 The debilitating illness was diagnosed in September 1995. 3 The issue fought and lost at trial was whether that injury arose out of or in the course of the appellant's employment with the respondent. 4 In his Application for Determination, the appellant pleaded that the injury happened through exposure to infection-inducing agents while working as a driver for the Roads & Traffic Authority at the F3 extension Minmi Swamp Stockrington. The date of injury was pleaded as July to September 1995. 5 In fact the appellant worked at the site between 17 and 21 July 1995. He used a tip truck to haul crushed slag and sand. He said that he was splashed with grey water which smelled strongly of sewage and at times he drove through a mist containing traces of such water. 6 It was found by the primary judge, Judge Maguire, that a week or so after starting at the Minmi job the appellant became ill with symptoms of fever, chills and a lung infection: but this was not pneumonia. 7 The hearing took place on 30 March 1998, 23 June 1998 and 4 February 1999. 8 The case initially advanced by the appellant and maintained during the first two hearing days was that the grey water at Minmi was the source of the Chlamydia bacteria which led to the pneumonia detected in September 1995. This case failed when it became apparent that the incubation period for Chlamydia infection detected in September was too long to be consistent with the onset of the symptoms revealed back in July. The appellant accepts this. Indeed the appellant appears to have accepted the inevitability of such a conclusion during the hearing because the case left to the court at the conclusion of the hearing on 4 February 1999 was, as the appellant admits, of a different complexion. 9 On the third hearing day the appellant sought to rely upon the evidence of a microbiologist, Dr Marianne Muir. Her draft report is dated September 1998 and her final report November 1998. Dr Muir expressed the opinion 10 that: A. In July 1995 the waste water at Minmi STP used for dust suppression, exceeded NSW EPA and ANZECC faecal coliform levels recommended for reuse of this type of water. (Moreover the NSW EPA recommends exclusion of the public while spraying.)

B. Viruses such as enteroviruses found in human sewage, have been documented to survive a secondary sewage treatment process, such as that at Minmi, even when bacterial indicators of faecal pollution meet regulatory requirements. These viruses have been implicated in causing human diseases through direct exposure to viral particles in the water, or through inhalation of aerosols of the contaminated water (eg in the surf).

C. Enteroviruses such as the Coxsackie group A and B viruses have been known to cause the symptoms initially reported by Mr Kelly in July, 1995. The incubation period for this type of virus is consistent with the period between exposure of Mr Kelly to the Minmi waste water, and the appearance of fevers, chills etc as his first symptoms.

D. Infection of Mr Kelly with this virus could easily have been acquired through aerosol inhalation, and/or by direct contact with the contaminated wastewater on his hands, then failing to wash his hands before eating, as reportedly occurred.

E. More probably than not, Mr Kelly became infected in July, 1995 with an enterovirus, during the course of the work he carried out on the F3 Freeway, when he was exposed to the Minmi wastewater.

F. This virus caused respiratory symptoms, fever and chills and lung infection which debilitated Mr Kelly to the point that he became susceptible to a common community pathogen ( Chlamydia pneumoniae ) by September, 1995. This organism has an incubation period of several weeks and caused to Mr Kelly an atypical pneumonia/pneumonitis which became chronic, lasting over two and a half years.

11 It can be seen that the key steps in this opinion are those in paragraphs (e) and (f) and that they depend in part upon a medical assessment of Mr Kelly's symptoms in July 1995 as much as upon general information about microbiology within Dr Muir's speciality. 12 What I will call the Muir theory of indirect or sequential infection had not been put to any of the medical or scientific witnesses who had given evidence earlier in the case. Indeed it can be said that, with the possible exception of Dr Brown, an occupational physician, even the possibility of a two stage process of Chlamydia Pneumoniae infection did not seem to have been considered by any of the medical experts. 13 In a reserved judgment delivered on 20 August 1999, Judge Maguire reviewed the extensive medical and scientific evidence tendered by both sides. Some of the medical evidence came from the appellant's treating doctors. 14 Several of the experts reported that the actual organism causing the Chlamydia Pneumoniae that affected the appellant was unknown and indeterminable in light of the evidence. Possible theories were explored including the trigger of Psittacosis, or Parrot Disease, through contact the appellant had had with ostriches in August or early September 1995; or a dog bite in June 1995. The mechanism preferred by the experts and acknowledged by Dr Muir herself was that contact with the bacterium that could lead to the atypical pneumonia was most likely to come through the air. Of course, none of the experts was able to pin point a particular time or place where that contact had occurred as regards the appellant, although, as I have indicated, it was ultimately I think common ground that this would have happened some time after the term of the relevant employment. 15 Some of the experts were not prepared to rule out the possibility that the appellant's occupation had been a trigger in some undetectable manner. But with the exception of Dr Muir those who did so expressed and justified strong views against the probability of this being the case. Most of the experts concluded that the exact cause of the pneumonia remained a mystery. 16 Some of the medico-legal experts expressed themselves in stronger terms that can be viewed as adverse to the appellant's case as ultimately presented. I refer to the evidence of Dr Brown (RB 16), Dr Wilcox (RB 17), Professor Lloyd (RB 18), Professor Dwyer (RB 20) and Dr Greenaway (RB 21). 17 This was a weighty body of expert evidence that can be viewed as being, in a general sense, against the probability of the case ultimately advanced by the appellant through Dr Muir. However, none of the medical experts were ever confronted with the Muir two stage theory and this is a matter which obviously told in the trial judge's conclusions on the facts. I mention that more by way of background than as a vital step in addressing the critical issues in the appeal. 18 The learned trial judge addressed Dr Muir's evidence. He explained her thesis and noted her opinion that more probably than not exposure to Minmi waste water caused an entero virus which caused respiratory symptoms which debilitated the appellant to the point that he became susceptible to a common community pathogen encountered some time after July 1995. His Honour noted that the theory was advanced by someone who was not a medical practitioner. 19 As I have already indicated and as advanced by senior counsel for the respondent, there were really three stages in the reasoning of Dr Muir. Stage one was that the conditions at Minmi probably caused an enteric virus. Stage two was that that virus was evidenced by or caused the symptoms of fever, chills, back pain etcetera that were found to exist in late July 1995. Stage three was that the Chlamydia infection was a secondary infection acquired as a result of general debilitation resulting from the primary viral infection. 20 To understand the primary ground of appeal advanced, I should set out the concluding portion of his Honour's judgment. I am reading from pages 25 and 26: During cross-examination I intervened to clarify Dr Muir's position. A. His primary infection from the sewerage water was a virus that nobody looked for in his blood because you do not routinely look for these viruses. So it's not surprising that no-one looked for it and therefore no-one found it so there is no proof one way or the other that the symptomatology and timing of the symptoms are consistent with that type of virus. Q. So is this your position, you have a theory about a series of events. A. That's correct. Q. Which theory depends upon a causal link which has never been established. [by testing] A. Well, it can't be established in hindsight and because none of the testing was done at the time we don't have any evidence one way or the other. Does that mean we have to assume that he never got sick from the sewerage? I don't feel that's the case. I feel on the balance of probability he would have. He must have got the initial symptomatology from the association with the aerosols of sewerage water. Q. On no evidence. [of testing] A. On the basis that in the previous hearing apparently Mr Kelly and in one of Mr Wilcox's reports it states that he was driving through a fog of sewerage spray so much so that - Q. I know about that, but you are saying - A. He couldn't see out the windows. That's the most effective way of acquiring a virus is through just inhaling it. Q. But you are saying, as I understand it, that you do not know and nobody knows because nobody tested for it whether he ever had such a virus or not. A. That's correct. Just like no-one knew if he had a bacteria or not initially because the first result didn't come through until two months later. It seems to me that this passage in Dr Muir's evidence really destroys completely the hypothesis that she had advanced. This man's illness remains a mystery to me. If I accept, as I think likely, that he became ill a week or so after starting the Minmi job plainly he did not then have the only disease pleaded. There is an alternative view of the fact of his illness. That is, that he was ill from the time of the dog bite. The third possibility, and it is no more than that, is that he contracted a virus from the water at Minmi, thereby became debilitated and then contracted chlamydia. That is the Muir hypothesis. There is no view of the evidence which I accept which establishes in my mind any causal link between exposure to the grey water and the condition pleaded. There will be an award for the respondent. I make no order as to costs. 21 Counsel for the appellant has skilfully assumed the difficult task of detecting a point of law in this unfavourable material. Two matters are raised. First it is submitted that his Honour misdirected himself in law because he proceeded on the basis that there was no evidence of an earlier entero viral infection. 22 The appellant has taken us to a passage in Dr Muir's evidence. (Black 95), which explains why she supported the probability that treated sewage caused an entero viral infection. This passage is not set out in the judgment but it is impossible to think that the trial judge overlooked it. In any event, it does little more than explicate the written evidence that is set out in the judgment at Red Book 16. Furthermore, the complaint is not about absence of reasons. 23 In my view, the primary ground of appeal is not made out because it misconstrues the reasoning as exposed in the judgment. The learned judge was not saying that the evidence of Dr Muir was incapable of supporting a finding based on the indirect or sequential infection theory. Rather his Honour was indicating that he was not persuaded on the totality of the evidence to accept that theory in its application to the appellant, having regard to the three steps involved to make the theory do the work for which it was advanced. 24 It is important that Dr Muir was not a medical practitioner, as his Honour observed. Her evidence really went to the possibility or even probability of the water at Minmi leading to a viral infection. His Honour recognised that this was the thrust of her evidence. 25 Dr Muir was not, however, in a position to diagnose that such infection had occurred nor had any attempt been made to put such a hypothesis to any of the medical experts. In this sense a vital factual step in Dr Muir's reasoning lay upon little more than conjecture. 26 I mention this, not to suggest that this is the way in which his Honour reasoned in his judgment, but to show that it was clearly open to the trial judge to reject the Muir thesis. This is a relevant backdrop to examining the critical paragraph of the judgment to see if its words or silences reveal the legal error that has been assigned. 27 In Briginshaw v Briginshaw (1938) 60 CLR 336 at 361 Dixon J said: The truth is that, when the law requires the proof of any fact, the tribunal must feel an actual persuasion of its occurrence or existence before it can be found. It cannot be found as a result of a mere mechanical comparison of probabilities independently of any belief in its reality. 28 A fortiori, a mere mechanical comparison of possibilities. 29 As I read the critical passage in the penultimate paragraph of the judgment, what the trial judge was saying was that the passage in Dr Muir's cross-examination earlier set out showed that she acknowledged that there was no hard evidence by way of testing or otherwise to show that an entero virus had afflicted the appellant even if he had inhaled infectious grey water at Minmi. Absent medical testing and absent medical opinion from Dr Muir or anyone else, this did effectively rob the Muir hypothesis of any weight. 30 I do not read his Honour as saying any more than that. The very fact that he acknowledges Dr Muir's hypothesis as a "third possibility" shows that her views were not dismissed on evidentiary grounds. 31 The concluding sentence of the penultimate paragraph was: There is no view of the evidence which I accept which establishes in my mind any causal link between exposure to the grey water and the condition pleaded. 32 In my view what his Honour is there saying is that he was not persuaded, in the sense adverted to in the passage from Briginshaw that I have quoted, that any of the possibilities advanced in the evidence, including the Muir possibility, was the one which accounted for the pneumonia which disabled the appellant. That is the ultimate finding. It is one of fact and it is one that was clearly open. More importantly is not susceptible to challenge by way of appeal. 33 The second ground of appeal was that the primary judge erred in law in finding that a dog bite which the appellant suffered in June 1995 was a possible cause of his pneumonia, there being no evidence capable of supporting the conclusion that the dog bite was a possible cause of that infection. 34 Once again, I think that this ground does not do justice to the trial judge's reasoning. The dog bite was mentioned as a second possibility. It had been raised by the appellant himself in histories given to Dr Merrill and at hospital, accompanied with a history to the effect that the appellant had been ill from the time of the dog bite. It is true that none of the medical witnesses seemed to have saluted that flag as it was run up the mast, but it is hardly an error of law for it to be adverted to in the judgment. 35 His Honour was not saying that that possibility assisted him in rejecting the Muir hypothesis which is the case now advanced by the appellant. He was just saying that that was one of three theories that had been raised in the case, each of which did not fall over the probability line. 36 In my view the appeal should be dismissed with costs. 37 GILES JA: I agree. 38 DAVIES AJA: I agree with the President. 39 MASON P: That is the order of the court.

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