AUSTRALIAN MILITARY FORCES
Headquarters,
NEW GUINEA Force
16 Apr 44
Dear Bob,
We seem to have got into quite a profitable and mutually instructive discussion. I myself think it fine and am learning lots going out in new fields to try and outflank you. Would like to keep it up but sensed I thought, a little acrimony here and there in your latest. So will make this personal instead of official and hope you will respond by lashing out at my new arguments, as straight as you did at the others, hoping always too that argument will not engender bitterness.
Please get it out of your head that I’m trying to derate your work or kill anti-mite fluid. I know I have strong views on the subject of typhus transmission – I can get no authority to support me and I recognise I may be entirely wrong. I have never translated this into official action to the detriment of anti-mite prophylaxis, nor will I. My chief concern is that we should ascertain whether the Betty treatment is a practicable field prophylaxis or not, and that we should not be satisfied with anything short of indisputable proof that it cannot be improved. If my friendly resistance to your thesis makes you strengthen the weaknesses in your scaffolding that a less well disposed critic might publicly assail, we shall both have been well served. Now let’s get going …
Uncertainties of individual movement and imponderable variations in incubations make dogmatic conclusions as to the locality of scrub typhus infection very unwise. I was careful therefore to say that study of scrub typhus in 21 and 25 Aust Inf Bdes had led me to the conclusion that infection originated in the hill positions. A report upon the RAMU outbreak giving the reasons for the conclusion is in course of preparation. Meantime there is nothing in para 1 of your memo to raise in me any new doubt as to the accuracy of the data on which the conclusion is based or to occasion misgiving as to the validity of the conclusion itself.
Figures showing that many patients suffering from scrub typhus in a treated Bde had I fact applied repellent imperfectly are of little value as support for the contention that infection is due to incorrect application unless the ratio of imperfect/perfect application in troops generally is ascertained by equally exhaustive inquiry for comparison.
If for example in a group of typhus patients only 10% can be accepted after exhaustive inquiry to have made application properly, this figure is of no significance as evidence against the failure of the prophylactic method unless it is shown by equally exhaustive inquiry that 10% is not the perfect/imperfect application ratio for the whole Brigade.
To take your own figures since you don’t like mine. These are at the moment coloured in favour of your argument by the circumstance that they have not been correlated to onset time. If you do this and neglect outsiders you have reported –
To my mind all these figures show at the moment is that there has been an encouraging and progressive improvement in the efficiency of application of anti-mite fluid amongst men subsequently contracting scrub typhus. Until you can show that the perfect/imperfect application ratio amongst men similarly exposed but not infected is higher than it is in patients you have proved nothing.
Application of anti-mite fluid to the socks alone was considered adequate for protection on the ATHERTON Tablelands and routine adoption of this prophylactic measure was indeed followed by cessation of infection in treated troops. How far an assumption that these two events were related as cause and effect, was justified is not indicated by the fact that proper treatment of all clothes is considered essential before protection can be expected. Care must be taken to avoid falling into the same pitfall once again.
Challenge to the statement that onset dates are not available here is ill founded. Onset dates supplied by Hospitals are often patently inaccurate, commonly post dating evacuation from Fd Ambs with a provisional diagnosis already made.
The grounds for my statement that infected areas are purely focal are in my view quite adequate and indisputable. They will be available for critical analysis in due course.
Similarly there is good ground for the statement that sustained occupation and clearing tend to mop up and eliminate infection. My own views on this subject are, or were, share by the U.S. Typhus Commission and by yourself at BUNA. The fact that you were able to find mites abundantly in camp sites which had been occupied for months is of no weight as a denial that scrub typhus infection can be mopped up by occupation.
This and the suggestion in previous para that widespread mite prevalence means Typhus cannot be focal, derive from the unwarranted assumption that endemic typhus in NEW GUINEA is mite borne, and the equally fallacious and often invalidated assumption that heavy mite prevalence is an index of typhus endemicity.
In view of the fact that undisputed protection from mokkas has not uniformly protected from typhus, I think it is time some of you entomologists opened your minds to the possibility of alternative transmission. After all mite carriage was never scientifically proved in MALAYA, JAPAN or N.E. I. and even if it had been, it does not follow that it is mite borne here, particularly as a similar infection is carried elsewhere by a wide range of wogs – fleas, lice, ticks and etc.