War Surgery and Medicine
CHAPTER 2 — Typhoid Fever
THE history of typhoid fever in New Zealand troops is really a testimony of the worth of TAB inoculations. In the First World War New Zealand troops were inoculated, either in New Zealand or on the transports going overseas, with a vaccine prepared against typhoid. In part this resulted in a striking reduction of the incidence and death-roll of typhoid compared with that experienced by troops in the South African War. Troops in Gallipoli, Mudros, and Egypt, however, in 1915 incurred several hundred cases of enteric fever, which was proved to be due in the majority of instances to paratyphoid A and B infections, and a number had to be invalided to New Zealand. In March 1916, when the hospital ship Maheno brought back to New Zealand 317 invalids from Gallipoli and Egypt, there were 56 enteric cases among the invalids. When the men were inoculated against paratyphoid in November and December 1915 the incidence of these infections decreased so much that typhoid was no longer a problem. Very few cases arose during the campaign in France. Of course, allied with inoculations was the success of preventive measures through efficient sanitation.
In the Second World War New Zealand troops were inoculated, either in camp in New Zealand or on troopships, with the triple vaccine, TAB, offering protection against the typhoid and paratyphoid infections. The result was that, apart from an epidemic among the 10th Reinforcements upon their arrival in Egypt in 1943, there were fewer than a hundred cases of typhoid in 2 NZEF and only three deaths.
In 1941, when the incidence of typhoid was high among civilians in the Cairo Health Area (for instance, 170 crude notifications and 30 deaths in four weeks ended 11 November 1941), there were only 8 cases in 2 NZEF and no deaths. In February and March 1942 there were 3 cases of typhoid among the recently arrived WAACs at 3 General Hospital at Helmieh, with 1 death. The source of infection was not discovered, though the eating of unwashed fruit and vegetables was thought to be a possible cause.
Again, in October and November 1942 there was an outbreak of typhoid among the WAAC personnel at 3 General Hospital at page 494 Beirut. There were 7 cases, but no deaths. In spite of investigations no definite source of infection could be detected. The only link between the cases was that they fed at the same mess. All the WAAC personnel who had contracted typhoid fever were invalided back to New Zealand during the period of their convalescence.
On 18 August 1943 the 10th Reinforcements (6000 men) arrived from New Zealand and an epidemic commenced in September among the new arrivals in the camp at Mena where, Maadi Camp being full, they were quartered upon disembarkation. The outbreak subsided in November after there had been 130 New Zealand cases. The attacks were quite severe but no New Zealander died. The carrier was apparently a man who washed up in a Reinforcement mess.
The Helwan hospital reported that though there were only 3 deaths, in other than New Zealand patients, many patients were severely affected, pyrexia was prolonged, and relapse frequent. All the usual complications were seen. In inoculated men the disease tended to be milder and the temperature chart abnormal. Headache was always a prominent feature, and mild respiratory signs were usually present. Convalescence was slow and debility marked, with many suffering from foot strain; these men were usually recommended for down-grading, some for return to New Zealand. It was felt that the ultimate prognosis in many cases was poor as regards further military service.
There was doubt about the vaccine used in New Zealand giving full protection against the organisms found in Egypt. In some cases the inoculation state was found to be faulty. All the 10th Reinforcement draft was re-inoculated with RAMC vaccine and the inoculation interval for TAB injections throughout 2 NZEF reduced from one year to nine months. A supplement to 2 NZEF Orders was issued to educate all ranks in the preventive measures necessary to reduce the possibility of typhoid infection. It was emphasized that the anti-typhoid inoculation was not a substitute for sanitary precautions, but an additional protective measure.
The slight rise in incidence among troops in Italy in June, July, and August 1944 was probably due to the eating of infected food, most likely lettuce. A number of cases among Italians in the locality were also reported at the time.
In August 1944 there were unfortunately 2 deaths from typhoid, 1 from toxaemia associated with deep and extensive ulceration, and 1 due to a second perforation following some days after an operation to close a first.
Although cases in 2 NZEF in Italy were fewer than in the Middle East, it was the impression of the Consultant Physician page 495 2 NZEF that the Italian was the more severe type. A thoroughly well-inoculated man might not only acquire the disease but might die from it.
A new typhoid vaccine, alcoholised TAB vaccine, came into general use towards the end of 1944. It was introduced after experiments had proved a reduction in general reactions and also enhanced keeping properties besides a greater measure of protection.
Besides warding off infection to a remarkable extent, inoculation also modified the severity of the illness among those who did contract typhoid. Recovery was much more rapid and the death-rate reduced. The mode of onset seemed to be modified by inoculation. This made diagnosis much more difficult and was thought to have been a cause of the spread of the outbreak in 1943.
Toxaemia was not so common and not so severe in well-inoculated cases. Sulphamethazine seemed to have a good effect on the toxic features of the disease. It was not found possible to distinguish the type of organismal strain of typhoid clinically before the laboratory findings were known. In September 1943 there were outbreaks of typhoid among British troops near Maadi and Helwan, the patients being admitted to 1 General Hospital along with the New Zealand cases. Three different types of organism were isolated, a separate type for each camp. (The introduction of phage-typing, by means of which many distinct types could be recognised with precision, had led to a marked advance in the tracing of foci of infection, and we were fortunate that this method of investigation was available in the Middle East.) It appears that some vaccine may not have been protective against certain types of organism, or else the immunity was not sufficiently strong to resist a heavy infection. The low overall incidence of typhoid in 2 NZEF in the Second World War was a triumph of preventive medicine, both as regards inoculation and hygiene and sanitation.
Efficacy of TAB Vaccine
The epidemic among the recently-arrived reinforcements in September 1943 led to questioning of the efficacy of the vaccine prepared in New Zealand. In one infantry depot there were 69 cases of typhoid, and an analysis of the 67 inoculation states available showed that 58 had received New Zealand vaccine only and that 6 of these states were faulty also, while 9 had received New Zealand and RAMC vaccine but 8 of these states were faulty in one way or another. Other troops fully protected with RAMC vaccine were exposed to the infection but did not develop typhoid, and it is possible that re-inoculation with RAMC vaccine brought the epidemic to a close.page 496
As the pathologist of 1 General Hospital pointed out, typhoid fever was of rare occurrence amongst Middle East troops properly inoculated with RAMC vaccine, and when an outbreak of typhoid fever did occur it affected almost exclusively those who had not been properly protected with RAMC vaccine. It was a common finding that the local and general reaction produced by the first dose of RAMC vaccine was often severe—surprisingly so if any great degree of immunity had been conferred by the previous inoculations in New Zealand. Subsequent doses of RAMC vaccine produced less severe reactions. It was found that a particular organismal type was common to the New Zealand cases in the epidemic and that British and RAF cases occurring at the same time were caused by different types of the organism. It seemed that the vaccine used in New Zealand did not give complete protection against organisms found in Egypt.
In the First World War the same question of the potency of vaccine given in New Zealand arose, and all the troops were re-inoculated with RAMC vaccine. The question was investigated by Major Bowerbank at 1 NZ General Hospital in Egypt in 1916. He held that the New Zealand vaccine had been effective and that nearly all the cases had been due to paratyphoid infection against which the original vaccine had not been prepared.
The use in 2 NZEF of RAMC vaccine made from local strains produced fairly complete immunity. It would appear from experience in the Middle East that vaccine should be made not from any local New Zealand strain, but from the proper strains of tested virulence and antigenic power obtained from the country of campaign. Experience also teaches that the meticulous carrying out of inoculation at specified intervals is important.