Report on an outbreak of mild smallpox in New South Wales in 1913, and the measures taken for its control / by W.G. Armstrong, J. Burton Cleland and E.W. Ferguson.
- New South Wales. Department of Public Health
- Date:
- [1914]
Licence: In copyright
Credit: Report on an outbreak of mild smallpox in New South Wales in 1913, and the measures taken for its control / by W.G. Armstrong, J. Burton Cleland and E.W. Ferguson. Source: Wellcome Collection.
Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.
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![A similar reaction to tl.c above was sometimes observed to follow the revaccina- tion of persons who had been previously vaccinated (in infancy), but had not suffered from smallpox. It was also occasionally observed in persons who had never either been vaccinated or suffered from smallpox. In these cases it appeared to be due to some defective qualiiy in the lymph, and as has already been stated, a primary vaccination followed by such a reaction gave no protection against subsequent attack by smallpox. In Sydney most of the instances in which ihe “mulberry” reaction followed the vaccination of persons who had not had smallpox were consequent upon vaccination done with a particular strain of lymph which was soon discarded on account of its proving inefficient. It is to be noted here that the vaccination of persons actually suffering from the eruption of smallpox in the Sydney epidemic was occasionally, though very rarely, followed by a good reaction. Most of such successful vaccinations were done within one or two days after the smallpox rash appeared, and the latest case noted was one in which successful vaccination was performed on the third day after the appearance of the small- pox rash. This observation is in accord with the observations of Ricketts and of Hibbert and Robinson, all of which relate to the classical and more severe type of smallpox. The following Table shows the number of Vaccinations performed annually by Government Vaccinators during the twenty years preceding the epidemic of 1913 :— Year. Vaccinations. Year. Vaccinations. Year. Vaccinations. 1893 2,547 1900 911 1907 39 . 1894 1,957 1901 2,081 1908 42 1895 2,437 1902 893 1909 11 1896 945 1903 605 1910 280 1897 245 1904 20 1911 20 1898 592 1905 32 1912 35 1899 1,197 1996 42 Infectivity of the Sydney Epidemic of Smallpox. • Infectivity in this epidemic appears frequently to have had a low intensity. For instance, in two cases early in the epidemic, before the diagnosis of smallpox was made, persons who suffered from very mild attacks (in one case there were only three or four lesions on the whole surface of the body) failed to carry infection into their families though they occupied the same bedrooms as other unvaccinated members of the family. In cases accompanied by a copious rash, the infectivity of the disease appears to have been fairly intense, and in households unprotected by vaccination as soon as a diagnosis of smallpox in one member of the family was made, the disease has generally attacked all the members of the household This state of affairs was chiefly observed at the beginning of the epidemic, or in families where the earliest case was concealed or overlooked, as later on, when one member of a household was found to he attacked, all the other inmates were promptly protected by vaccination. The slow spread of the epidemic in an almost entirely unvaccinated population was no doubt due to the degraded infectivity. In most cases infection appears to have been conveyed by direct personal contact, and in quite a number of instances young men and women were found to have infected members of the opposite sex with whom they had been “ keeping company ;” on the other hand, the convection of infection by fomites was not much in evidence. Two striking examples to the contrary were that of a young woman who borrowed a handkerchief from an acquaintance suffering from a mild attack of smallpox, and was herself attacked twelve or thirteen days later; and the case of an old man who slept one night in a bed which had the previous night been occupied by a smallpox patient with whom he had not been otherwise in contact. He also sickened with smallpox about a fortnight later. But, in both these cases, there were special oppor- tunities for infection. As a rule, the progress of the epidemic could be traced by direct and clo«c personal infection from person to person. The evidence from the behaviour of the epidemic outside Sydney also points to low infectivity. In the course of the epidemic twenty-eight country towns or districts of New South Wales were invaded by smallpox, and the total number of cases diagnosed in these localities only amounted to fifty-eight. The greatest number of persons attacked in any one locality was eight, and in sixteen localities only one person was attacked. In all but six of the localities invaded, the first person, or the only person attacked, had come from Sydney, where he had been infected. In five instances the evidence of the source of infection was doubtful, and in one instance the person attacked had been infected in New Zealand. In country places, therefore, when the authorities were on their guard, and ordinary measures of segregation and vaccination were enforced from the earliest diagnosis of an imported case of smallpox, the disease did not spread. Conclusion's. 1. The epidemic prevalent-in Sydney during the latter half of the year 1913 was a mild type of smallpox, and was identical with the epidemic infectious disease variously known as “ Cuban itch,” “ Alastrim,” “ Spanish measles,” Milk-pox,” “Lumber- men’s itch,” ifec, which has prevailed during recent years in various parts of the Americas. The disease was ptobably introduced into Sydney from Canada. 2. Recent successful vaccination conferred absolute protection against infection during the Sydney epidemic. 3. Resides being mild in its manifestations, the disease had a relatively low infective power, and was, as a rule, transmitted only by persona] contact. Transmission by fomites, or by aerial convection, rarely occurred, 4 *24707 (2)—C](https://iiif.wellcomecollection.org/image/b2136056x_0017.jp2/full/800%2C/0/default.jpg)
