10
suffered from dysentery during these five years is 37 in the Tung Wah, and the corresponding percentage in the government hospitals is ; in the former case only Chinese are patients, and in the second case patients are derived from all nationalities. For the same period only 35 cases of abscess of the liver have been found recorded as occur- ing in three hospitals and the public mortuaries from which these statistics are derived. The total number of cases of abscess of the liver probably includes abscesses due to other causes than the amoeba of dysentery, but even if this be not taken into account, tropical abscess of the liver seems to be less frequent here than in other places in which amoebic dysentery is common, eg, in parts of India. The presence of the amoeba histolytica does not seem to be the only factor in determining that dysentery or abscess of the liver shall follow, for it is considered as proven that the parasite exists in a proportion of people who have never been outside of the United Kingdom, and it is very seldom that either of these diseases are found in such persons.
Ankylostomiasis. The results obtained by different observers vary greatly almost certainly because of the different methods employed. For example, in 1913 the stools of 1045 persous were examined in the Civil Hospital to ascertain the frequency with which various parasites occur and ankylostoma eggs were found in 44 per cent of the cases. Again in 1917 the stools of 500 prisoners were examined and the eggs were found in 22 per cent. The explanation of this inequality probably is that in the first series examined the sedimentation of the ova was not provided for. Very few cases of patients suffering from ankylostomiasis are returned from the various hospitals, the anemie, dropsical patient is not as frequently seem as in other countries in which the disease abounds. But it is likely that some of the cases returned as being due to 'anaemia' or 'debility' are really cases of this infection. The number of emigrants examined by the health officers of the port during the last ten years was well over a million; and of these 13,471 were rejected for various reasons as physically unfit, but only 638 were rejected on account of anaemia, The figures are not exact as the examination could not be very thorough, but it is of some value as an indication of the frequency of infection with the hookworm. It is thought that 15% of the population of South China is infected with hookworms of one or other species, the ankylostoma duodenale being the commoner of the two kinds. The oil of chenopodium has been found effective in treatment, but the treatment of the infected in an area in which the disease is endemic is not a hopeful measure. The work of the Rockefeller investigators has proved that the worm lives not only in the surface of the soil but that it travels downwards to various levels thus rendering the treatment of the surface of the soil ineffective. The same enquirers have shown that the ordinary domestic animals, such Towls and pigs, are capable of effecting the distribution of the immature forms of this parasite, and they have described a new species of ankylostomo which is peculiar to the pig. The population in South China is not infeetod to the extent that obtains in the population of other places in the East. Possibly the custom of keeping the infected material in water tight tanks is responsible
as
(9:
11
for killing many of the larvae which would otherwise survive and pollute the soil to a greater degree than is the case.
On the transmission of leprosy.--I have been asked to give my opinion as to the usual mode of transmission. of leprosy in this region. In doing so it will hardly be necessary to reiterate the evidence on which it is based as this would require much space and it is available for those who may wish to study the evidence in detail for themselves. The hypothesis which seems to me to explain the geographical distribution as well as the means by which the disease is contracted is the one which supposes the infection to be conveyed by some article of food, and the particular food which is in universal demand wherever leprosy is found, is imperfectly cured or salted fish. At all times and in almost every country where leprosy occurs popular belief has associated in with the use of fish. Against this view it has been asserted that there are many races and people among whom leprosy prevails who do not eat fish because of religious scruples, or, because they live in the interior of the country and are unable to get it. This has been abundantly refuted whenever the question has been thoroughly investigated. It has been asserted of India, Ceylon, Persia, Africa, but it appears. to have been a statement based on preconceived opinion.
There are few lepers to be seen in this colony because the Chinese have a dread of the disease and segregate such patients in leper villages. They believe it to be a contagious disease. As to whether leprosy is contagious, the following observations seem to furnish cirenmstantial evidence that it is not contagious in the ordinary sense, although, it is admitted that the disease can be conveyed by means of any food which has been contaminated by the organisms.
Against the view that leprosy is a contagious disease the following arguments have been advanced by authorities on the subject and they seem to be well founded and in accordance with experience -
1. Under the ordinary conditions of social life leprosy is not communicable by touch of the leper's skin or by breathing the leper's breath.
2. Experiments to inoculate leprosy have been made often, and, with one single and very doubtful case, they have always failed,
3. The nurses, attendants, medical men, &c., working in
leper homes never take the disease in spite of prolong- ed and close exposure to risk.
4. In thousands of instances husbands and wives have continued to live together for years, the one a leper, the other in sound health. All observers of experience say that it is very exceptional to find both husband and wife affected together,
+
י
28