Varicella vaccination is optional and requires self-payment. On 1 December 2018, Wuxi City launched a free varicella vaccination program for children. This study aimed to evaluate the changes in varicella incidence before and after the implementation of the policy. The data were obtained from official information systems and statistical yearbooks. We divided the period into chargeable (January 2017 to November 2018) and free (December 2018 to December 2021) periods. Interrupt time series analysis was used to conduct a generalised least-squares regression analysis for the two periods. A total of 51,071 varicella cases were reported between January 2017 and December 2021. After the implementation of the policy, there was a statistically significant decrease in the incidence of varicella (β2 = −0.140, P = 0.017), and the slope of the incidence also decreased by 0.012 (P = 0.015). Following policy implementation, the incidence decreased in all age groups, with the largest decline observed among children aged 8–14 years (β2 = −1.109, P = 0.009), followed by children aged ≤7 years (β2 = −0.894, P = 0.013). Our study found a significant reduction in the incidence of varicella in the total population after the introduction of free varicella vaccination in Wuxi City.

The experiments now described were carried out in Lagos and Khartoum, and although the hoped-for end-result, the production of a sheep strain of neurovaccinia, was not realized, certain points of interest have arisen and are recorded in the hope that they may be of help to other workers concerned with vaccinia vaccine production.

This study examined relationships between foodborne outbreak investigation characteristics, such as the epidemiological methods used, and the success of the investigation, as determined by whether the investigation identified an outbreak agent (i.e. pathogen), food item and contributing factor. This study used data from the Centers for Disease Control and Prevention's (CDC) National Outbreak Reporting System and National Environmental Assessment Reporting System to identify outbreak investigation characteristics associated with outbreak investigation success. We identified investigation characteristics that increase the probability of successful outbreak investigations: a rigorous epidemiology investigation method; a thorough environmental assessment, as measured by number of visits to complete the assessment; and the collection of clinical samples. This research highlights the importance of a comprehensive outbreak investigation, which includes epidemiology, environmental health and laboratory personnel working together to solve the outbreak.

Radioimmunoassay (RIA) for rubella-specific IgM antibodies was compared with haemagglutination-inhibition (HI) in conjunction with gel filtration for the diagnosis of rubella infection in pregnant women during a 1-year period. In total 476 women were investigated of whom 221 were tested for rubella IgM. Both techniques gave positive results with 64 sera, and RIA alone with one additional serum.

Difficulties associated with the removal of non-specific HI activity were encountered with four sera all of which were negative by RIA.

RIA was found to have practical advantages over the gel filtration method but is at present technically more difficult to perform.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic disease transmitted from dromedary camels to people, which can result in outbreaks with human-to-human transmission. Because it is a subclinical infection in camels, epidemiological measures other than prevalence are challenging to assess. This study estimated the force of infection (FOI) of MERS-CoV in camel populations from age-stratified serological data. A cross-sectional study of MERS-CoV was conducted in Kenya from July 2016 to July 2017. Seroprevalence was stratified into four age groups: <1, 1–2, 2–3 and >3 years old. Age-independent and age-dependent linear and quadratic generalised linear models were used to estimate FOI in pastoral and ranching camel herds. Models were compared based on computed AIC values. Among pastoral herds, the age-dependent quadratic FOI was the best fit model, while the age-independent FOI was the best fit for the ranching herd data. FOI provides an indirect estimate of infection risk, which is especially valuable where direct estimates of incidence and other measures of infection are challenging to obtain. The FOIs estimated in this study provide important insight about MERS-CoV dynamics in the reservoir species, and contribute to our understanding of the zoonotic risks of this important public health threat.

1. That the epidemic was due to infection of the water supply is borne out by the following points:

(a) The explosive character of the outbreak as shown in Graph II which is characterised by a rapid rise to peak at the end of third week followed by a sharp fall and a gradual tailing off to the end of the epidemic.

(b) The widespread distribution of cases (see Map), no area supplied by water from the city having escaped.

(c) The rapid decline which followed the adoption of appropriate measures to deal with the water supply.

2. 255 persons in the city area (including the 12 military cases) were definitely affected (equivalent to a rate of 3·1 per 1000 of the population). As shown by the rise in the death-rate for the rural area it is apparent that a far greater number of persons were actually attacked.

3. The outbreak had its origin in a defective manhole in the Mental Hospital grounds whereby the sewage overflowed into a rubble drain and infected the water supply. This defect had existed for twenty-five years, and an epidemic in the hospital fifteen years previously established the reservoir from which infection was disseminated through the city.

4. The spread of typhoid was favoured by unsatisfactory arrangements for the filtration of the water supply. This is borne out by the endemic character of the disease prior to the installation of an effective filtration plant.

5. The institution of this plant was followed by an immediate reduction in the incidence of the disease until, as at the present time, water-borne typhoid has been practically eliminated.

6. The value of such a plant combined with chlorination and bacteriological examination has been shown.

The villages selected for the present series of observations were Dhand and Kasel in the Arnritsar District of the Punjab. They are situated about 10 miles south-west of Amritsar City and within a distance of ¾ mile of each other. They are typical Punjab villages of about 2,000 and 4,000 inhabitants respectively.

Most towns augment their water supply from wells, and in South Africa, where the rivers are said to run underground, Johannesburg is no exception.

Its chief supply is from deep wells in the dolomite some 20 miles to the south-west of the town, but one of the suburbs—Parktown—is not connected to the main supply, but at present draws its water from two wells (the property of the Rand Water Board) which will be subsequently referred to as No. 1 and No. 2, sunk in the shales of the upper Witwatersrand beds. From here the water is pumped to two Water Towers situated at the highest point of the suburb from whence it is distributed by gravitation. For various reasons, the Rand Water Board had decided on replacing the pumping machinery at these wells by electrically driven gear, and advantage was to be taken of the change to properly line and deepen the wells by a steel bore-hole.

It will be convenient to summarise the results of the foregoing observations and the conclusions which appear justified by a comparison of results obtained by the two methods of standardisation under consideration, namely (1) cutaneous, on the human subject, and (2) intracutaneous (intradermal) on the guinea-pig.

1. In the absence of knowledge regarding the essential chemistry of tuberculin, a chemical method of standardisation is excluded.

2. The phenomena of allergic reactivity point to a biological basis for standardisation.

3. The allergic reactions have been studied in the sensitised animal and in the human tuberculised subject.

4. Tuberculins of unknown potency have been compared with a tuberculin of known potency which has been selected as standard.

5. Comparative observations have been made as between the standard and the unknown tuberculin, by (a) making use of different dilutions, and (6) assessing results in animals (sensitised) and in human (tuberculised) subjects.

6. In the sensitised guinea-pig the intracutaneous method has been used, and a definite procedure followed in the determination of results.

7. In the human tuberculised subject the cutaneous method has been used, and similar procedure followed for the determination of results. The method and results are illustrated in the text.

8. The results in the two sets of observations are definite and comparable. Both afford a basis for standardisation.

9. The average probable errors by the two methods are approximately equal, that is, the accuracy of the one method is approximately equal to that of the other.

10. If this be so, a strong plea may be advanced in favour of the human test. Shortly expressed: human (tuberculised) subjects are readily available for observation. The procedure involves little preparation, and the results are easily read with exactness. The tuberculin under test is to be used thereafter in relation to the human subject. This fact enhances the value of the test observations.

If it be objected that in intracutaneous injection the amount of tuberculin introduced is measured more precisely, it may fairly be maintained that the droplet application of tuberculin is limited to a sharply defined area of skin surface and, further, that the clear skin of the human subject allows of more accurate estimation of the diameters of the areas of reaction.

The present enquiry has shown that assays on a variety of human (tuberculised) subjects yield consistent results, and similarly, assays on various animals give consistent results. Yet the animal results are not always contistent with the human results. The explanation of the discrepancy is not very clear. It is not impossible that certain strains of tuberculin act in less degree on the human subject and in greater degree on the animal, and conversely. The occurrence of such differences might be misleading and even involve risk, if standardisation tests were limited to animals without control from observations on the human subject.

If we grant, as the records have shown, that the procedure in relation to the human subject is sound and is innocuous to the human subject of the test, much may be said for the simplicity of the method and for the clarity of results obtained. As the tuberculins under test are destined for use on human subjects—for diagnostic and therapeutic purposes—it would seem reasonable, and probably safer, to base the standardisation of tuberculin (for human purposes) on observations in relation to man.

It has been found that carcinogenic tar acts upon the lymph glands of the rat in converting them into more or less pronounced haemolymph glands.

A study has been made of the epidemic and endemic aspects of infective hepatitis as it affects the civilian population of Palestine. Since the data analysed pertain primarily to Jews who have migrated to the country during the last 25 years, the results must be interpreted in terms of this group, although available data for other segments of the population are presented. The analysis was based on (a) records of persons who were members of the Sick Fund of the General Federation of Jewish Labour (W.S.F.) and the Rural Sick Benefit Fund (R.S.B.F.), (b) records of infants and children under the supervision of the Hadassah Medical Organization (H.M.O.) and the Tel-Aviv municipality, (c) records of persons admitted to H.M.O. hospitals over a 20-year period, and (d) records of the Government Department of Statistics for 1944.

Sick-fund records and those of supervised children afford reasonably reliable incidence rates for these groups in various parts of the country. Hospital records, however, which have been the only source of information regarding other aspects of the disease are affected to an unknown extent by various factors which determine the selection of persons who apply for hospital care. The analysis has brought out the following points:

1. Incidence of infective hepatitis has been estimated at 100 per 10,000 of the people of Palestine. About 2 per 10,000 Jews in the population were hospitalized with the disease. Incidence was significantly greater in rural districts.

2. Incidence rose to epidemic proportions during the years 1941–4 in the various administrative subdistricts inhabited largely by Jews. On the coastal plain the epidemic reached its peak in 1942, but in the interior incidence was highest in 1943. Rates declined in 1944.

3. Fatality was generally low, but the disease may pursue a severe and even fatal course among children and pregnant women.

4. The monthly distribution of hepatitis cases varied somewhat with age and district. In general monthly indices reached their peak in December and January and dropped to a minimum in May, but among young children a subsidiary peak appeared in July and August.

5. Among native Palestinians 50% of the hospitalized patients were under 5 years of age, whereas among those born elsewhere, whether in Europe, the Mediterranean basin or the Near East, some 60% were between 15 and 29 years of age.

6. Males and females born in Palestine were equally affected, but there were more immigrant males than females in the hospitalized group of cases. Unmarried persons evidently acquired the disease sooner after their arrival than did those that were married.

In conclusion it may be said that the information derived from the hospital records suggests that the disease is endemic in Palestine and is usually acquired in childhood. Immigrants from non-endemic regions are likely to become infected soon after their arrival. The monthly distribution of infective hepatitis cases resembles that of the respiratory diseases, but the secondary rise among children in July and August suggests that flies and food contamination may play a part in transmission.

A total of 637 strains of Salmonella bareilly received from different parts of India between 1959 and 1985 were phage typed using five locally isolated wild phages. The overall typability was 94·5% and 11 different phagc types could be defined. Phago types 10 and 1 were the most prevalent and the geographical and source distribution is described.

A multiple-tube technique based on peptone water incubated at 44 °C for 24 h followed by detection of indole was found to be sensitive and specific for the detection of Escherichia coli in oysters and mussels. The method has the advantage of providing rapid results and is both less expensive and less time-consuming than other MPN techniques.

In the present paper an attempt has been made to devise a method of determining mortality rates at ages from causes of death associated with childbearing. The sources of possible fallacy in this procedure have been discussed, and it is probable that the results found will represent fairly accurately the true course of mortality in this country.

From all causes of death in childbearing, mortality follows this course: beginning with a high value in the age group 15–20, the rate drops to a minimum in the second quinquennium of reproductive life and thereafter gradually increases with age.

The main components of the death rate exhibit a similar age distribution, but other less important causes of death show an uninterrupted increase with age from the commencement of the reproductive period.

Eclampsia is much more common in young women, but this may be entirely due to the greater proportion of primiparae at these young ages. Estimated in terms of first births the death rate increases rapidly and steadily with age, subject to a small exception in the first quinquennium which may possibly be a consequence of unfavourable marital selection at that age.

The high puerperal mortality of young mothers cannot wholly be accounted for by the excessive dangers of primiparity. Evidence has, however, been submitted that these young women are, on the average, a less healthy sample of the total female population at that age and that, apart from primiparity and adverse selection, the death rate from childbed causes probably follows the same law of mortality as of women in general from all other causes of death.

There has been within recent years a decline of nearly 50 per cent, in the puerperal mortality in young mothers of 15–20 and a smaller decrease in the second quinquennium of reproductive life; but there is no evidence of any improvement at later ages. These phenomena have been brought into relation with the change which has taken place in the death rate from all other causes in married women at these ages. The youngest group of married women, relative to unmarried of the same age, were in the more recent period studied in a much more favourable position with regard to their mortality from causes other than those connected with childbearing than they had been formerly. No corresponding improvement has taken place in the relative mortalities from all other causes in older women within the childbearing ages.

These results suggest that the general health of the mother is a factor of great importance in determining the height of the mortality rate in pregnancy.

In these experiments the hook-worm anaemia of dogs does not appear to be exactly analogous to the corresponding disease in man, but differs from it in two essential particulars, namely, that only young animals suffer and that in them its course progresses much more rapidly to a fatal termination.

Older dogs, although not altogether insusceptible, acquire infection only to a moderate extent, which gives rise to a minor degree of anaemia. From this they gradually recover, even in spite of repeated and continued attempts at re-infection.

The anaemia in young dogs was characterised by great loss of weight, emaciation, prostration and intestinal haemorrhage, but in no case was expistaxis observed.

The blood volume of dogs suffering from the minor degree of hookworm anaemia is not materially altered, but if anything is somewhat diminished. The oxygen capacity of the blood per unit of body weight is also, on the average, somewhat decreased.

Infection is generally accompanied by distinct though not profuse haemorrhage, which is most marked in the early stages, but tends to disappear.

Eosinophilia was not a constant sign either of infection or of disease.

Evidence of blood regeneration was furnished by the appearance of large numbers of erythroblasts (normoblasts) which increased with the progress of the disease.

Cats are much less easily infected than dogs, and monkeys are altogether insusceptible. Man, also, were found to be insusceptible to infection with the dog hook-worm.

Whatever may be the final form of the theories of Ehrlich as to the constitution of the bacterial toxines and as to the essential nature of immunity there can be no doubt of the stimulus they have given and are likely to give to inquiries relating to these subjects. As the present paper is intended to give a preliminary account of some researches bearing on the reactions of certain toxines it may be useful to recall the main features of the theories in question so far as they relate to the toxines investigated.

IN view of a previous failure1 to produce a skin infection with Ankylostoma, it seems worth while to put on record the present successful case. Dr J. B. Leathes very kindly offered himself as the subject of experiment. It is important to note that he has never, either before or during the course of the experiment, had anything to do with any Ankylosotoma material except that deliberately applied to his person for the purpose of this experiment, nor has he been to any infected place or even worked in the part of the Institute where the cultures of Ankylosotoma larvae have been kept. On March 21st a small quantity of water containing encapsuled larvae of A. duodenale, hatched artificially from infected faeces from Cornwall, and 13 days old, was applied to the forearm. After five minutes the arm was bandaged up and left for two hours, at the end of which time the wrappings were removed and the arm throughly cleansed. The purpose of the experiment and the precautions necessary were fully appreciated by the subject, and there is no doubt that there was not the slightest possibility of a mouth infection.