A. Results following the subcutaneous inoculation of 1400 grm. rabbits with a 2 per cent. suspension of living fixed virus in a dosage of 5 c.c. daily on 14 consecutive days (1·4 grm.):

(1) Fresh living fixed virus introduced into rabbits subcutaneously produces in the sera of these animals so high a degree of rabicidal power that one unit volume of undiluted serum is capable of neutralising, when antibody formation is at a maximum, 16 unit volumes of a 1:100 suspension of freshfixed virus in n.s.s.

(2) Rabicidal properties in the serum are demonstrable 18 days after the commencement of treatment, one unit volume of serum then neutralising one volume of a 1:100 f.v. suspension in n.s.s.

(3) Rabicidal antibody content reaches a maximum between 50 and 60 days after completion of treatment, and thereafter diminishes somewhat gradually.

(4) Immune sera retain their rabicidal properties for a period extending over 222 days, viz. from the 4th to the 226th day after completion of treatment.

B. Results following the subcutaneous inoculation of 1400 grm. rabbits with a 2 per cent. suspension of killed carbolised-fixed virus in a dosage of 5 c.c. daily on 14 consecutive days (1·4 grm.):

(1) Killed carbolised virus administered to rabbits subcutaneously produces a very considerable degree of rabicidal power. The maximum reached, however, falls much short of that attained by immunisation with fresh-fixed virus and is only one-third of that following the use of etherised vaccine, one unit volume of serum neutralising 8 unit volumes of a 1:100 f.v. suspension in n.s.s.

(2) Rabicidal properties in the serum are demonstrable 18 days after the commencement of treatment, one unit volume of serum neutralising one unit volume of a 1:100 f.v. suspension in n.s.s.

(3) Rabicidal antibody content reaches a maximum some 50–60 days after completion of treatment, and thereafter subsides fairly rapidly.

(4) Sera of rabbits immunised with carbolised-fixed virus retain their rabicidal properties for a period of 131 days, viz. from the 4th to the 135th day after completion of treatment.

C. Results following the subcutaneous inoculation of 1400 grm. rabbits with a 2 per cent. suspension of killed etherised virus in a dosage of 5 c.c. daily on 14 consecutive days (1·4 grm.):

(1) Killed etherised virus introduced into rabbits subcutaneously produces in these animals' sera such an extraordinary degree of rabicidal power that, when antibody formation has reached a maximum, one unit volume of undiluted serum is capable of neutralising as many as 24 volumes of a 1:100 f.v. suspension in n.s.s.

(2) Rabicidal properties in the serum are demonstrable on the last day of treatment (14 days after commencement), one unit volume of serum neutralising one unit volume of a 1:100 f.v. suspension in n.s.s.

(3) Rabicidal antibody content reaches a maximum between 50 and 60 days after completion of treatment, and thereafter diminishes fairly gradually.

(4) Sera of rabbits immunised with etherised-fixed virus retain their rabicidal properties for a period of 226 days, viz. from the 14th to the 240th day after commencement of treatment.

During the period July 1st—October 31st, 1911, 15,332 rats were examined for plague infection. These rats were obtained (see Map facing p. 311) partly from the area which in the previous year had been found to be infected with rat-plague and partly from the districts immediately adjacent to this area.

As a result of the present enquiry 27 farms or other premises were found to harbour plague-infected rats.

These 27 places are all within the area previously pronounced to be infected. No plague-infected rats have been discovered outside this area.

Experience of rat collection during the present enquiry showed that the rat destruction which had been maintained by local enterprise since the end of 1910 had in many localities appreciably diminished the rat population.

During 1962, twenty-seven food poisoning incidents due to Salmonella typhimurium, phage type 4, comprising thirty-two cases and twelve symptomless excreters, occurred in the south-east Lancashire conurbation. The source of infection was a single small producer of English liquid egg. Pasteurization of the product coincided with the end of the outbreak. The cases were sporadic in distribution. Investigation of previous incidents due to this phage type in the City of Manchester pointed to egg from the same producer. As a result an investigation was made into the amount and source of unpasteurized egg in use in the city. This revealed the frequent presence of salmonella infection and demonstrated the need for pasteurization of liquid egg before use.

1. An incomplete field study in Lincolnshire, England, suggested that toxoplasmosis might be transmitted from pig to man by mosquitoes. Although the results were inconclusive they suggested the experimental work recorded in this paper.

2. Trophozoites of the Beverley strain were obtained in increased yield from the peritoneal fluid of Mastomys treated with hydrocortisone. Cysts were obtained in increased yield by passage of the brain of Sigmodon into laboratory mice.

3. Four species of mosquitoes were fed through a membrane or on sucrose solution on media containing either cysts or trophozoites of Toxoplasma gondii. In some experiments blood was added to ensure passage of the feed to the mosquito stomach, in others it was excluded so that at least part would pass to the crop.

4. A spurious ‘cyst’ resembling but distinguishable from Toxoplasma was noted in the homogenate of mouse brain.

5. In no instance did mosquitoes retain infectivity as demonstrated by injection into mice, beyond the third day, but since experiments were not carried on beyond the fourteenth day the existence of an occult form cannot be excluded.

Eastern equine encephalitis (EEE) is a rare but severe emerging vector-borne disease affecting human and animal populations in the northeastern United States where it is endemic. Key knowledge gaps remain about the epidemiology of EEE virus (EEEV) in areas where its emergence has more recently been reported. In Eastern Canada, viral activity has been recorded in mosquitoes and horses throughout the 2000s but cases of EEEV in humans have not been reported so far. This study was designed to provide an assessment of possible EEEV human exposure by modelling environmental risk factors for EEEV in horses, identifying high-risk environments and mapping risk in the province of Quebec, Canada. According to logistic models, being located near wooded swamps was a risk factor for seropositivity or disease in horses [odds ratio (OR) 4·15, 95% confidence interval (CI) 1·16–14·8) whereas being located on agricultural lands was identified as protective (OR 0·75, 95% CI 0·62–0·92). A better understanding of the environmental risk of exposure to EEEV in Canada provides veterinary and public health officials with enhanced means to more effectively monitor the emergence of this public health risk and design targeted surveillance and preventive measures.

The concentrations of serum IgE (PRIST) and IgE- and IgG-specific antibodies to egg protein were determined in paired sera taken from students who had received influenza virus vaccine. Although persons who gave a history of allergy to egg or to chicken feathers were excluded, 10–16% of vaccinees possessed higher titres of serum IgE and IgE-specific antibody (RAST) to egg white (Fl) allergen before vaccination. The titres of IgG-specific antibody to egg protein (ovalbumin and ovomucoid antigens) were negligible, and did not show any significant response after vaccination. In contrast, IgE-specific antibody to Fl allergen rose significantly in a considerable number of the vaccinccs. The results obtained indicate possible contamination of vaccine products with allergens of egg origin and a potential risk of allergic manifestation after influenza vaccination.

A survey was carried out between June 1970 and December 1971 in which gall bladders from cattle either slaughtered for food consumption or disposed of through knackeries were cultured for salmonellas. Salmonella dublin was isolated from 28 of 1617 gall-bladders of adult cattle killed in the slaughterhouse at Carmarthen, and from 23 of 197 gall-bladders obtained from adult cattle sent to a knackery at Abergwili, near Carmarthen. The results are compared with a similar survey carried out in 1947 and 1948.

Between June and November 1971 gall-bladders and uteri were also obtained from a slaughterhouse in Newcastle Emlyn, North Carmarthenshire, and a knackery in Tanygroes, South Cardiganshire. S. dublin was cultured from two gall-bladders but from none of the uteri of the 161 slaughterhouse cases. Seven of the 46 cows from the knackery yielded S. dublin on culture: 2 in the gall-bladder only, 3 in the uterus only and 2 in both gall bladder and uterus.

A new dulcitol–salicin–sucrose–iron–urea medium is described which, on the basis of a single-tube culture, tests the fermentation of three sugars, H2S production and urea hydrolysis.

On this medium 91% of 228 Salmonellae gave easily recognized characteristic reactions, simulated only by some strains of the Bethesda-Ballerup group. Proteus strains and most paracolon strains gave equally characteristic pictures.

The reactions of some other Enterobacteria are described. It is suggested that the medium is good enough to deserve extended trial in routine work.

In March 2020, China had periodically controlled the coronavirus disease-19 (COVID-19) epidemic. We reported the results of health screening for COVID-19 among returned staff of a hospital and conducted a summary analysis to provide valuable experience for curbing the COVID-19 epidemic and rebound. In total, 4729 returned staff from Zhongnan Hospital of Wuhan University, Wuhan, China were examined for COVID-19, and the basic information, radiology and laboratory test results were obtained and systematically analysed. Among the 4729 employees, medical staff (62.93%) and rear-service personnel (30.73%) were the majority. The results of the first physical examination showed that 4557 (96.36%) were normal, 172 (3.64%) had abnormal radiological or laboratory test results. After reexamination and evaluation, four were at high risk (asymptomatic infections) and were scheduled to transfer to a designated hospital, and three were at low risk (infectivity could not be determined) and were scheduled for home isolation observation. Close contacts were tracked and managed by the Center for Disease Control and Prevention (CDC) in China. Asymptomatic infections are a major risk factor for returning to work. Extensive health screening combined with multiple detection methods helps to identify asymptomatic infections early, which is an important guarantee in the process of returning to work.

The impact of vanB vancomycin-resistant enterococci (VRE) bacteraemia on length of stay (LOS) in hospital, after adjusting for the time-varying nature of enterococcal bacteraemia (variable onset of bacteraemia post-admission), is unknown. Survival analyses (time-varying Cox and competing risks regression) were performed on vanB VRE bacteraemia patients, matched 1:1 with vancomycin-susceptible enterococci bacteraemia patients to determine the factors associated with LOS in these patients. In Cox regression analysis, vanB VRE bacteraemia, intensive-care-unit admission, Charlson co-morbidity index score ⩾4, and an increase in the time to receive appropriate antibiotics were associated with prolonged LOS. Competing risks regression which accounts for the influence of in-patient mortality on the ability to observe the event discharge alive from hospital suggests that, vanB VRE bacteraemia was not significantly associated with prolonged LOS. For the first time, the rate of discharge from hospital in patients with vanB VRE bacteraemia has been quantified.

We analysed Mycobacterium tuberculosis strains from children, hospitalized from January 2004 to July 2008 in the largest paediatric hospital complex in Cambodia. Specimens were tested for drug susceptibility and genotypes. From the 260 children, 161 strains were available. The East African-Indian genotype family was the most common (59·0%), increasing in frequency with distance from the Phnom Penh area, while the frequency of the Beijing genotype family strains decreased. The drug resistance pattern showed a similar geographical gradient: lowest in the northwest (4·6%), intermediate in the central (17·1%), and highest in the southeastern (30·8%) parts of the country. Three children (1·9%) had multidrug-resistant tuberculosis. The Beijing genotype and streptomycin resistance were significantly associated (P < 0·001). As tuberculosis in children reflects recent transmission patterns in the community, multidrug resistance levels inform about the current quality of the tuberculosis programme.

We have shown that in the laboratory the rat flea, P. cheopis, will readily bite man. When very numerous it will bite man even in the presence of its natural host. We have been able to keep this species of flea alive for more than three weeks by feeding it on man alone.

In the course of some experiments in godowns which were infested with P. cheopis alone, we have often taken fleas in considerable numbers on the legs of men who have entered the godowns for a short time.

In a building in Bombay, in which there had been a severe rat mortality, proved to be due to plague, we have taken rat fleas in large numbers on the legs of men who entered some of the rooms in this building even for a short time.

We can conclude, therefore, that the rat flea, P. cheopis, under certain circumstances, is attracted by man, and will readily bite and feed on him.

We examined factors affecting the immunogenicity of trivalent inactivated influenza vaccination (TIV) in children using the antibody titres of children participating in a Hong Kong community-based study. Antibody titres of strains included in the 2009–2010 northern hemisphere TIV [seasonal A(H1N1), seasonal A(H3N2) and B (Victoria lineage)] and those not included in the TIV [2009 pandemic A(H1N1) and B (Yamagata lineage)] were measured by haemagglutination inhibition immediately before and 1 month after vaccination. Multivariate regression models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following vaccination. Statistically significant rises in geometric mean antibody titres were observed against all strains, with a wide variety of standard deviations and correlations in rises observed, with the influenza type B antibodies showing more variability than the type A antibodies. The dynamics of antibody titres after vaccination can be used in more complex models of antibody dynamics in populations.

The Mahoney, Type 1, poliomyelitis virus had been through six to-and-fro monkey kidney-tissue culture and suckling mouse passages. Early paralysis was produced in groups of mice inoculated directly from infected tissue-culture fluid, but mouse-to-mouse passage failed to produce paralysis except in an occasional mouse. At the 7th tissue-culture mouse passage, the virus harvested from paralysed mice was inoculated into 100 mice. One mouse developed paralysis within 24 hr. From this mouse a variant of Mahoney virus was isolated which has now been through seventy-five mouse-to-mouse passages and produces paralysis in 90–100% of mice within 3 days.

The authors would like to express their deep appreciation of Prof. A. Kipps' constant interest and encouragement.

This investigation has been concerned with the changes that occur in the coliform and faecal coli content of water samples on storage at room and refrigerator temperatures for 6 hr. as compared with those occurring after 24 hr. storage.

The examination was conducted by a 70-tube method using twofold diminishing volumes.

The percentages of samples showing a significant change corresponding to at least a doubling or halving of the coliform content on storage were: (a) at room temperature after 6 hr. 24.7%, and after 24 hr. 38.3%; (b) at refrigerator temperature after 6 hr. 25.0%, and after 24 hr. 33.9%. The percentages of samples showing a significant change in the faecal coli content on storage were: (a) at room temperature after 6 hr. 18.7%, and after 24 hr. 34.6%; (b) at refrigerator temperature after 6 hr. 10.4%, and after 24 hr. 25.0%. The changes were preponderantly decreases and most of the large changes occurred after 24 hr.

The investigation has shown that fewer changes occur after 6 hr. storage than after 24 hr. storage, and that storage for 6 hr. at refrigerator temperature is preferable to storage for 6 hr. at room temperature. Even so, some samples show significant changes after 6 hr. storage at refrigerator temperature; the coliform content is significantly altered in 25% of samples and the faecal coli content in 10% of samples.

Samples of water should, therefore, be examined as soon as possible after collection, certainly within 6 hr., and during the period of transport to the laboratory they should be kept cold, if possible by ice.

We conducted a food consumption survey in the general adult population of 18 years and older in Germany to obtain data on the frequency of consumption of food items that caused foodborne disease outbreaks in the past. A total of 1010 telephone interviews were completed that queried the consumption of 95 food items in the 7-day period before the interview. Survey results were weighted to be representative. Six exemplary ‘high risk’ food items were consumed by 6% to 16% of the general population. These were raw ground pork: 6.5%; ‘Teewurst’ (=spreadable sausage-containing raw pork): 15.7%; unpasteurised milk consumed without prior heating: 9.0%; food items prepared with raw eggs: 9.8%; unheated sprouts or seedlings: 8.8% and frozen berries consumed without prior heating: 6.2%. Data from our food consumption survey were comparable to data obtained from control persons in case-control studies conducted during past foodborne disease outbreak investigations. We consider our survey an additional helpful tool that will allow comparison with food consumption data from case-patients obtained in exploratory, hypothesis-generating interviews early on in outbreak investigations, and which may assist in forming hypotheses regarding associations of illnesses with suspected food vehicles. This may facilitate and accelerate investigations of future foodborne disease outbreaks.

‘The opportunities of a pathologist at a large Eastern Hospital are many; but his time for research work is short, and his conveniences are few.’ So begins this landmark paper written by Alfred Whitmore and published in the journal in 1913 [1]. He goes on to demonstrate just how well that short time can be used by someone with the energy, intelligence and scientific rigour in order to make the most of those opportunities. I first read this paper 15 years ago and have re-read it many times since, usually reflecting on how remarkably little our knowledge of melioidosis has advanced since 1913. I notice something new each time I read it and, most importantly of all, each time it is an absolute pleasure to read. How many modern scientific papers leave one feeling the same way?

The rapid transmissibility of the severe acute respiratory syndrome-coronavirus-2 causing coronavirus disease-2019, requires timely dissemination of information and public health responses, with all 47 countries of the WHO African Region simultaneously facing significant risk, in contrast to the usual highly localised infectious disease outbreaks. This demanded a different approach to information management and an adaptive information strategy was implemented, focusing on data collection and management, reporting and analysis at the national and regional levels. This approach used frugal innovation, building on tools and technologies that are commonly used, and well understood; as well as developing simple, practical, highly functional and agile solutions that could be rapidly and remotely implemented, and flexible enough to be recalibrated and adapted as required. While the approach was successful in its aim of allowing the WHO Regional Office for Africa (WHO AFRO) to gather surveillance and epidemiological data, several challenges were encountered that affected timeliness and quality of data captured and reported by the member states, showing that strengthening data systems and digital capacity, and encouraging openness and data sharing are an important component of health system strengthening.

An outbreak of salmonellosis occurred among 63 wedding participants. The outbreak was investigated through cohort, laboratory, and environmental studies. Consumption of rice-dressing made from a commercially cooked, meat-based, rice-dressing mix was strongly associated with illness. Nineteen patient isolates, six company/grocery store isolates cultured from the rice-dressing mix, and one environmental isolate from a pump in the production line were of an identical outbreak strain of Salmonella Infantis characterized by pulsed-field gel electrophoresis. In the production line, cooked rice-dressing mix tested negative for S. Infantis before and positive after contact with the contaminated pump. The dressing-mix had an estimated 200 colony-forming units of salmonella per gram of product, and > 180 000 pounds were distributed in 9 states for [ges ] 2 months before contamination was recognized. Food manufacturers should be required to use systematic, hazard analysis critical control point risk management practices for all processed meat products, validated by periodic microbiologic monitoring of the end product.