An international collection of 419 isolates of Salmonella agona was phage typed, biotyped and colicine typed. Of 16 recognized phage types, 15 were represented. Three phage types (I, V and XVI) accounted for 84% of all isolates, were widely distributed and may be interconvertible. Biotyping afforded little type differentiation; thus 92·6% of the isolates belonged to biotype 1 a. A rhamnose non-fermenting variant line (of biotype 5a) became established in Zaire from 1979 to 1980. A maltose late-fermenting line of biotype 1 a, isolated in Scotland in 1974, did not thereafter become established. Two Col+ lines (producing colicine I b) accounted for 45 of 68 colicinogenic isolates. The implication of type diversification and the phylogenetic significance of these findings are discussed.

Notwithstanding several efforts, a satisfactory method of serological diagnosis of foot-and-mouth disease has not been arrived at. This uncertainty of serological methods delayed the discovery of the plurality of type of the virus, although the observations of epizootics and the irregular results obtained by active and passive immunisation suggested multiplicity of type. Stimulated by such observations, Vallée and Carré (1922) experimented with two viruses of foot-and-mouth disease, one of which was of German and the other of French origin. They were able to show by experimental infection, confirmed by subsequent testing for active immunity, that cases of foot-and-mouth disease with the same clinical course and symptoms could be caused by two distinct types of virus. These they called A (Allemand) and O (Oise). The only difference between these two types was their inability to produce reciprocal immunity. The existence of more than one type of virus has been confirmed in England by Stockman and Minett (1926), and by Bedson, Maitland and Burbury (1927); in Germany, by Waldmann and Trautwein (1926), and Trautwein (1927); in France, by Lebailly (1926), Olitsky (1927), and in Sweden, by Magnusson and Hermansson (1926).

1. A preparation containing 0·7% scilliroside (the glucoside of red squill) had been tested as a poison for Rattus norvegicus and R. rattus.

2. The preparation has been found to be effective in the field against norvegicus but not against rattus.

3. Assayed against a strain of white rats, the preparation had an LD 50 for males of about 25mg./kg., and for feamales of about 5 mg./kg.

4. The LD 50 for adult Rhode Island Red fowls was greater than 400 mg. /kg. Pigs, dogs and cats were treated with doses up to 16mg./kg. without fatal results.

5. Silmurine was unpalatable to pigs, dose and cates, but fowls readily consumed a mash containing 1% Slimurine.

A method for typing ECHO and Coxsackie B viruses using counter-electrophoresis has been developed using stock strains of 15 different ECHO types and 5 Coxsackie B viruses. Work is continuing to see whether the method is a practical one to use for typing of strains from patients infected with ECHO or Coxsackie B viruses.

One hundred and eighty-two raw, 112 pre-cooked and 750 cooked hamburgers composed mainly of beef or beef and pork were subjected to microbiological examination.

Raw hamburgers gave total bacterial counts from 105 to 108 per g, counts of Enterobacteriaceae from 104 to 108 per g, of Escherichia coli from 103 to 105, of group D streptococci from 102 to 104, of Staphylococcus aureus from 3 to 102 and of Clostridium perfringens less than 10 bacteria per g. Of the samples, 32 % contained salmonellas; the highest most probable number was 102 per g but most estimates were below 1 per g. Corresponding figures for the pre-cooked samples were 2–3 log cycles lower, and only one sample contained salmonella. Yersinia enterocolitica was not isolated from any raw or pre-cooked sample.

Three hundred and ninety-five of the cooked hamburgers were prepared by grilling raw hamburgers for between 2 and 5·5 min. These gave total bacterial counts from 105 to 107 per g, and counts of Enterobacteriaceae from 102 to 105 per g. Of the samples, 9·4 % contained salmonellas, always in numbers below 1 per g. The remaining 355 cooked hamburgers were prepared from samples pre-cooked for 10 min at 80 °C. Some were grilled and some fat fried. The total bacterial counts were from 103 to 105 per g, and counts of Enterobacteriaceae below 102 perg. Salmonellae, again in small numbers only, were recovered from 3·5 % of samples.

When hamburgers were artificially contaminated with Salmonella typhimurium it took 5·5 min on a commercial grill, 2·25 min frying in a frying pan and 1·75 min on a household grill to reliably reduce the salmonella count one hundredfold. This means that at many vending places hamburgers are often cooked for too short a time.

D-values were determined for S. typhimurium in hamburger meat at 50, 55, 60, 65 and 70 °C, these values were 7·1, 5·1, 1·2, 0·9 and 0·6 min respectively. It can be concluded that the heating action in the centre of the hamburgers will take place more slowly than in the hamburger as a whole, and that the time between cooking and consumption is very important in reducing the microbial load to acceptable levels.

Pre-cooking (10 min at 80 °C in a water bath) gives a reduction in the numbers of salmonella of about 4 × 103, after which cooking gives a further reduction as mentioned above.

A significant proportion of Q fever patients from the first Dutch Q fever outbreak in 2007 showed impairment in health status up to 1 year after infection. Interested in whether this decrease in health status persisted, we set out to determine the health status in the same cohort of patients, 4 years after primary infection and to compare health status scores at the individual patient level between 1 and 4 years follow-up. Health status was assessed with the Nijmegen Clinical Screening Instrument (NCSI). Patients were serologically tested to exclude patients with possible, probable or proven chronic Q fever. Results on the NCSI sub-domains at group level [2008 (n = 54) and 2011 (n = 46)] showed a persistent significant percentage of patients exhibiting clinically relevant (‘severe’) scores for all NCSI sub-domains. After 4 years, undue fatigue was present in 46% and exactly half of all patients experienced a severely impaired general quality of life. Patients with NCSI scores available in both 2008 and 2011 (n = 37) showed no difference in all sub-domain scores, except for a small decrease in dyspnoea emotions in 2011. In this group, a significant proportion of patients either improved or worsened in one or more sub-domains of health status. We conclude that at the group level, health status of Q fever patients remained impaired 4 years after primary infection. At the individual patient level, health status may change.

India has the third-largest burden of human immunodeficiency virus (HIV) infection in the world. The coronavirus disease 2019 (COVID-19) pandemic has only exposed the cracks in the Indian healthcare infrastructure concerning HIV. The prevalence of HIV in India is more among the destitute or sections of society shrouded by years of social stigma such as prostitutes, truck drivers, transsexuals and intravenous drug users. National AIDS Control Organisation and The Joint United Nations Programme on HIV/AIDS (UNAIDS) organisation have many several efforts over the years to set up counselling and testing centres all over the country and spread awareness about HIV among the masses. COVID-19 pandemic has reversed years of progress made by the same. HIV patients are biologically more susceptible to COVID-19, and the lockdown has led to the loss of jobs, economic crises, shortage of drugs and necessities such as food and housing among this vulnerable population, which can result in lowered CD4-T cell counts in the coming months and make way for dangerous opportunistic infection outbreaks in this population increasing the overall HIV burden of India. This article explores how COVID-19 has impacted India's already existing HIV epidemic and tries to put forth recommendations based on the evidence found to be better prepared in treating the HIV-positive population in India in the face of another catastrophe like the COVID-19.

Two epidemics among mice are described that were closely associated with Morgan's No. 1 bacillus. In both of these epidemics the mice, which were fed on oats and raw beef, were found at autopsy to be suffering from peculiar lesions—an advanced degree of anaemia, pale and swollen kidneys, and general pallor and dryness of the tissues—not hitherto encountered in any other epidemic. Evidence is advanced to show that Bact. morgani was the specific cause of these epidemics; and it is suggested that the peculiar lesions described were the result of a chronic intestinal infection with this organism.

The close analogy existing between the bacteriological findings in summer diarrhoea and in our experiments is discussed. The tentative conclusion is advanced that summer diarrhoea is not a bacteriological entity, but is a disease that can be caused by a number of different members of the non-lactose-fermenting group.

A cluster of three cases of listeriosis cases occurred against a background of endemic listeriosis in Western Australia. Human and environmental isolates of Listeria monocytogenes obtained during the outbreak investigation were rapidly subtyped by automated ribotyping using an EcoRI protocol and a RiboPrinter®. DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) was used to confirm the relatedness of isolates. Serogroup 1/2 predominated among the food samples and the four clinical isolates from the outbreak cluster were also of this serogroup. All isolates from chicken material were serogroup 1/2 and indistinguishable by ribotype pattern. PFGE subdivided strains of this ribotype into four subtypes. The preliminary analysis had an immediate impact on hypothesis generation, environmental health investigations, environmental specimen collection and initial control measures. Sufficient typing data to guide environmental health and disease control initiatives was generated in less than one week by combining automated ribotyping with PCR-based detection of L. monocytogenes in suspect foodstuffs and an L. monocytogenes DNA probe. There were no further cases of bacteriologically confirmed listeriosis in Western Australia for six months after completion of the investigation.

Contamination of a laboratory environment with pathogenic or non-pathogenic micro-organisms may be relevant to safety of technicians and quality of technical performance. Two widely separated incidents in 1968 and 1974 initiated a study of aspects of the laboratory environment. Water-baths, water of syneresis and portions of salmonella cultures spurting out of the sterilizing flame were examined. The water of water-baths was shown to be contaminated from the fluid cultures incubated in them. This raised questions of potential cross-contamination and reporting of false positives. Water of syneresis was sometimes contaminated with salmonellas. A few quantitative counts were made. The range of counts varied between 16 salmonellas per ml. and 13,000,000 salmonellas per ml. Five hundred portions of salmonella cultures and 571 portions of Shigella sonnei cultures which had spurted from the sterilizing flame were examined. All these samples failed to grow salmonellas or shigellas.

Precautions necessary to avoid environmental contamination are briefly discussed.

The aim of this study was to demonstrate the epidemiological use of multiple correspondence analysis (MCA), as applied to tuberculosis (TB) data from North East London. Data for TB notifications in North East London primary care trusts (PCTs) between the years 2002 and 2007 were used. TB notification data were entered for MCA allowing display of graphical data output (n=4947); MCA analyses were performed on the whole dataset, by PCT, and by year of notification. Graphical MCA output displayed variance of data categories; clustering of variable categories in MCA output signified association. Clustering patterns in MCA output demonstrated different associations by year of notification, within PCTs and between PCTs. MCA is a useful technique for displaying association of variable categories used in TB epidemiology. Results suggest that MCA could be a useful tool in informing commissioning of TB services.

The performance of the rodenticide 5-p-chlorophenyl silatrane at 0.5% in a wholemeal flour/pinhead oatmeal/corn oil bait was compared with that of zinc phosphide at 3% in the same base in poison treatments carried out against urban infestations of the house mouse (Mus musculus L.). Each poison treatment was conducted for 1 day and after 3 days' pre-baiting. The success of the treatments was assessed from census baitings conducted before and after treatment. Treatment success varied considerably with both poisons used but in general 5-p-chlorophenyl silatrane proved to be at least as effective as zinc phosphide, a commonly used acute rodenticide for the control of mice.

Cryptosporidiosis and giardiasis have been recognized by the WHO as ‘Neglected Diseases’. Minimal attention has been paid to the spatial and temporal distribution of disease incidence patterns. Using disease notification data, we detected spatio-temporal clusters of cryptosporidiosis and giardiasis across three time periods: (i) 1997–2000, (ii) 2001–2004, (iii) 2005–2008. There was substantial variation in the geographical location and timing of recurrent cryptosporidiosis and giardiasis clusters. Statistically significant (P < 0·05) giardiasis clusters tended to occur in predominantly urban areas with little apparent seasonal influence, while statistically significant cryptosporidiosis clusters were detected in spring, in areas with high livestock land use. The location and timing of cryptosporidiosis clusters suggest an influence of livestock production practices, while urban exposures and host behaviour are likely to influence giardiasis clusters. This approach provides a resource-efficient method for public health authorities to prioritize future research needs and areas for intervention.

A dipthericin typing scheme has been constructed using 441 strains of Corynebacterium diptheriae isolated in eastern Australia from 1962 to 1971. Ten types have been distinguished using seven strains of C. diphtheriae and two strains of C. belfanti as indicators of the diphthericins produced by the newly isolated strains. Strains grouped into types L2, L3 and L3a were found only in Melbourne and types L1 and L4 were predominant in Sydney. Type L5 strains were isolated intermittently throughout the period of study and were found in all eastern states. Numerical analysis of the characteristics of the strains suggests that associations exist between, on the one hand, diphthericin type and, on the other hand, bacteriophage type, serotype and biochemical activity.

Between 1961 and 1972, 4547 independent strains of Staphylococcus aureus isolated from one hospital were examined for phage type. After 1967 there was a decline in the number of strains received, which we consider reflects a decline in the number of infections in the hospital, and which was largely accounted for by a great reduction in the number of strains in four ‘epidemic’ types. Overall, the number of multiple-resistant staphylococci received also declined; this was in part due to the decline in the epidemic types and in part to a reduction in the proportion of multiple-resistant strains of all types.

A technique is developed by which minimal changes in haemagglutinin inhibitors can be detected.

It is shown that the inhibitor index of normal human nasal secretions is 33·2 with a standard deviation of ±7·4. This value is independent of the donor, of the absolute amount of mucus collected, of the time of extraction, and of the period of storage.

Minimal amounts of influenza viruses (less than one agglutinating dose) are capable of causing significant alteration in the inhibitor index upon interaction in vitro for 60 min. at 37° C.

We argue that the spread of unhealthy behaviour shows marked similarities with infectious diseases. It is therefore interesting and challenging to use infectious disease methodologies for studying the spread and control of unhealthy behaviour. This would be a great addition to current methods, because it allows taking into account the dynamics of individual interactions and the social environment at large. In particular, the application of individual-based modelling holds great promise to address some major public health questions.

In France, surveillance of bronchiolitis is based on a pilot network of hospital emergency departments. The study was a 1-year observational study (2007–2008) carried out in a central region of metropolitan France. The hospitalization rate for bronchiolitis was 17·7/1000 children aged <1 year and the estimated prevalence of bronchiolitis ranged from 17·7% to 34·4% in children aged <1 year. Such a network constitutes a valuable tool to estimate the dynamic and the burden of infant bronchiolitis.

In Norway, incidence of sporadic domestically acquired salmonellosis is low, and most frequently due to Salmonalla Typhimurium. We investigated the risk factors for sporadic Salmonella infections in Norway to improve control and prevention measures. Surveillance data for all Salmonella infections from 2000 to 2015 were analysed for seasonality and proportion associated with domestic reservoirs, hedgehogs and wild birds. A prospective case–control study was conducted from 2010 to 2012 by recruiting cases from the Norwegian Surveillance System for Communicable Diseases and controls from the Norwegian Population Registry (389 cases and 1500 controls). Univariable analyses using logistic regression were conducted and a multivariable model was developed using regularised/penalised logistic regression. In univariable analysis, eating snow, dirt, sand or playing in a sandbox (aOR 4.14; CI 2.15–7.97) was associated with salmonellosis. This was also the only exposure significantly associated with illness in the multivariable model. Since 2004, 34.2% (n = 354) of S. Typhimuirum cases had an MLVA profile linked to a domestic reservoir. A seasonal trend with a peak in August for all Salmonella types and in February for S. Typhimurium was observed. Indirect exposure to domestic reservoirs remains a source of salmonellosis in Norway, particularly for children. Information to the public about avoiding environmental exposure should be strengthened and initiatives to combat salmonellosis in the food chain should be reinforced.

We evaluated the prevalence of human papillomavirus (HPV) infection in Amerindian women from a tribe in Brazilian Amazonia. Demographic data, pap smears and cervical samples for HPV DNA detection by polymerase chain reaction (PCR) were obtained for women aged above 10 years old. In total, 79 (85·9%) out of 92 eligible women who lived there were interviewed; all women already had engaged in sexual activity. Seventy-eight and 49 women allowed collection of pap smears and PCR samples, respectively. Cytological signs of HPV infection were observed in 11 patients; 6 of these were probed for HPV infection and 1 shown to be HPV 16. Overall prevalence of HPV infection detected by PCR was 14·3%. Three patients presented high-risk HPV DNA types[ratio ]two HPV 16 and one co-infection of HPV 16 and 58. Cervical infection by oncogenic HPV types occurs in Amerindian women and cervical cancer screening should be a priority in this setting.