Vedder and Clark (1912), reporting observations on polyneuritis gallinarum based on experiments lasting for several years during which time over 200 fowls were used, make the following statement with regard to the relation between the amount of polished rice eaten and the time of development of neuritis.

1. An M-producing strain of Streptococcus pyogenes type-12 was shown to be carried on the surface of apparently healthy tonsils for at least 3 years.

2. Loss of M substance in a strain of type-3 in a tonsillar carrier was shown to be by gradual replacement of matt forms by glossy variants. This pair of naturally occurring variants showed very different growth rates as mixtures in liquid media.

3. Under suitable conditions, glossy variants regularly appeared and replaced the M-producing strain from which they were derived in these and all other strains of type-3 and type-12 tested from a wide variety of sources.

4. It is suggested that the selection of variants by the differential nutrient value of the micro-environment is the deciding factor in carrier strains showing loss of M substance.

A series of spontaneous epidemics of a paratyphoid infection among guinea-pigs is described. It is shown that an epidemic may result from the introduction of a fresh susceptible population into an infected area and vice versa. Such epidemics developed only when the new population was exposed during certain months. The bringing in of a fresh population at the end of November was not followed at the time by an epidemic outbreak; the epidemic did not occur until the following July.

The observed seasonal occurrence was not due to a change in virulence. The strains isolated at the end of the 1926 epidemic did not differ in virulence from those cultivated at the height of the 1927 epidemic.

The guinea-pig may remain a carrier for a long time whilst eliminating bacteria in the faecal discharges only intermittently and in small numbers. In general, even in the case of infected animals, the discharge of pathogenic bacteria is relatively small, except a few days before death.

Attention is called to the parallelism between the seasonal prevalence of human typhoid epidemics in this country and the epidemics of paratyphoid observed in our guinea-pig stock.

It is pointed out that a sound theory of the epidemiology of certain diseases must take into account the seasonal variation in host susceptibility.

A clinical trial to determine the effect of oral Humatin therapy on the course of the chronic enteric carrier state in a group of twenty-seven typhoid and paratyphoid B carriers is described. It is concluded that the drug when administered orally in this group of carriers fails in the dosage given to effect a cure of the carrier state.

Haemagglutination-inhibiting antibodies against A, A′ and A2 strains of influenza virus and against one strain of influenza B were estimated in sera from blood donors in Sydney in February 1958 and in April and October 1961.

The A2 antibody increased substantially while both A and A′ antibodies declined slightly. There was a great decline in influenza B antibody during the same period.

Thanks are due to Dr Phyllis M. Rountree who suggested this study. Miss Patricia Taylor gave excellent technical assistance in the early part of this work.

Studies on climate variables and food pathogens are either pathogen- or region-specific, necessitating a consolidated view on the subject. This study aims to systematically review all studies on the association of ambient temperature and precipitation on the incidence of gastroenteritis and bacteraemia from Salmonella, Shigella, Campylobacter, Vibrio, and Listeria species. PubMed, Ovid MEDLINE, Scopus, and Web of Science databases were searched up to 9 March 2023. We screened 3,204 articles for eligibility and included 83 studies in the review and three in the meta-analysis. Except for one study on Campylobacter, all showed a positive association between temperature and Salmonella, Shigella, Vibrio sp., and Campylobacter gastroenteritis. Similarly, most of the included studies showed that precipitation was positively associated with these conditions. These positive associations were found regardless of the effect measure chosen. The pooled incidence rate ratio (IRR) for the three studies that included bacteraemia from Campylobacter and Salmonella sp. was 1.05 (95 per cent confidence interval (95% CI): 1.03, 1.06) for extreme temperature and 1.09 (95% CI: 0.99, 1.19) for extreme precipitation. If current climate trends continue, our findings suggest these pathogens would increase patient morbidity, the need for hospitalization, and prolonged antibiotic courses.

Rubella is a highly contagious mild viral illness. It is a leading cause of congenital rubella syndrome (CRS). Routine data of rubella do not exist in Ethiopia. However, laboratory-based conformation of rubella cases from measles negative samples were collected from a measles surveillance system. The current study was to analyse the epidemiological distribution of rubella cases from measles-suspected cases in Ethiopia from 2011 to 2015. National-based secondary data analysis of rubella through measles-based surveillances was carried out. Measles-suspected cases were investigated using the case investigation form, and a serum sample collected and sent to the Ethiopian laboratory for conformation. Samples tested for measles immunoglobulin M (IgM) were tested for rubella. The investigation results were entered into an electronic database using SPSS version 25 for analysis. Out of 11749 samples tested for rubella IgM from 2011 to 2015, 2295 (19.5%) were positive for rubella IgM and 51% of rubella-positive cases were female. Five per cent of all cases were female aged between 15 and 49. Cases were confirmed from all regions, two administrative towns and seasonal variations were observed with peaks in the first and fourth seasonal periods of the years. As fear of congenital abnormality (CRS), the Ethiopian government should focus on rubella syndrome surveillance with the aim of starting a rubella vaccine.