We investigated whether there are differences between the natural history of B and C chronic hepatitis in a southern Italian population, and whether the chronic viral hepatitis population was modified by the introduction of the anti-HCV test in 1989. We examined clinical charts of 1120 patients consecutively admitted to our division from January 1979 to December 1998 with the histological diagnosis of chronic viral hepatitis (304 from 1979 to 1988; 816 from 1989 to 1998). We found significant differences only in age at diagnosis (higher in the second decade, P=0·001), and in aetiology (HBV decreased in the second decade, P<0·0001). We were able to follow up 449 patients for 2–20 years (311 with HCV and 138 with HBV infection), and found that chronic HCV evolved to cirrhosis more frequently than did chronic HBV; but in both types time to development of cirrhosis and the incidence of death were similar. Our data confirm that a higher onset age of HBV and of HCV is frequently observed in those subjects who have a faster disease progression.

The following contribution to the aetiology of cerebrospinal meningitis is published with a view to calling attention to the possible part played by dust in the causation of this disease. The strong connection between dusty occupations and cases of cerebrospinal fever, as here detailed afford, it is believed, a prima facie presumption that dust may be one of the vehicles of the specific germ.

Streptococcus pneumoniae serotype 35B, a non-vaccine type, is a major contributor to the increase in pneumococcal infection post-vaccination. We aimed to understand the mechanism of its spread by characterizing 35B. The serotype, type 1 pilus (T1P) positivity, and antimicrobial susceptibility of 319 isolates in 2018–2022 were analysed and compared with those of isolates in 2014–2017 to find the changes. 35B accounted for 40 (12.5%) isolates. T1P positivity was notably higher in 35B (87.5%) than in the other serotypes. To confirm the role of T1P, an adhesion factor, we compared adherence to A549 cells between T1P-positive 35B isolates and their T1P-deficient mutants, showing contribution of T1P to adherence. Penicillin-non-susceptible rate of 35B was 87.5%, and meropenem-resistant 35B rate was 35.0%, which increased from 14.5% of 2014–2017 (p = 0.009). Multilocus sequence typing was performed in 35B strains. Prevalence of clonal complex 558, harbouring T1P and exhibiting multidrug non-susceptibility, suggested the advantages of 35B in attachment and survival in the host. The emergence of ST156 isolates, T1P-positive and non-susceptible to β-lactams, has raised concern about expansion in Japan. The increase of serotype 35B in pneumococcal diseases might have occurred due to its predominant colonizing ability after the elimination of the vaccine-serotypes.

Following the emergence of SARS-CoV-2, early outbreak response relied on behavioural interventions. In the USA, local governments implemented restrictions aimed at reducing movements and contacts to limit viral transmission. In Pennsylvania, restrictions closed schools and businesses in the spring of 2020 and interventions eased later through the summer. Here we use passive monitoring of vehicular traffic volume and mobile device-derived visits to points of interest as proxies for movements and contacts in a rural Pennsylvania county. Rural areas have limited health care resources, which magnifies the importance of disease prevention. These data show the lowest levels of movement occurred during the strictest phase of restrictions, indicating high levels of compliance with behavioural intervention. We find that increases in movement correlated with increases in reported SARS-CoV-2 cases 9–18 days later. The methodology used in this study can be adapted to inform outbreak management strategies for other locations and future outbreaks that use behavioural interventions to reduce pathogen transmission.

Women infected during pregnancy with TORCH (Toxoplasmosis, Other, Rubella, Cytomegalovirus, and Herpes simplex viruses) pathogens have a higher risk of adverse birth outcomes including stillbirth / miscarriage because of mother-to-child transmission. To investigate these risks in pregnant women in Kenya, we analyzed serum specimens from a pregnancy cohort study at three healthcare facilities. A sample of 481 participants was selected for TORCH pathogen antibody testing to determine seroprevalence. A random selection of 285 from the 481 participants was selected to measure seroconversion. These sera were tested using an IgG enzyme-linked immunosorbent assay against 10 TORCH pathogens. We found that the seroprevalence of all but three of the 10 TORCH pathogens at enrollment was >30%, except for Bordetella pertussis (3.8%), Treponema pallidum (11.4%), and varicella zoster virus (0.5%). Conversely, very few participants seroconverted during their pregnancy and were herpes simplex virus type 2 (n = 24, 11.2%), parvovirus B19 (n = 14, 6.2%), and rubella (n = 12, 5.1%). For birth outcomes, 88% of the participant had live births and 12% had stillbirths or miscarriage. Cytomegalovirus positivity at enrolment had a statistically significant positive association with a live birth outcome (p = 0.0394). Of the 10 TORCH pathogens tested, none had an association with adverse pregnancy outcome.

In works on Public Health and Water Analysis, it is a common observation that the amount of chlorine in inland surface waters near the seaboard is considerably higher than what obtains in samples from more inland parts.

The organisms examined have been killed, (a) by temperatures which should not have destroyed the reducing enzyme, (b) by sodium fluoride and four other antiseptics, derivatives of phenol, and (c) by acetone. In each case there has been total destruction of the reducing power, any apparent production of nitrite from nitrate being too slight to justify the assumption that it is due to anything more than experimental error. Filtrates of fluid cultures have also failed to reduce. The results may be summed up as follows:

(1) The reduction of nitrite by certain dysentery bacilli is not due to a soluble extra-cellular enzyme.

(2) Dysentery bacilli and B. coli killed by a minimal degree of heat have little if any effect in reducing nitrites.

(3) Organisms killed by antiseptics or by acetone do not reduce nitrates and nitrites.

(4) Even where all the organisms are not dead, reduction may be prevented by antiseptics.

(5) The high antiseptic value of tetrachlor-o-biphenol, tetrabrom-o-kresol, p-chlor-m-kresol and hexabrom-dioxy-diphenyl-carbinol has been established for the organisms of the dysentery group.

(1) Strains of B. pestis, kept in culture for 7 and 9 months, showed no loss of virulence.

(2) Virulent strains, when subjected to passage through an immunised Cricetomys gambianus (African pouched rat), suffer distinct loss of virulence for this species, and virulence is not regained in culture or on repeated passage through susceptible C. gambianus. The so-called avirulent plague bacillus, obtained in this way, appears to be a rough variant. It differs in micro-scopical appearance from the ordinary virulent forms, tending to the appearance from the ordinary virulent forms, tending to the appearance of involution forms, which develop in salt media.

(3) As regards immunising properties:

(a) Vaccine prepared from virulent strain gives considerable protection against infection with virulent strain.

(b) Vaccine prepared from virulent strain gives no protection against infection with avirulent strain.

(c) Vaccine prepared from avirulent strain gives little or no protection against infection with virulent strain.

(4) Animals, which recover from infection with an avirulent strain, are immune to subsequent infection with virulent strain.

Typhoid fever is one of the prevailing endemic diseases of Palestine. In 1925 and 1926 epidemic outbreaks of considerable magnitude occurred in various parts of the country (Kligler, 1927). As a part of a general programme of the study of the epidemiology of this disease, we have attempted to ascertain the incidence of typhoid carriers in a general population group. Owing to the large number of typhoid cases which occurred there in 1925 and 1926, Afule, a village of some 1200 inhabitants, was chosen as a desirable spot for such an investigation.

An experimental model simulating infection of the urinary tract was used to investigate factors influencing the transfer of plasmid-mediated drug resistance in the human bladder in the absence of antibiotic therapy. When a small number of cells carrying plasmid-mediated drug resistance was added to an established population of sensitive cells, it was found that varying the physical conditions of the bladder model had no significant effect on the spread of the plasmid and, under all conditions used, exponential spread of the plasmid through the originally sensitive population occurred. When the initial donor cells were killed shortly after addition to the model, exponential transfer of resistance amongst the established sensitive population still occurred. Thus, even in the absence of antibiotic therapy, only a small number of initial transfer events was required for a fully resistant population to be developed. This was true of both actively multiplying and early stationary phase cultures. An initially greater proportion of resistant cells, or the use of an antimicrobial agent to which some of the cells are resistant, would ensure that this process occurred more rapidly.

This study compares the presence and level of measles haemagglutination inhibiting antibody in the sera of primary school children in selected rural and urban areas of Kaduna State, Nigeria following a vaccination campaign. The results, analysed by Mann-Whitney statistical test at α=0·05, showed significantly higher levels of haemagglutination inhibiting antibody in all the age groups in urban areas when compared with rural areas. The implications of these findings on measles vaccination campaigns are discussed.

The investigation deals with the bacteriological examination of 386 samples of water from Manchester swimming baths where the method of purification could be studied.

There were 339 samples from chlorinated pools of which 160 gave acid and gas in MacConkey broth at 37° C. and 2130 strains were isolated. The remaining forty-seven samples were from untreated open-air pools. Thirty of these samples were positive and 270 strains were isolated. The strains were classified according to Wilson's method into the coli, intermediate, aerogenes and irregular groups, and only 1·78% of the total were found to be irregular. Both series of samples included more than 72% which contained coli, and among the chlorinated samples no less than 70% yielded aerogenes and nearly 49% intermediate type, while among the non-chlorinated baths there were 43% with aerogenes and 40% with intermediate type. There was a similar difference in the proportions of coli, aerogenes and intermediate type in chlorinated and in non-chlorinated baths when the results were considered on the basis of strains (Table II).

Since these differences in proportion were considered significant, and since the chief variation in conditions between outdoor and indoor baths consists of chlorination, a series of experiments was devised to test the effect of chlorine on pure cultures of coli, aerogenes, and intermediate type. There was very little change after adding 0·1 part of chlorine per million, but the addition of 0·3 and 0·5 part was followed by very rapid reduction in numbers with diminution in free chlorine. This reduction was on the whole least with aerogenes. The numbers continued to fall for about 48 hr. until all trace of chlorine had disappeared and then regrowth occurred. This regrowth was most vigorous and most rapid with aerogenes (see figures) but was very slow in all cases.

1. The tuberculin reaction properly applied is a reliable test of the presence of tuberculosis in cattle.

2. A method of segregation is described by which any herd can be rendered tuberculin negative in three to four years without diminution of the herd.

3. Evidence is given that recovery from a tuberculous infection can take place in cattle.

4. Calves can only be infected with tuberculosis after birth, such an infection may, however, take place extremely rapidly within the first few days of life.

5. Artificial feeding of calves with sterilised milk must be supplemented by some vitamine-containing food, otherwise “joint ill,” corresponding to rickets in human beings, will develop at about the third or fourth month. Bull calves are more susceptible to “joint ill” than heifers.

1. A food-borne outbreak of streptococcal infection in a cavalry regiment is described.

2. A controlled therapeutic experiment was carried out on the forty-nine patients admitted to hospital. Those given chemotherapy recovered more quickly than the controls, recovery being most rapid in the group given intramuscular penicillin.

3.Typical scarlatiniform eruptions were seen in ten cases. Streptococcal antitoxin appeared to prevent the occurrence of rashes, but had no significant effect on the duration of fever and toxaemia.

4. Upper respiratory complications supervened in ten cases. Evidence is presented which suggests that they were due to cross-infection.

Cytomegalovirus (CMV) infection is endemic worldwide but its seroprevalence varies widely. The goal of this study was to estimate the age-specific seroprevalence of CMV infection in Belgium based on two cross-sectional serological datasets from 2002 and 2006. The seroprevalence was estimated relying on diagnostic test results based on cut-off values pre-specified by the manufacturers of the tests as well as relying on mixture models applied to continuous pathogen-specific immunoglobulin G antibody titre concentrations. The age-specific seroprevalence of hepatitis A virus (HAV), based on three Belgian cross-sectional serological datasets from 1993, 2002 and 2006, was used as a comparator since individuals acquire lifelong immunity upon recovery, implying an increasing seroprevalence with age. The age group weighted overall CMV seroprevalence derived from the mixture model was 32% (95% confidence interval (CI) 31–34%) in 2002 and 31% (95% CI 30–32%) in 2006. We demonstrated that CMV epidemiology differs from the immunizing infection HAV. This was the first large-scale study of CMV and HAV serial datasets in Belgium, estimating seroprevalence specified by age and birth cohort.

The effective reproduction number $ R $ was widely accepted as a key indicator during the early stages of the COVID-19 pandemic. In the UK, the $ R $ value published on the UK Government Dashboard has been generated as a combined value from an ensemble of epidemiological models via a collaborative initiative between academia and government. In this paper, we outline this collaborative modelling approach and illustrate how, by using an established combination method, a combined $ R $ estimate can be generated from an ensemble of epidemiological models. We analyse the $ R $ values calculated for the period between April 2021 and December 2021, to show that this $ R $ is robust to different model weighting methods and ensemble sizes and that using heterogeneous data sources for validation increases its robustness and reduces the biases and limitations associated with a single source of data. We discuss how $ R $ can be generated from different data sources and show that it is a good summary indicator of the current dynamics in an epidemic.