According to the European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC) annual report, human salmonellosis is mostly related to consumption of contaminated poultry products. Since 2003 in Europe, the Salmonella serovars considered relevant for human health and subject to control in breeding hens of Gallus gallus are: S. Enteritidis, S. Typhimurium (including the monophasic variant), S. Infantis, S. Hadar and S. Virchow. Herein, we investigated the Italian epidemiological situation from 2016 to 2018, comparing Salmonella serovar distributions in humans and poultry, in order to identify the target Salmonella serovars that, if controlled, would potentially have the largest public health impact in Italy. The results showed that control of S. Virchow and S. Hadar does no longer seem to be a priority in Italy and that S. Napoli and S. Derby, which are not included in the group of EU target serovars, are among the most frequent serovars isolated from humans in Italy. While S. Derby has its main reservoir in pigs, S. Napoli does not have a specific reservoir. However, because this serovar is frequently isolated from breeding poultry flocks and is characterised by causing severe human illness, it is a potential target Salmonella serovar in breeding hens of Gallus gallus in Italy.

The burden of tuberculosis (TB) among adolescents and young adults in endemic settings is poorly characterised. This study aimed to review published and unpublished estimates of the incidence and prevalence of bacteriologically confirmed TB among young people aged 10–24 years. We searched PubMed and World Health Organization archives for publications and unpublished data from population-based epidemiologic studies reporting confirmed pulmonary TB among young people, conducted from January 2000 onwards. We identified 27 publications and unpublished data from two national surveys, representing a total of 26 studies in 19 countries. The prevalence of bacteriologically confirmed TB ranged from 45 to 799 per 100 000 in the Asia-Pacific region and from 160 to 462 per 100 000 in African settings. We did not identify any epidemiologic studies of confirmed TB among adolescents living with human immunodeficiency virus (HIV). Many studies were excluded due to absent or inadequately reported age-specific data. Adolescents and young adults living in many endemic settings appear to be at substantial risk of developing active TB. There is a pressing need to improve the routine reporting of age in epidemiologic studies of TB, and to generate high-quality epidemiologic data regarding TB among adolescents living with HIV.

Traditionally, the routine artificial digestion test is applied to assess the presence of Trichinella larvae in pigs. However, this diagnostic method has a low sensitivity compared to serological tests. The results from artificial digestion tests in Switzerland were evaluated over a time period of 15 years to determine by when freedom from infection based on these data could be confirmed. Freedom was defined as a 95% probability that the prevalence of infection was below 0·0001%. Freedom was demonstrated after 12 years at the latest. A new risk-based surveillance approach was then developed based on serology. Risk-based surveillance was also assessed over 15 years, starting in 2010. It was shown that by using this design, the sample size could be reduced by at least a factor of 4 when compared with the traditional testing regimen, without lowering the level of confidence in the Trichinella-free status of the pig population.

From August 2002 to February 2003 25 cases of hepatitis A were notified from one town in Jutland. The first cases were children of three families who returned from an endemic country. The infection spread subsequently in the local community and within households. A case-control study among household index cases showed that hepatitis A was associated with contact to a case in an after-school group (OR 29·6) and with contact to a case household member in a school class or day-care centre group (OR 9·5). From a serosurvey it was estimated that for each notified patient approximately one additional infection has occurred in the households. The infection was imported by children of immigrants, born in Denmark, returning from a visit to friends and relatives in the high-incidence country of origin of their parents and was then propagated through contact between children in after-school groups, schools and their families. Immunoprophylaxis should be given to children prior to visits to friends and relatives in endemic countries and to case contacts.

There occurred during the planning and publication of this review: the twentieth anniversary of the start of the intensified WHO Smallpox Eradication Campaign and the tenth anniversary of the last endemic case of smallpox; debate about the fate of smallpox virus and possibly its irrevocable destruction; claims that mass smallpox vaccination campaigns may have helped the spread of AIDS in Africa; publication of the definitive account of Smallpox and its Eradication (Fenner et al. 1988), and the closure of the WHO Smallpox Eradication Unit (SEU). It is therefore perhaps an appropriate moment to assess the current status of human poxvirus infections and their epidemiology; this review concentrates on those viruses antigenically related to smallpox (i.e. orthopoxviruses).

Campylobacter fetus was isolated from five recent cases of human vibriosis, of which two were adults and three were children. One adult presented with pericarditis and the other with recurrent pyrexia. Campylobacter fetus subsp. intestinalis which resembled cattle strains serologically, was isolated under CO2 or anaerobic conditions from blood cultures of these patients. Two of the three children had kwashiorkor and the third was only 8 days old. Isolates identified as Campylobacter fetus subsp. jejuni were cultured from blood of these patients, two of whom had diarrhoea. Three patients succumbed, despite adequate antibiotic therapy. The epidemiology of the disease is discussed and it is suggested that infection may have been from the patients' own flora.

The outbreak which is the subject of the present paper was discovered in the course of an enquiry which is at present being made on the request of the Home Secretary by Mr J. S. Martin, Inspector of Mines, and one of us, into the ventilation of Cornish mines. A number of cases of anaemia had occurred among the miners employed at Dolcoath Mine, Cornwall; and as the anaemia was generally attributed to some defect in the ventilation, this mine, was among the first visited. On examination into the state of the mine, the symptoms of the affected men, and the history of the outbreak, it appeared that the anaemia was almost certainly caused by ankylostomiasis. A more detailed enquiry, in which we have both been engaged, established beyond all doubt the nature of the disease, and has furnished the opportunity of investigating a number of points bearing on the nature and method of spread of ankylostomiasis. A short report on the outbreak has already appeared. We are indebted to Dr S. G. Scott, who has also been engaged in the Home Office Enquiry, for a number of valuable notes as to blood-examinations, and many other details.

Dengue fever (DF) is the most prevalent and rapidly spreading mosquito-borne disease globally. Control of DF is limited by barriers to vector control and integrated management approaches. This study aimed to explore the potential risk factors for autochthonous DF transmission and to estimate the threshold effects of high-order interactions among risk factors. A time-series regression tree model was applied to estimate the hierarchical relationship between reported autochthonous DF cases and the potential risk factors including the timeliness of DF surveillance systems (median time interval between symptom onset date and diagnosis date, MTIOD), mosquito density, imported cases and meteorological factors in Zhongshan, China from 2001 to 2013. We found that MTIOD was the most influential factor in autochthonous DF transmission. Monthly autochthonous DF incidence rate increased by 36·02-fold [relative risk (RR) 36·02, 95% confidence interval (CI) 25·26–46·78, compared to the average DF incidence rate during the study period] when the 2-month lagged moving average of MTIOD was >4·15 days and the 3-month lagged moving average of the mean Breteau Index (BI) was ⩾16·57. If the 2-month lagged moving average MTIOD was between 1·11 and 4·15 days and the monthly maximum diurnal temperature range at a lag of 1 month was <9·6 °C, the monthly mean autochthonous DF incidence rate increased by 14·67-fold (RR 14·67, 95% CI 8·84–20·51, compared to the average DF incidence rate during the study period). This study demonstrates that the timeliness of DF surveillance systems, mosquito density and diurnal temperature range play critical roles in the autochthonous DF transmission in Zhongshan. Better assessment and prediction of the risk of DF transmission is beneficial for establishing scientific strategies for DF early warning surveillance and control.

In two trials the efficacy of inactivated vaccines against contagious bovine pleuropneumonia was tested by exposing vaccinated cattle to droplet infection provided by close contact with experimentally infected ‘donors’. Complete protection was given by an extreme form of vaccination in which a heavy suspension of killed Mycoplasma mycoides subsp. mycoides emulsified with Freund's complete adjuvant was given in two large doses. ‘Mouse-protective antibody’ (MPA) was also produced, i.e. serum transferred to mice 2–4 h before intraperitoneal challenge prevented the development of mycoplasmaemia. However, the study did not answer the question ‘Is MPA protective for cattle?’. No protection was given by a milder form of vaccination in which a lighter suspension of killed Hiycoplasmas emulsified with Freund's incomplete adjuvant was given in a comparatively small dose on a single occasion.

The causes of death of the grouse are, of course, various. We ourselves have seen pleuropneumonia (in a bird long kept in captivity in Cambridge), pericarditis, necrotic patches in the liver, an obscure chronic disease of the peritoneum, and septic infection from a gangrenous fracture of the wing. On the other hand the great majority of birds, either picked up dead on the moor, or caught by keepers when weak and unable to fly, have been found to be all more or less in the same condition; they were wasted, badly infested with Trichostrongylus pergracilis, and often also with Davainea urogalli or Hymenolepis microps, or with both. More or less pathological change was seen in the caeca; the mucous membrane was often reddened, and under the binocular microscope considerable changes were seen, though we did not observe gross ulceration. Sections examined under the higher powers showed serious chronic inflammatory changes particularly in the immediate neighbourhood of the worms.

Sera from 823 wild rabbits (Oryctolagus cuniculus) collected from a number of geographic regions of Victoria, Australia over the past eight years were examined for antibodies to Encephalitozoon cuniculi, along with sera from 46 hares (Lepus europaeus) (Pallas) and 57 New Zealand wild rabbits. No sera were positive, implying that this common laboratory rabbit parasite is absent from wild rabbits in these areas. However, wild rabbits were found to be readily infected by the oral route with small numbers of tissue-culture-grown spores of E. cuniculi. A possible explanation for the absence of encephalitozoonosis in wild rabbits is that E. cuniculi infection places them at a biological disadvantage for survival. The natural hygiene habit of wild rabbits may also significantly decrease post-natal infection.

The seasonality and periodicity of infections, and the mechanisms underlying observed dynamics, can have implications for control efforts. This is particularly true for acute childhood infections. Among these, the dynamics of measles is the best understood and has been extensively studied, most notably in the UK prior to the start of vaccination. Less is known about the dynamics of other childhood diseases, particularly outside Europe and the United States. In this paper, we leverage a unique dataset to examine the epidemiology of six childhood infections – measles, mumps, rubella, varicella, scarlet fever and pertussis – across 32 states in Mexico from 1985 to 2007. This dataset provides us with a spatio-temporal probe into the dynamics of six common childhood infections, and allows us to compare them in the same setting over the same time period. We examine three key epidemiological characteristics of these infections – the age profile of infections, spatio-temporal dynamics, and seasonality in transmission – and compare them with predictions from existing theory and past findings. Our analysis reveals interesting epidemiological differences between the six pathogens, and variations across space. We find signatures of term-time forcing (reduced transmission during the summer) for measles, mumps, rubella, varicella, and scarlet fever; for pertussis, a lack of term-time forcing could not be rejected.

A report is given of a milk epidemic of septic sore throat, comprising about 100 cases.

The epidemic originated from a cow with a slight degree of mastitis, produced by a Streptococcus pyogenes (Lancefield's group A).

The same Streptococcus (which we did not succeed in typing) was isolated from 74% of the patients examined and from three persons who were handling the milk.

It seems reasonable to assume that the cow was infected from the milkers. Owing to particular conditions in the distribution of the raw milk, it is possible that the milk delivered raw in the village involved on one day a massive contamination.

The epidemic is characterized as moderately severe. No case terminated fatally.

A 3-year study of Escherichia coli infections in Grampian Region was conducted to ascertain the incidence, document clinical sequelae and identify at-risk groups. Approximately 30000 stools from patients with acute diarrhoea were screened for E. coli O157, and an epidemiological questionnaire filled in for each patient whose stool was positive. Eighty-three patients were studied. The annual incidence was 6 per 100000. Proportionately more infections occurred in people involved in agriculture. Evidence was seen of case-to-case transmission, and contamination of a water supply. Eight cases developed haemolytic uraemic syndrome (HUS). There were 2 deaths due to HUS and 2 due to haemorrhagic colitis (HC). Symptomatic E. coli infection is relatively common in the Grampian Region, more common in the agricultural community, and is the main cause of HUS in this Region.

We estimated the excess risk of in-patient hospitalization in a large cohort of persons diagnosed with hepatitis C virus (HCV) infection, controlling for social deprivation. A total of 20 749 individuals diagnosed with HCV in Scotland by 31 December 2006 were linked to the Scottish hospital discharge database, and indirectly standardized hospitalization rates, adjusting for sex, age, year and deprivation were calculated. We observed significant excess morbidity considering episodes for: any diagnosis [standardized morbidity ratio (SMR) 3·4, 95% CI 3·3–3·5]; liver-related diagnoses (SMR 41·3, 95% CI 39·6–43·0); and only non-liver-related diagnoses (SMR 2·14, 95% CI 2·08–2·19). Cox regression analyses of the 2000–2006 data indicated increased relative risks of hospitalization for males [hazard ratio (HR) 1·1, 95% CI 1·0–1·2], older age (per 10 years) (HR 1·55, 95% CI 1·5–1·6), and those testing HIV-positive (HR 1·6, 95% CI 1·3–1·8). This study has revealed substantial excess all-cause and liver-related morbidity in the Scottish HCV-diagnosed population, even after allowing for deprivation.

No case of transformation (in vivo) of the “xylose-positive” typhoid bacillus to the “xylose-negative”, or vice versa, has been observed in any of the material dealt with at the State Serum Institute, Copenhagen.

On the other hand, the types of paratyphoid B bacilli that can be established on the basis of their relation to rhamnose and inositol did not prove to be absolutely constant; actual or apparent transformation of one type to the other having been observed in several cases.

In this connexion the suggestion is made that Bitter's rhamnose reaction be omitted; the distinction between types R1 and R2 would thus disappear.

Patients with symptoms of diseases of the liver and biliary system and also chronic carriers were represented in greater numbers for type R3I1 than for type R2I1, but it is doubtful whether this observation can be taken as a general one. Apart from this, the behaviour of these two types was very uniform as to the clinical course of the infections they produced. The cases of infection with the rarer types, also, did not seem to vary clinically from those with the more frequent types. On the other hand, the difference between the clinical course of paratyphoid B and the infection with Salmonella typhi murium was very marked.

The group of organisms included in the term B. mucosus capsulatus has continued to intrigue bacteriologists for more than thirty years, mainly on account of the problems of academic interest which arise when any attempt is made to define the characters of the group as a whole or to classify its members into types. Proof that such problems still exist is to be found in current text-books in which certain discrepancies occur regarding the biochemical reactions ascribed to the various members. There is also uncertainty as to the inclusion of B. lactis aerogenes in the group (Topley and Wilson, 1929; Wilson, 1929). Much of the difficulty arose from the fact that Friedländer's bacillus, one of the first members of the group to be isolated (1883), was studied from a morphological standpoint, while Escherich who described B. lactis aerogenes in 1886 stressed its biological similarity to B. coli. A chasm was thus created between B. lactis aerogenes and Friedländer's bacillus which has not been bridged to the present day, although these organisms must always have resembled, more than they differed from, each other; e.g. Bergey (1929) classifies B. lactis aerogenes with coliform types under Bacterieae and places Friedländer's bacillus in the tribe Klebsielleae Trevisan, i.e. encapsulated Gram negative organisms encountered principally in the respiratory tract, whose fermentation reactions are not given in full. Organisms morphologically similar to Friedländer's bacillus were found to be widely distributed, and in 1896 Fricke named the group B. mucosus capsulatus. There is still little criticism to be made of his general description to the effect that the members were Gram-negative, possessed capsules, showed marked pleomorphism and did not form spores; they grew on a variety of media in a profuse slimy layer, and in gelatin stabs they did not liquefy, but showed the so-called “nail” growth; in addition to this, most of the bacteria classed under this head formed a moderate amount of indole and fermented carbohydrates in solution with production of acid and gas. In an attempt to type members of this group Perkins (1904) admitted that the current knowledge of technique had been almost exhausted in the effort to separate one member from another, but on the basis of certain biochemical differences he was able to distinguish three classes, of which the first was the largest:

Factors affecting the formation and destruction of sulphide in the Thames Estuary have been discussed. Measurements of oxidation-reduction potentials show that the effect of oxygen in the water on conditions in deposits of mud is limited to the surface layer. The rate of formation of sulphide increases with temperature, doubling approximately for each 10° C. rise. Reduction of sulphate to sulphide will occur at temperatures as low as 5° C., but even at 25° C. is inhibited by traces of dissolved oxygen. Mud in suspension in the estuary can produce as much sulphide as compact layers of similar mud which might be more anaerobic.

Oxidation of sulphide in the Thames Estuary is shown to be of a purely chemical nature; the rate of oxidation, when oxygen is present, is increased by the presence of suspended matter and iron. In the Thames Estuary, however, the rate is limited by the rate at which oxygen enters the water.

Much of the experimental work described in this paper was carried out by Miss A. Laird, Mr A. E. Sutton and Mr R. B. Peel of this Laboratory. The paper is published by permission of the Department of Scientific and Industrial Research.

Salmonella enterica serovar Infantis is endemic in Finnish cattle. Feed contaminated with S. Infantis was distributed to cattle farms in May 1995. Following increased sampling, S. Infantis was detected on 242 farms in 1995. Molecular typing was used to differentiate the farms that were infected by the feed-related Infantis from those infected by other endemic strains. Twenty-three isolates from feed in 1995 and 413 from cattle (72 from 1992–4, 324 from 1995, 17 from 1996–7) were analysed. The feed-related Infantis was clonally related to the endemic infection by the ribotype, IS200-type and XbaI-profile. The feed isolates had a distinctive plasmid that appeared in pulsed-field gel electrophoresis as a 60 kb band when cleaved with XbaI or linearized by S1-nuclease. This plasmid appeared in cattle only since the outbreak and seemed stable on the follow-up farms. In addition to contact farms, the feedborne strain was found on 19% of the farms infected with S. Infantis in 1995 but not having bought suspected feedstuffs, possibly as secondary infections.

Recent evidence of bluetongue (BT) virus infection of livestock in scattered localities in the neotropics prompted a serologic survey of cattle in Colombia and Costa Rica. In Costa Rica 48·1% of 1435 bovine animals had BT virus antibody in the agar gel precipitation test (AGPT). In Colombia 51·8% of 635 cattle were AGPT-positive for BT virus. Antibody prevalence ranged from over 50% in the lowlands to 0% in Costa Rica and 19% in Colombian cattle above 2000 m altitude. Neutralization tests indicated that Costa Rican cattle had been exposed to BT virus types 6, 12, 14 and 17.