Analysis of the transmission dynamics of Cowdria ruminantium, the tick-borne rickettsial agent of heartwater in ruminants, requires accurate measures of infection in vector populations. To obtain these, Amblyomma hebraeum ticks were collected at two heartwater-endemic locations in the lowveld and highveld regions of Zimbabwe and assessed for C. ruminantium infection with specific polymerase chain reaction (PCR) and DNA probe detection assays. At the lowveld site, 11·2% (50/446) of adult ticks and 8·5% (23/271) of nymphs carried C. ruminantium, as detected by PCR. At the highveld site, the prevalence of infection in adult ticks was 10·2% (40/392). DNA probe analysis revealed that most infections at both sites were of low intensity; only 9% and 23% of all nymph and adult tick infections, respectively, were greater than 70000 organisms, the detection limit of the DNA probe. However, the majority (70%) of probe- detectable adult tick infections were high, between 107 and 109 organisms/tick, while those within nymphs were lower, between 105 and 106 organisms/tick.

Avian mortality and encephalomyelitis in equines are considered good indicators for West Nile virus (WNV) activity. We retrospectively tested 385 horse sera for WNV antibodies and looked for WNV nucleic acid and/or WNV antigen in paraffin embedded tissues from 12 horses with aetiologically unresolved encephalomyelitis and 102 free-living birds of different species which had been found dead. With the exception of four horses originating from eastern European countries investigated on the occasion of transit through Austria, all horse sera were negative. Nested RT-PCR of the horse tissues yielded no amplification of WNV-RNA. Also, all bird samples, examined by immunohistochemistry, in situ hybridization and nested RT-PCR were negative for WNV. These results indicate that currently WNV cannot be considered a significant pathogen in Austria.

Forty-five samples of unsliced, cooked, ready-to-eat meats on sale in retail premises and supermarkets were examined. Thirty-six (80%) had Escherichia coli I and 21 (47%) had coagulase positive staphylococci in numbers ranging from 1 to > 1000/100 cm.2. Twenty-one samples contained Clostridium spp. in numbers from 1 to > 100/100cm.2. Of the 45 samples tested, 11 (factory-produced) and 7 (home-produced) were examined after cooking but before being offered for sale. Cooked hams were contaminated after handling in a factory, as were samples of canned corned beef after sale and exposure for 24 hr. Some sources of contamination were: (a) raw beef, (b) factory and shop surfaces and equipment, and (c) workers' hands. Curing brines used in retail shops and supermarkets to produce corned beef were a potent source of contamination. The effect of holding cooked meats at ambient temperature on their spoilage (22° C) and food-poisoning (37° C) microflora was demonstrated.

Incubation period for non-typhoidal Salmonella (NTS) infections is generally reported as 6–72 h despite numerous reports of foodborne NTS outbreaks with median incubation periods >3 days. We summarised 16 years of Minnesota foodborne NTS outbreaks to better estimate the expected range of incubation periods for NTS infections. Of the 1517 NTS outbreak cases, 725 had enough data to calculate a precise incubation period. The median incubation period was 45 h; 77 (11%) cases had incubations ⩽12 h and 211 (29%) cases had incubations >72 h. Incubation period length varied by outbreak vehicle type, Salmonella serotype and outbreak setting. Based on our data, a more accurate description would be that the incubation of NTS infection is usually from 12 to 96 h, that incubations in >96 to 144 h (>4 to 6-day) range are not unusual and that incubations from 7 to 9 days and occasionally longer also occur.

For 29 months the Veterinary Investigation Centres, covering the whole of Great Britain, forwarded trimethoprim-resistant gram negative enteric bacteria to the Wellcome Research Laboratories. These were examined for degree of resistance, presence and type of R factors. Trimethoprim resistance was found in 0·6 % of the total number of strains examined by the Veterinary Investigation Centres. Trimethoprim R factors were demonstrated in one quarter of the resistant strains, and R factors were found in two strains of Salmonella typhimurium. It was concluded that while the incidence of trimethoprim resistance revealed by the survey gave no cause for alarm, the detection of resistant strains, and particularly R factors, indicated that the drug should continue to be used only for specific therapeutic purposes.

We determined the prevalence of microsporidia Enterocytozoon (Ent.) bieneusi and Encephalitozoon (E.) intestinalis infection in patients with chronic diarrhoea and hepatocellular carcinoma (HCC). A total of 330 stool samples were examined from 171 (52%) patients with chronic diarrhoea, 18 (5%) with HCC while 141 (43%) were controls. Stool microscopy, polymerase chain reaction (PCR) with species-specific primers for Ent. bieneusi and E. intestinalis and sequencing were carried out. Microsporidia were found by trichrome staining in 11/330 (3%) and E. intestinalis by PCR in 13/330 (4%) while Ent. bieneusi was not detected. PCR for E. intestinalis was positive in 8/171 (5%) stool samples from patients with chronic diarrhoea, 2/141 (1·4%) samples from healthy controls and in 3/18 (17%) samples from patients with HCC. In the chronic diarrhoea group, E. intestinalis was positive in 4/171 (2·3%) (P=0·69) stool samples compared to 2/18 (11%) (P=0·06) in the HCC group and 2/141 (1·4%) from healthy controls. E. intestinalis infection was significantly associated with chronic diarrhoea and HCC in these patients who were negative for HIV. Stool examination with trichrome or species-specific PCR for microsporidia may help establish the cause of chronic diarrhoea.

In the preceding report (Topley and Ayrton, 1923 a) we have described a technique by which measurements may be obtained of the excretion of B. enteritidis (aertrycke)1 in the faeces of mice.

Of 173 epidemiologically unrelated strains of Escherichia coli isolated from the pericardial sac of chickens that had died from infection with these organisms in England in 1972, approximately 1 year after the introduction of legislation forbidding the routine use of feeds containing ‘therapeutic’ antibiotics, 83·8% were resistant to sulphonamides, 31·2 % to tetracyclines, 20·8% to furazolidone, 18·5% to streptomycin, 2·9% to spectinomycin and 1·2% to ampicillin; none of the strains were resistant to chloramphenicol, neomycin, polymixin, trimethoprim or nalidixic acid. The sulphonamide resistance and possibly some of the resistance to other agents might have been the consequence of sulphonamides being exempted from the legislation. Much of the resistance, with the exception of that to furazolidone, was of the transferable type. Many strains possessed transfer factors in the absence of any known transferable characteristic. Colicine production was twice as common in the pathogenic strains as in a collection of strains isolated from the faeces of healthy chickens; about half of it was transferable.

By means of serology, antibiotic resistance and other markers, it was found that several different kinds of E. coli were usually incriminated in any one outbreak of E. coli infection in broiler chickens. Sometimes the same kinds of E. coli were found in outbreaks in consecutive crops of chickens on the same farm. New kinds, too, appeared to be brought in by replacement chickens.

A cross-sectional study into risk factors for Salmonella was undertaken using data gathered from 252 fattening turkey flocks in the UK. The data was derived from the EU baseline survey conducted during 2006 and 2007, in addition to a voluntary questionnaire. Multivariate logistic regression models identified significant risk factors for Salmonella spp. and Salmonella Typhimurium. A decreased risk of Salmonella spp. infection was associated with a history of intestinal illness in the sampled flock (OR 0·17), the use of wood shavings as litter (OR 0·21), use of disinfectant in the cleaning process (OR 0·25), incineration of dead birds on farm (OR 0·29), seasonal production (OR 0·31), farm staff also working with cattle (OR 0·31), and the presence of pigs on neighbouring farms (OR 0·38). The risk of isolating Salmonella spp. varied according to the company from which the poults were sourced. A reduced risk of S. Typhimurium infection was associated with the use of wax blocks to control rodents (OR 0·09), using mains water (OR 0·19) and having a Salmonella test programme (OR 0·23). An increased risk of S. Typhimurium infection was associated with storage of items around the turkey house (OR 5·20), evidence of mice (OR 4·71) and a soil surface surrounding the turkey house (OR 2·70). This study therefore identifies a number of important practical measures which can be implemented by farmers and veterinarians within the turkey industry to assist in the control of salmonellosis at the farm level.

The clinical impact of antimicrobial resistance on the outcome of pneumococcal bacteraemia has remained unclear. This study aimed to evaluate risk factors for mortality and determine the impact of antimicrobial resistance on clinical outcomes. A total of 150 adult patients with pneumococcal bacteraemia were identified over a period of 11 years at Seoul National University Hospital. Of the 150 patients, 122 (81·3%) had penicillin-susceptible (Pen-S) strains and 28 (18·7%) penicillin-non-susceptible (Pen-NS) strains; 43 (28·7%) had erythromycin-susceptible (EM-S) strains and 107 (71·3%) erythromycin-non-susceptible (EM-NS) strains. On multivariate analysis, elevated APACHE II score [odds ratio (OR) 1·24, 95% confidence interval (CI) 1·14–1·34, P<0·001) and presence of solid organ tumour (OR 2·99, 95% CI 1·15–7·80, P=0·025) were independent risk factors for mortality. Neither erythromycin resistance nor penicillin resistance had a significant effect on clinical outcomes. However, for the 76 patients with pneumococcal pneumonia, the time required for defervescence was significantly longer in the EM-NS group than in the EM-S group (5·45±4·39 vs. 2·93±2·56, P=0·03 by log rank test). In conclusion, antimicrobial resistance does not have an effect on mortality in adult patients with pneumococcal bacteraemia.

One hundred and eighty–one stool specimens from patients with various types of diarrhoea (135 patients) or from non-diarrhoeal controls (23 acute medical patients, 23 inflammatory bowel disease in remission) were investigated using a colony–blot DNA hybridization assay for the presence of Verocytotoxin–producing (VTEC), enteroaggregative (EAggEC) and diffusely adherent (DAEC) Escherichia coli. Twelve patients had probe–positive EAggEC in the stool and 8 of these had diarrhoea, 6 following recent travel. Eight patients had DAEC, 7 of whom had travellers diarrhoea. Six of 10 (60%) travellers with gastroenteritis, but without a recognized enteric pathogen, were positive for EAggEC (4) or DAEC (2). Five of 10 (50%) travellers with gastroenteritis related to a recognized enteric pathogen also had DAEC identified in their stool. Of the 23 acute medical control patients 11 had been abroad, 4 of these were immigrants and had EAggEC. VTEC were not found and, with one exception, immunoassays for antibodies to E. coli O 157 and O 2 lipopolysaccharides were negative.

Recently, two independent research teams reported evidence of infection with SARS-like coronaviruses in insectivorous horseshoe bats (genus Rhinolophus) in China [1, 2]. SARS emerged in China in 2002, and eventually infected over 8000 people around the world, killing about 10% of them. Early epidemiological studies suggested that the human disease may have originated in Chinese live-animal food markets, and the hunt for a source of the virus quickly identified apparently healthy Himalayan palm civets (Paguma larvata) as prime suspects [3]. Other studies, however, failed to find any evidence of widespread infection in civets [4] or a variety of other animals traditionally used as food in China. Rather, palm civets, like human beings, seem to be only accidental hosts of the virus, becoming infected, again like people, when mixed with other species in markets. More structured hunts for the reservoir continued, although not before thousands of palm civets had been slaughtered.

Although rabies incidence in humans in Western Europe is low, the repeated importation of rabid animals from enzootic areas threatens the rabies-free status of terrestrial animals and challenges the public health systems in this area. Most rabid animals imported into the European Union (EU) in recent years came from Morocco. The aim of this study was to develop a probabilistic risk assessment model to estimate the probability of rabies introduction, which was applied to the risk to the EU from dogs coming from Morocco. The mean annual probability of rabies introduction was 0·21 (90% CI 0·02–0·65). The pathways that contributed the most to this probability were: (a) EU citizens who adopted a dog in Morocco (59% of the total probability) and (b) EU citizens who travelled with their dog to Morocco by ferry (34% of the total probability). The model showed a marked seasonality in the risk of rabies with almost 40% of the annual probability occurring during the months of July and August. The application of stricter border controls (assuming 100% compliance) would result in a >270-fold reduction in the likelihood of rabies introduction into the EU from Morocco.

During the course of our experiments on the lethal effectiveness of organic smokes to bacteria in the air (Baker & Twort, 1940, p. 587), we experienced, as time went on, more and more difficulty in obtaining satisfactory results, whereas in the early days of these investigations our findings were relatively consistent. In the first place, our charcoal-incense ‘candles’, when smouldered, failed to give the results expected, and in-seeking an explanation for the failure it was thought possible that the temperature of smouldering was too high and that there was pyrolysis of the emitted smoke as it passed over the glowing point of the candle. Attempts were made to elucidate the matter by (1) smouldering the ‘candle’ inverted, and (2) heating the crushed ‘candle’ on a hot plate of regulated temperature. Both methods gave somewhat improved results, but these still remained very poor, and our next procedure was to examine the effect of the smokes obtained from incense supplied from different sources. The results were irregular, as they were with several other substances which were re-tested. Only Peru balsam continued to give good ‘kills’ for some time, but, finally, we were unable to reproduce our original results even with this product. While there seemed to be evidence that the smoke, generated by smouldering on a hot plate such substances as cardboard and the incense-charcoal mix, was somewhat more lethally effective than when generated by smouldering as a ‘candle’ or strip, the experimental results as a whole had, by this time, become consistently bad.

In late 2014, a gastroenteritis outbreak occurred in a school in Shandong Province, eastern China. Hundreds of individuals developed the symptoms of diarrhoea and vomiting. Epidemiological investigation showed that food consumption was not linked to this outbreak, and unboiled direct drinking water was identified as the independent risk factor with a relative risk of 1·37 (95% confidence interval 1·03–1·83). Furthermore, examination of common bacterial and viral gastroenteritis pathogens was conducted on different specimens. Norovirus GI.1, GI.2, GI.6, GII.4, GII.6 and GII.13 were detected in clinical specimens and a water sample. GII.4 sequences between clinical specimens and the water sample displayed a close relationship and belonged to GII.4 variant Sydney 2012. These results indicate that direct drinking water contaminated by norovirus was responsible for this gastroenteritis outbreak. This study enriches our knowledge of waterborne norovirus outbreaks in China, and presents valuable prevention and control practices for policy-makers. In future, strengthened surveillance and supervision of direct drinking-water systems is needed.

In April 2015, Finnish public health authorities alerted European Union member states of a possible multi-country Salmonella enteritidis outbreak linked to an international youth ice-hockey tournament in Latvia. The European Centre for Disease Prevention and Control (ECDC), Finnish and Latvian authorities initiated an outbreak investigation to identify the source. The investigation included a description of the outbreak, retrospective cohort study, microbiological investigation and trace-back. We identified 154 suspected and 96 confirmed cases from seven countries. Consuming Bolognese sauce and salad at a specific event arena significantly increased the risk of illness. Isolates from Finnish, Swedish and Norwegian cases had an identical multiple-locus variable-number of tandem repeats analysis-profile (3-10-6-4-1). Breaches in hygiene and food storing practices in the specific arena's kitchen allowing for cross-contamination were identified. Riga Cup participants were recommended to follow good hand hygiene and consume only freshly cooked foods. This investigation demonstrated that the use of ECDC's Epidemic Intelligence Information System for Food- and Waterborne Diseases and Zoonoses platform was essential to progress the investigation by facilitating information exchange between countries. Cross-border data sharing to perform whole genome sequencing gave relevant information regarding the source of the outbreak.

We investigated the genetic structure of 99 isolates of serotype 23F Streptococcus pneumoniae from children with acute respiratory infections collected over two periods from 1997 to 2006, and 2010. All isolates were susceptible to vancomycin and amoxicillin–clavulanic acid; 97 were resistant to erythromycin, 95 of which carried the ermB gene and two carried both mefA/E and ermB genes. Multidrug resistance to three or more classes of antibiotics was exhibited by 90 isolates. Sequence types ST342 and ST81 were the most frequent in 1997–2006 and 2010, respectively. All CC81 isolates were non-susceptible to β-lactam antibiotics and had higher minimum inhibitory concentration values for penicillin than other clone complexes and sequence types. The increased β-lactam antibiotic resistance may have resulted from the replacement of multidrug-resistant clones related to ST81. Long-term studies on S. pneumoniae serotype 23F, especially the ST81 clone, should be conducted to better understand the epidemiological picture of this pathogen in China.

Previous respiratory tract infections (RTI) and antibiotics consumption as possible risk factors for extended duration of PRP carriage were investigated in 24 children (cases) with previous carriage of penicillin-resistant pneumococci (PRP) for a duration exceeding 120 days (median 168 days) and a control group of 53 children with a duration of PRP carriage less than 90 days (median 21 days). The cases had experienced 0·99 episodes of acute otitis media (AOM) per life-year compared to 0·79 episodes in the controls (P=0·32). For antibiotic-treated RTI other than AOM, the corresponding numbers were 0·49 and 0·29 episodes per life-year, respectively (P=0·01). No differences in antibiotic consumption in the 3 months preceding the carriage, nor during the carriage period were noted. Other factors than impaired host defence to respiratory tract pathogens or antibiotics consumption seem to be more important in determining the duration of PRP carriage.

The experiments detailed above have already been discussed in the sections in which they have been recorded. The following is a brief summary of the results obtained.

(1) In many ways a clear watery extract of B. typhosus behaves like an ordinary emulsion of the bacilli. This is true in a general sense in respect of agglutination by serum, and the property of agglutinability by weak salts, which some emulsions of B. typhosus possess, is also exhibited by a watery extract of the same strain.

(2) The optimum hydrogen-ion concentration for the agglutination of an emulsion is also approximately the optimum for the agglutination of a watery extract made from the same emulsion. The washed bacilli and the original emulsion show a second optimum. Agglutination appears later at this secondary optimum which is in stronger acid. There is a zone of absent or deficient agglutination in solutions of intermediate strength. The lower [H·] of the two is the characteristic optimum for B. typhosus, i.e. about 3·6×10−5. The second optimum [H·], i.e. 1·1 × 10−3 to 2·2 × 10−3, is approximately the same as the optimum for the agglutination of emulsions of many different bacteria, e.g. some strains of B. coli, staphylococcus, etc., and moreover is about the optimum for the agglutination of an emulsion of B. typhosus after it has been heated to 100°C.

These two optima appear to indicate the presence of two acid agglutinable substances in an emulsion of B. typhosus, (a) which is characteristic of this bacillus and is present in a watery extract (this substance is rendered inagglutinable by heating to 80° C. for 30 minutes or to 100° C. for five minutes, or longer, e.g. one hour), and (b) which is present in the bodies of the bacilli after repeated washing and which is not characteristic of B. typhosus, but has characters shared by similar substances in other bacilli; it resists heating to 100° C. for five minutes and is apparently little, if at all, affected by heating to 80° C. for half an hour.

(3) The substance agglutinable by serum and that agglutinable by acid No. 5, i.e. [H·] 3·6 × 10−5, are both present in a watery extract and can both be completely removed from the bacillary bodies by washing with distilled water. The serum-agglutinable substance is however less easily completely removed. This apparent difference is perhaps due to the fact that serum is a more delicate reagent for testing for the presence of agglutinable substance. If an extract is diluted it will give a precipitate in higher dilution with serum than with acid and the bacillary bodies when repeatedly washed often react with serum after the acid agglutination in solution 5 or 6 has ceased to appear. These substances agglutinable by acid and by serum are however closely associated and are both precipitated by acid No. 5 or 6.

The identity of the two substances has however not been proved and the following considerations are very strongly opposed to this assumption, (a) a considerable number of strains of B. typhosus are agglutinable by serum and not by acid; (b) strains have been described which are agglutinable by acid No. 5 or 6 but not by serum; (c) the diminished agglutinability by serum exhibited by some strains which are inagglutinable by acid is apparently due to a total diminution of the “soluble” or extractible substance; (d) the substance agglutinable by acid, tube 5 or 6, i.e. [H·] 3·6 × 10−3, is rendered inagglutinable by heating to 100° C. for five minutes, whereas Porges and Prantschoff (1906) have shown that the serum agglutinable substance is still active after being boiled.

It is not possible at present to say for certain whether the substances agglutinable by serum and acid are identical or distinct. If they are identical and there is only a single substance, its agglutination properties vary independently in different strains of B. typhosus.

(4) The importance for agglutination by serum of the substances in “solution” in the liquid part of a bacterial emulsion, and the impossibility of distinguishing between agglutination and the precipitation of bacterial extracts by serum, were first pointed out by Kraus and Paltauf, and by Kraus and v. Pirquet.

Their view is confirmed and extended to the agglutination by acids Nos. 5 and 6 by the result of some of the experiments described above. The facts adduced in support of the view that agglutination is essentially the formation of a coagulum in the liquid part of an emulsion are the following:

(a) The property of agglutination may be completely removed from B. typhosus by washing with water; the resulting washed bacterial bodies no longer agglutinate with specific serum or in acid solution Nos. 5 to 7.

(b) The washings of the bacteria or watery extracts are agglutinable by specific serum or by acid solution No. 5 or 6.

(c) The watery extract even in very small quantities when added to the washed bacilli, indifferent bacilli or other finely divided particles, confers on them the property of being agglutinated by specific serum or acid solution 5 or 6.

(d) The extract reacts with highly diluted serum, e.g. 1/27,000, and may be considerably diluted, e.g. 1/96, without entirely losing its agglutinable properties with serum or acid.

(e) In order to demonstrate the presence of agglutinable substance in very low concentration (especially if highly diluted serum or if acid is used) it is necessary to add some indifferent substance, e.g. B. coli, kieselguhr, globulin, etc. in order to increase the bulk of the precipitate.

(f) The extract or successive extracts appear to contain all the characteristic agglutinable substance of the original emulsion. This is shown by the delicacy of the reaction, and the small amount of extract required to agglutinate an indicator, e.g. B. coli. The demonstration of the reaction with highly diluted serum 1/27,000 and much diluted extract 1/96 appears to be an advance on the work of previous writers. Nicolle did not use indifferent particles with high dilutions of serum or of extract, and the only other use of an indicator under such conditions appears to be the use of conglutinin by Bordet and Gay, and Streng, and of mid-piece by Dean.

(g) The microscopic demonstration of the coagulum formed in the process of agglutination has been made easy by taking a watery extract containing very few bacilli, i.e. ordinary emulsion from which most of the bacilli have been removed by centrifuging. After adding dilute specific serum or acid the formation of the coagulum may be watched in a microscope cell with dark ground illumination or by adding dilute fuchsin or eosin to the microscope cell.

The European rabbit flea Spilopsyllus cuniculi (Dale) was introduced into Australia to act as a vector of myxoma virus. It was first released in the semi-arid Mallee region of Victoria in 1970 where epizootics caused by field strains of myxoma virus occur each summer. Introductions of the readily identified Lausanne strain were made annually following the release of the flea. The introductions were successful and the strain persisted for up to 16 weeks despite competition from field strains.

The Lausanne strain is more readily spread by fleas than the Glenfield strain which has been widely used in rabbit control. The ability of the Lausanne strain to persist and its effective transmission compared with the Glenfield strain may be due in part to the more florid symptoms of the disease.