MecA, a structural gene located on the chromosome of Staphylococcus aureus, characterizes methicillin-resistant S. aureus (MRSA), and femA and femB(fem) genes encode proteins which influence the level of methicillin resistance of S. aureus. In order to examine effectiveness of detecting mecA and fem genes in identification of MRSA, the presence of these genes in 237 clinically isolated strains of staphylococci was investigated by polymerase chain reaction (PCR). An amplified mecA DNA fragment of 533 base pairs (bp) was detected in 100% of oxacillin-resistant S. aureus, in 16·7 % of oxacillin-sensitive S. aureus, in 81·5% of S. epidermidis, and in 58·3% of other coagulase-negative staphylococci (CNS). While the PCR product of femA (509 bp) or femB (651 bp) was obtained from almost all the S. aureus strains except for five oxacillin-resistant strains (2·5%), neither of these genes were detected in CNS. Therefore, the detection of femA and femB together with mecA by PCR was considered to be a more reliable indicator to identify MRSA by differentiating it from mecA-positive CNS than single detection of mecA.

The effectiveness of influenza vaccination in reducing hospitalization of people with diabetes for influenza, pneumonia, or diabetic events during influenza epidemics was assessed in a case control study in Leicestershire, England. Cases were 80 patients on the Leicestershire Diabetes Register who were admitted and discharged from hospital with International Classification of Disease codes for pneumonia, bronchitis, influenza, diabetic ketoacidosis, coma and diabetes, without mention of complications, during the influenza epidemics of 1989–90 and 1993. One hundred and sixty-controls, who were not admitted to hospital during this period, were randomly selected from the Register. Immunization against influenza was assessed in 37 cases and 77 controls for whom consent was obtained to access their clinical notes and for whom notes were available. Significant association was detected between reduction in hospitalization and influenza vaccination during the period immediately preceding an epidemic. Multiple logistic regression analysis estimated that influenza vaccination reduced hospital admissions by 79% (95% CI 19–95%) during the two epidemics, after adjustment for potential confounders.

In 2009, the number of foodborne norovirus outbreaks in Finland seemed markedly high, and many outbreaks seemed to be linked to imported frozen raspberries. We reviewed the data regarding all notified foodborne outbreaks in 2009 in Finland in order to assess the magnitude of the problem and to summarize the information on raspberry–linked outbreaks. Between March and August, 13 norovirus outbreaks affecting about 900 people could be linked to imported frozen raspberries. Two raspberry samples corresponding to two batches of raspberries were positive for norovirus. These two batches proved to have been the likely source in six of the 13 outbreaks. Analytical studies had not been conducted for six outbreaks, and virological test results were inconclusive in two. However, combining epidemiological and microbiological methods often enabled finding the source, as exemplified in investigation of a large school outbreak. To ensure prompt control measures in similar situations in the future, both aspects of outbreak investigations should be strengthened.

An abattoir survey was undertaken to determine the prevalence of foodborne zoonotic organisms colonizing cattle, sheep and pigs at slaughter in Great Britain. The study ran for 12 months from January 2003, involved 93 abattoirs and collected 7703 intestinal samples. The design was similar to two previous abattoir surveys undertaken in 1999–2000 allowing comparisons. Samples were examined for VTEC O157, Salmonella, thermophilic Campylobacter and Yersinia enterocolitica. The prevalence of VTEC O157 faecal carriage was 4·7% in cattle, 0·7% in sheep and 0·3% in pigs. A significant decrease in sheep was detected from the previous survey (1·7%). Salmonella carriage was 1·4% in cattle, a significant increase from the previous survey of 0·2%. In sheep, faecal carriage was 1·1% a significant increase from the previous survey (0·1%). In pigs, carriage was 23·4%, consistent with the previous study. Thermophilic Campylobacter spp. were isolated from 54·6% of cattle, 43·8% of sheep and 69·3% of pigs. Y. enterocolitica was isolated from 4·5% of cattle, 8·0% of sheep and 10·2% of pigs.

Bergamo province was badly hit by the coronavirus disease 2019 (COVID-19) epidemic. We organised a public-funded, multidisciplinary follow-up programme for COVID-19 patients discharged from the emergency department or from the inpatient wards of ‘Papa Giovanni XXIII’ Hospital, the largest public hospital in the area. As of 31 July, the first 767 patients had completed the first post-discharge multidisciplinary assessment. Patients entered our programme at a median time of 81 days after discharge. Among them, 51.4% still complained of symptoms, most commonly fatigue and exertional dyspnoea, and 30.5% were still experiencing post-traumatic psychological consequences. Impaired lung diffusion was found in 19%. Seventeen per cent had D-dimer values two times above the threshold for diagnosis of pulmonary embolism (two unexpected and clinically silent pulmonary thrombosis were discovered by investigating striking D-dimer elevation). Survivors of COVID-19 exhibit a complex array of symptoms, whose common underlying pathology, if any, has still to be elucidated: a multidisciplinary approach is fundamental, to address the different problems and to look for effective solutions.

The opportunities of a pathologist at a large Eastern Hospital are many; but his time for research work is short, and his conveniences are few. I, therefore, feel that we, at the Laboratory of the Rangoon General Hospital, are more than usually fortunate to be able to give, within the first two years of the official existence of the Laboratory, an account of a strange disease. Doubtless it is to chance that we owe the first discrimination of the disease; but I hope that it has been by accurate observation and precise experiment that we have sought to fulfil our knowledge. The guidance and application of our observations have been my care, and upon me rests the responsibility for the accuracy of our work; but the work itself has been carried out entirely by my assistants, and to them belongs the credit for the zeal and patient perseverance with which the task has been performed.

The bacterium Francisella tularensis causes the vector-borne zoonotic disease tularemia, and may infect a wide range of hosts including invertebrates, mammals and birds. Transmission to humans occurs through contact with infected animals or contaminated environments, or through arthropod vectors. Tularemia has a broad geographical distribution, and there is evidence which suggests local emergence or re-emergence of this disease in Europe. This review was developed to provide an update on the geographical distribution of F. tularensis in humans, wildlife, domestic animals and vector species, to identify potential public health hazards, and to characterize the epidemiology of tularemia in Europe. Information was collated on cases in humans, domestic animals and wildlife, and on reports of detection of the bacterium in arthropod vectors, from 38 European countries for the period 1992–2012. Multiple international databases on human and animal health were consulted, as well as published reports in the literature. Tularemia is a disease of complex epidemiology that is challenging to understand and therefore to control. Many aspects of this disease remain poorly understood. Better understanding is needed of the epidemiological role of animal hosts, potential vectors, mechanisms of maintenance in the different ecosystems, and routes of transmission of the disease.

Infection by Listeria monocytogenes in pregnant women may result in fetal loss or invasive disease in the newborn. We examined listeriosis cases reported through the U.S. Listeria Initiative during 2004–2007. Cases were classified as pregnancy-associated if illness occurred in a pregnant woman or an infant aged <28 days. Of 758 reported Listeria cases, 128 (16·9%) were pregnancy-associated. Maternal infection resulted in four neonatal deaths and 26 (20·3%) fetal losses. Invasive illnesses in newborns (n=85) were meningitis (32·9%) and sepsis (36·5%). Pregnant women with Listeria were more likely to report Hispanic ethnicity (52·8% vs. 25·6%, respectively; OR 3·3 95% CI 2·2–4·8) than mothers giving live birth in the USA during 2005 and were more likely to report consumption of Mexican-style cheese (OR 2·6, 95% CI 1·6–4·2) than were non-pregnant patients with Listeria infection. Pregnant woman comprised a considerable proportion of reported listeriosis cases. Further declines in pregnancy-associated listeriosis will require education about avoiding high-risk foods, and continued regulatory and industry efforts to decrease Listeria in foods.

We followed up a cohort of 446 toxoplasma-infected pregnant women to determine the median and variability of the duration of positive toxoplasma–IgM (immunoglobulin M) results measured by an immunofluorescence test (IFT) and an immunosorbent agglutination assay (ISAGA). IgM antibodies were detected for longer using the ISAGA test [median 12·8 months, interquartile range (IQR) 6·9–24·9] than the IFT (median 10·4, IQR 7·1–14·4), but the variability between individuals in the duration of IgM positivity was greatest for the ISAGA test. IgM-positive results persisted beyond 2 years in a substantial minority of women (27·1% ISAGA, 9·1% IFT). Variation in the duration of the IgM response measured by ISAGA and IFT limit their usefulness for predicting the timing of infection in pregnant women. However, measurement of IgM and IgG antibodies in a cross-sectional serosurvey offers an efficient method for estimating the incidence of toxoplasma infection.

Yersinia enterocolitica is a recognized cause of gastroenteritis in northern Europe. During October 1988-January 1990, a prospective case-control study was performed to address risk factors associated with sporadic. Y. enterocolitica infections in southeastern Norway. Sixty-seven case-patients (mean age 23.4 years, range 8 months-88 years) and 132, age-, sex- and geographically-matched controls were enrolled in the study. Multivariate analysis of the data showed that persons with Y. enterocolitica infection reported having eaten significantly more pork items(3.79 v. 2.30 meals, P = 0.02) and sausage (2.84 v. 2.20 meals, P = 0.03) in the 2 weeks before illness onset than their matched controls; only one patient had eaten raw pork. Patients were also more likely than controls to report a preference for eating meat prepared raw or rare (47 v. 27%, P = 0.01), and to report drinking untreated water (39 v. 25%, P = 0.01) in the 2 weeks before illness onset. Each of these factors was independently associated with disease, suggesting a link between yersiniosis and consumption of undercooked pork and sausage products and untreated water. Efforts should be directed towards developing techniques to reduce Y. enterocolitica contamination of pork and educating consumers about (1) proper handling and preparation of pork items and (2) the hazards of drinking untreated water.

Rift Valley fever virus (RVFV) is an arbovirus associated with periodic outbreaks, mostly on the African continent, of febrile disease accompanied by abortion in livestock, and a severe, fatal haemorrhagic syndrome in humans. However, the maintenance of the virus during the inter-epidemic period (IEP) when there is low or no disease activity detected in livestock or humans has not been determined. This study report prevalence of RVFV-neutralizing antibodies in sera (n=896) collected from 16 Kenyan wildlife species including at least 35% that were born during the 1999–2006 IEP. Specimens from seven species had detectable neutralizing antibodies against RVFV, including African buffalo, black rhino, lesser kudu, impala, African elephant, kongoni, and waterbuck. High RVFV antibody prevalence (>15%) was observed in black rhinos and ruminants (kudu, impala, buffalo, and waterbuck) with the highest titres (up to 1:1280) observed mostly in buffalo, including animals born during the IEP. All lions, giraffes, plains zebras, and warthogs tested were either negative or less than two animals in each species had low (⩽1:16) titres of RVFV antibodies. Of 249 sera collected from five wildlife species during the 2006–2007 outbreak, 16 out of 19 (84%) of the ruminant (gerenuk, waterbuck, and eland) specimens had RVFV-neutralizing titres ⩾1:80. These data provide evidence that wild ruminants are infected by RVFV but further studies are required to determine whether these animals play a role in the virus maintenance between outbreaks and virus amplification prior to a noticeable outbreak.

The patterns of disease caused by five common viruses which infect the respiratory tract are described. The viruses were strains of rhinovirus types 2, 9, and 14, a strain of coronavirus type 229E and of respiratory syncytial virus. Volunteers were given nasal drops containing a low infections dose of one of the viruses, quarantined from 2 days before to 5 days after inoculation, and examined daily by a clinician using a standard checklist of respiratory signs and symptoms. Only subjects who developed clinical illness accompanied by viral shedding and/or specific antibody production were analysed [n = 116]. The results confirm indication from earlier studies that the main difference between colds induced by different viruses is in duration of the incubation period. Patterens of symptom development were not substantially different with different viruses. Analyses of signs and symptoms in different categories, e.g. nasal symptoms v. coughing, justify treatment with different drugs either successively or simultaneously.

Influenza and respiratory syncytial virus (RSV) are similarly structured viruses with similar environmental survival, but different routes of transmission. While RSV is transmitted predominantly by direct and indirect contact, influenza is also transmitted by aerosol. The cold, dry conditions of temperate winters appear to encourage the transmission of both viruses, by increasing influenza virus survival in aerosols, and increasing influenza and RSV survival on surfaces. In contrast, the hot, wet conditions of tropical rainy seasons appear to discourage aerosol transmission of influenza, by reducing the amount of influenza virus that is aerosolized, and probably also by reducing influenza survival in aerosol. The wet conditions of tropical rainy seasons may, however, encourage contact transmission of both viruses, by increasing the amount of virus that is deposited on surfaces, and by increasing virus survival in droplets on surfaces. This evidence suggests that the increased incidence of influenza and RSV in tropical rainy seasons may be due to increased contact transmission. This hypothesis is consistent with the observation that tropical rainy seasons appear to encourage the transmission of RSV more than influenza. More research is required to examine the environmental survival of respiratory viruses in the high humidity and temperature of the tropics.

Five years have passed since Campylobacter jejuni became generally recognized as a common cause of acute diarrhoea (Skirrow, 1977) – although the essential scientific discovery which led to this had been made several years earlier (Butzler et al. 1973) – so this is an appropriate time to take stock of what has happened in that time and consider what we might usefully be doing to control the disease.

Previous reports in the literature suggest that Burkholderia pseudomallei strains can be differentiated on the basis of animal virulence. Twenty environmentally and clinically derived isolates of Burkholderia pseudomallei were examined for the production of exoenzymes, morphological and biochemical phenotypes and virulence for Syrian golden hamsters. The partial sequence of the 16S ribosomal RNA [rRNA] genes from a number of these strains was also determined. Based upon these observations, it is suggested that highly virulent Burkholderia pseudomallei strains are true Burkholderia pseudomallei strains. The DNA sequences of the 16S rRNA genes of the true Burkholderia pseudomallei strains were identical to the published sequences for Burkholderia pseudomallei while differences were revealed between the published sequences and those of the lowly virulent strains. Thus, these latter strains have been designated as Burkholderia pseudomallei-like organisms since they demonstrate significant differences in exoenzyme production, hamster virulence and 16S rRNA gene sequences.

Usutu virus (USUV) is an emerging arbovirus that was first isolated in South Africa in 1959. This Flavivirus is maintained in the environment through a typical enzootic cycle involving mosquitoes and birds. USUV has spread to a large part of the European continent over the two decades mainly leading to substantial avian mortalities with a significant recrudescence of bird infections recorded throughout Europe within the few last years. USUV infection in humans is considered to be most often asymptomatic or to cause mild clinical signs. Nonetheless, a few cases of neurological complications such as encephalitis or meningoencephalitis have been reported. USUV and West Nile virus (WNV) share many features, like a close phylogenetic relatedness and a similar ecology, with co-circulation frequently observed in nature. However, USUV has been much less studied and in-depth comparisons of the biology of these viruses are yet rare. In this review, we discuss the main body of knowledge regarding USUV and compare it with the literature on WNV, addressing in particular virological and clinical aspects, and pointing data gaps.

Emergence of the highly pathogenic avian influenza (HPAI) H5N1 virus in Egypt in mid-February 2006 caused significant losses for the poultry industry and constituted a potential threat to public health. Since late 2007, there has been increasing evidence that stable lineages of H5N1 viruses are being established in chickens and humans in Egypt. The virus has been detected in wild, feral and zoo birds and recently was found in donkeys and pigs. Most of the outbreaks in poultry and humans occurred in the highly populated Nile delta. The temporal pattern of the virus has changed since 2009 with outbreaks now occurring in the warmer months of the year. Challenges to control of endemic disease in Egypt are discussed. For the foreseeable future, unless a global collaboration exists, HPAI H5N1 virus in Egypt will continue to compromise the poultry industry, endanger public health and pose a serious pandemic threat.

After a primary infection Coxiella burnetii may persist covertly in animals and recrudesce at parturition to be shed in the products of conception and the milk. Similar latent persistence and recrudescence occurs in man: namely, infection of placenta, heart valve or mural endocardium, bone or liver. The numbers of organisms, their viability and cellular form, and the underlying organ sites of latent infection for the coxiella are obscure. During investigations of 29 patients with a chronic sequel to acute Q fever, the post-Q fever fatigue syndrome (QFS) [1–3], sensitive conventional and TaqMan-based PCR revealed low levels of C. burnetii DNA in blood mononuclear cells (5/29; 17%), thin needle liver biopsies (2/14; 14%) and, notably, in bone marrow aspirates (13/20; 65%). Irrespective of the ultimate significance of coxiella persistence for QFS, the detection of C. burnetii genomic DNA in bone marrow several years after a primary infection unveils a new pathological dimension for Q fever.

(a) Primary Stimulus. In animals possessing no normal antitoxin a single injection of toxin either “attenuated” or under cover of antitoxin, whether injected previously or at the same time or present in the form of passive immunity maternally transmitted, is followed by a latent period of about three weeks, and the maximum immunity is reached in about eight weeks.

(b) Secondary Stimulus. In immune animals, whether naturally immune or artificially immunised, a single injection of toxin or of a toxin-antitoxin mixture is followed by a latent period of about four days and the maximum immunity is reached in about ten days; the great and rapid immunity response to the secondary stimulus offers a striking contrast to the small and gradual response to the primary stimulus.

(c) Intermediate Stimulus. In partially immune animals the response to an injection of toxin is in magnitude and rapidity of a character intermediate between the responses following a primary and a secondary stimulus.

This study examines the validity of using ICD-10 codes to identify hospitalized pneumonia cases. Using a case-cohort design, subjects were randomly selected from monthly cohorts of patients aged ⩾65 years discharged from April 2000 to March 2002 from two large tertiary Australian hospitals. Cases had ICD-10-AM codes J10–J18 (pneumonia); the cohort sample was randomly selected from all discharges, frequency matched to cases by month. Codes were validated against three comparators: medical record notation of pneumonia, chest radiograph (CXR) report and both. Notation of pneumonia was determined for 5098/5101 eligible patients, and CXR reports reviewed for 3349/3464 (97%) patients with a CXR. Coding performed best against notation of pneumonia: kappa 0·95, sensitivity 97·8% (95% CI 97·1–98·3), specificity 96·9% (95% CI 96·2–97·5), positive predictive value (PPV) 96·2% (95% CI 95·4–97·0) and negative predictive value (NPV) 98·2% (95% CI 97·6–98·6). When medical record notation of pneumonia is used as the standard, ICD-10 codes are a valid method for retrospective ascertainment of hospitalized pneumonia cases and appear superior to use of complexes of symptoms and signs, or radiology reports.