In temperate zones, human respiratory syncytial virus (HRSV) outbreaks typically occur in cold weather, i.e. in late autumn and winter. However, recent outbreaks in Japan have tended to start during summer and autumn. This study examined associations of meteorological conditions with the numbers of HRSV cases reported in summer in Japan. Using data from the HRSV national surveillance system and national meteorological data for summer during the period 2007–2014, we utilized negative binomial logistic regression analysis to identify associations between meteorological conditions and reported cases of HRSV. HRSV cases increased when summer temperatures rose and when relative humidity increased. Consideration of the interaction term temperature × relative humidity enabled us to show synergistic effects of high temperature with HRSV occurrence. In particular, HRSV cases synergistically increased when relative humidity increased while the temperature was ⩾28·2 °C. Seasonal-trend decomposition analysis using the HRSV national surveillance data divided by 11 climate divisions showed that summer HRSV cases occurred in South Japan (Okinawa Island), Kyushu, and Nankai climate divisions, which are located in southwest Japan. Higher temperature and higher relative humidity were necessary conditions for HRSV occurrence in summer in Japan. Paediatricians in temperate zones should be mindful of possible HRSV cases in summer, when suitable conditions are present.

The hamadryas baboon (Papio hamadryas hamadryas) is the only indigenous species of non-human primates (NHP) found in the Kingdom of Saudi Arabia (KSA). There are no peer-reviewed publications on viral infections of the baboons of KSA. Apart from camels, other animals are likely sources of the novel Middle East Respiratory Syndrome coronavirus (MERSCoV) for humans. We investigated evidence of highly pathogenic coronavirus infections including MERSCoV in a large group of commensal baboons accompanied by feral dogs, on the outskirts of Ta'if city, KSA, in February 2013. Fifty baboons (16 juveniles and 34 adults) were screened for serum antibodies to human coronaviruses (HCoV-043/-NL63/-229) and canine coronaviruses (CCoV-1-3) using direct Enzyme-linked Immunosorbent Assay (ELISA) technique and for MERSCoV antibodies using Serum Neutralization Test (SNT). Of the 50 sampled baboons, 22% (n = 11) were seropositive to HCoVs, 10% (n = 5) were seropositive to CCoVs, while none had detectable MERSCoV antibodies. These findings bear potentially significant implications for public health, canine health and baboon conservation efforts, necessitating follow-up investigations and preventive measures at locations where baboons frequent human habitations, or are regarded as tourist attractions, in KSA.

Hepatitis C virus (HCV) infection is one of the leading causes of death and morbidity associated with liver disease. Risk factors identified for the transmission of HCV include contaminated blood products, intravenous drug use, body piercing, an infected mother at birth, sexual activity, and dental therapy, among others. However, the exact diversity of the HCV genotype and genetic variation among patients with low-risk factors is still unknown. In this study, we briefly described and analysed the genotype distribution and genetic variation of HCV infections with low-risk factors using molecular biology techniques. The results suggested that genotype 1b was predominant, followed by genotypes 2a and 1a. Genetic variations in the 5′ UTR sequences of HCV were identified, including point mutations, deletions, and insertions. The frequency of genetic variations in 1b was higher than in 2a. This study provides considerable value for the prevention and treatment of liver disease caused by HCV among patients with low-risk factors and for the development of HCV diagnostic reagents and vaccines.

Bats (Order: Chiroptera) have been widely studied as reservoir hosts for viruses of concern for human and animal health. However, whether bats are equally competent hosts of non-viral pathogens such as bacteria remains an important open question. Here, we surveyed blood and saliva samples of vampire bats from Peru and Belize for hemotropic Mycoplasma spp. (hemoplasmas), bacteria that can cause inapparent infection or anemia in hosts. 16S rRNA gene amplification of blood showed 67% (150/223) of common vampire bats (Desmodus rotundus) were infected by hemoplasmas. Sequencing of the 16S rRNA gene amplicons revealed three novel genotypes that were phylogenetically related but not identical to hemoplasmas described from other (non-vampire) bat species, rodents, humans, and non-human primates. Hemoplasma prevalence in vampire bats was highest in non-reproductive and young individuals, did not differ by country, and was relatively stable over time (i.e., endemic). Metagenomics from pooled D. rotundus saliva from Peru detected non-hemotropic Mycoplasma species and hemoplasma genotypes phylogenetically similar to those identified in blood, providing indirect evidence for potential direct transmission of hemoplasmas through biting or social contacts. This study demonstrates vampire bats host several novel hemoplasmas and sheds light on risk factors for infection and basic transmission routes. Given the high frequency of direct contacts that arise when vampire bats feed on humans, domestic animals, and wildlife, the potential of these bacteria to be transmitted between species should be investigated in future work.

Verotoxin-producing Escherichia coli (VTEC) is a significant problem in the under-six population in the Midlands, Ireland. VTEC spreads by person-to-person transmission and children attending childcare facilities are excluded until they achieve two consecutive negative stool samples. This report analyses 10 years data on the number of days children under the age of six take to microbiologically clear VTEC. We identified from our data that the median clearance time for VTEC was 39 days, interquartile range (IQR) 27–56 days, maximum clearance time 283 days. At 70 days from onset of infection, 90% of children had cleared the infection. These findings were slightly more prolonged but consistent with international literature on VTEC clearance times for children. Asymptomatic children cleared VTEC infection significantly faster (median time 25 days IQR 13–43 days) than symptomatic children (median time 43 days IQR 31–58 days). Symptomatic children older than 1 year of age cleared VTEC infection significantly faster (median time 42 days IQR 31–57) than symptomatic children year under 1 year (median time 56 days IQR 35–74 days). This report identifies clear data which can be used to more accurately advise parents on time periods required to achieve microbiological clearance from VTEC.

A Bayesian Belief Network (BBN) for assessing the potential risk of dengue virus emergence and distribution in Western Australia (WA) is presented and used to identify possible hotspots of dengue outbreaks in summer and winter. The model assesses the probabilities of two kinds of events which must take place before an outbreak can occur: (1) introduction of the virus and mosquito vectors to places where human population densities are high; and (2) vector population growth rates as influenced by climatic factors. The results showed that if either Aedes aegypti or Ae. albopictus were to become established in WA, three centres in the northern part of the State (Kununurra, Fitzroy Crossing, Broome) would be at particular risk of experiencing an outbreak. The model can also be readily extended to predict the risk of introduction of other viruses carried by Aedes mosquitoes, such as yellow fever, chikungunya and Zika viruses.

Chlamydia gallinacea, a new chlamydial agent, has been reported in four European countries as well as Argentina and China. Experimentally infected chickens with C. gallinacea in previous study showed no clinical signs but had significantly reduced gains in body weight (6·5–11·4%). Slaughterhouse workers exposed to infected chickens have developed atypical pneumonia, indicating C. gallinacea is likely a zoonotic agent. In this study, FRET-PCR confirmed that C. gallinacea was present in 12·4% (66/531) of oral–pharyngeal samples from Alabama backyard poultry. Phylogenetic comparisons based on ompA variable domain showed that 16 sequenced samples represented 14 biotypes. We report for the first time the presence of C. gallinacea in North America, and this warrants further research on the organism's pathogenicity, hosts, transmission, and zoonotic potential.

Cross-sectorial surveillance and general collaboration between the animal and the public health sectors are increasingly recognized as needed to better manage the impacts of zoonoses. From 2009, the Swiss established a Campylobacter mitigation system that includes human and poultry surveillance data-sharing within a multi-sectorial platform, in a ‘One Health’ approach. The objective of this study was to explore the economics of this cross-sectorial approach, including surveillance and triggered interventions. Costs and benefits of the One Health and of the uni-sectorial approach to Campylobacter surveillance were identified using an economic assessment framework developed earlier. Cost information of surveillance activities and interventions was gathered and disability-adjusted life years (DALYs) associated with the disease estimated for 2008 and 2013. In the first 5 years of this One Health approach to Campylobacter mitigation, surveillance contributed with information mainly used to perform risk assessments, monitor trends and shape research efforts on Campylobacter. There was an increase in costs associated with the mitigation activities following integration, due mainly to the allocation of additional resources to research and implementation of poultry surveillance. The overall burden of campylobacteriosis increased by 3·4–8·8% to 1751–2852 DALYs in 2013. In the timing of the analysis, added value associated with this cross-sectorial approach to surveillance of Campylobacter in the country was likely generated through non-measurable benefits such as intellectual capital and social capital.

Climate change, by its influence on the ecology of vectors might affect the occurrence of vector-borne diseases. This study examines the effects of meteorological factors in Japan on the occurrence of scrub typhus, a mite-borne zoonosis caused by Orientia tsutsugamushi. Using negative binomial regression, we analysed the relationships between meteorological factors (including temperature, rainfall, snowfall) and spring–early summer cases of scrub typhus in Yamagata Prefecture, Japan, during 1984–2014. The average temperature in July and August of the previous year, cumulative rainfall in September of the previous year, snowfall throughout the winter, and maximum depth of snow cover in January and February were positively correlated with the number of scrub typhus cases. By contrast, cumulative rainfall in July of the previous year showed a negative relationship to the number of cases. These associations can be explained by the life-cycle of Leptotrombidium pallidum, a predominant vector of spring–early summer cases of scrub typhus in northern Japan. Our findings show that several meteorological factors are useful to estimate the number of scrub typhus cases before the endemic period. They are applicable to establish an early warning system for scrub typhus in northern Japan.

Pakistan is at the verge of polio eradication but isolation of non-polio enteroviruses (NPEVs) from acute flaccid paralysis (AFP) cases may result in serious or even fatal outcome. Many enteroviruses share similar symptoms and epidemiology as is the case with poliovirus and coxsackievirus (CV). The present study was designed to genetically characterize coxsackievirus B (CV-B) serotypes isolated from non-polio acute flaccid paralytic children, as well as to understand their probable role in paralysis. A total of 63 (20·1%) out of 313 stool samples during 2013 were found positive for NPEVs in rhabdomyosarcoma cells. Only 24 (38·0%) NPEVs were typed as CV-B by microneutralization assay and were further characterized by sequencing of the viral protein 1 (VP1) gene. Molecular phylogenetic analyses classified the study strains into six coxsackievirus B serotypes (coxsackievirus B1 to B6) with their respective prototype strains with evidence of epidemiological linkage and distinct clusters. Moreover, four major differences were found within the amino acid sequences of BC-loop in VP1 of CV-B strains. In conclusion, this study presented the molecular evolutionary genetic overview and distinct phylogenetic pattern of CV-B isolates from AFP cases in Pakistan, and explored the possible link between CV-B infections and AFP cases. Furthermore, our data reveal that these viruses might contribute to the incidence of paralysis in population and there is need of time to establish an enterovirus surveillance system for better understanding of epidemiological and virological characteristics of NPEV infections associated with AFP cases in the country.

Hepatitis C virus (HCV) infection is a public health issue worldwide. Injecting drug use remains the major mode of transmission in developed countries. Monitoring the HCV transmission dynamic over time is crucial, especially to assess the effect of harm reduction measures in drug users (DU). Our objective was to estimate the prevalence and incidence of HCV infection in DU in France using data from a repeated cross-sectional survey conducted in 2004 and 2011. Age- and time-dependent HCV prevalence was estimated through logistic regression models adjusted for HIV serostatus or injecting practices. HCV incidence was estimated from a mathematical model linking prevalence and incidence. HCV prevalence decreased from 58·2% [95% confidence interval (CI) 49·7–66·8] in 2004 to 43·2% (95% CI 38·8–47·7) in 2011. HCV incidence decreased from 7·9/100 person-years (95% CI 6·4–9·4) in 2004 to 4·4/100 person-years (95% CI 3·3–5·9) in 2011. HCV prevalence and incidence were significantly associated with age, calendar time, HIV serostatus and injecting practices. In 2011, the highest estimated incidence was in active injecting DU (11·2/100 person-years). Given the forthcoming objective of generalizing access to new direct antiviral agents for HCV infection, our results contribute to decision-making and policy development regarding treatment scale-up and disease prevention in the DU population.

Tuberculosis (TB) mortality rates in the USA fell rapidly from 1910 to 1933. However, during this period, racial disparities in TB mortality in the nation's expanding cities grew. Because of long delays between infection and disease, TB mortality is a poor indicator of short-term changes in transmission. We estimated the annual risk of TB infection (ARTI) in 11 large US cities to understand whether rising inequality in mortality reflected rising inequality in ARTI using city-level TB mortality data compiled by the US Department of Commerce from 1910 to 1933. We estimated ARTI for African-Americans and whites using pediatric extrapulmonary TB mortality data for African-Americans and whites in our panel of cities. We also estimated age-adjusted pulmonary TB mortality rates for these cities. We find that the ratio of ARTI for African-Americans vs. whites increased from 2·1 (95% CI = 1·7, 2·4) in 1910 to 4·2 (95% CI = 3·4, 5·2) in 1933. This change mirrored the increasing inequality in age-adjusted pulmonary TB mortality during this period. These findings may reflect the combined effects of migration, inequality in access to care, increasing population density, and racial residential segregation in northern cities during this period.

The aim of this study was to determine the prevalence and risk factors for human papillomavirus (HPV) infection in the Southern region of the State of Bahia, evaluating the performance of alternative complementary methods for cervical lesion detection. Cervical samples from women who attended healthcare units were collected and diagnosed by visual inspection, cervical cytology and nested polymerase chain reaction (PCR). Moreover, hemi-nested PCR was performed to detect different HPV genotypes. The prevalence of HPV infection was 47·7%, with genotype 16 detected in most cases. Infection was associated with dyspareunia and bleeding (P < 0·001, odds ratio (OR) 5·6, 95% confidence interval (CI) 2·815–11·14) and hormonal contraceptive use (P = 0·007, OR 2·33, 95% CI 1·25–4·34). There was a positive correlation between positive PCR and positive visual inspection, cervical cytology and symptoms reported. Furthermore, visual inspection was twice as specific, and had a greater positive predictive value than cytology. We showed a high prevalence of HPV infection in Southern Bahia, with HPV 16 being the most common type, and visual inspection being most effective at detecting HPV lesions, corroborating the suggestion that it can be applied in routine gynecologic examinations for low-income populations.

The order Chiroptera is considered the second largest group of mammals in the world, hosting important zoonotic virus and bacteria. Bartonella and hemotropic mycoplasmas are bacteria that parasite different mammals’ species, including humans, causing different clinical manifestations. The present work aimed investigating the occurrence and assessing the phylogenetic positioning of Bartonella spp. and Mycoplasma spp. in neotropical bats sampled from Brazil. Between December 2015 and April 2016, 325 blood and/or tissues samples were collected from 162 bats comprising 19 different species sampled in five states of Brazil. Out of 322 bat samples collected, while 17 (5·28%) were positive to quantitative PCR for Bartonella spp. based on nuoG gene, 45 samples (13·97%) were positive to cPCR assays for hemoplasmas based on 16S rRNA gene. While seven sequences were obtained for Bartonella (nuoG) (n = 3), gltA (n = 2), rpoB (n = 1), ftsZ (n = 1), five 16S rRNA sequences were obtained for hemoplasmas. In the phylogenetic analysis, the Bartonella sequences clustered with Bartonella genotypes detected in bats sampled in Latin America countries. All five hemoplasmas sequences clustered together as a monophyletic group by Maximum Likelihood and Bayesian Inference analyses. The present work showed the first evidence of circulation of Bartonella spp. and hemoplasmas among bats in Brazil.

Retreatment of tuberculosis (TB) often fails in China, yet the risk factors associated with the failure remain unclear. To identify risk factors for the treatment failure of retreated pulmonary tuberculosis (PTB) patients, we analyzed the data of 395 retreated PTB patients who received retreatment between July 2009 and July 2011 in China. PTB patients were categorized into ‘success’ and ‘failure’ groups by their treatment outcome. Univariable and multivariable logistic regression were used to evaluate the association between treatment outcome and socio-demographic as well as clinical factors. We also created an optimized risk score model to evaluate the predictive values of these risk factors on treatment failure. Of 395 patients, 99 (25·1%) were diagnosed as retreatment failure. Our results showed that risk factors associated with treatment failure included drug resistance, low education level, low body mass index (<18·5), long duration of previous treatment (>6 months), standard treatment regimen, retreatment type, positive culture result after 2 months of treatment, and the place where the first medicine was taken. An Optimized Framingham risk model was then used to calculate the risk scores of these factors. Place where first medicine was taken (temporary living places) received a score of 6, which was highest among all the factors. The predicted probability of treatment failure increases as risk score increases. Ten out of 359 patients had a risk score >9, which corresponded to an estimated probability of treatment failure >70%. In conclusion, we have identified multiple clinical and socio-demographic factors that are associated with treatment failure of retreated PTB patients. We also created an optimized risk score model that was effective in predicting the retreatment failure. These results provide novel insights for the prognosis and improvement of treatment for retreated PTB patients.

Tuberculosis (TB) remains a threat to public health and is the second cause of death due to a single infectious agent after HIV/AIDS. The worldwide distribution of TB is heterogeneous. The incidence is decreasing in most high-income regions, but the situation remains worrying in many parts of the world. The emergence of Mycobacterium tuberculosis strains resistant to key agents used in treatment (rifampin and isoniazid) contributes to TB transmission around the world. To achieve TB elimination, both high and low endemic countries must upscale their efforts to decrease disease transmission and improve cure rates. Management of drug-resistant TB is of particular importance. In this paper, we discuss the different models of care of multidrug-resistant TB (MDR-TB), the ethical considerations and the specific constraints present in high income countries. The management model chosen by the Belgian TB specialists in accordance with public health authorities as well as building of a specific MDR/XDR-TB isolation unit are also discussed.

Following an unusually heavy rainfall in June 2009, a community-wide outbreak of Campylobacter gastroenteritis occurred in a small Danish town. The outbreak investigation consisted of (1) a cohort study using an e-questionnaire of disease determinants, (2) microbiological study of stool samples, (3) serological study of blood samples from cases and asymptomatic members of case households, and (4) environmental analyses of the water distribution system. The questionnaire study identified 163 cases (respondent attack rate 16%). Results showed a significant dose-response relationship between consumption of tap water and risk of gastroenteritis. Campylobacter jejuni belonging to two related flaA types were isolated from stool samples. Serum antibody levels against Campylobacter were significantly higher in cases than in asymptomatic persons. Water samples were positive for coliform bacteria, and the likely mode of contamination was found to be surface water leaking into the drinking-water system. This geographically constrained outbreak presented an ideal opportunity to study the serological response in persons involved in a Campylobacter outbreak. The serology indicated that asymptomatic persons from the same household may have been exposed, during the outbreak period, to Campylobacter at doses that did not elicit symptoms or alternatively had been exposed to Campylobacter at a time prior to the outbreak, resulting in residual immunity and thus absence of clinical signs.

Accurate knowledge of pathogen incubation period is essential to inform public health policies and implement interventions that contribute to the reduction of burden of disease. The incubation period distribution of campylobacteriosis is currently unknown with several sources reporting different times. Variation in the distribution could be expected due to host, transmission vehicle, and organism characteristics, however, the extent of this variation and influencing factors are unclear. The authors have undertaken a systematic review of published literature of outbreak studies with well-defined point source exposures and human experimental studies to estimate the distribution of incubation period and also identify and explain the variation in the distribution between studies. We tested for heterogeneity using I2 and Kolmogorov–Smirnov tests, regressed incubation period against possible explanatory factors, and used hierarchical clustering analysis to define subgroups of studies without evidence of heterogeneity. The mean incubation period of subgroups ranged from 2·5 to 4·3 days. We observed variation in the distribution of incubation period between studies that was not due to chance. A significant association between the mean incubation period and age distribution was observed with outbreaks involving only children reporting an incubation of 1·29 days longer when compared with outbreaks involving other age groups.

Dengue fever is an arthropod-borne viral infection that has become endemic in several parts of India including Delhi. We studied occurrence of co-infection with dengue viruses during an outbreak in New Delhi, India in 2014. For the present study, blood samples collected from symptomatic patients were analysed by RT–PCR. Eighty percent of the samples were positive for dengue virus. The result showed that DENV-1 (77%) was the predominant serotype followed by DENV-2 (60%). Concurrent infection with more than one serotype was identified in 43% of the positive samples. Phylogenetic analysis clustered DENV-1 strains with the American African and DENV-2 strains in Cosmopolitan genotypes. Four common amino-acid mutations were identified in the envelope gene of DENV-1 sequences (F337I, A369T, V380I and L402F) and one common mutation (N390S) in the DENV-2 sequences. Further analysis revealed purifying selection in both the serotypes. A significant number of patients were co-infected with DENV-1 and DENV-2 serotypes. Although we do not have direct evidence to demonstrate co-evolution of these two stereotypes, nonetheless their simultaneous occurrence does indicate that they are favoured by evolutionary forces. An ongoing surveillance and careful analysis of future outbreaks will strengthen the concept of co-evolution or otherwise. Whether the concurrent dengue viral infection is correlated with disease severity in a given population is another aspect to be pursued. This study is envisaged to be useful for future reference in the context of overall epidemiology.

This study aimed to estimate the disease burden of hepatitis E in a rural region in China. A total of 489 hepatitis E cases were reported according to a community-based survey in an active hepatitis surveillance system between 2008 and 2015, the questionnaire and record-review methods were constructed to evaluate the economic and health burden of hepatitis E virus infections from societal perspectives. All costs were converted to US$ in 2015. The age-standardized cumulative incidence rate was 107·9/100 000, and the median age-standardized annual incidence rate was 16·5/100 000. The median direct, indirect, and intangible cost were $1046·0, $49·1, and $77·3/patient, respectively, and the median economic burden per patient was $1836·5, which accounted for 51·2% of per capita disposable income. Moreover, the median quality-adjusted life year and visual analogue scale score were 0·7 and 70·0/case, respectively. Both economic burden and health burden of inpatients was more serious than that of outpatients (P < 0·001). Disease burden of hepatitis E is heavy on patients, their families, and society. More studies on the disease burden of hepatitis E are necessary to increase social awareness of the disease and confirm reasonable disease-control measures.