Giardia duodenalis is the most common intestinal parasite of humans in the USA, but the risk factors for sporadic (non-outbreak) giardiasis are not well described. The Centers for Disease Control and Prevention and the Colorado and Minnesota public health departments conducted a case-control study to assess risk factors for sporadic giardiasis in the USA. Cases (N = 199) were patients with non-outbreak-associated laboratory-confirmed Giardia infection in Colorado and Minnesota, and controls (N = 381) were matched by age and site. Identified risk factors included international travel (aOR = 13.9; 95% CI 4.9–39.8), drinking water from a river, lake, stream, or spring (aOR = 6.5; 95% CI 2.0–20.6), swimming in a natural body of water (aOR = 3.3; 95% CI 1.5–7.0), male–male sexual behaviour (aOR = 45.7; 95% CI 5.8–362.0), having contact with children in diapers (aOR = 1.6; 95% CI 1.01–2.6), taking antibiotics (aOR = 2.5; 95% CI 1.2–5.0) and having a chronic gastrointestinal condition (aOR = 1.8; 95% CI 1.1–3.0). Eating raw produce was inversely associated with infection (aOR = 0.2; 95% CI 0.1–0.7). Our results highlight the diversity of risk factors for sporadic giardiasis and the importance of non-international-travel-associated risk factors, particularly those involving person-to-person transmission. Prevention measures should focus on reducing risks associated with diaper handling, sexual contact, swimming in untreated water, and drinking untreated water.

Community-led total sanitation (CLTS) is an intervention that strives to end the practice of open defaecation. This study measured the effectiveness of CLTS in Nyando District by examining the association between community open defaecation-free (ODF) status and childhood diarrhoeal illness. A cross-sectional study design was used among households with children ⩽5 years old to ascertain information on acute diarrhoea in the past year (outcome), sanitation and health behaviours. Water testing was conducted to determine Escherichia coli and turbidity levels for 55 water sources. Data were obtained from 210 parents or caregivers from an ODF community and 216 parents or caregivers in a non-ODF community. The non-ODF participants reported a non-significant 16% increased risk of diarrhoea compared with the participants from the ODF community. Children's HIV positivity (adjusted prevalence ratio (aPR) = 2.29; 95% CI 2.07–2.53), unsafe child stool disposal (aPR = 1.92; 95% CI 1.74–2.12) and low household income (aPR = 1.93; 95% CI 1.46–2.56) were associated with diarrhoea, in the non-ODF community. The ODF location had a higher percentage of E. coli in the drinking water compared with the non-ODF location (76.7% vs. 60%). Diarrhoeal disease rates in children ⩽5 years old did not differ by whether a latrine intervention was implemented. Water sampling findings suggest water safety may have decreased the effectiveness of the CLTS’ improvement of childhood diarrhoea. Improved water treatment practices, safe stool disposal and education may improve the CLTS intervention in ODF communities and therefore reduced the risk of childhood diarrhoea.

The effect of transportation and lairage on the faecal shedding and post-slaughter contamination of carcasses with Escherichia coli O157 and O26 in young calves (4–7-day-old) was assessed in a cohort study at a regional calf-processing plant in the North Island of New Zealand, following 60 calves as cohorts from six dairy farms to slaughter. Multiple samples from each animal at pre-slaughter (recto-anal mucosal swab) and carcass at post-slaughter (sponge swab) were collected and screened using real-time PCR and culture isolation methods for the presence of E. coli O157 and O26 (Shiga toxin-producing E. coli (STEC) and non-STEC). Genotype analysis of E. coli O157 and O26 isolates provided little evidence of faecal–oral transmission of infection between calves during transportation and lairage. Increased cross-contamination of hides and carcasses with E. coli O157 and O26 between co-transported calves was confirmed at pre-hide removal and post-evisceration stages but not at pre-boning (at the end of dressing prior to chilling), indicating that good hygiene practices and application of an approved intervention effectively controlled carcass contamination. This study was the first of its kind to assess the impact of transportation and lairage on the faecal carriage and post-harvest contamination of carcasses with E. coli O157 and O26 in very young calves.

Patients with chronic liver disease (CLD) have frequent exposure to Clostridium difficile infection (CDI) risk factors but the incidence and aetiology of CDI on this population is poorly understood. The aim of this study was to assess the incidence, disease presentation and outcomes of CDI in patients with underlying CLD. The Health Care and Utilization Project National Inpatient Sample (HCUP-NIS) 2009 dataset was used to identify patients with CLD who developed CDI along with matched non-CLD patients with CDI. Using the NIS dataset, the incidence rate of CDI was 189.4/10 000 discharges in CLD patients vs. 83.7/10 000 discharges in the non-CLD matched cohort (P < 0.001). Compared with non-CLD, comorbidity-matched controls with CDI, CLD patients with CDI had higher likelihood of in-hospital mortality (8.8% vs. 18.6%, P < 0.001), increased length of stay by 1.19 days (P < 0.001) and increased total costs by $8632 (P < 0.001). In separate analyses using a tertiary case database of hospitalised patients in Houston, Texas (2006–2016) with CLD and CDI (n = 41) compared with patients with CDI but not CLD (n = 111), CLD patients had significantly higher Charlson comorbidity index (P < 0.0001) but similar risk factors for CDI and CDI-related disease presentation compared with non-CLD patients. In conclusion, CDI-related risk factors were almost universally present in the CLD population. CDI resulted in worse outcomes in this population.

Significant increases in excess all-cause mortality, particularly in the elderly, were observed during the winter of 2014/15 in England. With influenza A(H3N2) the dominant circulating influenza A subtype, this paper determines the contribution of influenza to this excess controlling for weather. A standardised multivariable Poisson regression model was employed with weekly all-cause deaths the dependent variable for the period 2008–2015. Adjusting for extreme temperature, a total of 26 542 (95% CI 25 301–27 804) deaths in 65+ and 1942 (95% CI 1834–2052) in 15–64-year-olds were associated with influenza from week 40, 2014 to week 20, 2015. This is compatible with the circulation of influenza A(H3N2). It is the largest estimated number of influenza-related deaths in England since prior to 2008/09. The findings highlight the potential health impact of influenza and the important role of the annual influenza vaccination programme that is required to protect the population including the elderly, who are vulnerable to a severe outcome.

Influenza is a long-standing public health concern, but its transmission remains poorly understood. To have a better knowledge of influenza transmission, we carried out a detailed modelling investigation in a nosocomial influenza outbreak in Hong Kong. We identified three hypothesised transmission modes between index patient and other inpatients based on the long-range airborne and fomite routes. We considered three kinds of healthcare workers’ routine round pathways in 1140 scenarios with various values of important parameters. In each scenario, we used a multi-agent modelling framework to estimate the infection risk for each hypothesis and conducted least-squares fitting to evaluate the hypotheses by comparing the distribution of the infection risk with that of the attack rates. Amongst the hypotheses tested in the 1140 scenarios, the prediction of modes involving the long-range airborne route fit better with the attack rates, and that of the two-route transmission mode had the best fit, with the long-range airborne route contributing about 94% and the fomite route contributing 6% to the infections. Under the assumed conditions, the influenza virus was likely to have spread via a combined long-range airborne and fomite routes, with the former predominant and the latter negligible.

Pneumonia is one of the most common infectious diseases with a high mortality, especially in the elderly population. To date, there have been only a few population-based studies dealing with the incidence of pneumonia in nursing homes (NHs). We conducted a cohort study using data from a large German statutory health insurance fund. Between 2010 and 2014, 127 227 NH residents 65 years and older were analysed. For the calculation of incidences per 100 person-years (PY) and 95% confidence intervals (CIs), we assessed the first diagnosis of pneumonia during the time in NH. We compared the rates between sexes, age groups, care levels, and comorbidities and we performed a multivariate Cox regression analysis. The mean age in the cohort was 84.0 years (74.6% female). A total of 19 183 incident cases led to an overall 5-year-incidence of 11.8 per 100 PY (95% CI 11.7–12.0). The incidence in men was substantially higher than in women. Rates were highest in the first month after NH placement. Our study revealed that the incidence of pneumonia is high in German NH residents and especially in males. Due to demographic changes, pneumonia will likely be increasingly relevant in the health care of the elderly and institutionalised population.

Respiratory infections among infants constitute a major burden to health care systems in developed nations, yet the course and risk factors leading to these conditions are poorly understood. We examine the longitudinal patterns of respiratory infection hospitalisation (RIH) and how these patterns are influenced by neonatal pulmonary morbidities. We included all live births (n = 429 058) occurring in the Australian state of Queensland between January 2009 and December 2015. Data were structured so that each participant had a record (present/absent) of RIH for each month from birth to 12 months. Initially, latent class growth analysis was used to identify the trajectories of RIH adjusted for spatial–temporal factors; using the identified trajectories of RIH as outcomes, we built a multinomial logistic regression model to identify neonatal predictors of RIH trajectories. Our results indicated that a four-class solution was the best fit to the data, comprising a ‘no-risk’ trajectory, a ‘low-risk’ trajectory, an ‘early-risk’ trajectory and a ‘chronic-risk’ trajectory. Compared with the no-risk trajectory, membership in the other trajectories was predicted by a range of neonatal pulmonary morbidities, with transient tachypnoea of newborn showing a specific relationship with the early-risk group and sleep apnoea showing a specific and strong risk with the chronic-risk group. Our findings suggest the possibility of identifying neonates at risk of recurrent RIH and implementing effective intervention strategies prior to neonatal discharge.

Vaccination is increasingly being recognised as a potential tool to supplement ‘stamping out’ for controlling foot-and-mouth disease (FMD) outbreaks in non-endemic countries. Infectious disease simulation models provide the opportunity to determine how vaccination might be used in the face of an FMD outbreak. Previously, consistent relative benefits of specific vaccination strategies across different FMD simulation modelling platforms have been demonstrated, using a UK FMD outbreak scenario. We extended this work to assess the relative effectiveness of selected vaccination strategies in five countries: Australia, New Zealand, the USA, the UK and Canada. A comparable, but not identical, FMD outbreak scenario was developed for each country with initial seeding of Pan Asia type O FMD virus into an area with a relatively high density of livestock farms. A series of vaccination strategies (in addition to stamping out (SO)) were selected to evaluate key areas of interest from a disease response perspective, including timing of vaccination, species considerations (e.g. vaccination of only those farms with cattle), risk area vaccination and resources available for vaccination. The study found that vaccination used with SO was effective in reducing epidemic size and duration in a severe outbreak situation. Early vaccination and unconstrained resources for vaccination consistently outperformed other strategies. Vaccination of only those farms with cattle produced comparable results, with some countries demonstrating that this could be as effective as all species vaccination. Restriction of vaccination to higher risk areas was less effective than other strategies. This study demonstrates consistency in the relative effectiveness of selected vaccination strategies under different outbreak start up conditions conditional on the assumption that each of the simulation models provide a realistic estimation of FMD virus spread. Preferred outbreak management approaches must however balance the principles identified in this study, working to clearly defined outbreak management objectives, while having a good understanding of logistic requirements and the socio-economic implications of different control measures.

To study the antibody response to tetanus toxoid and measles by age following vaccination in children aged 4 months to 6 years in Entebbe, Uganda. Serum samples were obtained from 113 children aged 4–15 months, at the Mother-Child Health Clinic (MCHC), Entebbe Hospital and from 203 of the 206 children aged between 12 and 75 months recruited through the Outpatients Department (OPD). Antibodies to measles were quantified by plaque reduction neutralisation test (PRNT) and with Siemens IgG EIA. VaccZyme IgG EIA was used to quantify anti-tetanus antibodies. Sera from 96 of 113 (85.0%) children attending the MCHC contained Measles PRNT titres below the protective level (120 mIU/ml). Sera from 24 of 203 (11.8%) children attending the OPD contained PRNT titres <120 mIU/ml. There was no detectable decline in anti-measles antibody concentrations between 1 and 6 years. The anti-tetanus antibody titres in all 113 children attending MCHC and in 189 of 203 (93.1%) children attending the OPD were >0.15 IU/ml by EIA, a level considered protective. The overall concentration of anti-tetanus antibody was sixfold higher in children under 12 months compared with the older children, with geometric mean concentrations of 3.15 IU/ml and 0.49 IU/ml, respectively. For each doubling in age between 4 and 64 months, the anti-tetanus antibody concentration declined by 50%. As time since the administration of the third DTP vaccination doubled, anti-tetanus antibody concentration declined by 39%. The low measles antibody prevalence in the children presenting at the MCHC is consistent with the current measles epidemiology in Uganda, where a significant number of measles cases occur in children under 1 year of age and earlier vaccination may be indicated. The consistent fall in anti-tetanus antibody titre over time following vaccination supports the need for further vaccine boosters at age 4–5 years as recommended by the WHO.

Social contact between individuals is believed to be a fundamental cause in the transmission of many respiratory tract infections. Because they have not yet been fully vaccinated, infants are at high risk for contracting whooping cough, influenza and their serious complications. Therefore, determining infant social contact patterns is an important step in protecting them from respiratory tract infection. This study included 1200 healthy infants (<12 months of age). Social contact diaries were used to estimate the frequency and nature of the infants’ social contacts. This survey also gathered information regarding the infants’ respiratory symptoms and their frequency of attendance at crowded places over a period of 1 week. The diary return rate was 83.8% (N = 1006), and there was a total of 4706 contacts reported for these infants. The median daily contact number per capita was 4 (range 1–18). The median number of contacts with adolescents was 0 (range 0–7). Of the infants, 50.3% had contact with non-household individuals. The mothers had the longest contacts with their babies. Contacts with school children, frequency of attendance at crowded places and age were determined to be significant effective factors for reporting respiratory symptoms. Results suggest that school-age siblings and the mothers should be primarily vaccinated, and parents should keep their babies away from crowded places for protecting their infants.

Jamestown Canyon and snowshoe hare viruses are two emerging human pathogens associated with cases of neuroinvasive disease in North America. This study aimed to identify environmental and individual risk factors for seropositivity to these arboviruses in humans and pet dogs from Québec, Canada, 2012–2014. In humans, areas with moderate densities of white-tailed deer (Odocoileus virginianus) were associated with higher odds of seropositivity compared with areas with low densities of white-tailed deer (OR 2.50, P = 0.009) and odds of seropositivity were higher in males than in females (OR 2.03, P = 0.016). Among humans reporting more than 10 mosquito bites weekly, the odds of being seropositive were 4.44 times higher (P = 0.004) for people living in hardwood forested areas. Exposure to areas with coniferous forests was identified as the main environmental risk factor for seroconversion in dogs (OR 2.39, P = 0.04). These findings may help target further public health research, diagnostic and surveillance efforts in Canada.

Following a cluster of serious pseudomonas skin infections linked to a body piercing and tattooing premises, a look-back exercise was carried out to offer clients a screen for blood-borne viruses. Of those attending for screening 72% (581/809) had a piercing procedure in the premises of interest: 94 (16%) were under 16 years of age at the time of screening. The most common site of piercing was ear (34%), followed by nose (27%), nipple (21%) and navel (21%). A small number (<5) tested positive for hepatitis B and C, with no evidence this was linked to the premises. However, 36% (211/581) of clients reported a skin infection associated with their piercing. Using data from client forms, 36% provided a false age. Those aged under 16 years (OR 4.5, 95% CI 2.7–7.7) and those receiving a piercing at an intimate site (OR 2.1, 95% CI 1.3–3.6) were more likely to provide a false age. The findings from this exercise were used to support the drafting of the Public Health (Wales) Bill which proposed better regulation of piercing premises and the need to provide proof of being 18 years of age or over before having a piercing of an intimate site.

Persistent infection with high-risk human papillomavirus (HPV) is the main cause of cervical cancer and the prevalence of HPV types varies depending on the geographic region. Therefore, this study assessed the prevalence of HPV types in women with cervical lesions from Sergipe state, Northeastern Brazil. A cross-sectional study was conducted in women with cervical lesions from March to December 2014. These lesions were investigated by PCR and HPV types were identified by DNA sequencing. 432 patients were included, of which 337 patients tested positive for HPV. Eighteen different HPV types were detected, and high-risk HPV types were detected in 69.2%. HPV 16 (63.4%) was the most prevalent HPV type found, followed by HPV 66 (4.6%), HPV 18 (1.6%) and HPV 45 (1.4%). These results highlight the importance of the high prevalence of HPV 66, which is a possibly carcinogenic virus type not covered by the available vaccines. The prevalence of HPV 16 was high in the studied population, reaffirming the importance of young vaccination. However, the high prevalence of HPV 66 found in this study shows the importance of monitoring the diversity of HPV types in different populations and geographic regions to better understand the impacts of current HPV vaccines.

Prevalence of skin sores and scabies in remote Australian Aboriginal communities remains unacceptably high, with Group A Streptococcus (GAS) the dominant pathogen. We aim to better understand the drivers of GAS transmission using mathematical models. To estimate the force of infection, we quantified the age of first skin sores and scabies infection by pooling historical data from three studies conducted across five remote Aboriginal communities for children born between 2001 and 2005. We estimated the age of the first infection using the Kaplan–Meier estimator; parametric exponential mixture model; and Cox proportional hazards. For skin sores, the mean age of the first infection was approximately 10 months and the median was 7 months, with some heterogeneity in median observed by the community. For scabies, the mean age of the first infection was approximately 9 months and the median was 8 months, with significant heterogeneity by the community and an enhanced risk for children born between October and December. The young age of the first infection with skin sores and scabies reflects the high disease burden in these communities.

This study aimed to molecularly survey Bartonella in dogs from Chile. Quantitative real-time PCR (qPCR) for Bartonella spp. based on nuoG gene was performed in 139 blood samples taken from dogs belonging to rural localities of the Valdivia Province, Los Ríos region, southern Chile. nuoG qPCR-positive samples were submitted to conventional PCR assays for ftsZ, gltA, rpoB and nuoG genes and sequencing for speciation and phylogenetic analysis. Based upon qPCR results, Bartonella spp. occurrence in dogs was 4.3% (6/139). Out of six nuoG qPCR-positive samples, six, three, two and none showed positive results in cPCR assays based on gltA, ftsZ, rpoB and nuoG genes, respectively. Consistent sequencing results were obtained only for the ftsZ gene from sample #1532 (GeneBank accession number: MG252491), and gltA gene from samples #1535 (MG252490) and #1532 (148 bp fragment that was not deposited in GenBank). Phylogenetic analysis of ftsZ and gltA genes allowed speciation of two nuoG-positive samples, one as Bartonella vinsonii subsp. berkhoffii and the other as B. henselae. Bartonella vinsonii subsp. berkhoffii and B. henselae are detected for the first time in dogs from Chile, highlighting the importance of the canine population as a source of zoonotic agents and potential infection risk to humans.