45 research outputs found
Low gonorrhoea antimicrobial resistance and culture positivity rates in general practice: a pilot study
Objective In the Netherlands, the Gonococcal Resistance
to Antimicrobials Surveillance (GRAS) programme is carried
out at Centres for Sexual Health (CSH), which provide
care for sexual high-risk populations. However, half of
gonorrhoea infections are diagnosed in general practice
(GP). We performed a pilot study to explore expanding
GRAS to GPs using laboratory-based surveillance.
Additionally, antimicrobial resistance patterns of GP and
CSH patients were compared.
Methods Three laboratories from different regions were
included, which all perform gonorrhoea diagnostics for
GPs and used ESwab for patient sampling. Additional
culturing for all GP patients with gonorrhoea took place
from February to July 2018. After positive PCR-nucleic
acid amplification test, residual ESwab material was used
for culture. In positive cultures, susceptibility testing was
performed for azithromycin, ciprofloxacin, cefotaxime
and ceftriaxone using Etest.
Results During the study period, 484 samples were
put in culture. 16.5% of cultures were positive (n=80).
Antimicrobial resistance levels were low, with 2.6%
resistance to azithromycin, 21.5% to ciprofloxacin and
0.0% to cefotaxime and ceftriaxone. Resistance levels
in CSH GRAS data (first half of 2018) were 19.2%
for azithromycin, 31.5% for ciprofloxacin, 1.9% for
cefotaxime and 0.0% for ceftriaxone.
Conclusions Culture positivity rates for GP patients
were low, probably due to long transportation times
and awaiting PCR test results before attempting culture.
Positivity rates might be improved by making changes in
sampling and/or transportation methods, but that would
require involvement of GPs and patients instead of keeping
the surveillance lab based. Resistance levels appeared to
be lower at GPs than at the CSH, indicating that resistance
might emerge first in more high-risk populations. It is
important to consider all potentially relevant patient
populations when establishing a gonococcal antimicrobial
resistance surveillance programme. However, based on the
findings from this study the current GRAS programme will
not be extended to GPs
Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.
BACKGROUND: Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. METHODS AND FINDINGS: We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. CONCLUSIONS: Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary
Pregnancies and Time to Pregnancy in Women With and Without a PreviousChlamydia trachomatisInfection
Background: A Chlamydia trachomatis infection (chlamydia) can result
in tubal factor infertility in women. To assess if this association results in
fewer pregnant women, we aimed to assess pregnancy incidences and time
to pregnancy among women with a previous chlamydia infection compared
with women without one and who were participating in the Netherlands
Chlamydia Cohort Study (NECCST).
Methods: The NECCST is a cohort of women of reproductive age tested
for chlamydia in a chlamydia screening trial between 2008 and 2011 and
reinvited for NECCST in 2015 to 2016. Chlamydia status (positive/negative)
was defined using chlamydia screening trial–nucleic acid amplification test
results, chlamydia immunoglobulin G presence in serum, or self-reported
chlamydia infections. Data on pregnancies were collected via questionnaires in 2015–2016 and 2017–2018. Overall p
Widespread fear of dengue transmission but poor practices of dengue prevention : A study in the slums of Delhi, India
Background This study has been conducted to throw light on the knowledge and practices related to dengue fever among the poor population living in Delhi's slums. Materials A household survey was conducted in 2013 among 3,350 households. The households were stratified by a number of variables related to socio-economic status and health events such as hospitalisation. The data collection was completed through face-to-face interviews conducted with the help of 25 field investigators. Results About 8% of the households had at least one diagnosed dengue case. In comparison to the population surveyed, teenagers (15-19 years) and adults (30-34 years) were more affected whereas children under four years of age were underrepresented. Housewives are more affected by dengue (24%) compared to their share of the population surveyed (17%). Despite the fact that 77% of the respondents are worried about mosquitoes, only 43% of them monitor environment to avoid the presence of breeding sites. Conclusion One cannot exclude the possibility that though young children under the age of four years are exposed to the virus, either their cases were asymptomatic or family members infected during this period had potentially more serious symptoms leading to hospitalisation. This result could thus be explained by budget-related health choices made by this population which do not favour small children. Educational programs should target housewives to improve their impact, as they are the ones mostly responsible for water storage and cleanliness of the house and its neighbourhood. Even with a dengue experience and potentially an acute perception of the risk and its factors, a proper management of environmental conditions is lacking. This along with the fact that word-of-mouth is the main source of information quoted should be a message for municipality health workers to give door-to-door information on how to prevent breeding sites and dengue infection
VoxLogicA : A Spatial Model Checker for Declarative Image Analysis
Spatial and spatio-temporal model checking techniques have a wide range of application domains, among which large scale distributed systems and signal and image analysis.We explore a new domain, namely (semi-)automatic contouring in Medical Imaging, introducing the tool VoxLogicA which merges the state-of-the-art library of computational imaging algorithms ITK with the unique combination of declarative specification and optimised execution provided by spatial logic model checking. The result is a rapid, logic based analysis development methodology. The analysis of an existing benchmark of medical images for segmentation of brain tumours shows that simple VoxLogicA analysis can reach state-of-the-art accuracy, competing with best-in-class algorithms, with the advantage of explainability and easy replicability. Furthermore, due to a two-orders-of-magnitude speedup compared to the existing generalpurpose spatio-temporal model checker topochecker, VoxLogicA enables interactive development of analysis of 3D medical images, which can greatly facilitate the work of professionals in this domain
Beyond word frequency: Bursts, lulls, and scaling in the temporal distributions of words
Background: Zipf's discovery that word frequency distributions obey a power
law established parallels between biological and physical processes, and
language, laying the groundwork for a complex systems perspective on human
communication. More recent research has also identified scaling regularities in
the dynamics underlying the successive occurrences of events, suggesting the
possibility of similar findings for language as well.
Methodology/Principal Findings: By considering frequent words in USENET
discussion groups and in disparate databases where the language has different
levels of formality, here we show that the distributions of distances between
successive occurrences of the same word display bursty deviations from a
Poisson process and are well characterized by a stretched exponential (Weibull)
scaling. The extent of this deviation depends strongly on semantic type -- a
measure of the logicality of each word -- and less strongly on frequency. We
develop a generative model of this behavior that fully determines the dynamics
of word usage.
Conclusions/Significance: Recurrence patterns of words are well described by
a stretched exponential distribution of recurrence times, an empirical scaling
that cannot be anticipated from Zipf's law. Because the use of words provides a
uniquely precise and powerful lens on human thought and activity, our findings
also have implications for other overt manifestations of collective human
dynamics
Pregnancy rates and predictors in women with HIV/AIDS in Rio de Janeiro, Southeastern Brazil
OBJECTIVE: To assess incidence and predictors of first pregnancy among women with HIV/AIDS. METHODS: Prospective cohort study was conducted in Rio de Janeiro, southeastern Brazil, between 1996 and 2003. This study comprised 225 women with HIV/AIDS followed up until their first pregnancy or first censored event (hysterectomy, tubal ligation, menopause, 50 years of age, loss to follow-up, death or the end of December 2003). Pregnancy and abortion rates were estimated, and Cox proportional hazards models were used to identify baseline characteristics associated with pregnancy risk. RESULTS: The women were followed up for 565 person/years with a median follow-up of 3 years per women. The mean age was 32 years (SD: 7), and 54.7% were white. There were 60 pregnancies in 39 women, and 18 were terminated (induced abortions), accounting for a rate of 6.9% and 2.1% women/year, respectively. Repeated pregnancies occurred in 33.3% of the women (13/39). Higher pregnancy risk was seen among younger women (HR=3.42; 95%CI: 1.69;6.95) and those living with their partners (HR=1.89; 95%CI: 1.00;3.57). Lower pregnancy risk was associated with higher education level (HR=0.43; 95%CI: 0.19;0.99) and use of antiretroviral therapy (HR=061; 95%CI: 0.31;1.17). CONCLUSIONS: Lower pregnancy rates were found in our cohort than in the general population. Sociodemographic characteristics should be taken into consideration in the management of reproductive health in HIV-positive childbearing age women. Reproductive and family planning counseling must be incorporated into HIV/AIDS programs for women to help preventing HIV transmission to their partners and offspring
Clostridium difficile infection in Europe: a hospital-based survey
Comment in
Lancet. 2011 Jan 1;377(9759):8-9.
Lancet. 2011 Apr 23;377(9775):1407.BACKGROUND: Little is known about the extent of Clostridium difficile infection in Europe. Our aim was to obtain a more complete overview of C difficile infection in Europe and build capacity for diagnosis and surveillance.
METHODS: We set up a network of 106 laboratories in 34 European countries. In November, 2008, one to six hospitals per country, relative to population size, tested stool samples of patients with suspected C difficile infection or diarrhoea that developed 3 or more days after hospital admission. A case was defined when, subsequently, toxins were identified in stool samples. Detailed clinical data and stool isolates were collected for the first ten cases per hospital. After 3 months, clinical data were followed up.
FINDINGS: The incidence of C difficile infection varied across hospitals (weighted mean 4·1 per 10,000 patient-days per hospital, range 0·0-36·3). Detailed information was obtained for 509 patients. For 389 of these patients, isolates were available for characterisation. 65 different PCR ribotypes were identified, of which 014/020 (61 patients [16%]), 001 (37 [9%]), and 078 (31 [8%]) were the most prevalent. The prevalence of PCR-ribotype 027 was 5%. Most patients had a previously identified risk profile of old age, comorbidity, and recent antibiotic use. At follow up, 101 (22%) of 455 patients had died, and C difficile infection played a part in 40 (40%) of deaths. After adjustment for potential confounders, an age of 65 years or older (adjusted odds ratio 3·26, 95% CI 1·08-9·78; p=0·026), and infection by PCR-ribotypes 018 (6·19, 1·28-29·81; p=0·023) and 056 (13·01; 1·14-148·26; p=0·039) were significantly associated with complicated disease outcome.
INTERPRETATION: PCR ribotypes other than 027 are prevalent in European hospitals. The data emphasise the importance of multicountry surveillance to detect and control C difficile infection in Europe.FUNDING: European Centre for Disease Prevention and Contro