Toxicoepidemiology and predictors of death in 2,4-dinitrophenol (DNP) toxicity.

INTRODUCTION: 2,4-Dinitrophenol (DNP) is a highly toxic industrial chemical that is sometimes misused to reduce body fat. Toxicity following ingestion of DNP has recently become more common in the United Kingdom. This research was performed to document the frequency of DNP toxicity as reported to poisons centres in the United States (US) and United Kingdom (UK) and to identify the clinical features associated with fatality. METHODS: Calls to UK and US poisons centres involving systemic exposure to DNP were extracted for the 12 calendar years 2007-2018. These were analysed using univariate and multivariate statistical techniques. RESULTS: There were 204 cases (n = 86, US; n = 118, UK) of systemic DNP exposure identified, of which 86% were under the age of 40 and 71% were males. Over the study period the incidence of reported DNP toxicity was higher in the United Kingdom than the United States (1.78 vs. 0.26 cases per million population) and annual case numbers have increased in both countries since 2011. Case fatality was high and did not differ significantly between countries (US 11.6%; 95% CI: 6.4-20.1%: UK 16.9%; 95% CI: 11.3-24.7%; X2(1) = 1.12, p = 0.29). Univariate analysis demonstrated significant associations between risk of death and the presence of hypoglycaemia (OR = 17.1, 95% CI 1.7-174.3), hypertonia (OR = 12.9, 95% CI 3.5-47.6), acidosis (OR = 12.5, 95% CI 4.8-32.9), raised lactate (OR = 8.3, 95% CI 2.4-28.4), hyperpyrexia (OR = 6.5, 95% CI 2.8-15.2), tachycardia (OR = 6.4, 95% CI 2.5-16.4), agitation or confusion (OR = 6.0, 95% CI 2.6-13.7), hypertension (OR = 5.6, 95% CI 1.9-16.4) and tachypnoea/dyspnoea (OR = 2.8, 95% CI 1.2-6.1). After backwards stepwise logistic regression, the following were retained as significant independent predictors of mortality: acidosis (OR = 5.4, 95% CI: 1.8 - 16.5), tachycardia (OR = 3.6, 95% CI: 1.2 - 11.0), agitation/confusion (OR = 3.4, 95% CI: 1.2 - 9.7) and hyperpyrexia (OR = 2.8, 95% CI: 1.0 - 7.4). DISCUSSION: DNP toxicity is uncommonly reported to poisons centres but has recently become more frequent in the United States and United Kingdom. Tachycardia, hyperpyrexia, acidosis, and agitation/confusion are independent risk factors for mortality and their presence should prompt rapid escalation to an intensive care environment for aggressive supportive treatment and monitoring.

Seroepidemiology of Leptospira infection in slaughtered cattle in Gauteng province, South Africa.

Leptospirosis is an important economical disease of livestock globally, especially in Asia, the Caribbean, and the African continent. Its presence has been reported in a wide range of livestock. However, information on leptospirosis in South Africa is scanty. We conducted a cross-sectional study in 11 randomly selected abattoirs to determine the seroprevalence and risk factors for leptospirosis in slaughtered cattle in Gauteng province, South Africa. During abattoir visits to selected abattoirs, blood samples were collected from 199 cattle and demographic data obtained on the slaughtered animals. The microscopic agglutination test (MAT) was performed on all sera using a 26-serotype panel using cutoff titer ≥ 1:100. Animal- and abattoir-level risk factors were investigated for their association with seropositivity for leptospirosis. The seroprevalence of leptospirosis in the cattle sampled was 27.6% (55/199). The predominant serogroups detected in seropositive cattle were Sejroe (sv. Hardjo) (38.2%) and Mini sv. Szwajizak) (14.5%) but low to Canicola (sv. Canicola) (1.8%) and Pomona (sv. Pomona) (1.8%). The differences were statistically significant (P < 0.05). Of the five variables investigated, only one (abattoirs) had statistically significantly (P < 0.001) differences in the seroprevalence of leptospirosis among abattoirs. The study documented for the first time in South Africa, the occurrence of serogroups Sejroe (Hardjo bovis strain lely 607), Tarassovi, Hebdomadis, and Medanensis in slaughtered cattle. It was concluded that six of the nine serovars (representing seven serogroups) of Leptospira spp. circulating in cattle population in South Africa are not vaccine serogroups. The clinical, diagnostic, and public health importance of the findings cannot be ignored.

Synthetic cannabinoid receptor agonists: classification and nomenclature.

Introduction: The emergence of novel psychoactive substances has changed the epidemiology of drugs used recreationally throughout Europe and have posed significant challenges for clinicians, researchers and regulators. Synthetic cannabinoid receptor agonists have made up a large proportion of these novel psychoactive substances. Developed for legitimate scientific research, synthetic cannabinoid receptor agonists are potent agonists at CB1 and CB2 receptors and there have been many case reports of severe or fatal toxicity following their recreational use. At least 180 analytically confirmed compounds belonging to this group of drugs have been reported in Europe as of January 2019. Synthetic cannabinoid receptor agonists have a complex molecular structure, consisting of four pharmacophore components termed the 'core', 'tail', 'linker' and 'linked' groups. This structural complexity offers multiple opportunities for chemical modification to evade drug control legislation based on chemical structure, and this explains the large numbers of individual products that have been detected.Objectives: To discuss the chemical structure of synthetic cannabinoid receptor agonists and to describe the different nomenclature used to identify individual compounds thereby increasing understanding of their chemical heterogenicity and the potential relevance of their molecular structure to the risk of toxicity.Methods: The European Database on New Drugs (EDND) and EMCDDA-Europol annual implementation reports (2010-2017) was searched for compounds with known agonist activity at CB1 and/or CB2 receptors. Information on the different names and chemical structures of each compound was extracted and analysed for patterns. PUBMED, Google Scholar and MEDLINE databases were searched, in addition to non-peer reviewed sources, for data on structure, structure-activity relationships and nomenclatures for each compound.Nomenclature of synthetic cannabinoid receptor agonists: The structural complexity of synthetic cannabinoid receptor agonists presents challenges for nomenclature. There are several nomenclature systems in use.Colloquial and clandestine names: Non-scientific names (e.g. AKB-48, 2NEI, XLR-11) have been used to refer to specific compounds and most have probably been invented by vendors, presumably for the purpose of successful marketing of recreational products, however such names do not convey useful information about structure.Systematic chemical names: Each compound has a systematic chemical name that describes its exact structure; however, it is complex, unwieldy, inaccessible to non-chemists and not suitable for routine communication or clinical use.Serial names: Represent iterative designations assigned to compounds produced as a series in a laboratory (e.g. 'WIN-', 'HU-', 'CP-', 'JWH-' and 'AM-'). This nomenclature does not provide structural information or reflect structural similarities between compounds.Systematic abbreviated names: Succinctly describe each compound utilising structural pharmacophores. The chemical motif in each pharmacophore group is assigned a unique code-letter and assembled into a name with the format of 'Linked Group - TailCoreLinker'. Frequently encountered groups include indole and indazole cores, amino-acid-like like groups, most notably methyl-3,3-dimethylbutanoate (MDMB), methanone linker groups and pentyl, 5-fluoropentyl and 4-fluorobenzyl tails. There has been inconsistent usage of this nomenclature, likely due to a lack of consensus and identification of code-letters for several chemical motifs.Emerging compounds and practices: Tricyclic carbazole and γ-carbolinone core analogues have been identified and may represent the next significant structural analogues to emerge onto the recreational market. There is a need to establish basic pharmacological and toxicological data for these analogues.Conclusions: There is a need for international consensus on the nomenclature used to name synthetic cannabinoid receptor agonists to ensure precise and effective communication between professional groups in the clinic and for the purposes of research and regulation, especially with the emergence of analogues of existing compounds and novel structural motifs. A well-defined nomenclature system also supports quick and accurate communication of the structure-activity of these compounds, potentially highlighting compounds that carry a significant risk of toxicity.

Experiential contributions to social dominance in a rat model of fragile-X syndrome.

Social withdrawal is one phenotypic feature of the monogenic neurodevelopmental disorder fragile-X. Using a 'knockout' rat model of fragile-X, we examined whether deletion of the Fmr1 gene that causes this condition would affect the ability to form and express a social hierarchy as measured in a tube test. Male fragile-X 'knockout' rats living together could successfully form a social dominance hierarchy, but were significantly subordinate to wild-type animals in mixed group cages. Over 10 days of repeated testing, the fragile-X mutant rats gradually showed greater variance and instability of rank during their tube-test encounters. This affected the outcome of future encounters with stranger animals from other cages, with the initial phenotype of wild-type dominance lost to a more complex picture that reflected, regardless of genotype, the prior experience of winning or losing. Our findings offer a novel insight into the complex dynamics of social interactions between laboratory living groups of fragile-X and wild-type rats. Even though this is a monogenic condition, experience has an impact upon future interactions with other animals. Gene/environment interactions should therefore be considered in the development of therapeutics.

An experimental and theoretical study of the valence shell photoelectron spectra of 2-chloropyridine and 3-chloropyridine.

The valence shell photoelectron spectra of 2-chloropyridine and 3-chloropyridine have been studied both experimentally and theoretically. Synchrotron radiation has been employed to record angle resolved photoelectron spectra in the photon energy range 20-100 eV, and these have enabled anisotropy parameters and branching ratios to be derived. The experimental results have been compared with theoretical predictions obtained using the continuum multiple scattering Xα approach. This comparison shows that the anisotropy parameter associated with the nominally chlorine lone-pair orbital lying in the molecular plane is strongly affected by the atomic Cooper minimum. In contrast, the photoionization dynamics of the second lone-pair orbital, orientated perpendicular to the molecular plane, seem relatively unaffected by this atomic phenomenon. The outer valence ionization has been studied theoretically using the third-order algebraic-diagrammatic construction (ADC(3)) approximation scheme for the one-particle Green's function, the outer valence Green's function method, and the equation-of-motion (EOM) coupled cluster (CC) theory at the level of the EOM-IP-CCSD and EOM-EE-CC3 models. The convergence of the results to the complete basis set limit has been investigated. The ADC(3) method has been employed to compute the complete valence shell ionization spectra of 2-chloropyridine and 3-chloropyridine. The relaxation mechanism for ionization of the nitrogen σ-type lone-pair orbital (σN LP) has been found to be different to that for the corresponding chlorine lone-pair (σCl LP). For the σN LP orbital, π-π* excitations play the main role in the screening of the lone-pair hole. In contrast, excitations localized at the chlorine site involving the chlorine πCl LP lone-pair and the Cl 4p Rydberg orbital are the most important for the σCl LP orbital. The calculated photoelectron spectra have allowed assignments to be proposed for most of the structure observed in the experimental spectra. The theoretical work also highlights the formation of satellite states, due to the breakdown of the single particle model of ionization, in the inner valence region.

Ionization of pyridine: Interplay of orbital relaxation and electron correlation.

The valence shell ionization spectrum of pyridine was studied using the third-order algebraic-diagrammatic construction approximation scheme for the one-particle Green's function and the outer-valence Green's function method. The results were used to interpret angle resolved photoelectron spectra recorded with synchrotron radiation in the photon energy range of 17-120 eV. The lowest four states of the pyridine radical cation, namely, 2A2(1a2-1), 2A1(7a1-1), 2B1(2b1-1), and 2B2(5b2-1), were studied in detail using various high-level electronic structure calculation methods. The vertical ionization energies were established using the equation-of-motion coupled-cluster approach with single, double, and triple excitations (EOM-IP-CCSDT) and the complete basis set extrapolation technique. Further interpretation of the electronic structure results was accomplished using Dyson orbitals, electron density difference plots, and a second-order perturbation theory treatment for the relaxation energy. Strong orbital relaxation and electron correlation effects were shown to accompany ionization of the 7a1 orbital, which formally represents the nonbonding σ-type nitrogen lone-pair (nσ) orbital. The theoretical work establishes the important roles of the π-system (π-π* excitations) in the screening of the nσ-hole and of the relaxation of the molecular orbitals in the formation of the 7a1(nσ)-1 state. Equilibrium geometric parameters were computed using the MP2 (second-order Møller-Plesset perturbation theory) and CCSD methods, and the harmonic vibrational frequencies were obtained at the MP2 level of theory for the lowest three cation states. The results were used to estimate the adiabatic 0-0 ionization energies, which were then compared to the available experimental and theoretical data. Photoelectron anisotropy parameters and photoionization partial cross sections, derived from the experimental spectra, were compared to predictions obtained with the continuum multiple scattering approach.

A study of leptospirosis in South African horses and associated risk factors.

Most leptospiral infections in horses are asymptomatic; however, acute disease manifestations as well as reproductive failure and recurrent uveitis have been reported. In South Africa, the epidemiology of the disease in horses is not well documented. A serosurvey to determine what serovars were present in horses from Gauteng, KwaZulu-Natal and Western Cape Provinces and to get an estimate of the seroprevalence of leptospirosis was carried out from January 2013 until April 2014 with the assistance of four large equine hospitals located in these provinces. Furthermore, associations between potential risk factors and both seropositive horses to the predominant serovar Bratislava and to Leptospira spp. were statistically evaluated using univariate analysis and multivariable logistic regression models. A total of 663 horse sera were collected and tested against a panel of 24 leptospiral serovars using the microscopic agglutination test. The most predominant serovars in Gauteng were Bratislava [32%, 95% CI: 29-35%]; Djasiman [10.4%, 95% CI: 8-12%] and Arborea [8.9%, 95% CI: 7-11%], in the Western Cape Province, Bratislava [27.35%, 95% CI: 23-32]; Djasiman [15.4%, 95% CI: 12-19%] and Arborea [14.5%, 95% CI: 11-18%] and in KwaZulu-Natal, Bratislava [39.4%, 95% CI: 34-44%]; Arborea [9.6%, 95% CI: 7-13%]; and Tarassovi [7.7%, 95% CI: 5-10%] respectively. Twenty one serovars representing 17 serogroups were detected with serovar Bratislava being the most serodominant. The apparent prevalence to one or more serovars of Leptospira spp. at a serum dilution of 1:100 in Gauteng, KwaZulu-Natal and Western Cape Provinces were 49%; 37% and 32% respectively. The true prevalence was calculated for each province taking into account the clustering effect during the sampling and was found to be between 24 and 74% in Gauteng; 26-39% in the Western Cape and 20-54% in KwaZulu-Natal. Nooitgedacht (South African horse breed) horses were found to be at greater risk of being seropositive to both serovar Bratislava (OR=5.08) and Leptospira spp. (OR=6.3). Similarly, horses residing on properties with forestry in the vicinity were found to be at greater risk of being seropositive to both serovar Bratislava (OR=9.3) and Leptospira spp. (OR=5.2). This study has shown that a high proportion of horses in South Africa are exposed to a wide range of serovars, inferring a complex epidemiology. It also describes for the first time new serovars of Leptospira in South African horses that have not previously been reported.

Circulating serovars of Leptospira in cart horses of central and southern Ethiopia and associated risk factors.

Little work has been done on diseases of horses in Ethiopia or tropical regions of the world. Yet, Ethiopia has the largest horse population in Africa and their horses play a pivotal role in their economy as traction animals. A serological and questionnaire survey was therefore conducted to determine the circulating serovars of Leptospira and their association with potential risk factors in the cart horse population of Central and Southern Ethiopia. A total of 184 out of 418 cart horses from 13 districts had antibody titres of 1:100 or greater to at least one of 16 serovars of Leptospira species in Central and Southern Ethiopian horses. A significantly higher seropositivity (62.1%) was noted in horses from the highland agroecology followed by midland (44.4%) and lowland (39.8%). Serovar Bratislava (34.5%) was the predominant serovar followed by serovars Djasiman (9.8%), Topaz (5.98%) and Pomona (5.3%). Age and location proved to be associated with seropositive horses with older horses being more commonly affected and the districts of Ziway (Batu) (Apparent Prevalence (AP)=65.5%), Shashemene (AP=48.3%) and Sebeta (AP=41.4%) having the highest prevalence. Multivariable logistic regression found risk factors significantly associated with Leptospira seropositive horses were drinking river water (OR=2.8) and horses 7-12 years old (OR=5) and risk factors specifically associated with serovar Bratislava seropositive horses were drinking river water (OR=2.5), horses ≥13 years (OR=3.5) and the presence of dogs in adjacent neighbouring properties (OR=0.3). Dogs had a protective effect against seropositivity to serovars Bratislava and Djasiman, which may be due to their ability to control rodents. The high seroprevalence confirm that leptospirosis is endemic among horses of Central and Southern Ethiopia. The predominance of serovar Bratislava supports the idea that serovar Bratislava may be adapted to and maintained by the horse population of Central and Southern Ethiopia. This study emphasizes the need for further countrywide serological surveys and isolation of circulating leptospires in animals and humans in order to understand the role of horses in the epidemiology of this disease.

Reduction of low- and high-grade cervical abnormalities associated with high uptake of the HPV bivalent vaccine in Scotland.

BACKGROUND: In Scotland, a national HPV immunisation programme began in 2008 for 12- to 13-year olds, with a catch-up campaign from 2008 to 2011 for those under the age of 18. To monitor the impact of HPV immunisation on cervical disease at the population level, a programme of national surveillance was established. METHODS: We analysed colposcopy data from a cohort of women born between 1988 and 1992 who entered the Scottish Cervical Screening Programme (SCSP) and were aged 20-21 in 2008-2012. RESULTS: By linking datasets from the SCSP and colposcopy services, we observed a significant reduction in diagnoses of cervical intraepithelial neoplasia 1 (CIN 1; RR 0.71, 95% CI 0.58 to 0.87; P=0.0008), CIN 2 (RR 0.5, 95% CI 0.4 to 0.63; P<0.0001) and CIN 3 (RR 0.45, 95% CI 0.35 to 0.58; P<0.0001) for women who received three doses of vaccine compared with unvaccinated women. CONCLUSIONS: To our knowledge, this is one of the first studies to show a reduction of low- and high-grade CIN associated with high uptake of the HPV bivalent vaccine at the population level. These data are very encouraging for countries that have achieved high HPV vaccine uptake.

Introduction and sustained high coverage of the HPV bivalent vaccine leads to a reduction in prevalence of HPV 16/18 and closely related HPV types.

BACKGROUND: In 2008, a national human papillomavirus (HPV) immunisation programme began in Scotland for 12-13 year old females with a three-year catch-up campaign for those under the age of 18. Since 2008, three-dose uptake of bivalent vaccine in the routine cohort aged 12-13 has exceeded 90% annually, while in the catch-up cohort overall uptake is 66%. METHODS: To monitor the impact of HPV immunisation, a programme of national surveillance was established (pre and post introduction) which included yearly sampling and HPV genotyping of women attending for cervical screening at age 20. By linking individual vaccination, screening and HPV testing records, we aim to determine the impact of the immunisation programme on circulating type-specific HPV infection particularly for four outcomes: (i) the vaccine types HPV 16 or 18 (ii) types considered to be associated with cross-protection: HPV 31, 33 or 45; (iii) all other high-risk types and (iv) any HPV. RESULTS: From a total of 4679 samples tested, we demonstrate that three doses (n=1100) of bivalent vaccine are associated with a significant reduction in prevalence of HPV 16 and 18 from 29.8% (95% confidence interval 28.3, 31.3%) to 13.6% (95% confidence interval 11.7, 15.8%). The data also suggest cross-protection against HPV 31, 33 and 45. HPV 51 and 56 emerged as the most prevalent (10.5% and 9.6%, respectively) non-vaccine high-risk types in those vaccinated, but at lower rates than HPV 16 (25.9%) in those unvaccinated. CONCLUSIONS: This data demonstrate the positive impact of bivalent vaccination on the prevalence of HPV 16, 18, 31, 33 and 45 in the target population and is encouraging for countries which have achieved high-vaccine uptake.

An assessment of zoonotic and production limiting pathogens in rusa deer (Cervus timorensis rusa) from Mauritius.

A population of approximately 70,000 rusa deer (Cervus timorensis russa) represents the most important mammal species reared for food on the island of Mauritius, being the main source of red meat for the local population. However, very limited information is available on the circulation of pathogens affecting the productivity and health of this species. To produce baseline data on the circulation of infectious pathogens in rusa deer under production, a serological survey and/or direct pathogen detection for six selected infectious diseases was undertaken in 2007 in a sample of 53% of the herds reared in semi-free-ranging conditions in hunting estates. Seropositive results were recorded for Johne's disease with an indirect ELISA test (1.7%, n = 351), heartwater with an immunofluorescence antibody test (IFAT) (95.5%, n = 178) and leptospirosis with a Microscopic Agglutination Test (MAT) (25.9%, n = 363). Significant associations were found between seroprevalence to some of the leptospiral serogroups detected (Tarassovi, Pomona, Sejroe and Mini) and age of the animals, animal density or location of the estates (being more prevalent in hotter and more humid areas). In addition, Mycobacterium bovis and M. avium subspecies paratuberculosis were confirmed in two deer carcasses by culture and PCR, respectively. No antibodies against Brucella spp. nor Rift Valley Fever virus were detected with the use of respective indirect ELISA's. The results obtained suggest that the population of rusa deer from Mauritius is exposed to a wide range of pathogens which may affect their productivity. In addition, the results highlight the potential public health risks incurred by deer industry workers and consumers. This survey fills an important gap in knowledge regarding the health of tropical deer meat in Mauritius and justifies the need to implement more regular surveys of selected pathogens in the deer population.

Measles in Scotland, 2013.

In 2013, Wales and England experienced large outbreaks of measles, a disease that has been targeted by the World Health Organisation for European elimination by 2015. Unfortunately, measles-mumps-rubella vaccine uptake declined to less than 80% in Wales and England after the Wakefield publicity and this resulted in increased population susceptibility to measles. In Scotland, measles-mumps-rubella vaccine uptake dropped to 87% in 2003. Scottish public health efforts in response to this decline aimed to maximise uptake of MMR1 by two years; ensure at least 95% uptake of one dose of measles-mumps-rubella before starting school at age five; and maximise uptake of the second dose of measles-mumps-rubella by age six. Although Scotland has not had any large outbreaks reported to date, transmission of measles from healthcare workers to patients has occurred and reiterates the importance of all healthcare workers accurately knowing their immune status and, when needed, to be fully immunised.

Cluster of Legionnaires disease cases caused by Legionella longbeachae serogroup 1, Scotland, August to September 2013.

We report six confirmed cases of Legionnaires' disease in Scotland caused by Legionella longbeachae serogroup 1, identified over a four-week period in August­September 2013. All cases required admission to hospital intensive care facilities. All cases were amateur gardeners with frequent exposure to horticultural growing media throughout their incubation period. L. longbeachae was identified in five samples of growing media linked to five cases. Product tracing did not identify a common product or manufacturer.

High uptake of HPV immunisation in Scotland--perspectives on maximising uptake.

In September 2008, Scotland introduced a national human papillomavirus (HPV) immunisation programme with bivalent HPV vaccine, to prevent cervical cancer. This school-based programme routinely vaccinates girls aged between 12 and 13 years. A catch-up campaign, running over three years, also began at this time, offering vaccination to all girls aged 13 years to under 18 years old. The HPV immunisation campaign presented challenges due to this vaccine being targeted to girls in school and older girls who had left school. Following a long and comprehensive planning process, this campaign was successfully implemented across Scotland, delivering high vaccine uptake of 91.4% for three doses of vaccine in the first year (September 2008 to August 2009) for the routine cohort and 90.1% in the second year (September 2009 to August 2010) for the routine cohort. We describe the planning process, challenges and implementation strategies employed to achieve this high uptake.