Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item The Characterisation of Carbapenem-Resistant Acinetobacter baumannii and Klebsiella pneumoniae in a Teaching Hospital in Malaysia.(MDPI (Basel, Switzerland), 2024-11-20) Lau MY; Ponnampalavanar S; Chong CW; Dwiyanto J; Lee YQ; Woon JJ; Kong ZX; Jasni AS; Lee MCC; Obaidellah UH; Teh CSJ; Christodoulides MBackground/Objectives: The emergence and dissemination of carbapenem-resistant organisms, particularly Acinetobacter baumannii and Klebsiella pneumoniae, pose a significant threat to healthcare systems worldwide. This retrospective study aims to characterise carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Klebsiella pneumoniae (CRKP) strains in a teaching hospital and to determine the risk factors associated with patients' in-hospital mortality. Methods: A total of 90 CRAB and 63 CRKP were included in this study. Carbapenemase genes and MLST types of CRAB and CRKP were determined using specific primers. Risk factors associated with in-hospital mortality were analysed with collected data. Results: All the CRAB strains consisted of OXA carbapenemase genes, with 98% of the strains co-harbouring blaOXA-23-like and blaOXA-51-like carbapenemase genes. Conversely, blaNDM is the predominant carbapenemase gene in CRKP, followed by blaOXA-48-like carbapenemase genes. ST2 and ST20 are the dominant MLST types in CRAB and CRKP, respectively. In CRAB, multivariate analysis identified age, ethnicity, the presence of a mechanical ventilator, and patients who experienced previous exposure to clindamycin in the last 90 days as associated with an increased risk of in-hospital mortality. In contrast, older age, male, ICU admission, and the presence of an indwelling urinary catheter were significantly associated with an increased risk of mortality for patients with CRKP. Conclusions: Both CRAB and CRKP lead to high rates of mortality. The MLST profile showed that the genomic patterns of CRKP were highly diverse, whereas CRAB strains had low genetic diversity. To tackle these challenging pathogens, robust surveillance and an in-depth understanding of molecular epidemiology and genomics studies are needed to tailor infection control strategies and individualise treatment approaches.Item Effect of Vaccination on Pneumococci Isolated from the Nasopharynx of Healthy Children and the Middle Ear of Children with Otitis Media in Iceland.(American Society for Microbiology, 2018-11-27) Quirk SJ; Haraldsson G; Erlendsdóttir H; Hjálmarsdóttir MÁ; van Tonder AJ; Hrafnkelsson B; Sigurdsson S; Bentley SD; Haraldsson Á; Brueggemann AB; Kristinsson KGVaccination with pneumococcal conjugate vaccines (PCVs) disrupts the pneumococcal population. Our aim was to determine the impact of the 10-valent PCV on the serotypes, genetic lineages, and antimicrobial susceptibility of pneumococci isolated from children in Iceland. Pneumococci were collected between 2009 and 2017 from the nasopharynges of healthy children attending 15 day care centers and from the middle ears (MEs) of children with acute otitis media from the greater Reykjavik capital area. Isolates were serotyped and tested for antimicrobial susceptibility. Whole-genome sequencing (WGS) was performed on alternate isolates from 2009 to 2014, and serotypes and multilocus sequence types (STs) were extracted from the WGS data. Two study periods were defined: 2009 to 2011 (PreVac) and 2012 to 2017 (PostVac). The overall nasopharyngeal carriage rate was similar between the two periods (67.3% PreVac and 61.5% PostVac, P = 0.090). Vaccine-type (VT) pneumococci decreased and nonvaccine-type (NVT) pneumococci (serotypes 6C, 15A, 15B/C, 21, 22F, 23A, 23B, 35F, and 35B) significantly increased in different age strata post-PCV introduction. The total number of pneumococci recovered from ME samples significantly decreased as did the proportion that were VTs, although NVT pneumococci (6C, 15B/C, 23A, and 23B) increased significantly. Most serotype 6C pneumococci were multidrug resistant (MDR). Serotype 19F was the predominant serotype associated with MEs, and it significantly decreased post-PCV introduction: these isolates were predominantly MDR and of the Taiwan19F-14 PMEN lineage. Overall, the nasopharyngeal carriage rate remained constant and the number of ME-associated pneumococci decreased significantly post-PCV introduction; however, there was a concomitant and statistically significant shift from VTs to NVTs in both collections of pneumococci.Item A behaviour and disease transmission model: incorporating the Health Belief Model for human behaviour into a simple transmission model.(The Royal Society, 2024-06-05) Ryan M; Brindal E; Roberts M; Hickson RIThe health and economic impacts of infectious diseases such as COVID-19 affect all levels of a community from the individual to the governing bodies. However, the spread of an infectious disease is intricately linked to the behaviour of the people within a community since crowd behaviour affects individual human behaviour, while human behaviour affects infection spread, and infection spread affects human behaviour. Capturing these feedback loops of behaviour and infection is a well-known challenge in infectious disease modelling. Here, we investigate the interface of behavioural science theory and infectious disease modelling to explore behaviour and disease (BaD) transmission models. Specifically, we incorporate a visible protective behaviour into the susceptible-infectious-recovered-susceptible (SIRS) transmission model using the socio-psychological Health Belief Model to motivate behavioural uptake and abandonment. We characterize the mathematical thresholds for BaD emergence in the BaD SIRS model and the feasible steady states. We also explore, under different infectious disease scenarios, the effects of a fully protective behaviour on long-term disease prevalence in a community, and describe how BaD modelling can investigate non-pharmaceutical interventions that target-specific components of the Health Belief Model. This transdisciplinary BaD modelling approach may reduce the health and economic impacts of future epidemics.Item An Assessment of the Epidemiology and Herd-Level Impact of the Fractured Humerus Epidemic in New Zealand Dairy Cattle, 2007-2015: Results from Four Studies(MDPI (Basel, Switzerland), 2024-02-05) Hunnam JC; Lawrence K; Rashid ZBA; Hitchcock B; McDougall S; Wehrle-Martinez A; Weston JF; Miranda Castañón MIA multi-method approach integrating data from four independent sources was used to describe some key features of the epidemiology and estimate the herd and within-herd incidence of fractured humeri in New Zealand dairy cattle for the period 2007-2015. The first dataset was from a national case series where cases of humeral fractures in dairy cattle were identified by veterinarians across New Zealand between the 2007/2008 and 2011/2012 lactation seasons. The second dataset was from a pet food company based in the Waikato region, which collated the number of casualty first- and second-lactation cows found to have a fractured humerus post-slaughter in the 2014/2015 lactation season, and the third dataset was a case series conducted by veterinarians employed in a Waikato veterinary business, also from the 2014/2015 lactation season. For the final dataset, 505 randomly selected New Zealand dairy farmers completed a phone survey on the incidence of non-responsive, non-weight-bearing forelimb lameness in first- and second-lactation cows in the 2014/2015 lactation season. Using the telephone survey results, the within-herd and herd-level incidence of cases for first- and second-lactation dairy animals was calculated. The national case series reported 149 cases of humeral fractures in 22 dairy herds; the pet food case series identified 61 cases from 41 farms; and the practice-based case series found 14 cases from 10 farms. Humeral fractures exclusively affected first- and second-lactation dairy cows and had a peak incidence between calving and early mating. The national telephone survey found that non-weight-bearing forelimb lameness requiring euthanasia of first- or second-lactation cows occurred in 11.7% of herds, with a mean within-herd incidence of 2.6% for first lactation cows and 2.8% for second-lactation cows for affected herds. These combined datasets demonstrate that humeral fractures in young, lactating dairy cattle are more common than previously suspected and that they occur nationally and over multiple years on some farms. Further work on this condition is urgently required in New Zealand to establish cost-effective management practices that will reduce unnecessary animal suffering and waste.Item Editorial: Coronavirus Disease (COVID-19): Pathophysiology, Epidemiology, Clinical Management and Public Health Response(Frontiers Media S.A., 2021-11-30) Doolan DL; Kozlakidis Z; Zhang Z; Paessler S; Su L; Yokota YT; Shioda T; Rodriguez-Palacios A; Kaynar AM; Ahmed R; Samy A; Bradby H; Kalergis AM; Dutta MJ; Kogut M; Zhang S-Y; Petrosillo NItem Infection dynamics in ecosystems: on the interaction between red and grey squirrels, pox virus, pine martens and trees(The Royal Society Publishing, 2021-10) Roberts MG; Heesterbeek JAPEcological and epidemiological processes and interactions influence each other, positively and negatively, directly and indirectly. The invasion potential of pathogens is influenced by the ecosystem context of their host species’ populations. This extends to the capacity of (multiple) host species to maintain their (common) pathogen and the way pathogen dynamics are influenced by changes in ecosystem composition. This paper exemplifies these interactions and consequences in a study of red and grey squirrel dynamics in the UK. Differences and changes in background habitat and trophic levels above and below the squirrel species lead to different dynamic behaviour in many subtle ways. The range of outcomes of the different interactions shows that one has to be careful when drawing conclusions about the mechanisms and processes involved in explaining observed phenomena concerning pathogens in their natural environment. The dynamic behaviour also shows that planning interventions, for example for conservation purposes, benefits from understanding the complexity of interactions beyond the particular pathogen and its threatened host species.Item Is transportation a risk factor for African swine fever transmission in Australia: a review(John Wiley and Sons Australia, Ltd on behalf of Australian Veterinary Association, 2021-11-02) Neumann EJ; Hall WF; Dahl J; Hamilton D; Kurian AAfrican swine fever (ASF) is a viral disease of the pigs that was first described in Africa during the early part of the twentieth century. The disease has periodically occurred outside of Africa, including an ongoing epidemic in Europe and Asia that started in 2007; the disease has never occurred in Australia or New Zealand. Once introduced into a country, spread can occur through direct and indirect routes of transmission. Infected feral pig populations have the potential to act as a long-term reservoir for the virus, making eradication difficult. Just before and throughout the period of clinical signs, ASF virus is shed in oronasal fluids, urine, faeces and blood. This results in contamination of the pig's environment, including flooring, equipment and vehicles. Transportation-related risk factors therefore are likely to play an important role in ASF spread, though evidence thus far has been largely anecdotal. In addition to the existing AUSVETPLAN ASF plan, efforts should be made to improve transportation biosecurity, from the time a pig leaves the farm to its destination. Collection of data that could quantify the capabilities and capacity of Australia to clean and disinfect livestock trucks would help to determine if private and/or public sector investment should be made in this area of biosecurity. No peer-reviewed research was identified that described a specific process for cleaning and disinfecting a livestock truck known to be contaminated with ASF virus, though literature suggests that transportation is an important route of transmission for moving the virus between farms and countries.Item Social Isolation and Incident Dementia in the Oldest-Old—A Competing Risk Analysis(Frontiers Media S.A, 2022-06) Grothe J; Röhr S; Luppa M; Pabst A; Kleineidam L; Heser K; Fuchs A; Pentzek M; Oey A; Wiese B; Lühmann D; van den Bussche H; Weyerer S; Werle J; Weeg D; Bickel H; Scherer M; König H-H; Hajek A; Wagner M; Riedel-Heller SGPurpose: Social isolation is considered a risk factor for dementia. However, less is known about social isolation and dementia with respect to competing risk of death, particularly in the oldest-old, who are at highest risk for social isolation, dementia and mortality. Therefore, we aimed to examine these associations in a sample of oldest-old individuals. Methods: Analyses were based on follow-up (FU) 5–9 of the longitudinal German study AgeCoDe/AgeQualiDe. Social isolation was assessed using the short form of the Lubben Social Network Scale (LSNS-6), with a score ≤ 12 indicating social isolation. Structured interviews were used to identify dementia cases. Competing risk analysis based on the Fine-Gray model was conducted to test the association between social isolation and incident dementia. Results: Excluding participants with prevalent dementia, n = 1,161 individuals were included. Their mean age was 86.6 (SD = 3.1) years and 67.0% were female. The prevalence of social isolation was 34.7% at FU 5, 9.7% developed dementia and 36.0% died during a mean FU time of 4.3 (SD = 0.4) years. Adjusting for covariates and cumulative mortality risk, social isolation was not significantly associated with incident dementia; neither in the total sample (sHR: 1.07, 95%CI 0.65-1.76, p = 0.80), nor if stratified by sex (men: sHR: 0.71, 95%CI 0.28-1.83, p = 0.48; women: sHR: 1.39, 95%CI 0.77-2.51, p = 0.27). Conclusion: In contrast to the findings of previous studies, we did not find an association between social isolation and incident dementia in the oldest-old. However, our analysis took into account the competing risk of death and the FU period was rather short. Future studies, especially with longer FU periods and more comprehensive assessment of qualitative social network characteristics (e.g., loneliness and satisfaction with social relationships) may be useful for clarification.Item The role of education and income for cognitive functioning in old age: A cross-country comparison(John Wiley and Sons Ltd, 2021-12) Rodriguez FS; Hofbauer LM; Röhr SObjectives Previous studies have shown that higher education promotes cognitive health. This effect, however, is embedded in the living conditions of a particular country. Since it is not clear to what extent the country and its specific living standards are necessary preconditions for the observed effect, we investigated whether the impact of education and income on cognitive functioning differs between countries. Methods Analyses were based on harmonized data from the World Health Organization's multi-country Study on global AGEing and adult health, the Health and Retirement Study, and the Survey of Health, Ageing and Retirement in Europe of over 85,000 individuals aged 50 years and older. Analyses were conducted via multivariate regression analyses and structural equation modeling adjusted for age, gender, marital status, health status, and depression. Results The effect of education was twice as large as the effect of income on cognitive functioning and indirectly moderated the effect of income on cognitive functioning. The effect sizes varied strongly between countries. The country's gross domestic product per capita seems to influence cognitive functioning. Conclusions Our findings indicate that education has a dominant effect on cognitive functioning in people aged 50 years and older, which might even offset the adverse implications of living with low income on cognitive health. Therefore, expanding efforts to achieve universal education are essential to mitigate health disparities due to low income and early life disadvantages, including chances for good cognitive functioning over the life-span.Item Is dementia incidence declining in high-income countries? A systematic review and meta-analysis(Dove Medical Press, 2018) Roehr S; Pabst A; Luck T; Riedel-Heller SGPurpose: To perform a systematic review and quantitative synthesis of studies on recent trends in dementia incidence in high-income countries (HIC), considering study quality. Methods: PubMed and Web of Science were searched for eligible studies, that is, population-based/community-based prospective cohort studies investigating dementia incidence with similar methods over time, published after 1990. Study selection, data extraction, and quality assessment were performed independently by two investigators. Random-effect meta-analysis and meta-regression were used to estimate incidence change (IC) and to explore associations with study attributes. PRISMA standards were followed. Results: The systematic review included seven studies (42,485 individuals), and the meta-analysis included five studies of sufficient quality. Relating dementia incidence of later cohorts to earlier cohorts (reference) yielded a nonsignificant decrease across HIC (IC =0.82; 95% CI 0.51–1.33), with high heterogeneity (I²=94.9%, P<0.001) and without publication bias (Egger’s t=–1.77; P=0.18). Excluding the Japanese Hisayama study, the only study suggesting an increase, indicated borderline evidence for a decrease across Western HIC (IC =0.69; 95% CI 0.47–1.00; I²=88.1%, P<0.001; Egger’s t=–0.34, P=0.77), again with high heterogeneity. Meta-regression did not reveal an association of incidence rate with calendar year or study attributes; however, analyses were low powered. Conclusion: There is evidence of favorable trends in dementia incidence in Western HIC (stabilizing/decreasing). Reverse trends may occur in HIC of other regions, as exemplified by Japan. However, study number was small and heterogeneity was high. Further cohort studies using consistent methods are needed to draw definite conclusions. Our work may inform such future studies.