Current Control Programs Research Articles

Retrospective Assessment of Ventilator-Associated Pneumonias due to Acinetobacter baumannii in an Oncology Hospital.

Objectives:Ventilator-associated pneumonia (VAP) is associated with significant morbidity and mortality in critically ill patients and leads to increases in health-care costs. However, it is preventable, and hospitals can decrease VAP rates. This study aims to retrospectively assess VAP rates in the intensive care unit of Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital of the University of Health Sciences, with reference to Acinetobacter baumannii, one of the causative organisms.Methods:This study enrolled a total of 2277 patients hospitalized between the years of 2011 and 2015. The required data were collected by reviewing medical files of the patients through computerized hospital databases. VAP rate and ventilator utilization (VU) ratio were calculated using the United States Center for Disease Control National Healthcare Safety Network methodology.Results:Of the study patients, 302 (13.26%) were seen to have developed VAP. Among these patients, 191 (63.25%) were microbiologically diagnosed VAP caused by A. baumannii. Pooled means of VU ratio and VAP rate were 0.70 and 22.91, respectively.Conclusion:The results of this study will motivate the infection control committee of the study hospital to assess current infection control program and strategies so that high VAP rate in the study intensive care unit can be reduced to the minimum possible level.

Intra-vitam Diagnosis of Tuberculosis in Pigs: Concordance Between Interferon-Gamma Release Assay and Comparative Tuberculin Skin Test.

The role of pigs in the maintenance of bovine tuberculosis caused by Mycobacterium bovis has been demonstrated in many settings; however, the current control programs usually do not state any intra-vitam diagnostic procedure in this species, as for the cattle. Carcass inspection has shown to be insufficient to detect infection in swine; thus, the assessment of intradermal tuberculin test and interferon-gamma release assay (IGRA) in this species is mandatory. The current study compares the performances of the single intradermal comparative cervical tuberculin (SICCT) test and IGRA. A total of 628 Nebrodi Black pigs raised in free-roaming farms were subjected to the two tests simultaneously. Besides, 124 animals underwent postmortem examination for the detection of tuberculous lesions and isolation of mycobacteria from target organs. The two tests showed a concordance of 94.42% with a Cohen's k coefficient of 0.786 and McNemar chi-square of 4.83 (P = 0.03). Slightly lower levels of concordance (90.32%) between SICCT and IGRA were obtained in the group of 124 animals, with a Cohen's k = 0.797 and McNemar chi-squared value of 0.69 with a non-significant P = 0.41. Moreover, the results showed how IGRA tends to result positive in higher rates, mostly when non-tuberculous mycobacteria (NTM) were isolated, suggesting a possible impairment of specificity in the event of coinfections in the swine. In conclusion, the results obtained support the possibility of the strategic use of IGRA or SICCT in combination or alternatively one to the other, particularly IGRA which showed lower specificity but has evident advantages over SICCT.

Abiotic and biotic influences on the performance of two biological control agents, Neochetina bruchi and N. eichhorniae, in the Sacramento-San Joaquin River Delta, California (USA)

Variability in the effectiveness of biological control programs can be due to a myriad of abiotic and biotic interactions. Here, we explore these interactions in relation to the suboptimal biological control on the invasive water hyacinth, Pontederia (=Eichhornia) crassipes, by two weevils, Neochetina bruchi and N. eichhorniae, in the Sacramento-San Joaquin River Delta in California, USA (Delta). We conducted monthly surveys from 2015 to 2017 throughout 1667 km2 to analyze the impacts of temperature, nutrients, river flow, pathogens and genetic variation in relation to the performance of these biological control agents. Weevils (predominantly N. bruchi) demonstrated a positive numerical response to increased nitrogen content in water hyacinth crown and roots. Weevil densities and water hyacinth biomass declined significantly during periods of high river flow. We found negative impacts of cooler temperatures on weevil performance, with a significant lagged-response of weevil densities in the field to water temperature from three months prior and a lack of population growth under laboratory conditions simulating winter air temperatures in the Delta (3.9–13.9 °C). We confirmed the presence of a microsporidian pathogen, with 10.7% average prevalence of infection across four seasons and low infection loads. In addition, we found low genetic diversity of N. bruchi in the Delta compared to native populations, low population genetic structure and a lack of genetic isolation by distance among metapopulations. Overall we conclude that cooler temperatures and periods of high river flow are likely the main factors limiting the current biological control program in the Delta.

Baseline patterns of infection in regions of Benin, Malawi and India seeking to interrupt transmission of soil transmitted helminths (STH) in the DeWorm3 trial.

Global efforts to control morbidity associated with soil-transmitted helminth infections (STH) have focused largely on the targeted treatment of high-risk groups, including children and pregnant women. However, it is not clear when such programs can be discontinued and there are concerns about the sustainability of current STH control programs. The DeWorm3 project is a large multi-country community cluster randomized trial in Benin, India and Malawi designed to determine the feasibility of interrupting the transmission of STH using community-wide delivery of mass drug administration (MDA) with anthelmintics over multiple rounds. Here, we present baseline data and estimate key epidemiological parameters important in determining the likelihood of transmission interruption in the DeWorm3 trial. A baseline census was conducted in October-December 2017 in India, November-December 2017 in Malawi and in January-February 2018 in Benin. The baseline census enumerated all members of each household and collected demographic data and information on occupation, assets, and access to water, sanitation and hygiene (WASH). Each study site was divided into 40 clusters of at least 1,650 individuals per cluster. Clusters were randomized to receive twice yearly community-wide MDA with albendazole (GSK) targeting eligible individuals of all ages (20 clusters), or to receive the standard-of-care deworming program targeting children provided in each country. In each site, a randomly selected group of 150 individuals per cluster (6,000 total per site) was selected from the baseline census using stratified random sampling, and each individual provided a single stool sample for analysis of STH infection using the Kato-Katz technique. Study site, household and individual characteristics were summarized as appropriate. We estimated key epidemiological parameters including the force of infection and the degree of parasite aggregation within the population. The DeWorm3 sites range in population from 94,969 to 140,932. The population age distribution varied significantly by site, with the highest proportion of infants and young children in Malawi and the highest proportion of adults in India. The baseline age- and cluster-weighted prevalence, as measured by Kato-Katz, varied across sites and by species, Baseline hookworm prevalence in India was 21.4% (95% CI: 20.4-22.4%), while prevalence of Ascaris and Trichuris by Kato-Katz was low (0.1% and 0.3% overall). In Malawi, the overall age- and cluster-weighted STH prevalence was 7.7% (95% CI: 7.1-8.4%) predominantly driven by hookworm infections (7.4%) while Ascaris (0.1%) and Trichuris (0.3%) infections were rare. In Benin, the overall age- and cluster-weighted prevalence was significantly lower (5.6%, 95% CI: 5.1-6.2%) and Ascaris (2.0%, 95% CI: 1.6-2.3%) was more common than in other sites. Ascaris infections were more likely to be moderate- or heavy-intensity (43.7%, unweighted) compared to hookworm (5.0%). The force of infection for hookworm was highest in adults in India and Malawi but appeared relatively stable across age groups in Benin. These data demonstrate the significant variability between the sites in terms of demography, socio-economic status and environmental characteristics. In addition, the baseline prevalence and intensity data from DeWorm3 suggest that each site has unique epidemiologic characteristics that will be critical in determining correlates of achieving STH transmission interruption in the DeWorm3 trial. Trial registration: The trial was registered at ClinicalTrials.gov (NCT03014167).

Isolation of Beauveria bassiana from the Chagas Disease Vector Triatoma infestans in the Gran Chaco Region of Argentina: Assessment of Gene Expression during Host-Pathogen Interaction.

A native strain of the entomopathogenic fungus Beauveria bassiana (Bb-C001) was isolated from a naturally infected Triatoma infestans, Klug (Hemiptera: Reduviidae) adult cadaver in the Gran Chaco region, Salta province, Argentina. The isolate was both phenotypic and molecularly characterized in a context of fungus-insect interaction, by measuring the expression pattern of toxin genes during infection and immune response of T. infestans. The commercial strain GHA of B. bassiana, which was previously used in field interventions to control these vectors, was used as reference in this study. The phylogenetic trees based on both ribosomal internal transcribed spacer (ITS) and elongation factor 1-alpha (EF1-α) indicated that Bb-C001 fits into a B. bassiana cluster, and the sequence-characterized amplified regions (SCAR) showed that Bb-C001 is different from the GHA strain. There were no differences between both strains regarding viability, radial growth, and conidia production, either in the median survival time or insect mortality. However, Bb-C001 showed a higher expression than GHA of the bassianolide synthetase gene (BbbslS) during infection, and similar levels of the beauvericin synthetase gene (BbbeaS). Immune-related genes of T. infestans nymphs (limpet-2 and defensin-1, -2, and -6) were later expressed and thus insects failed to stop the infection process. These results showed that B. bassiana Bb-C001 is a promised fungal strain to be incorporated in the current biological control programs of T. infestans in Salta province, Argentina.

Modelling the effect of test‐and‐slaughter strategies to control bovine tuberculosis in endemic high prevalence herds

Bovine tuberculosis (bTB) prevalence substantially increased over the past two decades with relatively high impact on large dairy herds, raising the concern of regulatory authorities and industry stakeholders, and threatening animal and public health. Lack of resources, together with the economic and social consequences of whole-herd stamping-out, makes depopulation an impractical disease control alternative in these herds. The increase in bTB prevalence was associated with demographic and management changes in the dairy industry in Uruguay, reducing the efficacy of the current control programme (i.e. status quo) based on intradermal serial testing with caudal fold- and comparative-cervical tuberculin test-and-slaughter of reactors (CFT-CCT). Here, we aimed to assess the epidemiological effectiveness of six alternative control scenarios based on test-and-slaughter of positive animals, using mathematical modelling to infer bTB-within-herd dynamics. We simulated six alternative control strategies consisting of testing adult cattle (>1year) in the herd every 3months using one test (in vivo or in vitro) or a combination in parallel of two tests (CFT, interferon-gamma release assay-IGRA- or enzyme-linked immunosorbent assay). Results showed no significant differences overall in the time needed to reach bTB eradication (median ranging between 61 and 82months) or official bovine tuberculosis-free status (two consecutive negative herd tests) between any of the alternative strategies and the status quo (median ranging between 50 and 59months). However, we demonstrate how alternative strategies can significantly reduce bTB prevalence when applied for restricted periods (6, 12 or 24months), and in the case of IGRAc (IGRA using peptide-cocktail antigens), without incurring on higher unnecessary slaughter of animals (false positives) than the status quo in the first 6months of the programme (p-value<.05). Enhanced understanding bTB-within-herd dynamics with the application of different control strategies help to identify optimal strategies to ultimately improve bTB control and bTB eradication from dairies in Uruguay and similar endemic settings.

Multimodality of human epidermal growth factor receptor-2 antagonism restores the apoptotic capacity of liver cancer cells

Background: Hepatocellular carcinoma, the most widespread form of liver cancer and one of the most common and lethal malignancies, is characterized by poor prognosis, late onset, and a lack of clear-cut diagnostic markers. Novel therapeutic approaches are desperately required to develop effective treatment regimens. Methods: In this study, we attempted to reverse the proliferative capacity of liver cancer cells through employing a 3 – prong approach. We evaluated the antitumorigenic effects of some medicinal plant extracts that contain bioactive phytochemicals. In addition, we used Imatinib – a tyrosine kinase inhibitor (TKI), with human epidermal growth factor receptor (Her2)-specific small interfering RNA(siRNA) species to counteract the Her2-induced proliferative capacity of cancer cells. In our model, we evaluated the extent of activation of apoptotic mechanisms versus the proliferative and antiapoptotic strategies mounted by cancer cells. Results: Our results showed that HepG2 cells treated with 0.5 mM Imatinib exhibited marked downregulation of Her2 expression, upregulation of the proapoptotic marker, BAX and a downregulation of proliferative markers GPC3 and transforming growth factor (TGF)-β (45, 29, 95, and 115 folds, respectively). In the meantime, there was also significant downregulation of Her2, TGF-β, Mcl1, Spp1, GLUL and GPC3 expression and activation of apoptotic system in the cells treated with a mixture of anti-Her2 siRNA, Imatinib along with some selected extracts where the mixture successfully decreased viability of cancer cells. Conclusion: our study reveals the potential of using TKI along with phytochemical therapy and RNA interference as adjuvant regimen for treatment of liver cancer to augment the efficacy of the current control programs, yet, minimizing the side effects by transition to targeted rather than mass therapies.

Healthy China Strategy and schistosomiasis control

This paper summarizes the changes in the policy associated with schistosmiasis control in the new era, analyzes the background of Health China Strategy and its association with the current schistosomiasis control program in China, describes several schistosomiasis control models and proposes some suggestions responding to the challenges in current schistosomiasis control program of China, so as to provide insights into the development of the effective control strategy for schistosomiasis.

Geographical variation in the risk of H7N9 human infections in China: implications for risk-based surveillance

The influenza A (H7N9) subtype remains a public health problem in China affecting individuals in contact with live poultry, particularly at live bird markets. Despite enhanced surveillance and biosecurity at LBMs H7N9 viruses are now more widespread in China. This study aims to quantify the temporal relationship between poultry surveillance results and the onset of human H7N9 infections during 2013–2017 and to estimate risk factors associated with geographical risk of H7N9 human infections in counties in Southeast China. Our results suggest that poultry surveillance data can potentially be used as early warning indicators for human H7N9 notifications. Furthermore, we found that human H7N9 incidence at county-level was significantly associated with the presence of wholesale LBMs, the density of retail LBMs, the presence of poultry virological positives, poultry movements from high-risk areas, as well as chicken population density and human population density. The results of this study can influence the current AI H7N9 control program by supporting the integration of poultry surveillance data with human H7N9 notifications as an early warning of the timing and areas at risk for human infection. The findings also highlight areas in China where monitoring of poultry movement and poultry infections could be prioritized.

Prevalence of viral hepatitis B in Ghana between 2015 and 2019: A systematic review and meta-analysis.

Chronic hepatitis B (HBV) remains a significant public health problem in Ghana and past reviews conducted could not calculate a nationwide prevalence of the disease due to lack of primary research for some regions of the country. We therefore conducted this study to summarize and update the available information on HBV infection burden (prevalence) in Ghana from 2015-2019.We systematically searched PubMed, Embase, ScienceDirect, and Google Scholar to retrieve primary studies published in peer-reviewed journals from November 2015 to September 2019, assessing the prevalence of HBV among the Ghanaian populace. The review included 21 studies across all ten old regions of Ghana with a total sample population of 29 061. The HBV prevalence was estimated for subpopulations as follows: 8.36% in the adult population, 14.30% in the adolescent population, and 0.55% in children under five years (pre-school). Among adults, HBV infection prevalence was the highest in the special occupation group (14.40%) and the lowest prevalence rate of 7.17% was recorded among blood donors. Prevalence was lower in the north than in the southern part of the country. The Ashanti region had the most studies at 6/21 (29%), while no study was identified for the Upper West region. Across the country, the highest HBV infection prevalence rates were recorded in the age group of 20-40 years. The burden of hepatitis B is enormous and remains an important public health issue in Ghana. Addressing the issue will require an integrated public health strategy and rethinking of the implementation gaps in the current HBV infection control program. This will help propel the country towards eliminating the disease by 2030.

Epidemiology of intestinal helminthiases in a rural community of Ethiopia: Is it time to expand control programs to include Strongyloides stercoralis and the entire community?

BackgroundSoil transmitted helminths are highly prevalent worldwide. Globally, approximately 1.5 billion people are infected with Ascaris lumbricoides, Trichuris trichiura or hookworm. Endemic countries carry out periodic mass treatment of at-risk populations with albendazole or mebendazole as a control measure. Most prevalence studies have focused on school aged children and therefore control programs are implemented at school level, not at community level. In this study, the prevalence of intestinal helminths, including Strongyloides stercoralis, was examined using a comprehensive laboratory approach in a community in north-western Ethiopia.MethodsA cross-sectional survey was conducted on 792 individuals ≥5 years old in randomly selected houses in a rural district. Stools were examined using three techniques: a formol-ether concentration, the Baermann technique and a real time polymerase chain reaction test (these last two specific for S. stercoralis). Statistical analyses were performed between two large age groups, children (≤14 years old) and adults (≥15 years old).ResultsThe prevalence of helminths was 91.3%; (95% CI: 89.3–93.3%). Hookworm was the most prevalent, 78.7% (95% CI 75.6–81.4%), followed by S. stercoralis 55.7% (95% CI 52.2–59.1%). Co-infection with both was detected in 45.4% (95% CI 42.0–49.0%) of the participants. The mean age of hookworm-infected individuals was significantly higher than non-infected ones (p = 0.003). Also, S. stercoralis infection was significantly associated with age, being more prevalent in adults (p = 0.002).ConclusionsThis is the highest prevalence of S. stercoralis detected in Ethiopia so far. Our results highlight the need of searching specifically for infection by this parasite since it usually goes unnoticed if helminth studies rely only on conventional diagnostic techniques, i.e. Kato-Katz. Moreover, the focus of these programs on children undermines the actual prevalence of hookworm. The adult population acts as a reservoir for both hookworm and S. stercoralis and this fact may negatively impact the current control programs in Ethiopia which only target treatment of school aged children. This reservoir, together with a lack of adequate water, sanitation and hygiene, increases the probability of re-infection in children. Finally, the high prevalence of S. stercoralis found calls for a comprehensive diagnostic approach in endemic areas in addition to a revision of control measures that is, adding ivermectin to current albendazole/mebendazole, since it is the drug of choice for S. stercoralis.

Mycobacterium bovis: From Genotyping to Genome Sequencing.

Mycobacterium bovis is the main pathogen of bovine, zoonotic, and wildlife tuberculosis. Despite the existence of programs for bovine tuberculosis (bTB) control in many regions, the disease remains a challenge for the veterinary and public health sectors, especially in developing countries and in high-income nations with wildlife reservoirs. Current bTB control programs are mostly based on test-and-slaughter, movement restrictions, and post-mortem inspection measures. In certain settings, contact tracing and surveillance has benefited from M. bovis genotyping techniques. More recently, whole-genome sequencing (WGS) has become the preferential technique to inform outbreak response through contact tracing and source identification for many infectious diseases. As the cost per genome decreases, the application of WGS to bTB control programs is inevitable moving forward. However, there are technical challenges in data analyses and interpretation that hinder the implementation of M. bovis WGS as a molecular epidemiology tool. Therefore, the aim of this review is to describe M. bovis genotyping techniques and discuss current standards and challenges of the use of M. bovis WGS for transmission investigation, surveillance, and global lineages distribution. We compiled a series of associated research gaps to be explored with the ultimate goal of implementing M. bovis WGS in a standardized manner in bTB control programs.

Progress of schistosomiasis control in Dongting Lake regions

As an ancient parasitic disease, schistosomiasis has been endemic in Dongting Lake areas for more than 2 100 years. In the early 20th century, the first human case of schistosomiasis in China was reported in Dongting Lake areas, which was paid extensive attention. After the founding of the People's Republic of China, large-scale schistosomiasis control activities were launched promptly in Dongting Lake areas, and great successes have been achieved following the three stages of control efforts, including the snail control-based stage, synchronous chemotherapy for humans and livestock-based control stage and infectious source control-based control stage. In 2015, transmission control of schistosomiasis was achieved in Hunan Province. This paper comprehensively describes the discovery and control of schistosomiasis, analyzes the challenges for the current schistosomiasis control programs and proposes the emphasis for future control activities in Dongting Lake areas, so as to provide insights into the schistosomiasis control program in this area.

Expert elicitation of the diagnostic performance of two tests for Bacterial Kidney Disease (BKD) surveillance in Atlantic salmon (Salmo salar L.) broodstock in Chile

The objective of this study was to obtain diagnostic performance estimates for immunofluorescence antibody test (IFAT) and quantitative polymerase chain reaction (qPCR) tests, for Bacterial Kidney Disease (BKD) surveillance in farmed Atlantic salmon (Salmo salar.) broodstock without clinical signs compatible with the disease in Chile. To obtain diagnostic sensitivity (DSe) and specificity (DSp) estimates of those tests, an expert elicitation process was conducted using the trial roulette method during a workshop with 18 national experts on BKD diagnostics and control. A questionnaire was given to the experts to gather information on their previous experience with BKD, and 12 experts who received an introduction to the expert-elicitation process and graphical representation of statistical distributions. Experts were divided into three groups and requested to draw distributions of DSe and DSp parameters using an online tool. Then figures where projected and discussed among participants. After the discussion round, experts were requested to redraw their distributions (if considered necessary). The agreement between groups was assessed by calculating the overlapping areas between the three distributions for each parameter. Finally, a consensus distribution was generated.In general, groups had moderate to high agreement with overlapping areas between 53% to 93% for DSpIFAT, DSeqPCR, and DSpqPCR. Conversely, no agreement was reached for the DSeIFAT distribution. Specifically, median estimates of 89.5%, 90.5%, and 95.9%, were obtained for DSpIFAT, DSeqPCR, &DSpqPCR, respectively. In the case of DSeIFAT, the first group provided a median estimate of 28%, whereas groups 2 and 3 reached a consensus value of approximately 62%. This study provides information that is not available in the country, and will help to adjust current BKD control programs, which mainly rely on the use of qPCR assays.

An Epidemiological and Economic Simulation Model to Evaluate Strategies for the Control of Bovine Virus Diarrhea in Germany.

Models can be used to plan, evaluate, and improve programs for animal disease control. In Germany, a nationwide compulsory program to eradicate Bovine viral diarrhea (BVD) is in force since January 2011. As it is associated with substantial expenditures, the program is currently under revision. To provide the basis for a science-based decision on the future course of BVD control in Germany, we evaluated 13 scenarios (sc1-13) with respect to the chance of reaching freedom from disease and their economic implications for a period of 20 years (2011–2030). To simulate the impact of different control strategies on disease dynamics, a disease spread model was developed. To estimate the effects of a transient infection (TI) on animal level, a gross margin analysis was performed. To assess the value of cattle that died prematurely, a valuation model was used. Finally, an economic model was developed to perform a cost-benefit analysis and to compare each control scenario with a baseline setting with no BVD control. Costs comprised the expenditures for diagnostics, vaccination, preventive culling, and trade restrictions. Benefits were animal and production losses avoided by having control measures in place. The results show that reducing the PI prevalence on animal level to 0% is only feasible in scenarios that combine antigen or antibody testing with compulsory vaccination. All other scenarios, i.e., those based exclusively on a “test and cull” approach, including the current control program, will, according to the model, not achieve freedom of BVD by 2030. On the other hand, none of the scenarios that may lead to complete BVD eradication is economically attractive [benefit-cost ratio (BCR) between 0.64 and 0.94]. The average direct costs of BVD in Germany are estimated at 113 million Euros per year (34–402 million Euros), corresponding to 28.3 million Euros per million animals. Only the concepts of the former and the current national BVD control program (“ear tag testing and culling”) may reduce the BVD prevalence to 0.01% with an acceptable BCR (net present value of 222 and 238 million Euros, respectively, with a BCR of 1.22 and 1.24).

Force of Infection and True Infection Rate of Dengue in Singapore: Implications for Dengue Control and Management.

National data on dengue notifications do not capture all dengue infections and do not reflect the true intensity of disease transmission. To assess the true dengue infection rate and disease control efforts in Singapore, we conducted age-stratified serosurveys among residents after a 2013 outbreak that was the largest dengue outbreak on record. The age-weighted prevalence of dengue immunoglobulin G among residents was 49.8% (95% confidence interval: 48.4, 51.1) in 2013 and 48.6% (95% confidence interval: 47.0, 50.0) in 2017; prevalence increased with age. Combining these data with those from previous serosurveys, the year-on-year estimates of the dengue force of infection from 1930 to 2017 revealed a significant decrease from the late 1960s to the mid-1990s, after which the force of infection remained stable at approximately 10 per 1,000 persons per year. The reproduction number (R0) had also declined since the 1960s. The reduction in dengue transmission may be attributed to the sustained national vector program and partly to a change in the age structure of the population. The improved estimated ratio of notified cases to true infections, from 1:14 in 2005–2009 to 1:6 in 2014–2017, signifies that the national notification system, which relies on diagnosed cases, has improved over time. The data also suggest that the magnitudes of dengue epidemics cannot be fairly compared across calendar years and that the current disease control program remains applicable.

Smoking tobacco prevalence among college students in the Kingdom of Saudi Arabia: Systematic review and meta-analysis.

INTRODUCTIONDuring the last two decades, several studies have been published regarding the prevalence of tobacco smoking among college students in the Kingdom of Saudi Arabia (KSA). This systematic review and meta-analysis is intended to determine and examine the smoking prevalence in Saudi college students from 2010–2018.METHODSPubMed, Science Direct, APA PsycNET, Web of Science, and CINAHL were used to search for published articles reporting the smoking prevalence among Saudi college students. After eliminating irrelevant articles, investigators independently assessed the quality of each article, based on Russell & Gregory guidelines. MetaXL software was used to calculate the pooled prevalence among included studies, using the IVhert model. Heterogeneity among the included studies was evaluated, using I2 statistic. Sensitivity analyses were conducted between male and female genders.RESULTSOf the 295 published articles, 29 articles used a cross-sectional design to determine smoking prevalence among Saudi college students. Most of the studies were conducted in Riyadh at health-science-related colleges; the rest were performed in different cities and colleges. The meta-analysis showed that the pooled estimate of smoking prevalence among college students in the KSA was 17% (95% CI: 11–23%). Saudi male students had a prevalence rate of 26% (95% CI: 24–29%), whereas for Saudi female students the prevalence was 5% (95% CI: 3–7%).CONCLUSIONSSmoking among Saudi college students was higher than in the majority of regional countries (e.g. Iran). Saudi male students had a higher smoking prevalence than Saudi female college students. Additionally, studies that reported a high prevalence targeted students in specific disciplines. Public health authorities in the KSA should develop a surveillance system that monitors the prevalence of tobacco smoking on campuses. A surveillance system of monitoring tobacco use among Saudi college students could be beneficial in determining the degree of the tobacco problem and in improving current tobacco control programs.

Optimisation of &lt;i&gt;Bacillus thuringiensis&lt;/i&gt; var. &lt;i&gt;israelensis&lt;/i&gt; (Vectobac&lt;sup&gt;®&lt;/sup&gt;) applications for the blackfly control programme on the Orange River, South Africa

The Orange River, South Africa's largest river, is a critical water resource for the country. In spite of the clear economic benefits of regulating river flows through a series of impoundments, one of the significant undesirable ecological consequences of this regulation has been the regular outbreaks of the pest blackfly species Simulium chutteri and S. damnosum s.l. (Diptera: Simuliidae). The current control programme, carried out by the South African National Department of Agriculture, uses regular applications, by helicopter, of the target-specific bacterial larvicide Bacillus thuringiensis var. israelensis. While cost-benefit analyses show significant benefits to the control programme, benefits could potentially be further increased through applying smaller volumes of larvicide in an optimised manner, which incorporates upstream residual amounts of pesticide through downstream carry. Using an optimisation technique applied in the West African Onchocerciasis Control Programme, to a 136 km stretch of the Orange River which includes 31 blackfly breeding sites, we demonstrate that 28.5% less larvicide could be used to potentially achieve the same control of blackfly. This translates into potential annual savings of between R540 000 and R1 800 000. A comparison of larvicide volumes estimated using traditional vs. optimised approaches at different discharges, illustrates that the savings on optimisation decline linearly with increasing flow volumes. Larvicide applications at the lowest discharge considered (40 m3·s-1) showed the greatest benefits from optimisations, with benefits remaining but decreasing to a theoretical 30% up to median flows of 100 m3·s-1. Given that almost 70% of flows in July are less than 100 m3·s-1, we suggest that an optimised approach is appropriate for the Orange River Blackfly Control Programme, particularly for flow volumes of less than 100 m3·s-1. We recommend that trials be undertaken over two reaches of the Orange River, one using the traditional approach, and another using the optimised approach, to test the efficacy of using optimised volumes of B.t.i.

Public Opinions on Strategies for Managing Stray Cats and Predictors of Opposition to Trap-Neuter and Return in Brisbane, Australia.

A survey of Brisbane residents was undertaken to investigate community attitudes toward urban stray cats and their management. Surveys were distributed to 84 medical and dental practices across Brisbane City, and were completed by 305 patients and staff. Practices were targeted to achieve a sample of respondents from a representative distribution of socioeconomic backgrounds. After being informed about trap, neuter, and return (TNR) programs for management of urban stray cats, most respondents (79%), chose TNR as their preferred management strategy, while a lesser proportion (18%) expressed a preference to continue the current Brisbane City Council lethal control program (catching and culling ~1,000 cats annually), and 3.4% selected to leave the cats alone. Differences in beliefs and attitudes toward urban stray cats as a function of demographic variables were investigated. Statistical analyses indicated that respondents who were male, older, non-cat owners, those who believed euthanasia of stray cats was humane, and that urban stray cats spread disease to humans were significantly more likely to express a preference for lethal control, as opposed to non-lethal population management. Based on these findings, we recommend that information is disseminated to mitigate these concerns or negative beliefs, where warranted. Ultimately, findings from this study demonstrate that current Queensland legislation does not reflect public views and opinions on stray cat management and should be reviewed. Formal research evaluating the efficacy of TNR programs for urban stray cats in Australia would be in the public interest.

Development of a preliminary in vitro drug screening assay based on a newly established culturing system for pre-adult fifth-stage Onchocerca volvulus worms.

BackgroundThe human filarial parasite Onchocerca volvulus is the causative agent of onchocerciasis (river blindness). It causes blindness in 270,000 individuals with an additional 6.5 million suffering from severe skin pathologies. Current international control programs focus on the reduction of microfilaridermia by annually administering ivermectin for more than 20 years with the ultimate goal of blocking of transmission. The adult worms of O. volvulus can live within nodules for over 15 years and actively release microfilariae for the majority of their lifespan. Therefore, protracted treatment courses of ivermectin are required to block transmission and eventually eliminate the disease. To shorten the time to elimination of this disease, drugs that successfully target macrofilariae (adult parasites) are needed. Unfortunately, there is no small animal model for the infection that could be used for discovery and screening of drugs against adult O. volvulus parasites. Here, we present an in vitro culturing system that supports the growth and development of O. volvulus young adult worms from the third-stage (L3) infective stage.Methodology/Principal findingsIn this study we optimized the culturing system by testing several monolayer cell lines to support worm growth and development. We have shown that the optimized culturing system allows for the growth of the L3 worms to L5 and that the L5 mature into young adult worms. Moreover, these young O. volvulus worms were used in preliminary assays to test putative macrofilaricidal drugs and FDA-approved repurposed drugs.ConclusionThe culture system we have established for O. volvulus young adult worms offers a promising new platform to advance drug discovery against the human filarial parasite, O. volvulus and thus supports the continuous pursuit for effective macrofilaricidal drugs. However, this in vitro culturing system will have to be further validated for reproducibility before it can be rolled out as a drug screen for decision making in macrofilaricide drug development programs.