Inorganic-organic composite particle as a staged delivery platform for plasmid DNA-based biopharmaceuticals

Infectious diseases such as SARS, influenza and bird flu may spread exponentially throughout communities. In fact, most infectious diseases remain major health risks due to the lack of vaccine or the lack of facilities to deliver the vaccines. Conventional vaccinations are based on damaged pathogens, live attenuated viruses and viral vectors. If the damage was not complete, the vaccination itself may cause adverse effects. Therefore, researchers have been prompted to prepare viable replacements for the attenuated vaccines that would be more effective and safer to use. DNA vaccines are generally composed of a double stranded plasmid that includes a gene encoding the target antigen under the transcriptional directory and control of a promoter region which is active in cells. Plasmid DNA (pDNA) vaccines allow the foreign genes to be expressed transiently in cells, mimicking intracellular pathogenic infection and inducing both humoral and cellular immune responses. Currently, because of their highly evolved and specialized components, viral systems are the most effective means for DNA delivery, and they achieve high efficiencies (generally >90%), for both DNA delivery and expression. As yet, viral-mediated deliveries have several limitations, including toxicity, limited DNA carrying capacity, restricted target to specific cell types, production and packing problems, and high cost. Thus, nonviral systems, particularly a synthetic DNA delivery system, are highly desirable in both research and clinical applications.

Process engineering aspects of plasmid-based biopharmaceuticals production : tackling the threatening vaccine shortages to prevent global pandemics

Infectious diseases such as SARS, influenza and bird flu have the potential to cause global pandemics; a key intervention will be vaccination. Hence, it is imperative to have in place the capacity to create vaccines against new diseases in the shortest time possible. In 2004, The Institute of Medicine asserted that the world is tottering on the verge of a colossal influenza outbreak. The institute stated that, inadequate production system for influenza vaccines is a major obstruction in the preparation towards influenza outbreaks. Because of production issues, the vaccine industry is facing financial and technological bottlenecks: In October 2004, the FDA was caught off guard by the shortage of flu vaccine, caused by a contamination in a US-based plant (Chiron Corporation), one of the only two suppliers of US flu vaccine. Due to difficulties in production and long processing times, the bulk of the world's vaccine production comes from very small number of companies compared to the number of companies producing drugs. Conventional vaccines are made of attenuated or modified forms of viruses. Relatively high and continuous doses are administered when a non-viable vaccine is used and the overall protective immunity obtained is ephemeral. The safety concerns of viral vaccines have propelled interest in creating a viable replacement that would be more effective and safer to use.

How costs change with infection prevention efforts

Purpose of review: To describe articles since January 2013 that include information on how costs change with infection prevention efforts. Recent findings: Three articles described only the costs imposed by nosocomial infection and so provided limited information about whether or not infection prevention efforts should be changed. One article was found that described the costs of supplying alcohol-based hand run in low-income countries. Eight articles showed the extra costs and cost savings from changing infection prevention programmes and discussed the health benefits. All concluded that the changes are economically worthwhile. There was a systematic review of the costs of methicillin-resistant Staphylococcus aureus control programmes and a methods article for how to make cost estimates for infection prevention programmes. Summary: The balance has shifted away from studies that report the high cost of nosocomial infections toward articles that address the value for money of infection prevention. This is good as simply showing a disease is high cost does not inform decisions to reduce it. More research, done well, on the costs of implementation, cost savings and change to health benefits in this area needs to be done as many gaps exist in our knowledge.

Spatiotemporal analysis of indigenous and imported dengue fever cases in Guangdong province, China

Background Dengue fever has been a major public health concern in China since it re-emerged in Guangdong province in 1978. This study aimed to explore spatiotemporal characteristics of dengue fever cases for both indigenous and imported cases during recent years in Guangdong province, so as to identify high-risk areas of the province and thereby help plan resource allocation for dengue interventions. Methods Notifiable cases of dengue fever were collected from all 123 counties of Guangdong province from 2005 to 2010. Descriptive temporal and spatial analysis were conducted, including plotting of seasonal distribution of cases, and creating choropleth maps of cumulative incidence by county. The space-time scan statistic was used to determine space-time clusters of dengue fever cases at the county level, and a geographical information system was used to visualize the location of the clusters. Analysis were stratified by imported and indigenous origin. Results 1658 dengue fever cases were recorded in Guangdong province during the study period, including 94 imported cases and 1564 indigenous cases. Both imported and indigenous cases occurred more frequently in autumn. The areas affected by the indigenous and imported cases presented a geographically expanding trend over the study period. The results showed that the most likely cluster of imported cases (relative risk = 7.52, p < 0.001) and indigenous cases (relative risk = 153.56, p < 0.001) occurred in the Pearl River Delta Area; while a secondary cluster of indigenous cases occurred in one district of the Chao Shan Area (relative risk = 471.25, p < 0.001). Conclusions This study demonstrated that the geographic range of imported and indigenous dengue fever cases has expanded over recent years, and cases were significantly clustered in two heavily urbanised areas of Guangdong province. This provides the foundation for further investigation of risk factors and interventions in these high-risk areas.

A nationwide web-based automated system for early outbreak detection and rapid response in China

Timely reporting, effective analyses and rapid distribution of surveillance data can assist in detecting the aberration of disease occurrence and further facilitate a timely response. In China, a new nationwide web-based automated system for outbreak detection and rapid response was developed in 2008. The China Infectious Disease Automated-alert and Response System (CIDARS) was developed by the Chinese Center for Disease Control and Prevention based on the surveillance data from the existing electronic National Notifiable Infectious Diseases Reporting Information System (NIDRIS) started in 2004. NIDRIS greatly improved the timeliness and completeness of data reporting with real time reporting information via the Internet. CIDARS further facilitates the data analysis, aberration detection, signal dissemination, signal response and information communication needed by public health departments across the country. In CIDARS, three aberration detection methods are used to detect the unusual occurrence of 28 notifiable infectious diseases at the county level and to transmit that information either in real-time or on a daily basis. The Internet, computers and mobile phones are used to accomplish rapid signal generation and dissemination, timely reporting and reviewing of the signal response results. CIDARS has been used nationwide since 2008; all Centers for Disease Control and Prevention (CDC) in China at the county, prefecture, provincial and national levels are involved in the system. It assists with early outbreak detection at the local level and prompts reporting of unusual disease occurrences or potential outbreaks to CDCs throughout the country.

Ambient temperature and the rates of adverse reactions of pertussis vaccines

To the Editor—Diphtheria-tetanus-pertussis whole-cell (DTwP) and acellular (DTaP) vaccines are the 2 main pertussis-contained vaccines. DTwP, developed in the 1930s, has contributed to the reduction of pertussis, but has often been associated with vaccine-related adverse reactions (ARs) [1]. This had severely affected the public confidence in immunization programs, followed by decreased vaccine coverage and pertussis outbreaks in many industrialized countries in the 1970s [2]. DTaP, which was developed in the 1980s and replaced DTwP in developed countries in the 1990s, has been associated with fewer ARs due to removal/reduction of endotoxin [1]. China began replacing DTwP with DTaP in its national immunization programs in December 2007, and its passive Adverse Events Following Immunization (AEFI) surveillance system was established in 2005 [3]. The Intergovernmental Panel on Climate Change Fifth Assessment Report indicates that the planet is warming at...

Developing an epidemic forecasting model for Influenza A in Brisbane, Australia, based on climate and Hong Kong Influenza A surveillance data

Influenza is associated with substantial disease burden [ 1]. Development of a climate-based early warning system for in fluenza epidemics has been recommended given the signi fi - cant association between climate variability and influenza activity [2]. Brisbane is a subtropical city in Australia and offers free in fluenza vaccines to residents aged ≥65 years considering their high risks in developing life-threatening complications, especially for in fluenza A predominant seasons. Hong Kong is an international subtropical city in Eastern Asia and plays a crucial role in global infectious diseases transmission dynamics via the international air transportation network [3, 4]. We hypothesized that Hong Kong in fluenza surveillance data could provide a signal for in fluenza epidemics in Brisbane [ 4]. This study aims to develop an epidemic forecasting model for influenza A in Brisbane elders, by combining climate variability and Hong Kong in fluenza A surveillance data. Weekly numbers of laboratoryconfirmed influenza A positive isolates for people aged ≥65 years from 2004 to 2009 were obtained for Brisbane from Queensland Health, Australia, and for Hong Kong from Queen Mary Hospital (QMH). QMH is the largest public hospital located in Hong Kong Island, and in fluenza surveillance data from this hospital have been demonstrated to be representative for influenza circulation in the entirety of Hong Kong [ 5]. The Brisbane in fluenza A epidemics occurred during July –September, whereas the Hong Kong in fluenza A epidemics occurred during February –March and May –August.

Malaria imported from Ghana by returning gold miners, China, 2013

During May-August 2013, a malaria outbreak comprising 874 persons in Shanglin County, China, was detected among 4,052 persons returning from overseas. Ghana was the predominant destination country, and 92.3% of malarial infections occurred in gold miners. Preventive measures should be enhanced for persons in high-risk occupations traveling to malaria-endemic countries.

Modified MLVA for genotyping Queensland invasive Streptococcus pneumoniae

Background Globally, over 800 000 children under five die each year from infectious diseases caused by Streptococcus pneumoniae. To understand genetic relatedness between isolates, study transmission routes, assess the impact of human interventions e.g. vaccines, and determine infection sources, genotyping methods are required. The ‘gold standard’ genotyping method, Multi-Locus Sequence Typing (MLST), is useful for long-term and global studies. Another genotyping method, Multi-Locus Variable Number of Tandem Repeat Analysis (MLVA), has emerged as a more discriminatory, inexpensive and faster technique; however there is no universally accepted method and it is currently suitable for short-term and localised epidemiology studies. Currently Australia has no national MLST database, nor has it adopted any MLVA method for short-term or localised studies. This study aims to improve S. pneumoniae genotyping methods by modifying the existing MLVA techniques to be more discriminatory, faster, cheaper and technically less demanding than previously published MLVA methods and MLST. Methods Four different MLVA protocols, including a modified method, were applied to 317 isolates of serotyped invasive S. pneumoniae isolated from sterile body sites of Queensland children under 15 years from 2007–2012. MLST was applied to 202 isolates for comparison. Results The modified MLVA4 is significantly more discriminatory than the ‘gold standard’ MLST method. MLVA4 has similar discrimination compared to other MLVA techniques in this study). The failure to amplify particular loci in previous MLVA methods were minimised in MLVA4. Failure to amplify BOX-13 and Spneu19 were found to be serotype specific. Conclusion We have modified a highly discriminatory MLVA technique for genotyping Queensland invasive S. pneumoniae. MLVA4 has the ability to enhance our understanding of the pneumococcal epidemiology and the changing genetics of the pneumococcus in localised and short-term studies.

Molecular analysis of asymptomatic bacteriuria escherichia coli strain VR50 reveals adaptation to the urinary tract by gene acquisition

Urinary tract infections (UTIs) are among the most common infectious diseases of humans, with Escherichia coli responsible for >80% of all cases. One extreme of UTI is asymptomatic bacteriuria (ABU), which occurs as an asymptomatic carrier state that resembles commensalism. To understand the evolution and molecular mechanisms that underpin ABU, the genome of the ABU E. coli strain VR50 was sequenced. Analysis of the complete genome indicated that it most resembles E. coli K-12, with the addition of a 94-kb genomic island (GI-VR50-pheV), eight prophages, and multiple plasmids. GI-VR50-pheV has a mosaic structure and contains genes encoding a number of UTI-associated virulence factors, namely, Afa (afimbrial adhesin), two autotransporter proteins (Ag43 and Sat), and aerobactin. We demonstrated that the presence of this island in VR50 confers its ability to colonize the murine bladder, as a VR50 mutant with GI-VR50-pheV deleted was attenuated in a mouse model of UTI in vivo. We established that Afa is the island-encoded factor responsible for this phenotype using two independent deletion (Afa operon and AfaE adhesin) mutants. E. coli VR50afa and VR50afaE displayed significantly decreased ability to adhere to human bladder epithelial cells. In the mouse model of UTI, VR50afa and VR50afaE displayed reduced bladder colonization compared to wild-type VR50, similar to the colonization level of the GI-VR50-pheV mutant. Our study suggests that E. coli VR50 is a commensal-like strain that has acquired fitness factors that facilitate colonization of the human bladder.

Hospital infection control units: Staffing, costs, and priorities

Background: This article describes infection prevention and control professionals’ (ICPs’) staffing levels, patient outcomes, and costs associated with the provision of infection prevention and control services in Australian hospitals. A secondary objective was to determine the priorities for infection control units. Methods: A cross-sectional study design was used. Infection control units in Australian public and private hospitals completed a Web-based anonymous survey. Data collected included details about the respondent; hospital demographics; details and services of the infection control unit; and a description of infection prevention and control-related outputs, patient outcomes, and infection control priorities. Results: Forty-nine surveys were undertaken, accounting for 152 Australian hospitals. The mean number of ICPs was 0.66 per 100 overnight beds (95% confidence interval, 0.55-0.77). Privately funded hospitals have significantly fewer ICPs per 100 overnight beds compared with publicly funded hospitals (P < .01). Staffing costs for nursing staff in infection control units in this study totaled $16,364,392 (mean, $380,566). Infection control units managing smaller hospitals (<270 beds) identified the need for increased access to infectious diseases or microbiology support. Conclusion: This study provides valuable information to support future decisions by funders, hospital administrators, and ICPs on service delivery models for infection prevention and control. Further, it is the first to provide estimates of the resourcing and cost of staffing infection control in hospitals at a national level. Copyright

Lipid-modified azurin of Neisseria meningitidis is a copper protein localized on the outer membrane surface and not regulated by FNR

The laz gene of Neisseria meningitidis is predicted to encode a lipid-modified azurin (Laz). Laz is very similar to azurin, a periplasmic protein, which belongs to the copper-containing proteins in the cupredoxin superfamily. In other bacteria, azurin is an electron donor to nitrite reductase, an important enzyme in the denitrifying process. It is not known whether Laz could function as an electron transfer protein in this important pathogen. Laz protein was heterologously expressed in Escherichia coli and purified. Electrospray mass spectrometry indicated that the Laz protein contains one copper ion. Laz was shown to be redox-active in the presence of its redox center copper ion. When oxidized, Laz exhibits an intense blue colour and absorbs visible light around 626 nm. The absorption is lost when exposed to diethyldithiocarbamate, a copper chelating agent. Polyclonal antibodies were raised against purified Laz for detecting expression of Laz under different growth conditions and to determine the orientation of Laz on the outer membrane. The expression of Laz under microaerobic and microaerobic denitrifying conditions was slightly higher than that under aerobic conditions. However, the expression of Laz was similar between the wild type strain and an fnr mutant, suggesting that Fumarate/Nitrate reduction regulator (FNR) does not regulate the expression of Laz despite the presence of a partial FNR box upstream of the laz gene. We propose that some Laz protein is exposed on the outer membrane surface of N. meningitidis as the αLaz antibodies can increase killing by complement in a capsule deficient N. meningitidis strain, in a dose-dependent fashion.

Cross-border malaria: a major obstacle for malaria elimination

Movement of malaria across international borders poses a major obstacle to achieving malaria elimination in the 34 countries that have committed to this goal. In border areas, malaria prevalence is often higher than in other areas due to lower access to health services, treatment-seeking behaviour of marginalised populations that typically inhabit border areas, difficulties in deploying prevention programs to hard-to-reach communities, often in difficult terrain, and constant movement of people across porous national boundaries. Malaria elimination in border areas will be challenging, and key to addressing the challenges is strengthening of surveillance activities for rapid identification of any importation or reintroduction of malaria. This could involve taking advantage of technological advances, such as spatial decision support systems, which can be deployed to assist program managers to carry out preventive and reactive measures, and mobile phone technology, which can be used to capture the movement of people in the border areas and likely sources of malaria importation. Additionally, joint collaboration in the prevention and control of cross-border malaria by neighbouring countries, and reinforcement of early diagnosis and prompt treatment are ways forward in addressing the problem of cross-border malaria.

Diagnostic markers and uses therefor

The present invention relates generally to methods for diagnosing and treating infectious diseases and other conditions related thereto. More particularly, the present invention relates to methods for determining the presence of organisms of the Chlamydiaceae family in a subject, including species of Chlamydia, and to methods for determining the stage of an infection caused by such organisms. The present invention also relates to kits for use with the diagnostic methods. The methods and kits of the present invention are particularly useful in relation to human and non-human, i.e. veterinary subjects. The present invention further relates to methods for identifying proteins or nucleic acid sequences associated with chlamydial infection in a subject. Such proteins or nucleic acid sequences are not only useful in relation to the diagnostic methods of the invention but are also useful in the development of methods and agents for preventing and/or treating chlamydial infection in a subject, such as but not limited to, immunotherapeutic methods and agents.

Microscopy for the detection, identification and quantification of malaria parasites on stained thick and thin blood films in research settings

Summary This manual was developed to guide a move towards common standards for undertaking and reporting research microscopy for malaria parasite detection, identification and quantification. It contains procedures based on agreed quality assurance standards for research malaria microscopy defined at a consultation of: TDR, the Special Programme for Research and Training in Tropical Diseases; the Worldwide Antimalarial Resistance Network (WWARN), United Kingdom; the Foundation for Innovative New Diagnostics (FIND), Switzerland; the Centers for Disease Control and Prevention (CDC), USA; the Kenya Medical Research Institute (KEMRI) and later expanded to include Amref Health Africa (Kenya); the Eijkman-Oxford Clinical Research Unit (EOCRU), Indonesia; Institut Pasteur du Cambodge (IPC); Institut de recherche pour le Développement (IRD), Senegal; the Global Good and Intellectual Ventures Laboratory (GG-IVL), USA; the Mahidol-Oxford Tropical Medicine Research Unit (MORU), Thailand; Queensland University of Technology (QUT), Australia, and the Shoklo Malaria Research Unit (SMRU), Thailand. These collaborating institutions commit to adhering to these standards in published research studies. It is hoped that they will form a solid basis for the wider adoption of standardized reference microscopy protocols for malaria research.