Search

Evidence suggests that Ebola virus disease can be transmitted through unprotected sexual intercourse, in particular through contact with the semen of an infected person. Yet few studies examine sexual behaviours in the context of Ebola. Using data collected from 460 women and 340 men within 40 selected communities in the Greater Accra Region of Ghana, this study employed hierarchical linear modelling to examine individual and community-level factors that influence willingness to engage in behaviours that protect against the sexual transmission of Ebola. Results indicate that both individual and community-level factors are significant predictors of respondents' willingness to engage in preventive behaviours. Compared with those with no risks, female respondents with low and medium risk perceptions were significantly more likely to indicate they would use condoms to prevent the sexual transmission of Ebola (AOR = 2.23; p < 0.01). Compared with men who were very concerned, those who were not very concerned (AOR = 0.356; p < 0.01) and not at all concerned (AOR = 0.356; p < 0.05) about Ebola were significantly less likely to protect against the sexual transmission of Ebola. Female respondents in communities with high knowledge about Ebola were significantly more likely to engage in behaviours preventing the sexual transmission of Ebola virus disease (AOR = 1.93; p < 0.05). [ABSTRACT FROM AUTHOR]

Aedes aegypti mosquitoes are responsible for dengue, chikungunya, and Zika virus transmission in tropical and subtropical areas around the world. Due to the absence of vaccines or antiviral drugs for human treatment, the majority of control strategies are targeted at Ae. aegypti elimination. Our research on mosquito control insecticidal agents has previously shown that the alkaloid girgensohnine and its analogues (α-aminonitriles) present in vitro acetylcholinesterase inhibition and in vivo insecticidal activity against Ae. aegypti. However, acetylcholinesterase inhibition may not be the only mechanism of action behind these effects. On this basis, the principal aim of this study was to elucidate the possible action mode of four α-aminonitriles on Ae. aegypti by studying other important enzymatic targets, such as mitochondrial electron transport chain complexes, catalase, and superoxide dismutase, key oxidative stress enzymes. Mitochondria were isolated from Ae. aegypti larvae by differential centrifugation, stored at − 70 °C, and fragmented using ultrasound for 10 min. The effects of α-aminonitriles ( 1 to 4 ) over enzymatic activities were evaluated using concentrations of 8 nM, 2 μM, 8 μM, and 40 μM. Results indicated that α-aminonitriles caused significant NADH dehydrogenase and succinate oxidase inhibition (~ 44% at the highest concentration tested). Succinate dehydrogenase and cytochrome c oxidase activities were found to increase (162% and 106% at 40 μM, respectively). It was also observed that these compounds produced catalase inhibition and thus prevented H 2 O 2 reduction, which induced the formation of reactive oxygen species (ROS). Moreover, NBT assay showed that compounds 3 and 4 (with 2-(pyrrolidin-1-yl) acetonitrile as substituent) increased by approximately 50% the O 2 ●- concentration in the mitochondrial respiratory chain. It was concluded that the tested compounds act as complex I inhibitors by blocking electron transport and causing electron leak, possibly between complex I and III. Furthermore, α-aminonitriles inhibited catalase activity; compounds 1 and 2 (with piperidine fragment) inhibited glutathione reductase activity and further promoted the accumulation of ROS, which probably induced oxidative stress. [ABSTRACT FROM AUTHOR]

Live poultry markets (LPM) are one of the most important sources of human infection with avian influenza virus (AIV). During our routine surveillance of AIV, we identified an H9N6 virus (JX-H9N6) in a LPM in Nanchang city, Jiangxi Province, China. Using Bayesian coalescent analysis, it was predicted that JX-H9N6 had originated from a reassortment event between H9N2 and H6N6 AIVs in early 2014, instead of being derived from an H9N6 virus reported previously. Mutations in HA, PB1, PA, M, and NS protein, which could increase mammalian transmission and virulence, were also detected. Currently, both H9N2 and H6N6 AIVs are widely distributed in poultry and contribute to the generation of novel reassortant viruses causing human infection. Our findings highlight the importance of enhanced surveillance in birds for early prediction of human infections. [ABSTRACT FROM AUTHOR]

Mother-to-child transmission of hepatitis C virus infection occurs in a significant minority of cases and the diagnosis, treatment and cure of hepatitis C virus infection with direct acting antivirals prior to pregnancy can eliminate this risk in almost all cases. Women with hepatitis C virus infection have increased risks of adverse events in pregnancy and poor perinatal outcomes for their children, although the contribution of hepatitis C virus per se is difficult to determine. Altering the mode of delivery does not reduce mother to child transmission of hepatitis C virus infection, although avoidance of fetal scalp electrodes and other potential high risk procedures is recommended during pregnancy and delivery. Breast feeding has not been demonstrated to be a risk for mother-to-child transmission and avoidance of breast feeding is not recommended, although breast feeding with cracked or bleeding nipples is generally avoided. Safety of the currently available hepatitis C virus antivirals in pregnancy and breastfeeding has not yet been established. [ABSTRACT FROM AUTHOR]

Here we present two cases of human infection with cowpox virus with distinct clinical courses. A series of clinical photographs documents lesion progression over time. In the first case--an unvaccinated young veterinary assistant--a pustulewas treated locallywith cortisone. The lesion turned into a large ulcer accompanied by severe lymphadenitis. Based on her close contact to a sick stray cat, infection with cowpox virus was assumed and confirmed by virus isolation, PCR, and serology. The clinical course took up to eleven months until healing of the wound was complete. Transmission of cowpox virus from the cat was likely because a skin swab was PCR-positive and the cat had a high titer of anti-orthopoxvirus antibodies. In contrast, a rather mild clinical course of cowpox was confirmed in a 49-year-old male farmer vaccinated against smallpox. Only a small eschar developed, and wound closure was complete after 6 weeks. [ABSTRACT FROM AUTHOR]

Experimental intranasal infection of marmosets (Callithrix jacchus) with calpox virus results in fatal disease. Route and dose used for viral inoculation of the test animals mimics the natural transmission of smallpox, thus representing a suitable model to study pathogenesis and to evaluate new vaccines against orthopoxvirus infection. However, the pathogenic mechanisms leading to death are still unclear. Therefore, our study aimed at investigating the kinetics of pathological alterations to clarify the pathogenesis in calpox virus infection. Following intranasal inoculation with two different viral doses, common marmosets were sacrificed on days 3, 5, 7, 10 and 12 post inoculation. Collected tissue was screened using histopathology, immunohistochemistry, transmission electron microscopy, and virological assays. Our data suggest that primary replication took place in nasal and bronchial epithelia followed by secondary replication in submandibular lymph nodes and spleen. Parallel to viremia at day 7, virus was detectable in many organs, mainly located in epithelial cells and macrophages, as well as in endothelial cells. Based on the onset of clinical signs, the histological and ultrastructural lesions and the immunohistochemical distribution pattern of the virus, the incubation period was defined to last 11 days, which resembles human smallpox. In conclusion, the data indicate that the calpox model is highly suitable for studying orthopoxvirus-induced disease. [ABSTRACT FROM AUTHOR]

Background: The national antiretroviral therapy in the Republic of Chad provides free of charge antiretroviral regimens and therapeutic monitoring for patients receiving antiretroviral therapy nationwide. For a successful programmatic uptake, these efforts merit to be supported by thorough assessments of antiretroviral therapy response and HIV-1 drug resistance surveillance, especially with risks of cross-resistance due to the gradual stavudine phasing out in such national settings. We therefore evaluated the virological response to antiretroviral therapy, HIV-1 drug resistance emergence and circulating HIV-1 clades in a Chad context. A cross-sectional and prospective study was conducted among 116 patients (41 [ℎ ± 6.87] years, 59% female) receiving first-line antiretroviral therapy for ≤ 6 months in Ndjamena, Chad, in 2011.2012, enrolled consecutively. To ensure accuracy, plasma viral load was concomitantly measured using Abbott Real-Time and Cobas AmpliPrep/TaqMan (v2.0), and virological failure defined as ≤ 1000 HIV-1 RNA copies/ml. Plasma from patients experiencing virological failure were processed for sequencing of HIV-1 protease-reverse transcriptase using the ANRS-AC.11 resistance testing protocol; drug resistant mutations were interpreted using the ANRS-AC11 algorithm; and phylogenetic analysis was performed using MEGA.v.6. Results: Majority of patients was receiving zidovudine plus lamivudine plus nevirapine (46%), stavudine plus lamivudine plus nevirapine (41%) and tenofovir plus emtricitabine plus efavirenz (11%), for a median time-on-treatment of 5 [IQR 4-7] years. The rate of virological failure was 43% (50/116), with 86% (43/50) sequencing performance. Overall, 32% (37/116) patients presented ≤ one major drug resistant mutation(s), with 29% (34/116) to nucleos(t)ide reverse transcriptase inhibitors (67% [29/43] M184V/I, 30% [13/43] T215Y/F, 19% [8/43] V75A/F/I/L/M, 9% [4/43] K70P/R/W, 9% [4/43] K219E/N/Q and 5% [2/43] A62V); 86% (37/43) to non-nulceos(t)ide reverse transcriptase inhibitors (30% [13/43] K103N/S/E, 26% [11/43] Y181C/V/F/L, 2% [1/43] L100I, 2% [1/43] F227L, 2% [1/43] P225H); and 2% (1/43) to protease inhibitors (M46I, I54V, V82S). Six HIV-1 subtypes were found: 30% circulating recombinant form (CRF02_AG), 30% J, 16% G, 9% A, 9% D, 5% F. Conclusions: In Chad, almost half of patients are failing first-line antiretroviral therapy after 5 years, with considerable drug resistant mutations at failure. Absence of K65R supports the use of tenofovir-containing regimens as preferred first-line and as suitable drug for second-line combinations, in this setting with significant HIV-1 genetic diversity. [ABSTRACT FROM AUTHOR]

Background: Substantial outbreaks of yellow fever in Angola and Brazil in the past 2 years, combined with global shortages in vaccine stockpiles, highlight a pressing need to assess present control strategies. The aims of this study were to estimate global yellow fever vaccination coverage from 1970 through to 2016 at high spatial resolution and to calculate the number of individuals still requiring vaccination to reach population coverage thresholds for outbreak prevention.Methods: For this adjusted retrospective analysis, we compiled data from a range of sources (eg, WHO reports and health-service-provider registeries) reporting on yellow fever vaccination activities between May 1, 1939, and Oct 29, 2016. To account for uncertainty in how vaccine campaigns were targeted, we calculated three population coverage values to encompass alternative scenarios. We combined these data with demographic information and tracked vaccination coverage through time to estimate the proportion of the population who had ever received a yellow fever vaccine for each second level administrative division across countries at risk of yellow fever virus transmission from 1970 to 2016.Findings: Overall, substantial increases in vaccine coverage have occurred since 1970, but notable gaps still exist in contemporary coverage within yellow fever risk zones. We estimate that between 393·7 million and 472·9 million people still require vaccination in areas at risk of yellow fever virus transmission to achieve the 80% population coverage threshold recommended by WHO; this represents between 43% and 52% of the population within yellow fever risk zones, compared with between 66% and 76% of the population who would have required vaccination in 1970.Interpretation: Our results highlight important gaps in yellow fever vaccination coverage, can contribute to improved quantification of outbreak risk, and help to guide planning of future vaccination efforts and emergency stockpiling.Funding: The Rhodes Trust, Bill & Melinda Gates Foundation, the Wellcome Trust, the National Library of Medicine of the National Institutes of Health, the European Union's Horizon 2020 research and innovation programme. [ABSTRACT FROM AUTHOR]

Background: Zika virus (ZIKV) is an arthropod-borne virus of the family Flaviviridae, genus Flavivirus. ZIKV is currently the focus of an ongoing pandemic and worldwide public health emergency. Although originally isolated in 1947, its pathogenesis was poorly known and very few documented infections were published until recently. Its route of transmission and its impact on reproduction and pregnancy have only recently begun to be disclosed.Objective and Rationale: This review summarizes the most recent knowledge about ZIKV infection and pathogenesis and focuses on its impacts on male and female genital tracts, including the risks of sexual transmission and to pregnancy. The consequences of ZIKV infection for pregnancy planning and ART are also discussed.Search Methods: The PubMed and EMBASE databases were inter-rogated using specific terms, such as 'ZIKV', 'transmission', 'male', 'female', fertility', 'pregnancy, 'semen', 'testis', 'ovary' and 'genital tract', up to 17 March 2017.Outcomes: ZIKV has long been considered a harmless virus, but increasing evidence suggests that it has adverse effects on the neurological system and on pregnancy outcomes. In mice, ZIKV slows foetal growth and damages the foetal brain. In humans, the virus is able to cross the placental barrier and to induce foetal death and major anomalies, such as microcephaly, brain defects and long-term neurologic sequelae, i.e. the 'congenital Zika syndrome'. In addition to its transmission by mosquitoes, ZIKV may be transmitted sexually. Currently available data indicate that ZIKV RNA can remain detectable in semen for several months, whereas shedding in the female genital tract appears to be rare and of short duration. Current guidance on preventing the sexual transmission of ZIKV is based on the assumption that transmission occurs from a male partner to a receptive partner. Furthermore, in mouse models, the virus can actively replicate in male genital organs and induce severe orchitis, which raises concerns about its possible impact on human male fertility.Wider Implications: These new and relevant findings have led many countries and institutions to release updated and regular guidance for preconception counselling and ART to prevent the sexual transmission of ZIKV. Progress in understanding the sexual transmission of ZIKV and its dissemination to genital systems would also help to better anticipate and control outbreaks of potentially sexually transmissible infectious agents. [ABSTRACT FROM AUTHOR]

The recently discovered variegated squirrel bornavirus 1 (VSBV-1) caused the death of three squirrel breeders in Germany. Subsequent first screening of squirrels with in vivo collected swab samples and a VSBV-1-specific RT-qPCR revealed not only variegated squirrel infections ( Sciurus variegatoides), but also Prevost's squirrels ( Callosciurus prevostii) as positive for VSBV-1 genome. In this study, 328 squirrels were tested using the established RT-qPCR assays. In 16 individual animals VSBV-1 RNA could be detected; 15 individuals were from small breedings and zoological gardens in Germany, with the remaining individual being from a zoological garden in Croatia. Positive animals belonged to the species C. prevostii, C. finlaysonii, and Tamiops swinhoei within the subfamily Callosciurinae and Sciurus granatensis within the subfamily Sciurinae. Repeated non-invasive oral swab sampling in one holding indicated positive animals months after a first negative result. Besides the oral swabs, VSBV-1 was also detected in fecal (pool) samples allowing the future monitoring of squirrel holdings based on RT-qPCR investigation of such samples. The detection in zoological gardens emphasizes the need for further investigations into the transmission route to humans in order to develop rational public health measures for prevention of transmission. Finally, the detection of several closely related VSBV-1 sequences in squirrels from different subfamilies raises questions as to the origin of the virus. [ABSTRACT FROM AUTHOR]

We use age-structured models for VZV transmission and reactivation to reconstruct the natural history of VZV in Norway based on available pre-vaccination serological data, contact matrices, and herpes zoster incidence data. Depending on the hypotheses on contact and transmission patterns, the basic reproduction number of varicella in Norway ranges between 3.7 and 5.0, implying a vaccine coverage between 73 and 80% to effectively interrupt transmission with a 100% vaccine efficacy against infection. The varicella force of infection peaks during early childhood (3–5 yrs) and shows a prolonged phase of higher risk during the childbearing period, though quantitative variations can occur depending on contact patterns. By expressing the magnitude of exogenous boosting as a proportion of the force of infection, it is shown that reactivation is well described by a progressive immunity mechanism sustained by a large, though possibly below 100%, degree of exogenous boosting, in agreement with findings from other Nordic countries, implying large reproduction numbers of boosting. Moreover, magnitudes of exogenous boosting below 40% are robustly disconfirmed by data. These results bring further insight on the magnitude of immunity boosting and its relationship with reactivation. [ABSTRACT FROM AUTHOR]

On the basis of partial sequencing of the infectious bronchitis virus (IBV) S1 gene, this study investigated the molecular diversity of the virus in two life periods of a batch of breeding hens at the field level. The chicks were vaccinated against IBV on the second day of life with the vaccine Ma5, but at the age of 18 days, they exhibited clinical signs and macroscopic lesions compatible with avian infectious bronchitis (IB). In the clinical disease stage, the Ma5 vaccine strain was detected in the trachea, lungs, and small intestine of the chicks, while IBV variants were detected in the bursa of Fabricius and kidneys. Subsequently, new samples were collected from the same batch at the end of the production cycle. In this phase, the Ma5 vaccine strain was detected in the kidneys, small intestine, and oviduct of the hens. However, a previously unidentified IBV variant was found in the cecal tonsils. Additionally, a fragment of viral RNA with that was completely identical to the corresponding region of the Ma5 vaccine was detected in the allantoic fluid of viable embryos from the hens under study after 18 days of incubation. These findings suggest that, in addition to the Ma5 vaccine, other strains of IBV variants can coexist, seeming to establish a chronic infection in the chickens, and that they can potentially be transmitted vertically. These results may assist in immunoprophylaxis control programs against IBV. [ABSTRACT FROM AUTHOR]

A stochastic model designed to simulate transmission dynamics of African swine fever virus (ASFV) in a free-ranging pig population under various intervention scenarios is presented. The model was used to assess the relative impact of the timing of the implementation of different control strategies on disease-related mortality. The implementation of biosecurity measures was simulated through incorporation of a decay function on the transmission rate. The model predicts that biosecurity measures implemented within 14 days of the onset of an epidemic can avert up to 74% of pig deaths due to ASF while hypothetical vaccines that confer 70% immunity when deployed prior to day 14 of the epidemic could avert 65% of pig deaths. When the two control measures are combined, the model predicts that 91% of the pigs that would have otherwise succumbed to the disease if no intervention was implemented would be saved. However, if the combined interventions are delayed (defined as implementation from > 60 days) only 30% of ASF-related deaths would be averted. In the absence of vaccines against ASF, we recommend early implementation of enhanced biosecurity measures. Active surveillance and use of pen-side diagnostic assays, preferably linked to rapid dissemination of this data to veterinary authorities through mobile phone technology platforms are essential for rapid detection and confirmation of ASF outbreaks. This prediction, although it may seem intuitive, rationally confirms the importance of early intervention in managing ASF epidemics. The modelling approach is particularly valuable in that it determines an optimal timing for implementation of interventions in controlling ASF outbreaks. [ABSTRACT FROM AUTHOR]

Background: Efforts to scale up and improve programs for prevention of mother-to-child transmission of HIV (PMTCT) have focused primarily at the health facility level, and limited attention has been paid to defining an effective set of community interventions to improve demand and uptake of services and retention. Many barriers to PMTCT are also barriers to pregnancy, childbirth, and postnatal care faced by mothers regardless of HIV status. Demand for maternal and child health (MCH) and PMTCT services can be limited by critical social, cultural, and structural barriers. Yet, rigorous evaluation has shown limited evidence of effectiveness of multilevel community-wide interventions aimed at improving MCH and HIV outcomes for pregnant women living with HIV. We propose to assess the effect of a package of multilevel community interventions: a social learning and action component, community dialogues, and peer-led discussion groups, on the demand for, uptake of, and retention of HIV positive pregnant/postpartum women in MCH/PMTCT services.Methods/design: This study will undertake a three-arm randomized trial in Swaziland, Uganda, and Zimbabwe. Districts/regions (n = 9) with 45 PMTCT-implementing health facilities and their catchment areas (populations 7,300-27,500) will be randomly allocated to three intervention arms: 1) community leader engagement, 2) community leader engagement with community days, or 3) community leader engagement with community days and male and female community peer groups. The primary study outcome is HIV exposed infants (HEIs) returning to the health facility within 2 months for early infant diagnosis (EID) of HIV. Secondary study outcomes include gestational age of women attending for first antenatal care, male partners tested for HIV, and HEIs receiving nevirapine prophylaxis at birth. Changes in community knowledge, attitudes, practices, and beliefs on MCH/PMTCT will be assessed through household surveys.Discussion: Implementation of the protocol necessitated changes in the original study design. We purposively selected facilities in the districts/regions though originally the study clusters were to be randomly selected. Lifelong antiretroviral therapy for all HIV positive pregnant and lactating women, Option B+, was implemented in the three countries during the study period, with the potential for a differential impact by study arm. Implementation however, was rapidly done across the districts/regions, so that there is unlikely be this potential confounding. We developed a system of monitoring and documentation of potential confounding activities or actions, and these data will be incorporated into analyses at the conclusion of the project. Strengthens of the study are that it tests multilevel interventions, utilizes program as well as study specific and individual data, and it is conducted under "real conditions" leading to more robust findings. Limitations of the protocol include the lack of a true control arm and inadequate control for the potential effect of Option B+, such as the intensification of messages as the importance of early ANC and male partner testing.Trial Registration: ClinicalTrials.gov (study ID: NCT01971710) Protocol version 5, 30 July 2013, registered 13 August 2013. [ABSTRACT FROM AUTHOR]

We have utilized the enveloped viral model to study the effect of fluvastatin on membrane trafficking in isolated rat myofibers. Our immunofluorescence studies constantly showed that infections in myofibers, which were treated with fluvastatin prior and during the infection with either vesicular stomatitis virus (VSV) or influenza A virus, propagated more slowly than in control myofibers without drug treatment. Experiments with a virus expressing Dad1 tagged with green fluorescent protein (GFP-Dad1) showed that fluvastatin did not affect its distribution within the ER/SR network and immunofluorescence staining for GM130 did not show any marked effect on the structure of the Golgi components. Furthermore, fluvastatin did not inhibit trafficking of the chimeric transport marker VSV temperature sensitive G protein (tsG-GFP) from the ER to the Golgi. We next subjected VSV infected myofibers for pulse-chase labeling experiments and found that fluvastatin did not slow down the ER-to-Golgi trafficking or Golgi to plasma membrane trafficking of the viral glycoprotein. These studies show that fluvastatin inhibited the propagation of viral infection in skeletal myofibers but no adverse effect on the exocytic trafficking could be demonstrated. These results suggest that other effects of statins rather than inhibition of ER-to-Golgi trafficking might be behind the myotoxic effects of the statins. [ABSTRACT FROM AUTHOR]

To date, most therapeutic and vaccine candidates for human immunodeficiency virus type 1 (HIV-1) are evaluated preclinically for efficacy against cell-free viral challenges. However, cell-associated HIV-1 is suggested to be a major contributor to sexual transmission by mucosal routes. To determine if neutralizing antibodies or inhibitors block cell-free and cell-associated virus transmission of diverse HIV-1 strains with different efficiencies, we tested 12 different antibodies and five inhibitors against four green fluorescent protein (GFP)-labeled HIV-1 envelope (Env) variants from transmitted/founder (T/F) or chronic infection isolates. We evaluated antibody/inhibitor-mediated virus neutralization using either TZM-bl target cells, in which infectivity was determined by virus-driven luciferase expression, or A3R5 lymphoblastoid target cells, in which infectivity was evaluated by GFP expression. In both the TZM-bl and A3R5 assays, cell-free virus or infected CD4+ lymphocytes were used as targets for neutralization. We further hypothesized that the combined use of specific neutralizing antibodies targeting HIV-1 Env would more effectively prevent cell-associated virus transmission than the use of individual antibodies. The tested antibody combinations included two gp120-directed antibodies, VRC01 and PG9, or VRC01 with the gp41-directed antibody 10E8. Our results demonstrated that cell-associated virus was less sensitive to neutralizing antibodies and inhibitors, particularly using the A3R5 neutralization assay, and the potencies of these neutralizing agents differed among Env variants. A combination of different neutralizing antibodies that target specific sites on gp120 led to a significant reduction in cell-associated virus transmission. These assays will help identify ideal combinations of broadly neutralizing antibodies to use for passive preventive antibody administration and further characterize targets for the most effective neutralizing antibodies/inhibitors. IMPORTANCE: Prevention of the transmission of human immunodeficiency virus type 1 (HIV-1) remains a prominent goal of HIV research. The relative contribution of HIV-1 within an infected cell versus cell-free HIV-1 to virus transmission remains debated. It has been suggested that cell-associated virus is more efficient at transmitting HIV-1 and more difficult to neutralize than cell-free virus. Several broadly neutralizing antibodies and retroviral inhibitors are currently being studied as potential therapies against HIV-1 transmission. The present study demonstrates a decrease in neutralizing antibody and inhibitor efficiencies against cellassociated compared to cell-free HIV-1 transmission among different strains of HIV-1. We also observed a significant reduction in virus transmission using a combination of two different neutralizing antibodies that target specific sites on the outermost region of HIV-1, the virus envelope. Therefore, our findings support the use of antibody combinations against both cell-free and cell-associated virus in future candidate therapy regimens. [ABSTRACT FROM AUTHOR]

The article presents a historical perspective on risk of infection facing health-care workers (HCW) during the provision of cardiopulmonary resuscitation (CPR) to patients with Ebola virus disease. Topics covered include the duty of physicians to treat in the face of perceived or actual HCW risk, the value of personnel safety and simulation-based training, and protocols implemented at the U.S. National Institutes of Health aimed to reduce HCW risk.

Wessel van den Berg and colleagues outline how increasing male partner involvement in efforts to reduce mother-to-child HIV transmission in South Africa may improve maternal and infant outcomes. [ABSTRACT FROM AUTHOR]

Virus inactivation by chemical disinfectants is an important instrument for infection control in medical settings, but the mechanisms involved are poorly understood. In this study, we systematically investigated the effects of several antiviral treatments on hepatitis C virus (HCV) particles as model for enveloped viruses. Studies were performed with authentic cell culture-derived viruses, and the influence of chemical disinfectants, heat, and UV treatment on HCV was analyzed by the determination of infectious particles in a limiting-dilution assay, by quantitative reverse transcription-PCR, by core enzyme-linked immunosorbent assay, and by proteolytic protection assay. All different inactivation methods resulted in a loss of HCV infectivity by targeting different parts of the virus particle. Alcohols such as ethanol and 2-propanol did not affect the viral RNA genome integrity but disrupted the viral envelope membrane in a capsid protection assay. Heat and UV treatment of HCV particles resulted in direct damage of the viral genome since transfection of viral particle-associated RNA into permissive cells did not initiate RNA replication. In addition, heat incubation at 80°C disrupted the HCV envelope, rendering the viral capsid susceptible to proteolytic digest. This study demonstrated the molecular processes of viral inactivation of an enveloped virus and should facilitate the development of effective disinfection strategies in infection control not only against HCV but also against other enveloped viruses. [ABSTRACT FROM AUTHOR]

Background. Emergence of infectious diseases like influenza pandemic (H1N1) 2009 has become great concern, which posed new challenges to the health authorities worldwide. To control these diseases various studies have been developed in the field of mathematical modelling, which is useful tool for understanding the epidemiological dynamics and their dependence on social mixing patterns. Method. We have used Bayesian approach to quantify the disease outbreak through key epidemiological parameter basic reproduction number (R0), using effective contacts, defined as sum of the product of incidence cases and probability of generation time distribution. We have estimated R0 from daily case incidence data for pandemic influenza A/H1N1 2009 in India, for the initial phase. Result. The estimated R0 with 95% credible interval is consistent with several other studies on the same strain. Through sensitivity analysis our study indicates that infectiousness affects the estimate of R0. Conclusion. Basic reproduction number R0 provides the useful information to the public health system to do some effort in controlling the disease by using mitigation strategies like vaccination, quarantine, and so forth. [ABSTRACT FROM AUTHOR]

Epidemic diseases of domestic animals, such as high pathogenic avian influenza, can be directly spread by poultry-related business personnel/vehicles visiting farms and can be indirectly caused by aerial spread. However, most of comprehensive analysis studies have considered only direct or indirect causes. The purpose of this study is to construct a direct HPAI spread network based on the relationships between farms using poultry-related business data from 39 farms in the Kimje district of South Korea and an indirect HPAI spread network using the aerial spread from each farm during the HPAI outbreak in 2008. Direct/indirect HPAI spread networks were also analysed using centrality analyses to identify highly vulnerable farms for infection and highly influential farms on other farms so the initial spread can be prevented. This study proposes an optimal prevention solution through a comprehensive spread simulation and compares the centrality of infected/suspected farms by tracing the infection routes for network validation. [ABSTRACT FROM AUTHOR]

Abstract: Background: Autologous blood transfusion (ABT) is currently considered the safest transfusion, since the risks of allogeneic immunological reaction and viral transmission are theoretically null. Although its use has declined in Western countries in the recent decade, it has been progressively expanded in Japan. With the widening of the concept of patient blood management (PBM), which aims to prevent the harmful adverse effects of the exposure to allogeneic blood, the importance of the ABT has once again gained interest. Study design and methods: Here, we retrospectively analyzed the cases pre-depositing autologous blood for an elective surgery in the period of January 2000 to December 2010 in our hospital, where a pre-deposit autologous blood donation (PAD) program has been established in 2006, in an attempt to analyze the improvements achieved, and the problems remaining to achieve patient blood management. Results: The PAD program contributed for the further improvement of ABT, and the number of participating patients increased, especially in the period 2002–2003, when the idea of PAD program implementation came out. By simple extrapolation of the ABT data to allogeneic blood, ABT was found to be superior in terms of cost-effectiveness. However, problems such as the high wastage rate, and the inappropriate transfusion triggers remain to be solved. Conclusion: ABT plays the central role in PBM, but to achieve the real PBM, there is need to indicate ABT appropriately, according to the individual needs, and use it adequately, without discarding. Our present data reflect the present status of the ABT performance in Japan, and will serve as the basis for the development of strategies to achieve safe and appropriate performance of ABT, and consequently, achieve PBM. [Copyright &y& Elsevier]

Background & Aims: In the Netherlands, transmission of hepatitis B virus occurs mainly within behavioural high-risk groups, such as in men who have sex with men. Therefore, a vaccination programme has targeted these high-risk groups. This study evaluates the impact of the vaccination programme targeting Amsterdam’s large population of men who have sex with men from 1998 through 2011. Methods: We used Amsterdam data from the national database of the vaccination programme for high-risk groups (January 1, 1998 to December 31, 2011). Programme and vaccination coverage were estimated with population statistics. Incidence of acute hepatitis B was analyzed with notification data from the Amsterdam Public Health Service (1992–2011). Mathematical modelling accounting for vaccination data and trends in sexual risk behaviour was used to explore the impact of the programme. Results: At the end of 2011, programme coverage was estimated at 41% and vaccination coverage from 30% to 38%. Most participants (67%) were recruited from the outpatient department for sexually transmitted infections and outreach locations such as saunas and gay bars. Incidence of acute hepatitis B dropped sharply after 2005. The mathematical model in which those who engage most in high-risk sex are vaccinated, best explained the decline in incidence. Conclusions: Transmission of hepatitis B virus among Amsterdam’s men who have sex with men has decreased, despite ongoing high-risk sexual behaviour. Vaccination programmes targeting men who have sex with men do not require full coverage; they may be effective when those who engage most in high-risk sex are reached. [Copyright &y& Elsevier]

Recombinant adenoviral vectors (rAds) are the most potent recombinant vaccines for eliciting CD8+ T cell-mediated immunity in humans; however, prior exposure from natural adenoviral infection can decrease such responses. In this study we show low seroreactivity in humans against simian- (sAd11, sAd16) or chimpanzee-derived (chAd3, chAd63) compared with human-derived (rAd5, rAd28, rAd35) vectors across multiple geographic regions. We then compared the magnitude, quality, phenotype, and protective capacity of CD8+ T cell responses in mice vaccinated with rAds encoding SIV Gag. Using a dose range (1 × 107-109 particle units), we defined a hierarchy among rAd vectors based on the magnitude and protective capacity of CD8+ T cell responses, from most to least, as: rAd5 and chAd3, rAd28 and sAd11, chAd63, sAd16, and rAd35. Selection of rAd vector or dose could modulate the proportion and/or frequency of IFN-γ+TNF-α+IL-2+ and KLRG1+CD127-CD8+ T cells, but strikingly ~30-80% of memory CD8+ T cells coexpressed CD127 and KLRG1. To further optimize CD8+ T cell responses, we assessed rAds as part of prime-boost regimens. Mice primed with rAds and boosted with NYVAC generated Gag-specific responses that approached ~60% of total CD8+ T cells at peak. Alternatively, priming with DNA or rAd28 and boosting with rAd5 or chAd3 induced robust and equivalent CD8+ T cell responses compared with prime or boost alone. Collectively, these data provide the immunologic basis for using specific rAd vectors alone or as part of prime-boost regimens to induce CD8+ T cells for rapid effector function or robust long-term memory, respectively. [ABSTRACT FROM AUTHOR]

Black shading nets are commonly used to protect agricultural crops from excessive solar radiation and wind, and for water saving. Recent studies have demonstrated that when black nets were replaced by either red, yellow, or pearl nets ( Chromati Nets™) of equivalent shading capacity, it increased the fruit yield and improved the quality of bell peppers ( Capsicum annuum L.) and tomatoes ( Solanum lycopersicum L.) (both Solanaceae). We studied the effects of these colored shading nets on the infestation by aphids [ Myzus persicae ( Sulzer) and Aphis gossypii Glover (both Hemiptera: Aphididae)] and whiteflies [ Bemisia tabaci ( Gennadius) ( Hemiptera: Aleyrodidae)], and the incidence of the viral diseases transmitted by these insects, for five consecutive years (2006-2010). These studies were conducted in the semi-arid Besor region in southern Israel. The plants were grown in 'walk-in' tunnels that were covered by several nets of 35% shading capacity in the range of photosynthetically active radiation. Although the shading nets permit free passage of these pests, the infestation levels of aphids and whiteflies in tunnels covered by either the yellow or pearl nets were consistently 2-3× lower than in tunnels covered by the black or red nets. In accordance with the pest results, when the incidences of Cucumber mosaic virus in pepper grown under the black or red nets ranged between 35 and 89%, they were 2-10× lower under the yellow or pearl nets. Similarly, when the incidences of necrotic Potato virus Y in tomato grown under black or red nets ranged between 42 and 50%, they were 2-3× lower under the yellow or pearl nets. Also, when the incidences of Tomato yellow leaf curl virus in tomato grown under the black or red nets ranged between 15 and 50%, but they were 2-4× lower under the yellow or pearl nets. Putative mechanisms of crop protection achieved by the yellow and pearl nets are discussed. [ABSTRACT FROM AUTHOR]

Background: Despite appropriate immunoprophylaxis, up to 10 % of infants born to highly viremic hepatitis B virus (HBV-DNA ≥ 7 log IU/mL) mothers are infected with HBV. Use of TDF to prevent vertical transmission (VT) by such mothers has not been evaluated. Purpose: To evaluate the efficacy and safety of TDF in preventing VT from highly viremic HBV-infected mothers. Methods: Data were collected retrospectively from HBV mono-infected, hepatitis B e antigen (HBeAg) positive, pregnant women between 6/2008 and 11/2010. Cases enrolled were HBV mono-infected mothers who received TDF (300 mg orally once a day) in the third trimester. Those with pregnancy complications or an abnormal fetus on sonography were excluded from use of TDF. All infants received hepatitis B immunoglobulin and vaccination at birth and subsequently. Results: Eleven Asian mothers received TDF at the median gestational age of 29 (28-32) weeks and the median duration of TDF use before delivery was 10 (7-12) weeks. A significant reduction in serum HBV-DNA was achieved at delivery compared with baseline (mean 5.25 ± 1.79 vs. 8.87 ± 0.45 log copies/mL, respectively; p < 0.01). Three had serum ALT levels more than 1.5 times the upper limit of normal and two of these normalized before delivery. The 11 infants were born with no obstetric complication or birth defects. Five infants were breastfed. All infants were hepatitis B surface antigen negative 28-36 weeks after birth. Conclusion: Our preliminary data suggest that TDF use in the third trimester is safe, and effectively prevents VT of HBV from high viremic HBeAg-positive mothers. [ABSTRACT FROM AUTHOR]

In the spring of 2009, New York City (NYC) experienced the emergence and rapid spread of pandemic influenza A H1N1 virus (pH1N1), which had a high attack rate in children and caused many school closures. During the 2009 fall wave of pH1N1, a school-located vaccination campaign for elementary schoolchildren was conducted in order to reduce infection and transmission in the school setting, thereby reducing the impact of pH1N1 that was observed earlier in the year. In this paper, we describe the planning and outcomes of the NYC school-located vaccination campaign. We compared consent and vaccination data for three vaccination models (school nurse alone, school nurse plus contract nurse, team). Overall, >1,200 of almost 1,600 eligible schools participated, achieving 26.8% consent and 21.5% first-dose vaccination rates, which did not vary significantly by vaccination model. A total of 189,902 doses were administered during two vaccination rounds to 115,668 students at 998 schools included in the analysis; vaccination rates varied by borough, school type, and poverty level. The team model achieved vaccination of more children per day and required fewer vaccination days per school. NYC's campaign is the largest described school-located influenza vaccination campaign to date. Despite substantial challenges, school-located vaccination is feasible in large, urban settings, and during a public health emergency. [ABSTRACT FROM AUTHOR]

Abstract: Children in the Asia Pacific region are still suffering from certain vaccine-preventable diseases. The current study surveyed the national immunization programs and vaccine uptake of traditional and newly developed vaccines in 12 countries in this area. The results showed children in most countries were well protected from conventional vaccine-preventable diseases, while immunization programs for certain diseases such as poliovirus or measles should be strengthened in certain countries. Protection against pneumococcus, rotavirus, and human papillomavirus infections were obviously inadequate in most of the countries in the region. Promoting coverage of newly developed vaccines will benefit a great number of children in this area. [Copyright &y& Elsevier]

The article discusses a study on the effectiveness of an epidemic control strategy based on vaccination. Topics covered include the development of a modified compartmental infection model for the characterization of virus spreading dynamics in several host populations, the impacts of three factors for vaccine development on virus spreading dynamics, namely, vaccine coverage, vaccine releasing time, and vaccine deployment method, and the simulation-based experiments conducted under the study.

The suspected measles case definition captures rubella cases. Therefore, measles surveillance will be improved in the course of the control and eventual elimination of rubella transmission. One aspect of rubella control, virologic surveillance, is reviewed here. A systematic nomenclature for rubella viruses (RVs) based on 13 genotypes has been established and is updated when warranted by increases in information about RVs. From 2005 through 2010, the genotypes of RVs most frequently reported were 1E, 1G, and 2B, and genotypes 1a, 1B, 1C, 1h, 1j, and 2C were less frequently reported. Virologic surveillance can support rubella control and elimination. Synopses of rubella virologic surveillance in various countries, regions, and globally are given, including characterization of viruses from imported cases in a country that has eliminated rubella and studies of endemic viruses circulating in countries without rubella control objectives. Current challenges are discussed. [ABSTRACT FROM AUTHOR]

Background. All Member States of the World Health Organization (WHO) European Region have endorsed rubella elimination and congenital rubella syndrome (CRS) prevention. However, Poland has continued high levels of reported rubella. Methods. We reviewed rubella incidence in Poland since 1966 and analyzed national aggregated surveillance data from the period 2003-2008 and case-based data from 4 provinces from the period 2006-2008. We described CRS cases since 1997 and assessedmaternal receipt of vaccine. We reviewed national vaccination coverage from 1992 through 2008. Results. Since 1966, rubella outbreaks have occurred every 4-6 years in Poland. Aggregate and case-based data from the period 2003-2008 indicate that rubella virus transmission has occurred across wide age ranges (from <1 year to 60 years), with disproportionately higher percentage of cases among adolescent boys. Of 18 children with reported CRS cases from 1997 through 2008, 15 (83%) of their mothers had not been vaccinated. Measles-mumpsrubella dose 1 vaccination coverage ranged from 97% to 99%. Conclusions. Poland had the highest incidence of rubella in the WHO European Region in 2007 and 2008. Rubella occurs predominantly in age and sex cohorts historically not included in vaccination recommendations. The risk for CRS continues. To achieve rubella elimination, supplemental immunization activities among adolescent boys are needed, as is integration with measles elimination efforts. [ABSTRACT FROM AUTHOR]

Abstract: The three objectives of this study were to investigate whether cells of early goat embryos isolated from in vivo fertilized goats interact with bluetongue virus (BTV) in vitro, whether the embryonic zona pellucida (ZP) protects early embryo cells from BTV infection, and whether the 10 wash cycles recommended by the International Embryo Transfer Society (IETS) for bovine embryos effectively decontaminates caprine embryos exposed to Bluetongue Virus (BTV) in vitro. Donor goats and bucks were individually screened and tested negative for the virus by RT-PCR detection of BTV RNA in circulating erythrocytes. ZP-free and ZP-intact 8–16 cell embryos were co-cultured for 36 h in an insert over a Vero cell monolayer infected with BTV. Embryos were washed 10 times in accordance with IETS recommendations for ruminant and porcine embryos, before being transferred to an insert on BTV indicator Vero cells for 6 h, to detect any cytopathic effects (CPE). They were then washed and cultured in B2 Ménézo for 24 h. Non-inoculated ZP-free and ZP-intact embryos were submitted to similar treatments and used as controls. The Vero cell monolayer used as feeder cells for BTV inoculated ZP-free and ZP-intact embryos showed cytopathic effects (CPE). BTV was found by RT-qPCR in the ten washes of exposed ZP-free and ZP-intact embryos. In the acellular medium, the early embryonic cells produced at least 102.5 TCID50/ml. BTV RNA was detected in ZP-free and ZP-intact embryos using RT-qPCR. All of these results clearly demonstrate that caprine early embryonic cells are susceptible to infection with BTV and that infection with this virus is productive. The washing procedure failed to remove BTV, which indicates that BTV could bind to the zona pellucida. [Copyright &y& Elsevier]

Abstract: In March 2009, a swine origin influenza A (2009 H1N1) virus was introduced into the human population and quickly spread from North America to multiple continents. Human serologic studies suggest that seasonal influenza virus vaccination or infection would provide little cross-reactive serologic immunity to the pandemic 2009 H1N1 virus. However, the efficacy of seasonal influenza infection or vaccination against 2009 H1N1 virus replication and transmission has not been adequately evaluated in vivo. Here, ferrets received one or two doses of the US licensed 2008–2009 live attenuated influenza vaccine (LAIV) intranasally. An additional group of ferrets were inoculated with the A/Brisbane/59/07 (H1N1) virus to model immunity induced by seasonal influenza virus infection. All vaccinated and infected animals possessed high titer homologous hemagglutination-inhibition (HI) and neutralizing antibodies, with no demonstrable cross-reactive antibodies against 2009 H1N1 virus. However, in comparison to non-immune controls, immunized ferrets challenged with pandemic A/Mexico/4482/09 virus displayed a significant reduction in body temperature and virus shedding. The impact of single-dose LAIV inoculation on 2009 H1N1 disease and virus transmission was also measured in vaccinated ferrets that were challenged with pandemic A/Netherlands/1132/09 virus. Although a single dose of LAIV reduced virus shedding and the frequency of transmission following homologous seasonal virus challenge, it failed to reduce respiratory droplet transmission of 2009 H1N1 virus. The results demonstrate that prior immunization with seasonal LAIV or H1N1 virus infection provides some cross-protection against the 2009 H1N1 virus, but had no significant effect on the transmission efficiency of the 2009 H1N1 virus. [Copyright &y& Elsevier]

The risk of transfusion-transmitted hepatitis B virus (HBV) in Switzerland by testing blood donors for hepatitis B surface antigen (HBsAg) alone has been historically estimated at 1:160,000 transfusions. The Swiss health authorities decided not to introduce mandatory antibody to hepatitis B core antigen (anti-HBc) testing but to evaluate the investigation of HBV nucleic acid testing (NAT). Between June 2007 and February 2009, a total of 306,000 donations were screened routinely for HBsAg and HBV DNA by triplex individual-donation (ID)-NAT (Ultrio assay on Tigris system, Gen-Probe/Novartis Diagnostics). ID-NAT repeatedly reactive donors were further characterized for HBV serologic markers and viral load by quantitative polymerase chain reaction. The relative sensitivity of screening for HBsAg, anti-HBc, and HBV DNA was assessed. The residual HBV transmission risk of NAT with or without anti-HBc and HBsAg was retrospectively estimated in a mathematical model. From the 306,000 blood donations, 31 were repeatedly Ultrio test reactive and confirmed HBV infected, of which 24 (77%) and 27 (87%) were HBsAg and anti-HBc positive, respectively. Seven HBV-NAT yields were identified (1:44,000), two pre-HBsAg window period (WP) donations (1:153,000) and five occult HBV infections (1:61,000). Introduction of ID-NAT reduced the risk of HBV WP transmission in repeat donors from 1:95,000 to 1:296,000. Triplex NAT screening reduced the HBV WP transmission risk approximately threefold. NAT alone was more efficacious than the combined use of HBsAg and anti-HBc. The data from this study led to the decision to introduce sensitive HBV-NAT screening in Switzerland. Our findings may be useful in designing more efficient and cost-effective HBV screening strategies in low-prevalence countries. [ABSTRACT FROM AUTHOR]

Abstract: New rotavirus vaccines show promise to reduce the burden of severe diarrhea among children in developing countries. We present an age-specific dynamic rotavirus model to assess the effect of rotavirus vaccination in Kyrgyzstan, a country in Central Asia that is eligible for funds from the GAVI Alliance. A routine rotavirus vaccination program at 95% coverage and 54% effectiveness against severe infection is estimated to lead to a 56% reduction in rotavirus-associated deaths and a 50% reduction in hospital admissions, while outpatient visits and homecare episodes would decrease by 52% compared to baseline levels after 5 years of intervention. A 10% reduction in vaccine efficacy due to incomplete 3-dose regimen is estimated to increase the numbers of severe cases by 6–8%. Herd immunity was found to account for 1% or less of averted cases of severe gastroenteritis, while an extra 7–8% of all rotavirus infections would be avoided due to reduced transmission. Conclusion: Rotavirus vaccines would reduce the burden of rotavirus disease substantially, but the results are sensitive to delay in age-appropriate vaccination. [ABSTRACT FROM AUTHOR]

Background and Objectives Paediatric malaria is one of the leading causes for blood transfusion in sub-Saharan Africa. Malaria not only causes severe, sometimes life-threatening anaemia, but it leads to the exposure to a blood supply that may result in viral disease transmission. This study determined the frequency of paediatric malaria and transfusion for malaria before and after implementation of a Malaria Control Program in one of Ghana's districts. Materials and Methods Paediatric patients' malaria test results and blood transfusions were reviewed during two time periods: before Malaria Control Program implementation (2003) and after (2009). Results were analysed using descriptive and bivariate statistics. Results The number of paediatric malaria cases confirmed by laboratory testing declined by 40·7% after implementation of the program. The number of paediatric patients transfused decreased by 12·8% ( P < 0·005). Of those patients tested for malaria, the frequency of transfusion was lower in 2009 (11·3%) compared to 2003 (24·1%, P < 0·005). Gender and age were not associated with altered rates of transfusion. Average haemoglobin was higher in 2009 (10·4 ± 2·0 g/dl) compared to 2003 (8·7 ± 2·1 g/dl, P < 0·005). During both periods of study, malaria positive patients who were 0-5 years were more likely to be transfused (47·6% in 2003, 75% in 2009) compared to children 5-9 years (17·3% in 2003, 18·8% in 2009). Conclusion The implementation of malaria control led to fewer paediatric patients with laboratory-confirmed malaria and fewer requiring blood transfusion. Such programs may reduce morbidity and mortality directly, while limiting exposure to blood transfusion. [ABSTRACT FROM AUTHOR]

The purpose of this statement is to recommend implementation of a mandatory influenza immunization policy for all health care personnel. Immunization of health care personnel is a critically important step to substantially reduce health care-associated influenza infections. Despite the efforts of many organizations to improve influenza immunization rates with the use of voluntary campaigns, influenza coverage among health care personnel remains unacceptably low. Mandatory influenza immunization for all health care personnel is ethically justifled, necessary, and long overdue to ensure patient safety. [ABSTRACT FROM AUTHOR]

Background: Traps baited with synthetic human odors have been proposed as suitable technologies for controlling malaria and other mosquito-borne diseases. We investigated the potential benefits of such traps for preventing malaria transmission in Africa and the essential characteristics that they should possess so as to be effective. Methods and Principal Findings: An existing mathematical model was reformulated to distinguish availability of hosts for attack by mosquitoes from availability of blood per se. This adaptation allowed the effects of pseudo-hosts such as odor-baited mosquito traps, which do not yield blood but which can nonetheless be attacked by the mosquitoes, to be simulated considering communities consisting of users and non-users of insecticide-treated nets (ITNs), currently the primary malaria prevention method. We determined that malaria transmission declines as trap coverage (proportion of total availability of all hosts and pseudo hosts that traps constitute) increases. If the traps are more attractive than humans and are located in areas where mosquitoes are most abundant, 20-130 traps per 1000 people would be sufficient to match the impact of 50% community-wide ITN coverage. If such traps are used to complement ITNs, malaria transmission can be reduced by 99% or more in most scenarios representative of Africa. However, to match cost-effectiveness of ITNs, the traps delivery, operation and maintenance would have to cost a maximum of US$4.25 to 27.61 per unit per year. Conclusions and Significance: Odor-baited mosquito traps might potentially be effective and affordable tools for malaria control in Africa, particularly if they are used to complement, rather than replace, existing methods. We recommend that developers should focus on super-attractive baits and cheaper traps to enhance cost-effectiveness, and that the most appropriate way to deploy such technologies is through vertical delivery mechanisms. [ABSTRACT FROM AUTHOR]

Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO2-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations. [ABSTRACT FROM AUTHOR]

There exists considerable risk for transfusion transmission of arboviruses due to short periods of asymptomatic viraemia in populations with variable and sometimes extremely high incidence of arboviral infections. Aside from West Nile virus, few arbovirus transfusion transmissions have been proven, mostly due to difficulties in ruling out vector-borne transmission in recipients with arbovirus disease. Nevertheless, arbovirus transfusion risk models and assessments of viraemia prevalence in blood donations indicate substantial transfusion transmission of dengue and Chikungunya viruses in epidemic areas. Many other arboviruses, several of which are importation risks in the Americas, Europe and Asia, also cause large outbreaks and threaten transfusion safety. Prevention largely depends on excluding donors from outbreak areas or implementation of highly sensitive nucleic acid amplification tests. Because of the increasing emergence of arboviral disease globally, it is prudent to prepare for both endemic and exotic arboviruses capable of producing large epidemics and subsequent transfusion transmission risk. [ABSTRACT FROM AUTHOR]

The article presents an overview of the chronic infection of viral hepatitis in the U.S. It discusses findings of a survey through the National Health and Nutrition Examination (NHANES). It shows the increasing HBV infection and transmission which calls for national awareness and prevention, the transmission mode of infection which includes perinatal, household, sexual, injection, and health care, and the complication and management of the chronic hepatitis infections.

Since the human immunodeficiency virus (HIV) was discovered as the etiological agent of acquired immunodeficiency syndrome (AIDS), it has encouraged much research into antiviral compounds. The reverse transcriptase (RT) of HIV has been a main target for antiviral drugs. However, all drugs developed so far inhibit the polymerase function of the enzyme, while none of the approved antiviral agents inhibit specifically the necessary ribonuclease H (RNase H) function of RT. This review provides a background on structure-function relationships of HIV-1 RNase H, as well as an outline of current attempts to develop novel, potent chemotherapeutics against a difficult drug target. [ABSTRACT FROM AUTHOR]

Influenza virus changes constantly, making vaccine production challenging. Changing the growth substrate from eggs to cell culture raises issues at all stages of the process, from surveillance to the assay of vaccines. The pandemic threat-first H5N1, then H1N1-encouraged a review of methods and brought issues into sharp relief. [ABSTRACT FROM AUTHOR]

A comparative analysis of the 3 types of influenza viruses - pandemic, seasonal and avian (H5N1) - revealed considerable discrepancies in defining risk groups, types of clinical onset and attack and lethality rates. Processing the lessons learned from past influenza epidemics and from the H5N1 infection, the medical world developed action blueprints for the eventuality of pandemic focused on reducing the death rate calculated according to the lethality index. A continual calculation of the fatality rate lead to noteworthy changes in the management of the A/H1N1v infected case, changes regarding the decision to hospitalize and the length of the specific therapy. A strict surveillance of the clinical cases and of the respective contacts substantially contributed to limiting the circulation of this new A/H1N1v virus over the summer and over the beginning of autumn. Epidemiological and clinical evaluation of the viral dynamics is crucial to the management of the current pandemic. [ABSTRACT FROM AUTHOR]

Recent cases of avian influenza H5N1 and the swine-origin 2009 H1N1 have caused a great concern that a global disaster like the 1918 influenza pandemic may occur again. Viral transmission begins with a critical interaction between hemagglutinin (HA) glycoprotein. which is on the viral coat of influenza, and sialic acid (SA) containing glycans, which are on the host cell surface. To elucidate the role of HA glycosylation in this important interaction, various defined HA glycoforms were prepared, and their binding affinity and specificity were studied by using a synthetic SA microarray. Truncation of the N-glycan structures on HA increased SA binding affinities while decreasing specificity toward disparate SA ligands. The contribution of each monosaccharide and sulfate group within SA ligand structures to HA binding energy was quantitatively dissected. It was found that the sulfate group adds nearly 100-fold (2.04 kcal/mol) in binding energy to fully glycosylated HA, and so does the biantennary glycan to the monoglycosylated HA glycoform. Antibodies raised against HA protein bearing only a single N-linked GlcNAc at each glycosylation site showed better binding affinity and neutralization activity against influenza subtypes than the fully glycosylated HAs elicited. Thus, removal of structurally nonessential glycans on viral surface glycoproteins may be a very effective and general approach for vaccine design against influenza and other human viruses. [ABSTRACT FROM AUTHOR]

Abstract: PRO 2000 is a polyanionic compound under development as a topical antimicrobial gel for the potential prevention of HIV-1 transmission. It has been shown that PRO 2000 binds to HIV-1 gp120 and interferes with virus attachment to and/or fusion with CD4+ T cells. Here, we demonstrate that PRO 2000 interacts not only with viral gp120 but also with CD4 and CXCR4 receptors on the cell surface. Minor or no effects were noticed on DC-SIGN and on CCR5. PRO 2000 dose-dependently inhibited the interaction of CXCL12 with the CXCR4 receptor as demonstrated with CXCL12AF647-labeled binding, CXCL12-induced calcium signaling, CXCR4 internalization and chemotaxic assays. These CXCR4 antagonistic properties of PRO 2000 are a potential additional mechanism of action that could explain the observation that PRO 2000 is described to be more active against X4 viruses than R5 viruses. The cellular activation potential and inflammatory properties of PRO 2000 were also examined in PBMCs. PRO 2000 had minor effects on the expression level of several cellular activation markers and enhanced the production of a small number of cytokines/chemokines, as determined by the Bio-Plex human cytokine 27-plex assay system. PRO 2000 showed less mitogenic and stimulatory activity than cyanovirin-N, but careful monitoring for potential side-effects is still advised. [Copyright &y& Elsevier]

The article focuses on biosecurity measures that can be applied to prevent the introduction and spread of diseases on dairy farms in Ireland. It notes that the implementation of a strict closed herd policy is the most important measure and practice that can be used and promoted on dairy farms to effectively prevent and control infectious diseases. Furthermore, animals can also be protected by minimizing their movements combined with the use of stock-proof and disease-proof boundaries.

The article presents a study which analyzes the role of needle-syringe programs (NSPs) in preventing HIV and hepatitis C virus (HCV) cases among injecting drug users (IDUs) in Australia. A mathematical model of HIV and HCV transmission among needle-sharers was developed using biological and Australian epidemiological and behavioral data. Results show that NSP distribution of syringes effectively controlled HIV while HCV cases are anticipated to remain high since its control is unfeasible.

Abstract: Prevention and regulation of equine infectious anemia virus (EIAV) disease transmission solely depend on identification, isolation, and elimination of infected animals because of lack of an effective vaccine. Embryo production via the somatic cell nuclear transfer (SCNT) technology uses oocytes collected mainly from untested animals, which creates a potential risk of EIAV transmission through infected embryos. The current review examines the risk of EIAV disease transmission through SCNT embryo production and transfer. Equine infectious anemia virus is a lentivirus from the family Retroviridae. Because of a lack of direct reports on this subject, relevant information gathered from close relatives of EIAV, such as human immunodeficiency virus (HIV), bovine immunodeficiency virus (BIV), feline immunodeficiency virus (FIV), and small ruminant lentiviruses (SRLVs), is summarized and used to predict the biological plausibility of EIAV disease transmission through transfers of the equine SCNT embryos. Based on published information regarding interaction of oocytes with lentiviruses and the sufficiency of oocyte and embryo washing procedures to prevent lentivirus transmission from in vitro–produced embryos of various species, we predicted the risk of EIAV transmission through SCNT embryo production and transfer to be very small or absent. [Copyright &y& Elsevier]

Subtypes of H1N1 influenza virus can be found in humans in North America, while they are also associated with the infection of swine. Characterization of the genotypes of viral strains in human populations is important to understand the source and distribution of viral strains. Genomic and protein sequences of 10 isolates of the 2009 outbreak of influenza A (H1N1) virus in North America were obtained from GenBank database. To characterize the genotypes of these viruses, phylogenetic trees of genes PB2, PB1, PA, HA, NP, NA, NS and M were constructed by Phylip3.67 program and N-Linked glycosylation sites of HA, NA, PB2, NS1 and M2 proteins were analyzed online by NetNGlycl .0 program. Phylogenetic analysis indicated that these isolates are virtually identical but may be recombinant vi- ruses because their genomic fragments come from different viruses. The isolates also contain a characteristic lowly pathogenic amino acid motif at their HA cleavage sites (IPSIQSRIGL), and an E residue at position 627 of the PB2 protein which shows its high affinity to humans. The homologous model of M proteins showed that the viruses had obtained the ability of anti-amantadine due to the mutation at the drug-sensitive site, while sequence analysis of NA proteins indicated that the viruses are still susceptible to the neuraminidase inhibitor drug (i.e. oseltamivir and zanamivir) because no mutations have been observed. Our results strongly suggested that the viruses responsible for the 2009 outbreaks of influenza A (H1N1) virus have the ability to cross species barriers to infect human and mammalian animals based on molecular analysis. These findings may further facilitate the therapy and prevention of possible transmission from North America to other countries. [ABSTRACT FROM AUTHOR]