Transmission of Novel Influenza A(H1N1) in Households with Post-Exposure Antiviral Prophylaxis

BACKGROUND: Despite impressive advances in our understanding of the biology of novel influenza A(H1N1) virus, little is as yet known about its transmission efficiency in close contact places such as households, schools, and workplaces. These are widely believed to be key in supporting propagating spread, and it is therefore of importance to assess the transmission levels of the virus in such settings. METHODOLOGY/PRINCIPAL FINDINGS: We estimate the transmissibility of novel influenza A(H1N1) in 47 households in the Netherlands using stochastic epidemic models. All households contained a laboratory confirmed index case, and antiviral drugs (oseltamivir) were given to both the index case and other households members within 24 hours after detection of the index case. Among the 109 household contacts there were 9 secondary infections in 7 households. The overall estimated secondary attack rate is low (0.075, 95%CI: 0.037-0.13). There is statistical evidence indicating that older persons are less susceptible to infection than younger persons (relative susceptibility of older persons: 0.11, 95%CI: 0.024-0.43. Notably, the secondary attack rate from an older to a younger person is 0.35 (95%CI: 0.14-0.61) when using an age classification of <or=12 versus >12 years, and 0.28 (95%CI: 0.12-0.50) when using an age classification of <or=18 versus >18 years. CONCLUSIONS/SIGNIFICANCE: Our results indicate that the overall household transmission levels of novel influenza A(H1N1) in antiviral-treated households were low in the early stage of the epidemic. The relatively high rate of adult-to-child transmission indicates that control measures focused on this transmission route will be most effective in minimizing the total number of infections

Uptake and transport of novel amphiphilic polyelectrolyte-insulin nanocomplexes by caco-2 cells - towards oral insulin

“The original publication is available at www.springerlink.com”. Copyright SpringerPurpose: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. Method: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake were investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER). Insulin transport through Caco-2 monolayers was determined during TEER experiments. Result: Pa and insulin were co-localised in the cell membranes while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly where the TEER values fell by up to 35 % within 30 minutes incubation with Caco-2 cells. Insulin transport through monolayers increased when QPa was used (0.27 ngmL-1 of insulin in basal compartment) compared to Pa (0.14 ngmL-1 of insulin in basal compartment) after 2 hours. Conclusion: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.Peer reviewe

Studies on effect of pH on cross-linking of chitosan with sodium tripolyphosphate: A technical note

The ionotropic gelation method for formation of crosslinked chitosan particles can be easily modified from ionic cross-linking to deprotonation by adjusting the pH of TPP. Chitosan was cross-linked ionically with TPP at lower pH and by deprotonation mechanism at higher pH. The swelling behavior of cross-linked chitosan appeared to depend on the pH of TPP. The ionically cross-linked chitosan showed higher swelling ability. Thus the nature of crosslinked chitosan can be tailor made to obtain the desired properties in terms of cross-linking density, crystallinity, and hydrophilicity

Jaarrapportage respiratoire infectieziekten 2005/2006

Respiratoire infectieziekten uiten zich vooral door een influenza-achtig ziektebeeld (IAZ) en pneumonie. Om de bestrijding van deze ziektelast meer te kunnen ondersteunen en voorbereid te zijn op nieuwe uitbraken, moet de surveillance van IAZ worden geintensiveerd en van pneumonie worden uitgebreid. Verder neemt het aantal meldingen van legionellose en psittacose toe. Dat vraagt om hernieuwde aandacht voor surveillance van besmettingsbronnen en identificatie van risicofactoren. Dat staat te lezen in de jaarlijkse rapportage van de projectgroep Respiratoire Infecties van het CIb, die de algemene surveillance van respiratoire infectieziekten in Nederland coordineert.VW

Jaarrapportage respiratoire infectieziekten 2007/2008

Alleen digitaal verschenenLuchtweginfecties hebben in de periode mei 2007 tot en met april 2008 opnieuw tot aanzienlijke ziektelast geleid. Net als voorgaande jaren werd longontsteking bij circa 10% van alle sterfte als doodsoorzaak geregistreerd. Dit wijst wederom op een groot effect van luchtweginfecties op de volksgezondheid. Het meest opvallende in 2007 was de uitbraak van Q koorts, een ziekte die door dieren (met name geiten en schapen) wordt overgebracht. Ook in 2008 heeft Q-koorts tot een groot aantal ziektegevallen geleid. Een eenduidige bron is nog niet aangetoond. Een andere opvallende ontwikkeling was een grote uitbraak van papegaaienziekte gerelateerd aan een vogelshow in Weurt (nabij Nijmegen). Daarnaast was opmerkelijk dat in 2007/2008 bij ruim een kwart van de griepvirussen van het subtype A(H1N1) resistentie tegen het antivirale middel oseltamivir werd gevonden. Het aantal meldingen van legionella was in 2007/2008 in lijn met de licht stijgende trend sinds 2003. Het aantal tuberculose-patiknten daalde in 2007 naar 960, het laagste aantal dat ooit in Nederland werd geregistreerd. De rol die specifieke virussen en bacterien bij luchtweginfecties spelen is slechts voor een deel bekend. Ook is nog weinig bekend over de andere factoren die mogelijk een rol spelen bij het ontstaan van luchtweginfecties. Daarom blijft het noodzakelijk verder onderzoek te doen naar oorzaken van ziekte en sterfte door luchtweginfecties en naar preventiemaatregelen en behandelingen.VW

Utility of the first few100 approach during the 2009 influenza A(H1N1) pandemic in the Netherlands

Abstract Background To guide policy and control measures, decent scientific data are needed for a comprehensive assessment of epidemiological, clinical and virological characteristics of the First Few hundred (FF100) cases. We discuss the feasibility of the FF100 approach during the 2009 pandemic and the added value compared with alternative data sources available. Methods The pandemic preparedness plan enabled us to perform a case–control study, assessing patient characteristics and risk factors for experiencing symptomatic influenza A(H1N1)2009 infection and providing insight into transmission. We assessed to what extent timely and novel data were generated compared to other available data sources. Results In May-December 2009, a total of 68 cases and 48 controls were included in the study. Underlying non-respiratory diseases were significantly more common among cases compared to controls, while a protective effect was found for frequent hand washing. Seroconversion was found for 7/30 controls (23%), and persisting high titers for 4/30 controls (13%). The labour-intensive study design resulted in slow and restricted recruitment. Conclusions The findings of our case–control study gave new insights in transmission risks and possible interventions for improved control. Nevertheless, the FF100 approach lacked timeliness and power due to limited recruitment. For future pandemics we suggest pooling data from several countries, to enable collecting sufficient data in a relatively short period.</p