Agricultural trade impacts global phosphorus use and partial productivity

The spatio-temporal distribution, flow and end use of phosphorus (P) embedded in traded agricultural products are poorly understood. Here we use global trade matrices to analyse the partial factor productivity of P (output per unit of P input) for crop and livestock products in 200 countries and their cumulative contributions to the export or import of agricultural products over 1961-2019. In these six decades, the trade of agricultural P products has increased global partial factor productivity for crop and livestock production and has theoretically saved 67 Tg P in fertilizers and 1.6 Tg P in feed. However, trade is now at risk of contributing to wasteful use of P resources globally due to a decline in trade optimality, as agricultural products are increasingly exported from low to high partial factor productivity countries and due to P embedded in imported agricultural products mainly lost to the environment without recycling. Integrated crop-livestock production systems and P-recycling technologies can help.

Multi-target scenario discovery to plan for sustainable food and land systems in Australia

The development of detailed national pathways towards sustainable food and land systems aims to provide stakeholders with clarity on how long-term goals could be achieved and to reduce roadblocks in the way to making commitments. However, the inability to perfectly capture the relationships between all variables in a system and the unknown probability of future values (deep uncertainty) makes it very difficult to design scenarios that account for the full breadth of system uncertainty. Here we use scenario discovery to systematically explore the effect of different parameter ranges on model outputs, and design resilient pathways to sustainability in which multiple target achievement requires a broad portfolio of solutions. We use a model of the Australian food and land system, the FABLE (Food, Agriculture, Biodiversity, Land-use, Energy) Calculator, to investigate conditions for achieving a sustainable Australian food and land system under scenarios based on the Shared Socioeconomic Pathways (SSP) 1, 2, and 3 narratives. Here we link the FABLE Calculator with a Monte Carlo simulation tool to explore hundreds of thousands of scenarios. This allows us to identify the ranges of systemic drivers that achieve multiple sustainability targets around diets, net forest growth, agricultural water consumption, greenhouse gas emissions, biodiversity conservation, and exports by 2050. Our results show that livestock productivity and density, afforestation, and dietary change are powerful influencers for sustainability target achievement. Around 10% of the SSP1 scenarios could achieve all modelled sustainability targets. However, practically none of the scenarios based on SSP2 and SSP3 narratives could achieve such targets. The results suggest that there are options to achieve a more sustainable and resilient Australian food and land-use system with better socio-economic and environmental outcomes than under current trends. However, its achievement requires significant structural changes and coordinated interventions in several components of the domestic food and land system to increase its resilience and environmental and socio-economic performance. Understanding the bounds within which this system needs to change and operate to achieve sustainability targets will enable greater clarity and flexibility during discussions between decision-makers and stakeholders.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11625-022-01202-2.

Pathway to achieve a sustainable food and land-use transition in India

India has committed to reducing the emissions intensity of GDP by 33-35% from the 2005 level by 2030 in alignment with objectives of the Paris Agreement. This will require a significant reduction in greenhouse gas (GHG) emissions from the food and land-use sector. In this paper, we construct three potential pathways for India to achieve its emissions target by 2050 involving moderate ambitions of mitigation action (BAU), moderate ambitions combined with achieving healthy diets (BAU + NIN), and high levels of mitigation action inclusive of healthy diets (SUSTAINABLE). Using an integrated accounting tool, the FABLE Calculator, that harmonizes various socioeconomic and biophysical data, we project these pathways under the conditions of cross-country balanced trade flows. Results from the projections show that the demand for cereals will increase by 2050, leading to increased GHG emissions under BAU. Under the SUSTAINABLE pathways, GHG emissions will decrease over the same period due to reduced demand for cereals, whereas significant crop productivity and harvest intensity gains would lead to increased crop production. The exercise reveals the indispensability of healthy diets, improved crop, and livestock productivity, and net-zero deforestation in achieving India's mid-century emission targets from the agriculture sector.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11625-022-01193-0.

A sustainable future for Africa through continental free trade and agricultural development

Developing and integrating agricultural markets may be key to addressing Africa's sustainability challenges. By modelling trade costs from farm gate to potential import markets across eight African regions, we investigate the impact of individual components of continental free trade and the complementary role of domestic agricultural development through increased market access for farmers and agricultural intensification. We find that free trade would increase intra-African agricultural trade sixfold by 2030 but-since it does not address local supply constraints-outside food imports and undernourishment would reduce only marginally. Agricultural development could almost eliminate undernourishment in Africa by 2050 at only a small cost of increased global greenhouse gas emissions. While continental free trade will be enabled in Africa through the African Continental Free Trade Area, aligning this with local agricultural development policies is crucial to increase intra-African trade gains, promote food security and achieve climate objectives.

The impact of climate change on Brazil's agriculture

Brazilian agricultural production provides a significant fraction of the food consumed globally, with the country among the top exporters of soybeans, sugar, and beef. However, current advances in Brazilian agriculture can be directly impacted by climate change and resulting biophysical effects. Here, we quantify these impacts until 2050 using GLOBIOM-Brazil, a global partial equilibrium model of the competition for land use between agriculture, forestry, and bioenergy that includes various refinements reflecting Brazil's specificities. For the first time, projections of future agricultural areas and production are based on future crop yields provided by two Global Gridded Crop Models (EPIC and LPJmL). The climate change forcing is included through changes in climatic variables projected by five Global Climate Models in two emission pathways (RCP2.6 and RCP8.5) participating in the ISIMIP initiative. This ensemble of twenty scenarios permits accessing the robustness of the results. When compared to the baseline scenario, GLOBIOM-Brazil scenarios suggest a decrease in soybeans and corn production, mainly in the Matopiba region in the Northern Cerrado, and southward displacement of agricultural production to near-subtropical and subtropical regions of the Cerrado and the Atlantic Forest biomes.

Influenza increases invasive meningococcal disease risk in temperate countries

OBJECTIVES

Invasive meningococcal disease (IMD) is a severe bacterial infection that displays wintertime seasonality in temperate countries. Mechanisms driving seasonality are poorly understood and may include environmental conditions and/or respiratory virus infections. We evaluated the contribution of influenza and environmental conditions to IMD risk, using standardized methodology, across multiple geographical regions.

METHODS

We evaluated 3276 IMD cases occurring between January 1999 and December 2011 in 11 jurisdictions in Australia, Canada, France and the United States. Effects of environmental exposures and normalized weekly influenza activity on IMD risk were evaluated using a case-crossover design. Meta-analytic methods were used to evaluate homogeneity of effects and to identify sources of between-region heterogeneity.

RESULTS

After adjustment for environmental factors, elevated influenza activity at a 2-week lag was associated with increased IMD risk (adjusted odds ratio (OR) per standard deviation increase 1.29; 95% confidence interval, 1.04-1.59). This increase was homogeneous across the jurisdictions studied. By contrast, although associations between environmental exposures and IMD were identified in individual jurisdictions, none was generalizable.

CONCLUSIONS

Using a self-matched design that adjusts for both coseasonality and case characteristics, we found that surges in influenza activity result in an acute increase in population-level IMD risk. This effect is seen across diverse geographic regions in North America, France and Australia. The impact of influenza infection on downstream meningococcal risk should be considered a potential benefit of influenza immunization programmes.

Expanding the Soy Moratorium to Brazil's Cerrado

The Cerrado biome in Brazil is a tropical savanna and an important global biodiversity hot spot. Today, only a fraction of its original area remains undisturbed, and this habitat is at risk of conversion to agriculture, especially to soybeans. Here, we present the first quantitative analysis of expanding the Soy Moratorium (SoyM) from the Brazilian Amazon to the Cerrado biome. The SoyM expansion to the Cerrado would prevent the direct conversion of 3.6 million ha of native vegetation to soybeans by 2050. Nationally, this would require a reduction in soybean area of approximately 2%. Relative risk of future native vegetation conversion for soybeans would be driven by the Brazilian domestic market, China, and the European Union. We conclude that, to preserve the Cerrado's biodiversity and ecosystem services, urgent action is required, including a zero native vegetation conversion agreement such as the SoyM.

Predicting seasonal occurrence of leatherback turtles (Dermochelys coriacea) in eastern Canadian waters from turtle and ocean sunfish (Mola mola) sighting data and habitat characteristics

Part of the western Atlantic population of leatherback turtles (Dermochelys coriacea (Vandelli, 1761)) forage in Canadian waters, where high-use areas have been identified using satellite telemetry and opportunistic sightings. Here, we use sightings of leatherback turtles and ocean sunfish (Mola mola (Linnaeus, 1758)) obtained during a systematic large-scale aerial survey, along with opportunistic turtle sightings, to examine the seasonal occurrence and distribution of leatherback turtles in eastern Canada. Using environmental correlates, we predict the spatial and seasonal development of potentially suitable habitats. All data sets confirmed the presence of leatherback turtles off Nova Scotia during summer. They also highlighted turtle occurrence off southern Newfoundland. Opportunistic sightings suggest a seasonal shift in main turtle concentrations from southwest to northeast, with use of southern Newfoundland waters extending into September. A generalized additive model linking environmental characteristics and turtle observations suggests adding the Grand Banks off Newfoundland and waters east of Anticosti Island in the Gulf of St. Lawrence to the potentially important habitat for leatherback turtles. Direct observations helped delineate habitat currently used by leatherback turtles. In the context of climate change, this modelling approach may improve our ability to forecast changes in turtle habitat suitability and the risks of entrapment or collision associated with potentially changing usage patterns.

Structural change as a key component for agricultural non-CO2 mitigation efforts

Agriculture is the single largest source of anthropogenic non-carbon dioxide (non-CO₂) emissions. Reaching the climate target of the Paris Agreement will require significant emission reductions across sectors by 2030 and continued efforts thereafter. Here we show that the economic potential of non-CO₂ emissions reductions from agriculture is up to four times as high as previously estimated. In fact, we find that agriculture could achieve already at a carbon price of 25 $/tCO₂eq non-CO₂ reductions of around 1 GtCO₂eq/year by 2030 mainly through the adoption of technical and structural mitigation options. At 100 $/tCO₂eq agriculture could even provide non-CO₂ reductions of 2.6 GtCO₂eq/year in 2050 including demand side efforts. Immediate action to favor the widespread adoption of technical options in developed countries together with productivity increases through structural changes in developing countries is needed to move agriculture on track with a 2 °C climate stabilization pathway.

To achieve the climate target of the Paris Agreement substantial emission reductions will be required across economic sectors. Here the authors show that agriculture can make a significant contribution to non-CO₂ mitigation efforts through structural change in the livestock sector and the deployment of technical options.

Influenza B burden during seasonal influenza epidemics in France

CONTEXT

Seasonal flu outbreaks are linked to the circulation of influenza virus type A or B. Special attention has always been paid to influenza A epidemics; but recently, several studies have investigated the impact of influenza B virus epidemics, particularly as, since the 1980s, two antigenically different influenza B lineages co-circulate, raising the issue of vaccine matching.

OBJECTIVES

We present the results of influenza B burden during nine influenza seasons (2003-2013) and vaccine matching of the circulating lineages.

PATIENTS AND METHODS

Clinical and virological influenza surveillance data, collected by the Regional Groups for Influenza Surveillance Network in France, allows for studying the burden of influenza in the practice of the population of ambulatory care physicians.

RESULTS AND CONCLUSION

Our analysis is based on 37,801 samples, of which 12,036 were virologically confirmed influenza cases (31.8%), including 3576 cases of influenza B (29.7% of influenza cases). Influenza B viruses significantly circulated during six seasons. For each season, the influenza B epidemic peaked later than the influenza A epidemic. Influenza B is very common in children of school age but also affects other age groups. Finally, more than one-third of the analyzed influenza B viruses belonged to a different lineage than the one used in the composition of the trivalent vaccine. Our results are comparable to those described in other countries.

Assessing the land resource-food price nexus of the Sustainable Development Goals

The 17 Sustainable Development Goals (SDGs) call for a comprehensive new approach to development rooted in planetary boundaries, equity, and inclusivity. The wide scope of the SDGs will necessitate unprecedented integration of siloed policy portfolios to work at international, regional, and national levels toward multiple goals and mitigate the conflicts that arise from competing resource demands. In this analysis, we adopt a comprehensive modeling approach to understand how coherent policy combinations can manage trade-offs among environmental conservation initiatives and food prices. Our scenario results indicate that SDG strategies constructed around Sustainable Consumption and Production policies can minimize problem-shifting, which has long placed global development and conservation agendas at odds. We conclude that Sustainable Consumption and Production policies (goal 12) are most effective at minimizing trade-offs and argue for their centrality to the formulation of coherent SDG strategies. We also find that alternative socioeconomic futures-mainly, population and economic growth pathways-generate smaller impacts on the eventual achievement of land resource-related SDGs than do resource-use and management policies. We expect that this and future systems analyses will allow policy-makers to negotiate trade-offs and exploit synergies as they assemble sustainable development strategies equal in scope to the ambition of the SDGs.

Mapping global cropland and field size

A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been developed which integrates a number of individual cropland maps at global to regional to national scales. The individual map products include existing global land cover maps such as GlobCover 2005 and MODIS v.5, regional maps such as AFRICOVER and national maps from mapping agencies and other organizations. The different products are ranked at the national level using crowdsourced data from Geo-Wiki to create a map that reflects the likelihood of cropland. Calibration with national and subnational crop statistics was then undertaken to distribute the cropland within each country and subnational unit. The new IIASA-IFPRI cropland product has been validated using very high-resolution satellite imagery via Geo-Wiki and has an overall accuracy of 82.4%. It has also been compared with the EarthStat cropland product and shows a lower root mean square error on an independent data set collected from Geo-Wiki. The first ever global field size map was produced at the same resolution as the IIASA-IFPRI cropland map based on interpolation of field size data collected via a Geo-Wiki crowdsourcing campaign. A validation exercise of the global field size map revealed satisfactory agreement with control data, particularly given the relatively modest size of the field size data set used to create the map. Both are critical inputs to global agricultural monitoring in the frame of GEOGLAM and will serve the global land modelling and integrated assessment community, in particular for improving land use models that require baseline cropland information. These products are freely available for downloading from the http://cropland.geo-wiki.org website.

Cattle ranching intensification in Brazil can reduce global greenhouse gas emissions by sparing land from deforestation

This study examines whether policies to encourage cattle ranching intensification in Brazil can abate global greenhouse gas (GHG) emissions by sparing land from deforestation. We use an economic model of global land use to investigate, from 2010 to 2030, the global agricultural outcomes, land use changes, and GHG abatement resulting from two potential Brazilian policies: a tax on cattle from conventional pasture and a subsidy for cattle from semi-intensive pasture. We find that under either policy, Brazil could achieve considerable sparing of forests and abatement of GHGs, in line with its national policy targets. The land spared, particularly under the tax, is far less than proportional to the productivity increased. However, the tax, despite prompting less adoption of semi-intensive ranching, delivers slightly more forest sparing and GHG abatement than the subsidy. This difference is explained by increased deforestation associated with increased beef consumption under the subsidy and reduced deforestation associated with reduced beef consumption under the tax. Complementary policies to directly limit deforestation could help limit these effects. GHG abatement from either the tax or subsidy appears inexpensive but, over time, the tax would become cheaper than the subsidy. A revenue-neutral combination of the policies could be an element of a sustainable development strategy for Brazil and other emerging economies seeking to balance agricultural development and forest protection.

International Fusion Materials Irradiation Facility injector acceptance tests at CEA/Saclay: 140 mA/100 keV deuteron beam characterization

In the framework of the ITER broader approach, the International Fusion Materials Irradiation Facility (IFMIF) deuteron accelerator (2 × 125 mA at 40 MeV) is an irradiation tool dedicated to high neutron flux production for future nuclear plant material studies. During the validation phase, the Linear IFMIF Prototype Accelerator (LIPAc) machine will be tested on the Rokkasho site in Japan. This demonstrator aims to produce 125 mA/9 MeV deuteron beam. Involved in the LIPAc project for several years, specialists from CEA/Saclay designed the injector based on a SILHI type ECR source operating at 2.45 GHz and a 2 solenoid low energy beam line to produce such high intensity beam. The whole injector, equipped with its dedicated diagnostics, has been then installed and tested on the Saclay site. Before shipment from Europe to Japan, acceptance tests have been performed in November 2012 with 100 keV deuteron beam and intensity as high as 140 mA in continuous and pulsed mode. In this paper, the emittance measurements done for different duty cycles and different beam intensities will be presented as well as beam species fraction analysis. Then the reinstallation in Japan and commissioning plan on site will be reported.

Factors associated with clinical and virological response in patients treated with oseltamivir or zanamivir for influenza A during the 2008-2009 winter

Oseltamivir or zanamivir are effective in outpatients with seasonal influenza; however, factors associated with response have been incompletely described. During the 2008/2009 epidemic, in a randomized trial for influenza A-infected outpatients, clinical (time to alleviation of flu-related symptoms) and virological (rate of patients with day 2 nasal viral load <200 cgeq/μL) responses to oseltamivir or zanamivir were assessed and associated factors were determined using multivariate analysis. For oseltamivir (141 patients) and zanamivir (149 patients) median times to alleviation of symptoms were 3 and 4 days, respectively; 59% and 34% had virological response. For oseltamivir, a lower clinical response was associated with female gender (HR, 0.53; 95% CI, 0.36-0.79), baseline symptoms score >14 (HR, 0.47; 0.32-0.70), viral load ≥5 log cgeq/μL (HR, 0.63; 0.43-0.93), and initiation of antibiotics (HR, 0.30; 0.12-0.76); a lower virological response was associated with female gender (OR, 0.45; 0.21-0.96), baseline viral load ≥5 log cgeq/μL (OR, 0.40; 0.20-0.84) and days 0-2 incomplete compliance (OR, 0.31; 0.10-0.98). For zanamivir, virological response was associated with age ≥50 years (OR, 0.29; 0.10-0.85) and initiation of antibiotics at baseline (OR, 4.24; 1.07-17.50). Factors associated with lower response to neuraminidase inhibitors in outpatients appeared to be easily identifiable during routine clinical examination and, when appropriate, by nasal sampling at baseline. The unknown association between gender and response to oseltamivir was not explained by compliance.

Progress in the surveillance of respiratory syncytial virus (RSV) in Europe: 2001-2008

Respiratory syncytial virus (RSV) surveillance is important to get insight into the burden of disease and epidemic pattern of RSV infection. This information is useful for healthcare resource allocation as well as the timing of preventive messages and palivizumab prophylaxis. For influenza surveillance the European Influenza Surveillance Scheme (EISS) was established in 1996, but no surveillance platform is available for RSV. To improve surveillance an RSV Task Group was established in 2003 and recommendations for RSV surveillance were developed. By 2008, progress was made for four out of six recommendations: the number of European countries testing specimens for RSV increased from six to fourteen; nose and/or throat swabs were generally used for detection of influenza and RSV; a total of 25 laboratories performed molecular testing for diagnosis and participated in a quality control assessment for RSV with an overall good performance; four of the ten countries that joined EISS in 2004 started reporting RSV detections in addition to influenza in the period 2004-8. Limited progress was achieved for standardising methods and the development of a sentinel surveillance system of representative hospitals. Improving RSV surveillance is possible by further harmonising the data collection and increased reporting of RSV.

Progress in the surveillance of respiratory syncytial virus (RSV) in Europe: 2001-2008

Respiratory syncytial virus (RSV) surveillance is important to get insight into the burden of disease and epidemic pattern of RSV infection. This information is useful for healthcare resource allocation as well as the timing of preventive messages and palivizumab prophylaxis. For influenza surveillance the European Influenza Surveillance Scheme (EISS) was established in 1996, but no surveillance platform is available for RSV. To improve surveillance an RSV Task Group was established in 2003 and recommendations for RSV surveillance were developed. By 2008, progress was made for four out of six recommendations: the number of European countries testing specimens for RSV increased from six to fourteen; nose and/or throat swabs were generally used for detection of influenza and RSV; a total of 25 laboratories performed molecular testing for diagnosis and participated in a quality control assessment for RSV with an overall good performance; four of the ten countries that joined EISS in 2004 started reporting RSV detections in addition to influenza in the period 2004-8. Limited progress was achieved for standardising methods and the development of a sentinel surveillance system of representative hospitals. Improving RSV surveillance is possible by further harmonising the data collection and increased reporting of RSV.

[General practice and surveillance: the example of influenza in France]

Data registration by the GROG national network (Regional Group for the Surveillance of Influenza) since 1984 has helped to identify methodological problems. The choice of sentinels and the selection of indicators depend on the analysis of actual influenza consequences. Various sentinels may be concerned: health insurance companies, private companies, schools, physicians, pharmacists. Health care organization modifies the validity of indicators. In France, for instance, home visits were an excellent indicator for early warning before 1995 but this indicator is no longer as efficient as before. The virological detection of Influenza depends on the organization of transportation (samples, results). The predictive value of cases definitions depends on the incidence of infection. The level of choice between specificity and sensibility modifies the perception of outbreaks. Sentinel participation rate influences the sample representativity. The farther this rate is from 100%, the more result validity decreases (in the same way that patients lost to follow-up compromise the validity of results in clinical trials). The publication of results can modify health expenses and behaviors.

CONCLUSION

The GROG network stresses the important role that general practitioners play in health surveillance; it also raises questions in the field of mathematics, statistics, professional organization, training, education, and politics.

[Epidemiology and diagnosis of respiratory syncitial virus in adults]

Introduction

Le virus respiratoire syncytial (VRS) est rarement recherché dans les infections respiratoires de l’adulte. Ce travail en étudie la fréquence et le diagnostic.

Méthodes

Trois enquêtes distinctes ont été menées chez des adultes atteints soit d’un syndrome pseudo-grippal, d’une infection respiratoire basse communautaire ou hospitalisés pour une pneumopathie infectieuse grave. La recherche du VRS a été faite par PCR dans tous les cas et comparée à la détection antigénique et la culture dans deux enquêtes.

Résultats

Le VRS est identifié chez 20 (11,7 %) des 170 adultes vaccinés contre la grippe atteints d’un syndrome pseudo-grippal. Dans 270 infections respiratoires basses communautaires sans signes de gravité on trouve un virus dans 86 (31,8 %) cas, dont 13 VRS (4,8 %) ; un virus est détecté dans 64 (36,7 %) des 164 bronchites aiguës : 11 VRS (6,3 %), 37 rhinovirus (21,3 %), 5 virus influenza A et B, et 12 autres virus ; dans les 60 bronchites chroniques surinfectées, il y a 9 rhinovirus (15 %), 2 virus parainfluenza 3 et aucun VRS ; dans les 21 pneumopathies infectieuses aiguës, on trouve 1 VRS, 1 virus influenza A et 2 rhinovirus, et dans les 11 cas d’infections respiratoires basses sur poumon pathologique, 1 VRS, 1 virus parainfluenza 3 et 4 rhinovirus ; il y a au total 19 infections bactériennes et virales associées. Enfin, dans les 51 pneumopathies infectieuses avec détresse respiratoire hospitalisées en réanimation, un virus est isolé dans 17 (33,3 %) cas : 3 VRS (5,8 %), 6 virus influenza A, 3 rhinovirus, 2 adénovirus, 2 herpes simplex et un CMV ; il y a 6 infections bactériennes associées dont 4 d’origine nosocomiale. Tous les patients infectés par le VRS sont âgés et présentent un facteur de risque respiratoire ou cardiaque.

Conclusions

Chez l’adulte le VRS est responsable de fréquents syndromes pseudo-grippaux et parfois d’infections respiratoires basses, qui peuvent être graves et qu’il faut penser à rechercher. La technique PCR est particulièrement efficace mais non disponible en routine.

Heterogeneous case definitions used for the surveillance of influenza in Europe

We reviewed the case definitions used by 21 influenza sentinel-based surveillance networks in Western Europe. Two clinical syndromes were used with a wide range of case definitions that nevertheless shared common criteria. Although there is currently no international consensus, efforts are being undertaken to standardise influenza case definitions in Europe.

Monitoring of influenza in the EISS European network member countries from October 2000 to April 2001

In countries covered by the European Influenza Surveillance Scheme (EISS), the 2000-2001 winter was marked mainly by the spread of influenza A(H1N1) viruses. Influenza B, which globally represented a minority of cases, was common later in the season and predominant in Great Britain, Ireland, and Portugal. Influenza activity was at its maximum during the period of January and February/March 2001 with little time lag between countries (maximum four weeks). Overall, the morbidity rates reported were much lower than for the previous season, illustrating a moderate level of influenza activity.

Monitoring of influenza in the EISS European network member countries from October 2000 to April 2001

In countries covered by the European Influenza Surveillance Scheme (EISS), the 2000-2001 winter was marked mainly by the spread of influenza A(H1N1) viruses. Influenza B, which globally represented a minority of cases, was common later in the season and predo-minant in Great Britain, Ireland, and Portugal. Influenza activity was at its maximum during the period of January and February/March 2001 with little time lag between countries (maximum four weeks). Overall, the morbidity rates reported were much lower than for the previous season, illustrating a moderate level of influenza activity.

Comparison of three non-nested RT-PCR for the detection of influenza A viruses

BACKGROUND

The viral isolation technique (VIT) is largely used as a gold standard for the detection of influenza A and B viruses in respiratory samples. Some recent studies have pointed out that the polymerase chain reaction (PCR) assays allow sensitive and rapid detection of influenza viruses, also providing excellent correlation with traditional methods.

OBJECTIVES AND DESIGN STUDY

The aim of this study was to evaluate the efficiency of three non-nested PCR, two PCR-hybridization assays using primers defined in M and NS genes, and one PCR which uses primers defined in NP, NS and HA genes and combines the detection of H3N2 and H1N1 hemagglutinin genes using defined primers in NP, NS and HA genes (PCR3), in comparison with an IF assay (IFA) and viral isolation technique (VIT). The study was carried out on 244 nasal samples collected mainly by practitioners of the GROG surveillance network during winter 1998-1999 for the detection of influenza A virus.

RESULTS

Overall influenza viruses were detected more frequently by PCR techniques in 157 (64.3%), 147 (60.2%), 110 (45%) cases for PCR1, PCR2, PCR3, respectively, than by VIT or IFA, in 100 (40.9%) and 74 (30.3%) cases, respectively. Taking the positive culture samples as a reference, 100 (41.8%) samples were found to be positive for influenza A, and the sensitivity of IFA, PCR 1, PCR 2 and PCR3 techniques were 70, 100, 99, and 90%, respectively as compared with viral isolation cultures. On the other hand, as 86.5% of positive samples were positive with at least two different techniques, the sensitivity, specificity, VPP and VPN of each technique were recalculated taking into account a further criterion defining a positive sample: positivity with two techniques. We observe that techniques PCR 2 and particularly PCR 1 have very good sensitivity, respectively 98.6 and 100%, far better than the traditional techniques, IFA and culture, whilst maintaining acceptable specificity: 94.1 and 86.1%, respectively. In both cases they enable 141 (57.7%) A-positive influenza samples to be detected instead of the 100 (40.9%) obtained when culture is the reference test. IFA, culture and PCR 3 are highly specific (VPP=100%), but in comparison with PCR 1 and 2 their sensitivity, respectively 51.7, 69. 9, 77.6%, and negative predictive value are unsatisfactory. PCR 1 and 2 are superior to the other techniques to a statistically highly significant degree in terms of sensitivity, but the difference between the two is not significant.

Surveillance of influenza in Europe from October 1999 to February 2000

Surveillance of influenza through EISS (European Influenza Surveillance Scheme) during the 1999 to 2000 winter shows that influenza affected most of the 11 participating countries and was particularly active in December 1999 and January 2000. Influenza A(