Disease Incidence Data Research Articles

Spatial heterogeneity, incidence-incidence and incidence-lesion density relationship of apple scab (Venturia inaequalis) in managed orchards

The spatial pattern of apple scab was characterized using 10 years of disease incidence and lesion density data collected in managed orchards located in Quebec, Canada. Distributional analyses indicated that scab incidence was better characterized by the beta-binomial than the binomial distribution in 53 and 65% of the data sets at the leaf and shoot scales, respectively. Median values of the beta-binomial parameter θ, a measure of small-scale aggregation, were near 0 (0.003 and 0.028) at both sampling scales, indicating that disease incidence was close to being randomly distributed (low degree of aggregation). For lesion density, the negative binomial distribution fitted the data better than the Poisson distribution in 86% of the data sets at the leaf scale. The median value of the index of dispersion k was 0.068, indicating that aggregation was present. For all apple scab measurements, the power law models provided a good fit to the data. The estimated slope and intercept parameters were significantly greater than 1 and 0, respectively, suggesting that spatial heterogeneity changed systematically with disease incidence. Results of a covariance analysis showed that spatial heterogeneity of scab incidence at both scales and lesion density was not dependent upon shoot type but that spatial heterogeneity of scab incidence and lesion density at the leaf scale was influenced by the sampling period. A hierarchical analysis showed that scab incidence at the tree scale increased as a saturation-type curve with respect to incidence at the leaf or shoot scales. A similar relationship was observed for incidences at the shoot and leaf scales. An effective sample size model based on the binary power law parameters (Madden and Hughes, Phytopathology 89:770–781, 1999) gave the best fit to the leaf and shoot data, respectively. The incidence-lesion density relationship at both scales was well described by a complementary log-log (CLL) and log transformation model $$ \left( {R_{{adj}}^2 = 0.97\,and\,R_{{adj}}^2 = 0.94} \right) $$ , however, the models tended to underestimate lesion density. The information of the spatial relations of apple scab within and between hierarchical scales acquired from this study can be used in developing and evaluating practical disease management strategies and to improve apple scab assessments for fungicide or cultivar susceptibility trials.

Effective reproduction numbers are commonly overestimated early in a disease outbreak

Reproduction numbers estimated from disease incidence data can give public health authorities valuable information about the progression and likely size of a disease outbreak. Here, we show that methods for estimating effective reproduction numbers commonly give overestimates early in an outbreak. This is due to many factors including the nature of outbreaks that are used for estimation, incorrectly accounting for imported cases and outbreaks arising in subpopulations with higher transmission rates. Awareness of this bias is necessary to correctly interpret estimates from early disease outbreak data.

Based on time series and RBF network plant disease forecasting

The RBF network is one novel effective forward neural network, it realizes through the nonlinear primary function's linear combination from space RN to the space RM nonlinear transformation, BFm and GM (1,1) combined model,especially qualify in nonlinear time series plant disease forecast. Model GM(1,1) was built for plant disease collected during simulative occurrence experiments. At the same time, the data of disease index and disease incidence were analyzed as reference.The results of experiments reveal that the co-deviation of Model GM(1,1) parameter a and b, cov(a,b), coincides with the standard deviation of disease index and disease incidence. This indicates that Grey system theory is effective for disease incidence analysis and the parameters of GM(1,1) can well reflect the change of plant disease occurrence.This article takes the forecast object by the wheat banded sclerotial blight, proposed that based on the RBF network's plant disease forecasting model, the simulation experiment showed that this model to the plant disease short and medium term forecast is possible effective.

Spatially disaggregated disease transmission risk: land cover, land use and risk of dengue transmission on the island of Oahu

Vector-borne diseases persist in transmission systems that usually comprise heterogeneously distributed vectors and hosts leading to a highly heterogeneous case distribution. In this study, we build on principles of classical mathematical epidemiology to investigate spatial heterogeneity of disease risk for vector-borne diseases. Land cover delineates habitat suitability for vectors, and land use determines the spatial distribution of humans. We focus on the risk of exposure for dengue transmission on the Hawaiian island of Oahu, where the vector Aedes albopictus is well established and areas of dense human population exist. In Hawai'i, dengue virus is generally absent, but occasionally flares up when introduced. It is therefore relevant to investigate risk, but difficult to do based on disease incidence data. Based on publicly available data (land cover, land use, census data, surveillance mosquito trapping), we map the spatial distribution of vectors and human hosts and finally overlay them to produce a vector-to-host ratio map. The resulting high-resolution maps indicate a high spatial variability in vector-to-host ratio suggesting that risk of exposure is spatially heterogeneous and varies according to land cover and land use.

A comparison of methods for spatial relative risk mapping of human neural tube defects

Birth defects are a major cause of infant mortality and disability in many parts of the world. Yet the etiology of neural tube defects (NTDs), the most common types of birth defects, is still unknown. The construction and analysis of maps of disease incidence data can help explain the geographical distribution of NTDs and can point to possible environmental causes of these birth defects. We compared two methods of mapping spatial relative risk of NTDs: (1) hierarchical Bayesian model, and (2) Spatial filtering method. Heshun county, which has the highest rate of NTDs in China, was selected as the region of interest. Both methods were used to produce a risk map of NTDs for rural Heshun for 1998–2001. Hierarchical Bayesian model estimated the relative risk for any given village in Heshun by “borrowing” strength from other villages in the study region. It did not remove all the random spatial noise in the rude disease rate. There were several areas of high incidence scattered around its risk map with no readily apparent pattern. The spatial filtering method calculated the relative risk for all villages based on a series of circulars. The risk map from the spatial filtering method revealed some spatial clusters of NTDs in Heshun. These two methods differed in their ability to map the spatial relative risk of NTDs. Distributional assumption of relative risk and the target of the risk assessment should be taken into consideration when choosing which method to use.

Annual and polyetic progression of citrus canker on trees protected with copper sprays

The effects of copper sprays on annual and polyetic progress of citrus canker, caused by Xanthomonas citri subsp. citri, in the presence of the Asian citrus leafminer (Phyllocnistis citrella), were evaluated in a study conducted in a commercial orchard in northwest Paraná state, Brazil, where citrus canker is endemic. Nonlinear monomolecular, logistic and Gompertz models were fitted to monthly disease incidence data (proportion of leaves with symptoms) for each treatment for three seasons. The logistic model provided the best estimate of disease progress for all years and treatments evaluated and logistic parameter estimates were used to describe polyetic disease dynamics. Although citrus canker incidence increased during each of the seasons studied, it decreased over the whole study period, more so in copper‐treated trees than in water‐sprayed controls. Copper treatment reduced disease incidence compared with controls in every year, especially 2004–2005, when incidence was ca. 10‐fold higher in controls than in treated plots (estimated asymptote values 0·82 and 0·07, respectively). Copper treatment also reduced estimated initial disease incidence and epidemic growth rates every year.

AAFP–AAHA: Feline Life Stage Guidelines

1Although most owners consider their cats to be family members, cats are substantially underserved, compared with dogs. In 2006, owners took their dogs to veterinarians more than twice as often as cats, averaging 2.3 times/year, compared with 1.1 times/year for cats, and significantly more dogs (58%) than cats (28%) were seen by a veterinarian one or more times/year. 2 Cat owners often express a belief that cats ‘do not need medical care’. Two reasons for this misconception are that signs of illness are often difficult to detect, and cats are perceived to be self-sufficient. 2 One role of the veterinarian is to develop a partnership with cat owners that will pave the way for a lifelong health care plan. These guidelines aim to outline an evidence-based life stage wellness program to aid the veterinary medical team in delivering the best comprehensive care for cats. Specific goals are to provide: ✜ Recommendations for optimal health care for cats throughout the different life stages. ✜ Practical suggestions and tools to facilitate improved veterinary visits and to enhance the client–veterinarian clinical encounter. ✜ A foundation from which to access sources of additional information. Life stage classification Distinct life stages (age groups) in cats are not well defined, in part because individual animals and body systems age at different rates, a process that is influenced by many factors. These guidelines follow one convenient classification (see box below). These age designations help to focus attention on the physical and behavioral changes that occur at different stages (eg, congenital defects in kittens, obesity prevention in the junior cat). It must be recognized, however, that any age groupings are inevitably arbitrary demarcations along a spectrum, and not absolutes. Evidence-based health care Supporting references for specific recommendations are supplied where possible, and any previously published guidelines on particular topics are referred to where relevant. Readers should note, however, that the guidelines panel was hampered in its efforts by the relative paucity of disease incidence data by age group that is available, and there is an urgent need for research to guide the future of evidence-based feline health care. 3

AAFP-AAHA: feline life stage guidelines.

Cats have become the most popular pet in the United States, yet statistics about veterinary care for cats remain troubling. Although most owners consider their cats to be family members, cats are substantially underserved, compared with dogs. In 2006, owners took their dogs to veterinarians more than twice as often as cats, averaging 2.3 times/year, compared with 1.1 times/year for cats, and significantly more dogs (58%) than cats (28%) were seen by a veterinarian one or more times/year. Cat owners often express a belief that cats 'do not need medical care'. Two reasons for this misconception are that signs of illness are often difficult to detect, and cats are perceived to be self-sufficient.(2) One role of the veterinarian is to develop a partnership with cat owners that will pave the way for a lifelong health care plan. These guidelines aim to outline an evidence-based life stage wellness program to aid the veterinary medical team in delivering the best comprehensive care for cats. Specific goals are to provide: *Recommendations for optimal health care for cats throughout the different life stages. *Practical suggestions and tools to facilitate improved veterinary visits and to enhance the client-veterinarian clinical encounter. *A foundation from which to access sources of additional information. Distinct life stages (age groups) in cats are not well defined, in part because individual animals and body systems age at different rates, a process that is influenced by many factors. These guidelines follow one convenient classification (see box below). These age designations help to focus attention on the physical and behavioral changes that occur at different stages (eg, congenital defects in kittens, obesity prevention in the junior cat). It must be recognized, however, that any age groupings are inevitably arbitrary demarcations along a spectrum, and not absolutes. EVIDENCE-BASED HEALTH CARE: Supporting references for specific recommendations are supplied where possible, and any previously published guidelines on particular topics are referred to where relevant. Readers should note, however, that the guidelines panel was hampered in its efforts by the relative paucity of disease incidence data by age group that is available, and there is an urgent need for research to guide the future of evidence-based feline health care.

Burden of disease caused by Streptococcus pneumoniae in children younger than 5 years: global estimates

Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, and sepsis in children worldwide. However, many countries lack national estimates of disease burden. Effective interventions are available, including pneumococcal conjugate vaccine and case management. To support local and global policy decisions on pneumococcal disease prevention and treatment, we estimated country-specific incidence of serious cases and deaths in children younger than 5 years. We measured the burden of pneumococcal pneumonia by applying the proportion of pneumonia cases caused by S pneumoniae derived from efficacy estimates from vaccine trials to WHO country-specific estimates of all-cause pneumonia cases and deaths. We also estimated burden of meningitis and non-pneumonia, non-meningitis invasive disease using disease incidence and case-fatality data from a systematic literature review. When high-quality data were available from a country, these were used for national estimates. Otherwise, estimates were based on data from neighbouring countries with similar child mortality. Estimates were adjusted for HIV prevalence and access to care and, when applicable, use of vaccine against Haemophilus influenzae type b. In 2000, about 14.5 million episodes of serious pneumococcal disease (uncertainty range 11.1-18.0 million) were estimated to occur. Pneumococcal disease caused about 826,000 deaths (582,000-926,000) in children aged 1-59 months, of which 91,000 (63,000-102,000) were in HIV-positive and 735,000 (519,000-825,000) in HIV-negative children. Of the deaths in HIV-negative children, over 61% (449,000 [316,000-501,000]) occurred in ten African and Asian countries. S pneumoniae causes around 11% (8-12%) of all deaths in children aged 1-59 months (excluding pneumococcal deaths in HIV-positive children). Achievement of the UN Millennium Development Goal 4 for child mortality reduction can be accelerated by prevention and treatment of pneumococcal disease, especially in regions of the world with the greatest burden. GAVI Alliance and the Vaccine Fund.

Modelos de alerta para o controle da ferrugem-do-cafeeiro em lavouras com alta carga pendente

O objetivo deste trabalho foi desenvolver árvores de decisão como modelos de alerta da ferrugem-do-cafeeiro em lavouras de café (Coffea arabica L.) com alta carga pendente de frutos. Dados de incidência mensal da doença no campo coletados durante oito anos foram transformados em valores binários considerando limites de 5 e 10 pontos percentuais na taxa de infecção. Foi gerado um modelo para cada taxa de infecção binária a partir de dados meteorológicos e do espaçamento entre plantas. O alerta é indicado quando a taxa de infecção, prevista para o prazo de um mês, atingir ou ultrapassar o respectivo limite. A acurácia do modelo para o limite de 5 pontos percentuais foi de 81%, por validação cruzada, chegando até 89% segundo estimativa otimista. Esse modelo apresentou bons resultados para outras medidas de avaliação importantes, como sensitividade (80%), especificidade (83%) e confiabilidades positiva (79%) e negativa (84%). O modelo para o limite de 10 pontos percentuais teve acurácia de 79%, e não apresentou o mesmo equilíbrio entre as demais medidas. Em conjunto, esses modelos podem auxiliar na tomada de decisão referente ao controle da ferrugem-do-cafeeiro no campo. A indução de árvores de decisão é alternativa viável às técnicas convencionais de modelagem e facilita a compreensão dos modelos.

The distribution and spread of citrus canker in Emerald, Australia

Citrus canker is a disease of citrus and closely related species, caused by the bacterium Xanthomonas citri subsp. citri. This disease, previously exotic to Australia, was detected on a single farm [infested premise-1, (IP1). IP is the terminology used in official biosecurity protocols to describe a locality at which an exotic plant pest has been confirmed or is presumed to exist. IP are numbered sequentially as they are detected] in Emerald, Queensland in July 2004. During the following 10 months the disease was subsequently detected on two other farms (IP2 and IP3) within the same area and studies indicated the disease first occurred on IP1 and spread to IP2 and IP3. The oldest, naturally infected plant tissue observed on any of these farms indicated the disease was present on IP1 for several months before detection and established on IP2 and IP3 during the second quarter (i.e. autumn) 2004. Transect studies on some IP1 blocks showed disease incidences ranged between 52 and 100% (trees infected). This contrasted to very low disease incidence, less than 4% of trees within a block, on IP2 and IP3. The mechanisms proposed for disease spread within blocks include weather-assisted dispersal of the bacterium (e.g. wind-driven rain) and movement of contaminated farm equipment, in particular by pivot irrigator towers via mechanical damage in combination with abundant water. Spread between blocks on IP2 was attributed to movement of contaminated farm equipment and/or people. Epidemiology results suggest: (i) successive surveillance rounds increase the likelihood of disease detection; (ii) surveillance sensitivity is affected by tree size; and (iii) individual destruction zones (for the purpose of eradication) could be determined using disease incidence and severity data rather than a predefined set area.

Estimates of worst case baseline West Nile virus disease effects in a suburban New York county

Serosurveys conducted where West Nile Virus (WNV) caused health impacts were used to construct a model of potential worst case health impacts in a suburban setting. This model addressed two common public perceptions regarding mosquito control activities and WNV disease: it is not a disease of major consequence, and exposed populations quickly become immune. Comparisons to blood bank infection and serious disease incidence data were similar to some of the serosurvey model results. Accounting for theoretical increasing immunity, even over a 20-year period, did not substantially reduce the potential impacts. The model results were approximately an order of magnitude greater than those actually experienced in Suffolk County, NY; differences in mosquito populations and/or the degree of mosquito control between Suffolk County and serosurvey sites seem to be the reason for the differences.

Towards elimination: measles susceptivility in Australia and 17 European countries

To evaluate age-specific measles susceptibility in Australia and 17 European countries. As part of the European Sero-Epidemiology Network 2 (ESEN2), 18 countries collected large national serum banks between 1996 and 2004. These banks were tested for measles IgG and the results converted to a common unitage to enable valid intercountry comparisons. Historical vaccination and disease incidence data were also collected. Age-stratified population susceptibility levels were compared to WHO European Region targets for measles elimination of < 15% in those aged 2-4 years, < 10% in 5-9-year-olds and < 5% in older age groups. Seven countries (Czech Republic, Hungary, Luxembourg, Spain, Slovakia, Slovenia and Sweden) met or came very close to the elimination targets. Four countries (Australia, Israel, Lithuania and Malta) had susceptibility levels above WHO targets in some older age groups indicating possible gaps in protection. Seven countries (Belgium, Bulgaria, Cyprus, England and Wales, Ireland, Latvia and Romania) were deemed to be at risk of epidemics as a result of high susceptibility in children and also, in some cases, adults. Although all countries now implement a two-dose measles vaccination schedule, if the WHO European Region target of measles elimination by 2010 is to be achieved higher routine coverage as well as vaccination campaigns in some older age cohorts are needed in some countries. Without these improvements, continued measles transmission and outbreaks are expected in Europe.

An Economic Analysis of the Universal Varicella Vaccination Program in the United States

Frequent varicella outbreaks with sizable impact on the US public health system have continued to occur despite the success of the country's 1-dose varicella vaccination program. The Advisory Committee on Immunization Practices recently recommended adding a routine second dose of varicella vaccine and weighed economic projections as well as public health goals in their deliberations. This decision-tree-based analysis was conducted to evaluate the economic impact of the projected 2-dose varicella vaccination program as well as the existing 1-dose program. The analysis used population-based vaccination coverage and disease incidence data to make projections for a hypothetical US birth cohort of 4,100,000 infants born in 2006. Compared with no vaccination, both the 1-dose program (societal benefit-cost ratio [BCR], 4.37) and 2-dose program (BCR, 2.73) were estimated to be cost saving from the societal perspective. Compared with the 1-dose program, the incremental second dose was not cost saving (societal incremental BCR, 0.56). The incremental cost-effectiveness ratio for the second dose was $343 per case prevented, or approximately $109,000 per quality-adjusted life-year saved, and these results were sensitive to assumptions about vaccine effectiveness and prices.

Modeling Disease Incidence Data with Spatial and Spatio Temporal Dirichlet Process Mixtures

Disease incidence or mortality data are typically available as rates or counts for specified regions, collected over time. We propose Bayesian nonparametric spatial modeling approaches to analyze such data. We develop a hierarchical specification using spatial random effects modeled with a Dirichlet process prior. The Dirichlet process is centered around a multivariate normal distribution. This latter distribution arises from a log-Gaussian process model that provides a latent incidence rate surface, followed by block averaging to the areal units determined by the regions in the study. With regard to the resulting posterior predictive inference, the modeling approach is shown to be equivalent to an approach based on block averaging of a spatial Dirichlet process to obtain a prior probability model for the finite dimensional distribution of the spatial random effects. We introduce a dynamic formulation for the spatial random effects to extend the model to spatio-temporal settings. Posterior inference is implemented through Gibbs sampling. We illustrate the methodology with simulated data as well as with a data set on lung cancer incidences for all 88 counties in the state of Ohio over an observation period of 21 years.

Spatiotemporal Analysis of Spread of Infections by Verticillium dahliae Pathotypes Within a High Tree Density Olive Orchard in Southern Spain

The development of Verticillium wilt epidemics in olive cv. Arbequina was studied from November 1999 to May 2003 in a drip-irrigated, nontillage orchard established in a soil without a history of the disease at Córdoba, southern Spain. Disease incidence measured at 1-month-intervals increased from 0.2 to 7.8% during this period. Verticillium dahliae infecting the trees was characterized as defoliating (D) or nondefoliating (ND) pathotypes by a specific, multiplex-polymerase chain reaction (PCR) assay. Of the symptomatic trees, 87.2 and 12.8% were infected by the D or ND pathotypes, respectively. Dynamics of disease incidence were described by a generalized logistic model with a multiple sigmoid pattern. In the fitted model, the infection rate was highest in the winter to spring period and decreased to minimum values in the summer to fall period. Binary data of disease incidence was analyzed for point pattern and spatial correlation, either directly or after parsing them in contiguous quadrats. Overall, ordinary runs analysis indicated a departure from randomness of disease within rows. The binomial index of dispersion, interclass correlation, and Taylor's power law for various quadrat sizes suggested aggregation of diseased trees within the quadrat sizes tested. Spatial analysis by distance indices showed a nonrandom arrangement of quadrats containing infected trees. Spatial pattern was characterized by the occurrence of several clusters of infected trees. Increasing clustering over time was generally suggested by stronger values of clustering index over time and by the increase in the size of patch clusters. Significant spatial association was found in the clustering of diseased trees over time across cropping seasons; however, clustering was significant only for infections by D V. dahliae, indicating that infections by the D pathotype were aggregated around initial infections. The number and size of clusters of D V. dahliae-infected trees increased over time. Microsatellite-primed PCR assays of a representative number of V. dahliae isolates from diseased trees indicated that the majority of infecting D isolates shared the fingerprinting profile with D V. dahliae isolated from soil of a naturally infested cotton field in close proximity to the orchard, suggesting that short distance dispersal of the pathogen from this soil to the olive orchard may have occurred.

Evaluation of Statistical Models for Analysis of Insect, Disease and Weed Abundance and Incidence Data

Analysis of variance (ANOVA) has been a fundamental method used for analysis of abundance and incidence data. However, abundance and incidence data often violate the assumptions of ANOVA. Researchers often ignore ANOVA assumptions, transform the data using arbitrarily chosen functions and then fail to evaluate whether or not the transformation actually corrected the problem. The statistical power of the tests used is also seldom reported. Therefore, the objectives of this paper are to demonstrate (1) implications of using arbitrarily chosen transformations and ANOVA to the validity of statistical inference on pest abundance and incidence and (2) the application of LMMs and GLMs for efficient analysis of such data. Abundance data were analyzed assuming normal, Poisson and negative binomial error distributions. Incidence data were analyzed assuming normal and binomial error distributions. Among the data transformation functions, logarithmic transformation gave better description of abundance data compared with square root. Working logits were better than angular or square root transformation of incidence data. The study has also demonstrated that the choice of transformation can influence the statistical significance and power of test. Transformation of either abundance or incidence data did not necessarily ensure normality or variance homogeneity. According to the Akaike information criterion (AIC), a GLM assuming negative binomial error distribution was better for description of most abundance datasets compared with a GLM assuming Poisson error distribution or LMM. LMM based on working logits also gave a better description of the data than a GLM assuming binomial distribution. It is concluded that LMMs and GLMs simultaneously consider the effect of treatments and heterogeneity of variance and hence are more appropriate for analysis of abundance and incidence data than ordinary ANOVA. Keywords : Mixed Models; Generalized Linear Models; Statistical Power East African Journal of Sciences Vol. 1 (1) 2007: pp. 1-9

Cultural, morphological, pathogenic and molecular variability amongst tomato isolates of Alternaria solani in India

Early blight (Alternaria solani) is an important disease causing severe damage in tomato. The eleven isolates of A. solani designated as So, Dh, Sh, Va-5, Ka, Ma, Hy, Ba-1, My, Va-3 and Mi were collected from different agroclimatic conditions and these isolates were characterized for cultural, morphological, pathogenic and molecular variations. The pigmentation varied from yellow, brown, black, brownish to greenish black in isolates of A. solani on potato dextrose agar medium. In general, radial growth of all isolates ranged between 14.9 mm and 32.2 mm on PDA and 24.3 mm to 53.7 mm on three selective media i.e., ASM, V-8 juice agar and V-8 juice agar (synthetic) on the fourth day. The fastest radial growth was recorded in the So isolate and slowest in the Ka isolate on PDA, while isolates Dh, Ba-1 and Va-3 were recorded to be faster in growth on ASM, V-8 juice agar and V-8 juice agar (synthetic) medium. The thickness of conidiogenous hyphae varied between 1.17 μ and 9.56 μ, with maximum in the Va-5 and Ma isolates. Most of the isolates showed smooth mycelial growth with circular and irregular margin and without concentric zonation. Sporulation was not found in any of the isolates on four different nutrient media, whereas conidiogenous hyphal length was observed in V-8 juice agar medium only. Based on the pathogenicity, isolates of A. solani were rated as virulent or less virulent based on percentage disease incidence data. Molecular variability studies were also done to find out the best annealing temperature and eighty-six primers were screened to select for maximum polymorphism of DNA. The best annealing temperature was recorded between 32.5 °C and 34.0 °C for the pathogen, and most efficient amplification and polymorphism of DNA was found with random primer 5′-CGCGTTCCTG-3′.

Age-specific seroprevalence of serogroup C meningococcal serum bactericidal antibody activity and serogroup A, C, W135 and Y-specific IgG concentrations in the Turkish population during 2005

Like many other developing countries; there is no accurate information about the antibody levels against Neisseria meningitidis in Turkey. We collected serum samples from four health centers located in different geographic regions and stratified according to age in order to obtain a baseline seroprevalence of protective antibodies to meningococcal serogroup C and provide data on seroprevalence of IgG antibodies to serogroups A, C, W135 and Y. Sera were tested for serum bactericidal antibodies (SBA) to serogroup C meningococci using rabbit serum as the complement source and by a bead based assay for serogroup A, C, W135 and Y-specific IgG. It was observed that 30% and 12% of individuals within the study population had SBA titers of > or =8 and > or =128, respectively. Overall; at least 70% of the population are susceptible (SBA titer <8) to meningococcal serogroup C disease. The rate of susceptibility was highest in infants aged 7-12 months and young children (1-4 years). Regardless of age, for serogroup A, C, W135 and Y, 60.5%, 27.2%, 12.3% and 19.2% of subjects, respectively, had serogroup-specific IgG concentrations > or =2 microg/mL. These data highlight that a large proportion of the Turkish population are susceptible to serogroups C, W135 and Y and should be considered, along with serogroup-specific disease incidence data, in future decisions on possible meningococcal vaccination programmes.

Tecnologías de información y comunicación para la prevención y control de la infección por el VIH y otras ITS

Innovative tools such as the Internet, personal digital assistants, tablet computers, cell phones, and other technologies are a growing arsenal in the global effort to prevent and control HIV and other sexually transmitted infections (STIs). While a variety of information and communication technology tools are in various stages of use for HIV/STI prevention, relatively few areas have accumulated a critical mass of evidence-based data about the most effective approaches. However, some of that evidence is compelling, and the potential for future uses appears large. Application to some areas of practice and research are nascent, the impact on disease incidence and economic evaluation data are still very limited, and evaluation of these tools would benefit from rigorous study designs. In this article we review the published literature regarding the use of information and communication technology applications to HIV/STI control. Appropriately utilized technologies may improve HIV/STI screening, prevention, surveillance, and care for patients and populations in both resource-constrained and resource-rich settings.