Estimating Infection Attack Rates and Severity in Real Time during an Influenza Pandemic: Analysis of Serial Cross-Sectional Serologic Surveillance Data

This study reports that using serological data coupled with clinical surveillance data can provide real-time estimates of the infection attack rates and severity in an emerging influenza pandemic

Sex- and age-dependent association of SLC11A1 polymorphisms with tuberculosis in Chinese: a case control study

BACKGROUND: Host genetic factors are important determinants in tuberculosis (TB). The SLC11A1 (or NRAMP1) gene has been studied extensively for genetic association with TB, but with inconsistent findings. In addition, no study has yet looked into the effect of sex and age on the relationship between SLC11A1 polymorphisms and TB. METHODS: A case-control study was conducted. In total, 278 pulmonary TB patients and 282 sex- and age-matched controls without TB were recruited. All subjects were ethnic Chinese. On the basis of linkage disequilibrium pattern, three genetic markers from SLC11A1 and one from the nearby IL8RB locus were selected and examined for association with TB susceptibility. These markers were genotyped using single strand conformation polymorphism analysis or fragment analysis of amplified products. RESULTS: Statistically significant differences in allele (P = 0.0165, OR = 1.51) and genotype (P = 0.0163, OR = 1.59) frequencies of the linked markers SLC6a/b (classically called D543N and 3'UTR) of the SLC11A1 locus were found between patients and controls. With stratification by sex, positive associations were identified in the female group for both allele (P = 0.0049, OR = 2.54) and genotype (P = 0.0075, OR = 2.74) frequencies. With stratification by age, positive associations were demonstrated in the young age group (age ≤65 years) for both allele (P = 0.0047, OR = 2.52) and genotype (P = 0.0031, OR = 2.92) frequencies. All positive findings remained significant even after correction for multiple comparisons. No significant differences were noted in either the male group or the older age group. No significant differences were found for the other markers (one SLC11A1 marker and one IL8RB marker) either. CONCLUSION: This study confirmed the association between SLC11A1 and TB susceptibility and demonstrated for the first time that the association was restricted to females and the young age group

Diversidade e inclusão, sensibilizar para o outro que é diferente de mim

A sociedade atual evidencia-se cada vez mais pela diversidade e idiossincrasias dos seus indivíduos, o que responsabiliza todo o sistema educativo na promoção de uma educação orientada para valores e práticas inclusivas. Este estudo, de natureza qualitativa, integrado no âmbito da formação de professores, dá conta de como alguns desses valores, e consequentes práticas, podem ser promovidos desde muito cedo, nomeadamente na Educação Pré-escolar e no 1º Ciclo do Ensino Básico. Com base na metodologia dos testes sociométricos, através de placas com imagens fotográficas de crianças, a investigação foi desenvolvida com um grupo de 24 crianças, entre os três e quatro anos, e uma turma do 4º ano com 20 alunos. Da análise de dados evidenciam-se as médias percentuais das suas preferências sobre aspetos culturais, de género,cor da pele e deficiência. Dos resultados destacam-se aspetos particulares de eleição, de como percecioname o que pensam sobre outras crianças consideradas“diferentes”. De salientar o papel fundamental dos docentes na promoção e sensibilização para a aceitação da diferença e da diversidade

Inferring influenza infection attack rate from seroprevalence data.

Seroprevalence survey is the most practical method for accurately estimating infection attack rate (IAR) in an epidemic such as influenza. These studies typically entail selecting an arbitrary titer threshold for seropositivity (e.g. microneutralization [MN] 1∶40) and assuming the probability of seropositivity given infection (infection-seropositivity probability, ISP) is 100% or similar to that among clinical cases. We hypothesize that such conventions are not necessarily robust because different thresholds may result in different IAR estimates and serologic responses of clinical cases may not be representative. To illustrate our hypothesis, we used an age-structured transmission model to fully characterize the transmission dynamics and seroprevalence rises of 2009 influenza pandemic A/H1N1 (pdmH1N1) during its first wave in Hong Kong. We estimated that while 99% of pdmH1N1 infections became MN1∶20 seropositive, only 72%, 62%, 58% and 34% of infections among age 3-12, 13-19, 20-29, 30-59 became MN1∶40 seropositive, which was much lower than the 90%-100% observed among clinical cases. The fitted model was consistent with prevailing consensus on pdmH1N1 transmission characteristics (e.g. initial reproductive number of 1.28 and mean generation time of 2.4 days which were within the consensus range), hence our ISP estimates were consistent with the transmission dynamics and temporal buildup of population-level immunity. IAR estimates in influenza seroprevalence studies are sensitive to seropositivity thresholds and ISP adjustments which in current practice are mostly chosen based on conventions instead of systematic criteria. Our results thus highlighted the need for reexamining conventional practice to develop standards for analyzing influenza serologic data (e.g. real-time assessment of bias in ISP adjustments by evaluating the consistency of IAR across multiple thresholds and with mixture models), especially in the context of pandemics when robustness and comparability of IAR estimates are most needed for informing situational awareness and risk assessment. The same principles are broadly applicable for seroprevalence studies of other infectious disease outbreaks

Clinical characteristics of the study subjects with full-length HBV genome amplified by rolling circle amplification (RCA).

<p>(OBI, occult hepatitis B infection; n.a.: not applicable; SEM: standard error of the mean; DR: direct repeat).</p

Comparison of the nucleotide (nt.) diversity (± SEM) on the HBV genome of occult hepatitis B and control subjects.

Δ<p>Full-length HBV: OBI sequence compared with 5 genotype B and 49 genotype C reference sequence obtained from Chinese patients with chronic HBV infection. *A statistical difference with p<0.05.</p

Rolling circle amplification (RCA) of full-length HBV genome.

<p>The number of initial HBV DNA template present in each RCA reaction is shown at the top. M, molecular weight marker; H2O, negative control. (A) The high-molecular-weight raw RCA products containing multiple copies of the initial HBV template. (B) The full-length HBV genomes recovered by restriction enzyme, <i>Spe</i>I digestion. (C) Full-length HBV genome amplified by using the RCA products as PCR template.</p