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bioRxiv2017

Long-Term Trends In The Contribution Of Major Causes Of Death To The Black-White Life Expectancy Gap By US State

States have fared differently in their progress towards eliminating the black-white life expectancy gap. Our objective is to describe the pattern of contributions of each of six major causes of deaths to the sex-specific black-white life expectancy gap across states over the last half-century, and identify divergent states.\n\nUsing vital statistics and census data, we extracted the number of deaths and population sizes for the years 1969 to 2013, by state, gender, race, 19 age groups, and six major causes of death.\n\nAlthough mortality from cardiovascular disease has decreased dramatically, its contribution to the life expectancy gap increased over time for men (from 0.9 to 1.2 years), but decreased for women (from 2.4 to 1 years). The contribution of non-communicable diseases to the gap was stable over time for men (approximately 0.4 years) but decreased for women (from 0.7 to 0.2 years), while cancers exhibited an inverted-U trend for men (peaking at 1.1 years in 1988) and a stable contribution for women (approximately 0.5 years). Both genders exhibited a decreased contribution from injuries (men: 2.2 to 0.4 years), that became negative for women (women: 0.5 to -0.1 years). Several states diverged from these general trends.\n\nLife expectancy for both races has improved substantially in the US. For men, much of this improvement was due to narrowing differences in injury-related mortality, but these contributions were rivaled by an increasing gap in CVD-related mortality. In women, a crossover in injury-related mortality led to a narrower gap, realized partially by increasing mortality among whites.

epidemiology↗

bioRxiv2017

Excess Mortality Related To Chikungunya Epidemics In The Context Of Co-circulation Of Other Arboviruses In Brazil

Chikungunya is an emerging arbovirus that reached the Western Hemisphere at the end of 2013. Studies conducted in Indie Ocean and India suggest that many of deaths associated with chikungunya cannot be recognized by passive surveillance system. The occurrence of these deaths can be inferred by an increase in the overall mortality observed during chikungunya epidemics. To evaluate the mortality associated with chikungunya epidemics in Brazil, we studied monthly mortality by age group comparing the pre-chikungunya period with the chikungunya epidemic period in the most affected states of Brazil. We obtained official data from National System of Notifiable Diseases (SINAN) and Mortality Information System (SIM), both maintained by the Ministry of Health. It was possible to identify a significant increase in all-cause mortality rate during chikungunya epidemics, there was no similar mortality in previous years, even during dengue epidemics. We estimated an excess of 4,842 deaths in Pernambuco during the chikungunya epidemics (51.4/100,000 inhabitants), the most affected age groups were the elderly and under 1 year of age, the same pattern occurred in all states. Further studies at other sites are needed to confirm the association between increased mortality and chikungunya epidemics. If these findings are confirmed, it will be necessary to revise guidelines to recognize the real mortality associated with chikungunya and to improve therapeutic approaches and protective measures in the most vulnerable groups.

epidemiology↗

bioRxiv2017

Age-specific prevalence of anti-Pgp3 antibodies and severe conjunctival scarring in the Solomon Islands

BackgroundTrachomatous trichiasis (TT) and ocular Chlamydia trachomatis (Ct) infection in the Solomon Islands are scarce, whereas trachomatous inflammation-follicular (TF) is prevalent.\n\nMethodsWe enrolled 1511 people aged [≥]1 year from randomly selected households in 13 villages in which >10% of the population had TF prior to a single round of azithromycin MDA undertaken six months previously. Blood was collected from people of all ages to be screened for anti-Pgp3 antibodies. Photographs were collected from people of all ages for analysis of scarring severity.\n\nResultsConjunctival scars were visible in 13.1% of photographs. Mild (p<0.0001) but not severe (p=0.149) scars increased in prevalence with age. Anti-Pgp3 antibody seroprevalence was 18% in 1-9 year olds, increased sharply around the age of sexual debut, and reached 69% in those over 25 years. Anti-Pgp3 seropositivity did not increase significantly between the ages of 1-9 years, and was not associated with scarring in children (p=0.472) or TF in children (p=0.581).\n\nConclusionsSigns of trachoma are common in the Solomon Islands but occur frequently in individuals who have no serological evidence of prior ocular infection with Ct. WHO recommendations for directing MDA provision based on signs alone may not be suitable in this context.

epidemiology↗

bioRxiv2017

Association Between A Functional Polymorphism rs10830963 In Melatonin Receptor 1B And Risk Of Gestational Diabetes Mellitus: An Updated Meta-Analysis

The melatonin receptor 1B (MTNR1B) as a candidate gene for gestational diabetes mellitus (GDM) on the basis of its association with T2DM, {beta}-cells function and fasting plasma glucose (FPG) level. Many studies have investigated the association between MTNR1B polymorphism rs10830963 C>G and GDM risk, but the conclusion is inconsistent. PubMed, Google Scholar and CNKI databases were searched to identify eligible studies. Pooled OR with corresponding 95% CI was used to estimate the strength of the association between rs10830963 and GDM risk using a fixed- or random-effect model. 12 eligible studies with a number of 4,782 GDM patients and 5,605 controls were included in this meta-analysis. Results indicated that the variant G allele of rs10830963 polymorphism was significantly associated with an increased risk of GDM (CG vs. CC: OR=1.23, 95% CI = 1.12-1.34, Pheterogeneity = 0.23; GG vs. CC: OR=1.74, 95% CI =1.41-2.15, Pheterogeneity = 0.002). In the stratified analysis by ethnicity, similar results were found in Asians (CG vs. CC: OR=1.15, 95% CI = 1.04-1.28, Pheterogeneity = 0.74; GG VS. CC: OR=1.48, 95% CI =1.23-1.78, Pheterogeneity = 0.08) and in Caucasians (CG vs. CC: OR=1.49, 95% CI =1.25-1.77, Pheterogeneity = 0.28; GG vs. CC: OR=2.68, 95% CI =2.03-3.54, Pheterogeneity = 0.58).

epidemiology↗

bioRxiv2017

Advancing A Science For Sustaining Health: Establishing A Model Health District in Madagascar

ObjectiveWe demonstrate a replicable model health district for Madagascar. The governments of many low-income countries have adopted health policies that follow international standards, and yet there are four hundred million people without basic access to primary care. Closing this global health delivery gap is typically framed as an issue of scale-up, accomplished primarily through integrating international donor funds with broad-based health system strengthening (HSS) efforts. However, there is no established process by which healthcare systems measure improvements at the point of service and how those, in turn, impact population health. There is no gold standard, equivalent to randomized trials of individual-level interventions, for health systems research. Here, we present a framework for a model district in Madagascar where national policies are implemented along with additional health system interventions to allow for bottom-up adaptation.\n\nSettingThe intervention takes place in a government district in Madagascar, which includes 1 district hospital, 20 primary care health centers, and a network of community health workers.\n\nInterventionThe program simultaneously strengthens the WHOs six building blocks of HSS at all levels of the health system within a government district and pioneers a data platform that includes 1) strengthening the districts health management information systems; 2) monitoring and evaluation dashboards; and 3) a longitudinal cohort demographic and health study of over 1,500 households, with a true baseline in intervention and comparison groups.\n\nConclusionThe integrated intervention and data platform allows for the evaluation of system output indicators as well as population-level impact indicators, such as mortality rates. It thus supports field-based implementation and policy research to fill the know-do gap, while providing the foundation for a new science of sustaining health.\n\nData Sharing StatementData can be made available upon request by emailing research@pivotworks.org.

epidemiology↗

bioRxiv2017

Metabolic Effects Of Risk Alleles In PNPLA3, TM6SF2, GCKR, And LYPLAL1 Inform About Heterogeneity Of Non-Alcoholic Fatty Liver Disease

Fatty liver has been associated with unfavourable metabolic changes in circulation and is considered as a risk factor for cardiometabolic complications such as type 2 diabetes and cardiovascular disease. We aimed to provide insights in fatty liver related metabolic deviations by studying the resemblance between the metabolic profile associated with fatty liver observationally and metabolic profiles of non-alcoholic fatty liver disease (NAFLD) risk increasing genotypes. We determined cross-sectional associations of ultrasound-ascertained fatty liver status with 123 metabolic traits in 1,810 individuals aged 34-49 years from The Cardiovascular Risk in Young Finns Study. The cross-sectional associations were compared with the association profiles of NAFLD risk alleles in PNPLA3, TM6SF2, GCKR, and LYPLAL1 with the corresponding metabolic traits obtained from a publicly available genome-wide association study including up to 24,925 European individuals. The analysis revealed substantially different metabolic effects of the risk alleles. PNPLA3 rs738409-G, the strongest genetic risk factor to NAFLD, did not associate with metabolic changes. GCKR rs1260326-T resulted in an association profile similar to the observational fatty liver associations. Metabolic effects of LYPLAL1 rs12137855-C were similar, but statistically less robust, to the effects of GCKR rs1260326-T. In contrast, NAFLD risk allele TM6SF2 rs58542926-T displayed opposite metabolic associations when compared with the observational association pattern.\n\nConclusionThe divergent effects of the risk alleles on circulating lipids and metabolites underline involvement of several metabolic pathways in NAFLD and suggest that there are pathogenically different subtypes of NAFLD with alternate metabolic consequences. NAFLD risk alleles may have neutral or even cardioprotective effect on circulating lipids and metabolites providing evidence that hepatic lipid accumulation by itself would not necessarily cause the metabolic deviations associated observationally with fatty liver.

epidemiology↗

bioRxiv2017

Breastfeeding And Risk Of Asthma, Hay Fever And Eczema

BackgroundBreastfeeding is commonly proposed to protect against atopic diseases. However, studies aiming to quantify these protective effects have shown conflicting results.\n\nMethodsTo entrench the effects of breastfeeding on risk of asthma, hay fever and eczema, our study included a large study cohort, UK Biobank (N=502,682). Information was collected on whether participants had been breastfeed and on the prevalence of disease. Disease was tested for association with breastfeeding, adjusting or matching for influential covariates.\n\nFindingsA total of 443,068 participants were included in our analyses of which 71{middle dot}2% had been breastfed. The prevalence of asthma was 11{middle dot}4 % and 12{middle dot}7% in the breastfed and non-breastfed groups, and hay fever or eczema (23{middle dot}9% and 24{middle dot}8 % in the two groups respectively. When correcting or matching for potential confounders, we could not see any association between being breastfed and asthma. However, there were increased odds of hay fever and eczema among participants that had been breastfed (P=7{middle dot}78x10-6).\n\nInterpretationThis study reports that breastfeeding is associated with increased odds of hay fever and eczema but it show no evidence for breastfeeding being associated with asthma diagnosis.\n\nFundingThe Swedish Society for Medical Research (SSMF), the Kjell and Marta Beijers Foundation, Goran Gustafssons Foundation, the Swedish Medical Research Council (Project Number 2015-03327), the Marcus Borgstrom Foundation, the [A]ke Wiberg Foundation and the Vleugels Foundation.\n\nEvidence before this studyAtopic diseases affect quality of life for a large part of the human population and pose a very high socio-economic burden. Genetic, environmental, and a number of lifestyle factors influence our risk of developing atopic disorders and high familial prevalence is one of the strongest known risk factors for disease. Several environmental and lifestyle risk factors have already been well established in the scientific community, such as smoking on the risk of developing asthma. Breastfeeding is commonly argued to be protective against atopic diseases. However, studies aiming to quantify these protective effects have shown conflicting results.\n\nAdded value of this studyOur study is, to our knowledge, the largest investigation on how breastfeeding is associated with being diagnosed with asthma, hay fever and eczema at adult age. The study found breastfeeding to be associated with increased odds of being diagnosed with hay fever and eczema during life, while we found no association between breastfeeding and asthma. Our results for hay fever and eczema is in line with the western world hygiene hypothesis, but contradict the general picture of breastfeeding being protective.\n\nImplications of all the available evidenceTo be able to give parents correct advice on lifestyles choices that will protect their kids against atopic diseases, we need to clarify the currently conflicting results on the effect of breastfeeding on risk of atopic diseases. However, these results should not be used to recommend breastfeeding or to discourage it since the present study only investigates the association between breastfeeding history and being diagnosed with asthma, hay fever and eczema during lifetime.\n\nAbbreviations

epidemiology↗

bioRxiv2017

Associations Of Prenatal And Postnatal Growth With Insulin-Like Growth Factor-I Levels In Pre-Adolescence

BackgroundRapid pre - and postnatal growth have been associated with later life adverse health outcomes, which could implicate (as a mediator) circulating insulin-like-growth-factor I (IGF-I), an important regulator of growth. We investigated associations of prenatal (birth weight and length) and postnatal growth in infancy and childhood with circulating IGF-I measured at 11.5 years of age.\n\nMethodsWe analysed 11.5-year follow-up data from 17,046 Belarusian children who participated in the Promotion of Breastfeeding Intervention Trial (PROBIT) since birth.\n\nResultsComplete data were available for 5422 boys and 4743 girls (60%). We stratified the analyses by sex, as there was evidence of interaction between growth and sex in their associations with IGF-I. Weight and length/height velocity during childhood were positively associated with IGF-I at 11.5 years; associations increased with age at growth assessment and were stronger for length/height gain than for weight gain. The change in internal run-normalized IGF-I z-score at 11.5 years was 0.038 (95% CI -0.004,0.080) per standard deviation (SD) increase in length gain at 0-3 months amongst girls and 0.025 (95% CI - 0.011,0.060) amongst boys, increasing to 0.336 (95% CI 0.281,0.391;) and 0.211 (95% CI 0.165,0.256) for girls and boys, respectively, for growth during 6.5-11.5 years.\n\nConclusionPostnatal growth velocities in childhood are positively associated with levels of circulating IGF-I in pre-adolescents. Future studies should focus on assessing whether IGF-I is on the causal pathway between early growth and later health outcomes, such as cancer and diabetes.

epidemiology↗

bioRxiv2017

The underestimated importance of acute infections by human papillomaviruses

Most infections by human papillomaviruses (HPVs) are acute, that is non-persistent. Yet, for HPVs, as for many other oncoviruses, there is a striking gap between our detailed understanding of chronic infections and our limited data on the early stages of infection. Here we argue that studying HPV acute infections is necessary and timely. Focusing on early interactions will help explain why certain infections are cleared while others become chronic or latent. From a molecular perspective, descriptions of immune effectors and pro-inflammatory pathways during the initial stages of infections have the potential to lead to novel treatments or to improved handling algorithms. From a dynamical perspective, adopting concepts from spatial ecology, such as meta-populations or meta-communities, can help explain why HPV acute infections sometimes last for years. Furthermore, cervical cancer screening and vaccines impose novel iatrogenic pressures on HPVs, implying that anticipating any viral evolutionary response remain essential. Finally, hints at the associations between HPV acute infections and fertility deserve further investigation given their high worldwide prevalence. Overall, understanding asymptomatic and benign infections may be instrumental in reducing HPV virulence.

epidemiology↗

bioRxiv2017

Staphylococcus aureus Colonization And Familial Transmission Over A One Year Period

Methods177 adults and 86 minors comprising 95 family units were enrolled from two counties in Iowa and followed up for 52 weeks. Random effects logistic regression was used to test the effect of different risk factors on the probability of an individual falling into a different S. aureus colonization categories. Additionally, the frequency of S. aureus colonization events and familial transmission events were calculated.\n\nResultsThe number of positive environmental sites within a participants house was associated with being a persistent carrier compared to being a non-carrier or intermittent carrier. Age, sharing bath towels, and the number of positive environmental sites within a participants house were associated with being a persistent or intermittent carrier. Colonization events per year were 3.95 for adults and 3.04 for minors. Duration of colonization was longest for persistent carriers (92.3 days for adults and 97.8 days for minors), and intermittent carriers had the most colonization events.\n\nConclusionsThe average duration of colonization was significantly different when comparing intermittent carriers and non-carriers. We have also established estimates of the duration of colonization and the frequency of transmission events among family units in a non-healthcare population.

epidemiology↗

bioRxiv2017

Demoralization among cancer patients in mainland China: validity of the Demoralization Scale (DS)

Demoralization, characterized by hopelessness, helplessness, and loss of meaning and purpose, reflects existential distress. The objectives is To assess the validity of a Mainland Chinese versions of the demoralization scale (MC-DS) for using with Mainland Chinese cancer patients. In-patients sequentially recruited from a specialist tertiary-level cancer hospital in Beijing between January 2016-April 2016 completed Demoralization Scale, (DS) Patient Health Questionnaire-9 (PHQ-9), Revised Life Orientation Test (CLOT-R), Beck Hopelessness Scale (BHS), and provided sociodemographic and clinical information. We determined DS factor structure and convergent and divergent validity. 296/424 (70.0%) participants reported mean DS score=30.42(SD=13.00). EFA identified 3-factors explaining 21.4%, 17.8%, and 10.6% respectively of observed variance. Respective Cronbach Alphas were 0.88, 0.84, and 0.64 (0.90 full-scale). Convergent was shown by PHQ-9 scores correlating with Factor 2 (r=0.606), and BHS and C-LOT-R scores correlating (r=0.632,r=0.407 respectively) with Factor 1. Dichotomizing demoralization (high >30, low[less double equals]30) cross-tabulated against PHQ-9 score (mood) scores revealed 47% of patients exceeded demoralization cut-off, 60% of whom were not depressed. Using mean value{+/-}SD indicated demoralization cutoffs at <17.4 (low), 17.4-43.4 (medium) and >43.4 (high). Overall 71% met criteria for medium demoralization, and 15% for high demoralization. Sixty percent of all medium demoralization patients were not depressed, but only 5% of high demoralization patients were not depressed. The conclusion is that the Mainland Chinese Demoralization Scale is useful for detecting mild-to-moderate demoralization in cancer patients but at higher scores has poor specificity against depression.

epidemiology↗

bioRxiv2017

Detecting Local Zika Virus Transmission In The Continental United States: A Comparison Of Surveillance Strategies

IntroductionThe 2015-2017 Zika virus (ZIKV) epidemic in the Americas has driven efforts to strengthen surveillance systems and to develop interventions, testing, and travel recommendations. In the continental U.S. and Hawaii, where limited transmission has been observed, detecting local transmission is a key public health objective. We assessed the effectiveness of three general surveillance strategies for this situation: testing all pregnant women twice during pregnancy, testing blood donations, and testing symptomatic people who seek medical care in an emergency department (ED).\n\nMethodsWe developed a simulation model for each surveillance strategy and simulated different transmission scenarios with varying population sizes and infection rates. We then calculated the probability of detecting transmission, the number of tests needed, and the number of false positive test results.\n\nResultsThe probability of detecting ZIKV transmission was highest for testing ED patients with Zika symptoms, followed by pregnant women and blood donors, in that order. The magnitude of the difference in probability of detection between strategies depended on the incidence of infection. Testing ED patients required fewer tests and resulted in fewer false positives than surveillance among pregnant women. The optimal strategy identified was to test ED patients with at least two Zika virus disease symptoms. This case definition resulted in a high probability of detection with relatively few tests and false positives.\n\nDiscussionIn the continental U.S. and Hawaii, where local ZIKV transmission is rare, optimizing the probability of detecting infections while minimizing resource usage is particularly important. Local surveillance strategies will be influenced by existing public health system infrastructure, but should also consider the effectiveness of different approaches. This analysis demonstrated differences across strategies and indicated that testing symptomatic ED patients is generally a more efficient strategy for detecting transmission than routine testing of pregnant women or blood donors.

epidemiology↗

bioRxiv2017

A Cross-Sectional Study Of Staphylococcus aureus Colonization And The Nasal And Oropharyngeal Microbiomes

BackgroundStaphylococcus aureus is a frequent cause of both infections globally. Colonization with the organism is known to increase the risk of developing infections and occurs in roughly one third of the general population. While many factors influence colonization, it has been demonstrated other members of the microbiome influence colonization with S. aureus. Here, we assessed the nasal and oropharyngeal microbiomes of healthy participants in relation to S. aureus colonization in a cross-sectional study using 16s rRNA sequencing of the v1-v3 region. As livestock workers have also been shown to be at an increased risk of carriage, we have also assessed microbiota differences in colonization status in a population of livestock workers.\n\nResultsIn both the nares and oropharynx, there were no microbiota differentially abundant between colonized and non-colonized persons. However, there was a significant difference in the beta diversity (Bray-Curtis distances) between carriers and non-carriers (P=0.002). When considering carriage stratified by livestock exposure, there were a number of differences. Most notably, colonized livestock workers had significantly more Porphyomonas (2-fold change = -8.54, P = 0.03) than the non-colonized livestock workers.\n\nConclusionsS. aureus is a frequent colonizer of the human upper respiratory tract, including the nares and oropharynx and causes a wide range of infections. Livestock workers are at increased risk for carriage. Interventions such as improving oral hygiene may lead to decreased S. aureus carriage by reducing other bacterial species such as Porphyomonas. Larger, longitudinal studies are needed to better explore what microorganisms may be associated with S. aureus colonization.

epidemiology↗

bioRxiv2017

Exposing the Exposome with Global Metabolomics andCognitive Computing

Concurrent exposure to a wide variety of xenobiotics and their combined toxic effects can play a pivotal role in health and disease, yet are largely unexplored. Investigating the totality of these exposures, i.e. the exposome, and their specific biological effects constitutes a new paradigm for environmental health but still lacks high-throughput, user-friendly technology. We demonstrate the utility of mass spectrometry-based global exposure metabolomics combined with tailored database queries and cognitive computing for comprehensive exposure assessment and the straightforward elucidation of biological effects. The METLIN Exposome database has been redesigned to help identify environmental toxicants, food contaminants and supplements, drugs, and antibiotics as well as their biotransformation products, through its expansion with over 700,000 chemical structures to now include more than 950,000 unique small molecules. More importantly, we demonstrate how the XCMS/METLIN platform now allows for the readout of the biological effect of a toxicant through metabolomic-derived pathway analysis and further, cognitive computing provides a means of assessing the role of a potential toxicant. The presented workflow addresses many of the outstanding methodological challenges current exposome research is facing and will serve to gain a deeper understanding of the impact of environmental exposures and combinatory toxic effects on human health.

epidemiology↗

bioRxiv2017

Changing geographic patterns and risk factors for avian influenza A(H7N9) infection in China

The 5th epidemic wave in 2016-2017 of avian influenza A(H7N9) virus in China caused more human cases than any previous waves but the factors that may explain the recent range expansion and surge in incidence remain unknown. We investigated the effect of anthropogenic, poultry and wetland information and of market closures on all epidemic waves (1-5). Poultry predictor variables recently became much more important than before, supporting the assumption of much wider H7N9 transmission in the chicken reservoir, that could be linked to increases in pathogenicity. We show that the future range expansion of H7N9 to northern China may translate into a higher risk of coinciding peaks with those of seasonal influenza, leading to a higher risk of reassortments. Live-poultry market closures are showed to be effective in reducing the local incidence rates of H7N9 human cases, but should be paired with other prevention and control measures to prevent transmission.

epidemiology↗

bioRxiv2017

Women’s estimated HIV infections from sex in trials of pre-exposure prophylaxis in Africa: Implications for HIV prevention strategies

IntroductionDuring 2004-15, nine randomized controlled trials (RCT) for HIV prevention tested pre-exposure prophylaxis (PrEP) with oral drugs, vaginal gels, or vaginal rings among more than 17,000 women in Africa.\n\nMethodsThis study uses information from the nine RCTs to estimate the proportions of HIV from sexual and bloodborne risks, to consider reasons for success or failure with oral PrEP, and to consider risks with vaginal PrEP.\n\nResultsEstimating from womens reported frequencies of unprotected coital acts in six RCTs, only a minority of womens infections came from sex. Oral PrEP may have succeeded in at least one trial by reducing infections from both bloodborne and sexual risks. Oral PrEP may have failed in several trials, at least in part, because some women used oral PrEP when they had sexual risks rather than daily as advised. Relatively high incidence with PrEP vaginal gels and rings vs. oral placebo suggests vaginal PrEP had little impact at best and may have been harmful.\n\nDiscussionEvidence from this and other studies challenges the common belief most HIV in Africa comes from sex. This challenge has implications for HIV prevention strategies, including: warning about bloodborne risks; and reconsidering PrEP for young women.

epidemiology↗

bioRxiv2017

Ecological characterization and infection of Anophelines (Diptera: Culicidae) of the Atlantic Forest in the southeast of Brazil over a 10 year period: Has the behaviour of the autochthonous malaria vector changed?

In the south and southeast of Brazil, autochthonous malaria cases can be found near Atlantic Forest fragments. The transmission is not totally clarified; thus, the behaviour of the possible vectors in those regions must be observed. An entomological and natural infection study was performed on anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espirito Santo state in 2004-2005. Similarly, between the years 2014 and 2015, 12 monthly collections were performed at the permanent trapping station of the study mentioned above (Valsugana Velha, Santa Teresa, ES). Light traps with CO2 (CO2-baited Center for Disease Control [CDC] traps) were set in open areas, at the edge of the forest (canopy and ground) and inside the forest (canopy and ground), whereas Shannon traps were set on the edge of the forest. A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most captured species in the CO2-baited CDC traps set in the forest canopy and was also the vector with the highest prevalence of Plasmodium vivax infection according to molecular PCR techniques. Regarding mosquitoes of the subgenus Nyssorhynchus, P. vivax was found only in abdomens, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.\n\nSponsorshipEspirito Santo Research Foundation (Fundacao de Amparo a Pesquisa e Inovacao do Espirito Santo - FAPES).

epidemiology↗

bioRxiv2017

On the relative role of different age groups during influenza A epidemics in Germany, 2002-2017

BackgroundThere is limited information about the role of different age groups, particularly subgroups of school-age children and younger adults in propagating influenza epidemics.\n\nMethodsFor a communicable disease outbreak, some subpopulations may play a disproportionate role during the ascent of the outbreak due to increased susceptibility and/or contact rates. Such subpopulations can be identified by considering the proportion that cases in a subpopulation represent among all cases in the population occurring before the epidemic peak (Bp), the corresponding proportion after the epidemic peak (Ap), to calculate the relative risk for a subpopulation, RR=Bp/Ap. We estimated RR for several age groups using data on reported influenza A cases in Germany between 2002-2017.\n\nResultsChildren aged 14-17y had the highest RR estimates for 7 out of 15 influenza A epidemics in the data, including the 2009 pandemic, and the large 2016/17, 2008/09, and 2006/07 seasons. Children aged 10-13y had the highest RR estimates during 3 epidemics, including the large 2014/15 and 2004/05 seasons. Children aged 6-9y had the highest RR estimates during two epidemics, including the large 2012/13 season. Children aged 2-5y had the highest RR estimate during the moderate 2015/16 season; adults aged 18-24y had the highest RR estimate during the small 2005/06 season; adults aged 25-34y had the highest RR estimate during the large, 2002/03 season.\n\nConclusionsOur results support the prominent role of all school-age children, particularly the oldest ones, in propagating influenza epidemics in the community. We note that national vaccination coverage levels among older school-age children were lower than among younger school-age children during the recent influenza seasons in the US, and influenza vaccination program in England has not been phased in yet for secondary school students.

epidemiology↗