Children with Congenital Zika Syndrome and microcephaly are at high risk for epilepsy; however, t... more Children with Congenital Zika Syndrome and microcephaly are at high risk for epilepsy; however, the risk is unclear in normocephalic children with prenatal Zika virus (ZIKV) exposure [Exposed Children (EC)]. In this prospective cohort study, we performed epilepsy screening in normocephalic EC alongside a parallel group of normocephalic unexposed children [Unexposed Children (UC)]. We compared the incidence rate of epilepsy among EC and UC at one year of life to global incidence rates. Pregnant women were recruited from public health centers during the ZIKV outbreak in Grenada, West Indies and assessed for prior ZIKV infection using a plasmonic-gold platform that measures IgG antibodies in serum. Normocephalic children born to mothers with positive ZIKV results during pregnancy were classified as EC and those born to mothers with negative ZIKV results during and after pregnancy were classified as UC. Epilepsy screening procedures included a pediatric epilepsy screening questionnaire ...
Additional File 1. Socioeconomic Status Survey. The 84-question socioeconomic status and family p... more Additional File 1. Socioeconomic Status Survey. The 84-question socioeconomic status and family planning survey used to determine SES using WAMI index and PCA asset score. Adapted from Psaki et al.
Additional file 1: Figure S1. Correlation of HOBO logger temperature data between nearest clinica... more Additional file 1: Figure S1. Correlation of HOBO logger temperature data between nearest clinical sites and with Weather Underground data. Left panel: comparison of HOBO logger temperature data between nearest clinical site (top: Msambweni and Ukunda; bottom: Kisumu and Chulaimbo). Middle and right panels: comparison of HOBO logger temperature data at a clinical site and Weather Underground data from the nearest weather station (weather station code for Msambweni and Ukunda is HKMO and for Kisumu and Chulaimbo is HKKI). Dashed black lines indicate the regression line where y = x; blue lines indicate the linear regression between the two data sets (y = mx + b). The linear regression equations (blue lines) were used to adjust source data to fill in missing data. Figure S2. The nonlinear effect of temperature on malaria smear positivity. The plot shows the nonlinear effect of temperature alone on the odds of malaria smear positivity using a structured additive regression model (R2Baye...
Additional file 1. Semi-structured interview guide (modified and reproduced from Baltzell et al. ... more Additional file 1. Semi-structured interview guide (modified and reproduced from Baltzell et al. [5] with permission).
Abstract: On a global basis, both potent vaccine efficacy and high vaccine coverage are necessary... more Abstract: On a global basis, both potent vaccine efficacy and high vaccine coverage are necessary to control and eliminate vaccine-preventable diseases. Emerging evi-dence from animal and human studies suggest that neglected tropical diseases (NTDs) significantly impair response to standard childhood immunizations. A review of efficacy and effectiveness studies of vaccination among individuals with chronic parasitic infections was conduct-ed, using PUBMED database searches and analysis of data from the authors ’ published and unpublished studies. Both animal models and human studies suggest that chronic trematode, nematode, and protozoan infections can result in decreased vaccine efficacy. Among pregnant women, who in developing countries are often infected with multiple parasites, soluble parasite antigens have
Background. ZikaVirus (ZIKV) infection during pregnancy has severe potential consequence to the f... more Background. ZikaVirus (ZIKV) infection during pregnancy has severe potential consequence to the fetus. Despite limited endemic transmission in the continental US, travel/ sexual exposurein the periconception/pregnancy period requires experienced multidisciplinary care to assess potential infection and effects in the fetus. Methods. The Congenital Zika Program at Children's National (CZPCN) was developed to meet need for pre-and post-natal consultation in the setting of Zika exposure/infection during pregnancy. CZPCR includes multidisciplinary expertise in fetal imaging, pediatric infectious diseases, fetal and pediatric neurology. Services include a hotline, facilitation of ZIKV testing and interpretation, detailed fetal MRI/ US, delivery instructions to faciliate postnatal evaluation of ZIKV exposed/infected fetuses and educational outreach to providers regarding ZIKV. Results. Between Jan 2016 and May 2017, 36 women/fetuses were evaulated atby CZPCN for possible ZIKV infection during pregnancy (32 US residents who traveled, 2 with partner who traveled, 2 emigrees). An additional 14 women/infant pairs were evaluated following postnatal referral to our program. Exposure route included direct arboviral (89 %) and/or potential sexual exposure (48%). Symptoms occurred in only 6/50 (12%). Exposure occurred in the preconceptual period in 10/50 (20%), first trimester in 23/50 (46%), second trimester in 13/50 (26%), and third trimester 4/50 (8%). Nearly 50% (24/50) of women presented outside the 12 week window of exposure and could not have infection excluded. ZIKV was confirmed in 22% (11/50) or suspected due to unspecified flavivirus infection in 28% (14/50). Only 7/50 (14%) had negative PCR/IgM testing in appropriate window to exclude infection. Two fetuses with severe involement were not carried to term, 1 was carried to term but died immediately after birth and 1 died within the first year of life. Conclusion. CZPCN fills a critical need within our region to faciliate evaluation of exposed/infected pregnant women/fetuses/infants including neurodevelopmental followup of affected suriving infants.. Lessons learned are instructive to other centers developing programs, needed as the range of endemic Zika transmission expands. Disclosures. All authors: No reported disclosures.
BackgroundRift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts... more BackgroundRift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts of Africa, the Arabian Peninsula, and the Indian Ocean. This systematic review’s objective was to consolidate understanding of RVFV epidemiology during 1999-2021 and highlight knowledge gaps relevant to plans for human vaccine trials.Methodology/Principal FindingsThe review is registered with PROSPERO (CRD42020221622). Reports of RVFV infection or exposure among humans, animals, and/or vectors in Africa, the Arabian Peninsula, and the Indian Ocean during the period January 1999 to June 2021 were eligible for inclusion. Online databases were searched for publications, and supplemental materials were recovered from official reports and research colleagues. Exposures were classified into five groups: 1) acute human RVF cases, 2) acute animal cases, 3) human RVFV sero-surveys, 4) animal sero-surveys, and 5) arthropod infections. Human risk factors, circulating RVFV lineages, and surveillanc...
Climate change and variability influence temperature and rainfall, which impact vector abundance ... more Climate change and variability influence temperature and rainfall, which impact vector abundance and the dynamics of vector-borne disease transmission. Climate change is projected to increase the frequency and intensity of extreme climate events. Mosquito-borne diseases, such as dengue fever, are primarily transmitted by Aedes aegypti mosquitoes. Freshwater availability and temperature affect dengue vector populations via a variety of biological processes and thus influence the ability of mosquitoes to effectively transmit disease. However, the effect of droughts, floods, heat waves, and cold waves is not well understood. Using vector, climate, and dengue disease data collected between 2013 and 2019 in Kenya, this retrospective cohort study aims to elucidate the impact of extreme rainfall and temperature on mosquito abundance and the risk of arboviral infections. To define extreme periods of rainfall and land surface temperature (LST), we calculated monthly anomalies as deviations f...
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Zika virus (ZIKV) is a mosquito-borne, single-stranded DNA flavivirus that is teratogenic and neu... more Zika virus (ZIKV) is a mosquito-borne, single-stranded DNA flavivirus that is teratogenic and neurotropic. Similar to the teratogenic effects of other TORCH infections, ZIKV infection during pregnancy can have an adverse impact on fetal and neonatal development. Epilepsy is detected in 48-96% of children with Congenital Zika Syndrome (CZS) and microcephaly. Early epilepsy surveillance is needed in children with prenatal ZIKV exposure; yet, most ZIKV-endemic regions do not have specialist epilepsy care. Here, we describe the demographic, clinical, imaging, and EEG characteristics of a 2-year-old child with CZS and microcephaly who presented with focal epileptiform activity, suboptimal growth, and severe neurodevelopmental delays. Administration of a brief seizure questionnaire by allied health professionals to the patient's caregiver helped to characterize the child's seizure semiology and differentiate focal from generalized seizure features. A telemedicine EEG interpretation platform provided valuable diagnostic information for the patient's local pediatrician to integrate into her treatment plan. This case illustrates that CZS can present with focal epilepsy features and that a telemedicine approach can be used to bridge the gap between epilepsy specialists and local care providers in resource limited ZIKV-endemic regions to achieve better seizure control in children with CZS.
Malaria is a longstanding public health problem in sub-Saharan Africa, while arthropod-borne viru... more Malaria is a longstanding public health problem in sub-Saharan Africa, while arthropod-borne viruses (arboviruses) like dengue and chikungunya cause an underrecognized burden of disease. While many human and environmental drivers affect the dynamics of vector-borne diseases, here we argue that the direct effects of warming temperatures are likely to promote greater environmental suitability for dengue and other arboviruses transmitted by Aedes aegypti while reducing the suitability for malaria transmitted by Anopheles gambiae. Environmentally-driven changes in disease dynamics will no doubt be complex and heterogeneous, but given that current public efforts are targeted to malaria control, we encourage the public health community to consider Aedes aeypgti and dengue, chikungunya, and other arboviruses as potential emerging public health threats in sub-Saharan Africa.
The goal of this study was to systematically review the published data on dengue virus (DENV) ser... more The goal of this study was to systematically review the published data on dengue virus (DENV) seroprevalence in Sudan and to estimate disease burden through meta-analysis. We searched, reviewed, and extracted online available reports on DENV in Sudan. Among 168 identified records, 19 were selected. Dengue infections were documented in 11/18 states. The overall seroprevalence of DENV in Sudan was estimated to be 27%, while the prevalence of dengue IgM was 22% and IgG was 38%. The prevalence of dengue estimated from community and hospital-based cross-sectional studies were 26% and 30% respectively. Additionally, one cohort study and a single PCR-based study reported a prevalence of 1% and 4%, respectively. Regional analysis revealed that the variation in seroprevalence in East, North, West, and Central Sudan was 23%, 24%, 36% and 43%, respectively. Interestingly, we found that DENV is circulating countrywide with a significant spatiotemporal variation in the disease seroprevalence. Fu...
Climate drives population dynamics through multiple mechanisms, which can lead to seemingly conte... more Climate drives population dynamics through multiple mechanisms, which can lead to seemingly context-dependent effects of climate on natural populations. For climate-sensitive diseases such as dengue, chikungunya, and Zika, climate appears to have opposing effects in different contexts. Here we show that a model, parameterized with laboratory measured climate-driven mosquito physiology, captures three key epidemic characteristics across ecologically and culturally distinct settings in Ecuador and Kenya: the number, timing, and duration of outbreaks. The model generates a range of disease dynamics consistent with observed Aedes aegypti abundances and laboratory-confirmed arboviral incidence with variable accuracy (28 – 85% for vectors, 44 – 88% for incidence). The model predicted vector dynamics better in sites with a smaller proportion of young children in the population, lower mean temperature, and homes with piped water and made of cement. Models with limited calibration that robus...
Background: Infectious disease epidemiology and planetary health literature often cite solid wast... more Background: Infectious disease epidemiology and planetary health literature often cite solid waste and plastic pollution as risk factors for vector-borne diseases and urban zoonoses; however, no rigorous reviews of the risks to human health have been published since 1994. This paper aims to identify research gaps and outline potential solutions to interrupt the vicious cycle of solid wastes; disease vectors and reservoirs; infection and disease; and poverty. We searched peer-reviewed publications from PubMed, Google Scholar, and Stanford Searchworks, and references from relevant articles using the search terms ("disease" OR "epidemiology") AND ("plastic pollution," "garbage," and "trash," "rubbish," "refuse," OR "solid waste"). Abstracts and reports from meetings were included only when they related directly to previously published work. Only articles published in English, Spanish, or Portuguese through 2018 were included, with a focus on post-1994, after the last comprehensive review was published. Cancer, diabetes, and food chain-specific articles were outside the scope and excluded. After completing the literature review, we further limited the literature to "urban zoonotic and biological vector-borne diseases" or to "zoonotic and biological vector-borne diseases of the urban environment." Results: Urban biological vector-borne diseases, especially Aedes-borne diseases, are associated with solid waste accumulation but vector preferences vary over season and region. Urban zoonosis, especially rodent and canine disease reservoirs, are associated with solid waste in urban settings, especially when garbage accumulates over time, creating burrowing sites and food for reservoirs. Although evidence suggests the link between plastic pollution/solid waste and human disease, measurements are not standardized, confounders are not rigorously controlled, and the quality of evidence varies. Here we propose a framework for solutions-based research in three areas: innovation, education, and policy. Krystosik et al. Solid Wastes and Disease Vectors and Reservoirs Conclusions: Disease epidemics are increasing in scope and scale with urban populations growing, climate change providing newly suitable vector climates, and immunologically naïve populations becoming newly exposed. Sustainable solid waste management is crucial to prevention, specifically in urban environments that favor urban vectors such as Aedes species. We propose that next steps should include more robust epidemiological measurements and propose a framework for solutions-based research.
Background Congenital Zika Syndrome (CZS) has a broad spectrum of clinical presentations that are... more Background Congenital Zika Syndrome (CZS) has a broad spectrum of clinical presentations that are still being described. This cohort study aimed to describe the orthopedic complications in children with microcephaly (MCP) related to Zika virus (ZIKV). Methods We evaluated 36 children with CZS up to 17 months of age followed at a pediatric rehabilitation center in the northeast of Brazil. Cohort enrollment occurred with children born between January 2015 and May 2016. We assessed their social profiles and orthopedic findings. Results Of the 36 cases, 25 were male. All of them lived in rural area. 25 had at least one congenital orthopedic alteration. Hip subluxation was the most common problem detected (n = 15); other lower limb abnormalities included knee subluxation (n = 7), clubfoot (n = 7); congenital vertical talus (n = 4); plano-valgus foot (n = 5). In relation to the upper limbs, 11 children presented with some shoulder and/or elbow abnormality and 16 had some alteration in the...
Background Infant mortality in Brazil has increased for the first time in 26 years. This study ai... more Background Infant mortality in Brazil has increased for the first time in 26 years. This study aimed to define the Zika Syndrome (ZS) perinatal case fatality rate (PCF) since the 2015 Zika outbreak in a Brazilian northeast state highly impacted by the virus. Methods Cross-sectional study conducted using data obtained through the State Health Department for cases of microcephaly (MCP) and congenital abnormalities (CA) in Rio Grande do Norte State (RN) from April 2015 to March 2, 2019. Perinatal period: commencing at 22 completed weeks (154 days) of gestation until 7 days after birth. PCF was defined as the number of deaths as a fraction of the number of sick persons with the specific disease (×100). Results There were 535 reported cases of MCP and others CA notified in RN during this period: 4 in 2014, 337 in 2015, 157 in 2016, 21 in 2017, 14 in 2018, and 2 in 2019. Of these, 151 were confirmed and 135 remain under investigation. The remaining 247 cases were ruled out by normal physi...
Background: Ambient temperature is an important determinant of malaria transmission and suitabili... more Background: Ambient temperature is an important determinant of malaria transmission and suitability, affecting the life-cycle of the Plasmodium parasite and Anopheles vector. Early models predicted a thermal malaria transmission optimum of 31 °C, later revised to 25 °C using experimental data from mosquito and parasite biology. However, the link between ambient temperature and human malaria incidence remains poorly resolved. To evaluate the relationship between ambient temperature and malaria risk, 5833 febrile children (<18 years-old) with an acute, non-localizing febrile illness were enrolled from four heterogenous outpatient clinic sites in Kenya (Chulaimbo, Kisumu, Msambweni and Ukunda). Thick and thin blood smears were evaluated for the presence of malaria parasites. Daily temperature estimates were obtained from land logger data, and rainfall from National Oceanic and Atmospheric Administration (NOAA)'s Africa Rainfall Climatology (ARC) data. Thirty-day mean temperature and 30-day cumulative rainfall were estimated and each lagged by 30 days, relative to the febrile visit. A generalized linear mixed model was used to assess relationships between malaria smear positivity and predictors including temperature, rainfall, age, sex, mosquito exposure and socioeconomic status. Results: Malaria smear positivity varied between 42-83% across four clinic sites in western and coastal Kenya, with highest smear positivity in the rural, western site. The temperature ranges were cooler in the western sites and warmer in the coastal sites. In multivariate analysis controlling for socioeconomic status, age, sex, rainfall and bednet use, malaria smear positivity peaked near 25 °C at all four sites, as predicted a priori from an ecological model. This study provides direct field evidence of a unimodal relationship between ambient temperature and human malaria incidence with a peak in malaria transmission occurring at lower temperatures than previously recognized clinically. This nonlinear relationship with an intermediate optimal temperature implies that future climate warming could expand malaria incidence in cooler, highland regions while decreasing incidence in already warm regions with average temperatures above 25 °C. These findings support efforts to further understand the nonlinear association between ambient temperature and vector-borne diseases to better allocate resources and respond to disease threats in a future, warmer world.
Nomadic pastoralists are among the worlds hardest-to-reach and least-served populations. Pastoral... more Nomadic pastoralists are among the worlds hardest-to-reach and least-served populations. Pastoralist communities are notoriously difficult to capture in household surveys due to factors including their high degree of mobility, remote terrain, fluid domestic arrangements, and cultural barriers. Most surveys utilize census-based sampling frames which do not accurately capture the demographic and health parameters of nomadic populations. As a result, pastoralists are largely invisible in population data such as the Demographic and Health Surveys (DHS). By combining remote sensing and geospatial analysis, we developed a sampling strategy designed to capture the current distribution of nomadic populations. We then implemented this sampling frame to survey a population of mobile pastoralists in southwest Ethiopia, focusing on maternal and child health (MCH) indicators. Using standardized instruments from DHS questionnaires, we surveyed this population in order to draw comparisons with reg...
Children with Congenital Zika Syndrome and microcephaly are at high risk for epilepsy; however, t... more Children with Congenital Zika Syndrome and microcephaly are at high risk for epilepsy; however, the risk is unclear in normocephalic children with prenatal Zika virus (ZIKV) exposure [Exposed Children (EC)]. In this prospective cohort study, we performed epilepsy screening in normocephalic EC alongside a parallel group of normocephalic unexposed children [Unexposed Children (UC)]. We compared the incidence rate of epilepsy among EC and UC at one year of life to global incidence rates. Pregnant women were recruited from public health centers during the ZIKV outbreak in Grenada, West Indies and assessed for prior ZIKV infection using a plasmonic-gold platform that measures IgG antibodies in serum. Normocephalic children born to mothers with positive ZIKV results during pregnancy were classified as EC and those born to mothers with negative ZIKV results during and after pregnancy were classified as UC. Epilepsy screening procedures included a pediatric epilepsy screening questionnaire ...
Additional File 1. Socioeconomic Status Survey. The 84-question socioeconomic status and family p... more Additional File 1. Socioeconomic Status Survey. The 84-question socioeconomic status and family planning survey used to determine SES using WAMI index and PCA asset score. Adapted from Psaki et al.
Additional file 1: Figure S1. Correlation of HOBO logger temperature data between nearest clinica... more Additional file 1: Figure S1. Correlation of HOBO logger temperature data between nearest clinical sites and with Weather Underground data. Left panel: comparison of HOBO logger temperature data between nearest clinical site (top: Msambweni and Ukunda; bottom: Kisumu and Chulaimbo). Middle and right panels: comparison of HOBO logger temperature data at a clinical site and Weather Underground data from the nearest weather station (weather station code for Msambweni and Ukunda is HKMO and for Kisumu and Chulaimbo is HKKI). Dashed black lines indicate the regression line where y = x; blue lines indicate the linear regression between the two data sets (y = mx + b). The linear regression equations (blue lines) were used to adjust source data to fill in missing data. Figure S2. The nonlinear effect of temperature on malaria smear positivity. The plot shows the nonlinear effect of temperature alone on the odds of malaria smear positivity using a structured additive regression model (R2Baye...
Additional file 1. Semi-structured interview guide (modified and reproduced from Baltzell et al. ... more Additional file 1. Semi-structured interview guide (modified and reproduced from Baltzell et al. [5] with permission).
Abstract: On a global basis, both potent vaccine efficacy and high vaccine coverage are necessary... more Abstract: On a global basis, both potent vaccine efficacy and high vaccine coverage are necessary to control and eliminate vaccine-preventable diseases. Emerging evi-dence from animal and human studies suggest that neglected tropical diseases (NTDs) significantly impair response to standard childhood immunizations. A review of efficacy and effectiveness studies of vaccination among individuals with chronic parasitic infections was conduct-ed, using PUBMED database searches and analysis of data from the authors ’ published and unpublished studies. Both animal models and human studies suggest that chronic trematode, nematode, and protozoan infections can result in decreased vaccine efficacy. Among pregnant women, who in developing countries are often infected with multiple parasites, soluble parasite antigens have
Background. ZikaVirus (ZIKV) infection during pregnancy has severe potential consequence to the f... more Background. ZikaVirus (ZIKV) infection during pregnancy has severe potential consequence to the fetus. Despite limited endemic transmission in the continental US, travel/ sexual exposurein the periconception/pregnancy period requires experienced multidisciplinary care to assess potential infection and effects in the fetus. Methods. The Congenital Zika Program at Children's National (CZPCN) was developed to meet need for pre-and post-natal consultation in the setting of Zika exposure/infection during pregnancy. CZPCR includes multidisciplinary expertise in fetal imaging, pediatric infectious diseases, fetal and pediatric neurology. Services include a hotline, facilitation of ZIKV testing and interpretation, detailed fetal MRI/ US, delivery instructions to faciliate postnatal evaluation of ZIKV exposed/infected fetuses and educational outreach to providers regarding ZIKV. Results. Between Jan 2016 and May 2017, 36 women/fetuses were evaulated atby CZPCN for possible ZIKV infection during pregnancy (32 US residents who traveled, 2 with partner who traveled, 2 emigrees). An additional 14 women/infant pairs were evaluated following postnatal referral to our program. Exposure route included direct arboviral (89 %) and/or potential sexual exposure (48%). Symptoms occurred in only 6/50 (12%). Exposure occurred in the preconceptual period in 10/50 (20%), first trimester in 23/50 (46%), second trimester in 13/50 (26%), and third trimester 4/50 (8%). Nearly 50% (24/50) of women presented outside the 12 week window of exposure and could not have infection excluded. ZIKV was confirmed in 22% (11/50) or suspected due to unspecified flavivirus infection in 28% (14/50). Only 7/50 (14%) had negative PCR/IgM testing in appropriate window to exclude infection. Two fetuses with severe involement were not carried to term, 1 was carried to term but died immediately after birth and 1 died within the first year of life. Conclusion. CZPCN fills a critical need within our region to faciliate evaluation of exposed/infected pregnant women/fetuses/infants including neurodevelopmental followup of affected suriving infants.. Lessons learned are instructive to other centers developing programs, needed as the range of endemic Zika transmission expands. Disclosures. All authors: No reported disclosures.
BackgroundRift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts... more BackgroundRift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts of Africa, the Arabian Peninsula, and the Indian Ocean. This systematic review’s objective was to consolidate understanding of RVFV epidemiology during 1999-2021 and highlight knowledge gaps relevant to plans for human vaccine trials.Methodology/Principal FindingsThe review is registered with PROSPERO (CRD42020221622). Reports of RVFV infection or exposure among humans, animals, and/or vectors in Africa, the Arabian Peninsula, and the Indian Ocean during the period January 1999 to June 2021 were eligible for inclusion. Online databases were searched for publications, and supplemental materials were recovered from official reports and research colleagues. Exposures were classified into five groups: 1) acute human RVF cases, 2) acute animal cases, 3) human RVFV sero-surveys, 4) animal sero-surveys, and 5) arthropod infections. Human risk factors, circulating RVFV lineages, and surveillanc...
Climate change and variability influence temperature and rainfall, which impact vector abundance ... more Climate change and variability influence temperature and rainfall, which impact vector abundance and the dynamics of vector-borne disease transmission. Climate change is projected to increase the frequency and intensity of extreme climate events. Mosquito-borne diseases, such as dengue fever, are primarily transmitted by Aedes aegypti mosquitoes. Freshwater availability and temperature affect dengue vector populations via a variety of biological processes and thus influence the ability of mosquitoes to effectively transmit disease. However, the effect of droughts, floods, heat waves, and cold waves is not well understood. Using vector, climate, and dengue disease data collected between 2013 and 2019 in Kenya, this retrospective cohort study aims to elucidate the impact of extreme rainfall and temperature on mosquito abundance and the risk of arboviral infections. To define extreme periods of rainfall and land surface temperature (LST), we calculated monthly anomalies as deviations f...
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Zika virus (ZIKV) is a mosquito-borne, single-stranded DNA flavivirus that is teratogenic and neu... more Zika virus (ZIKV) is a mosquito-borne, single-stranded DNA flavivirus that is teratogenic and neurotropic. Similar to the teratogenic effects of other TORCH infections, ZIKV infection during pregnancy can have an adverse impact on fetal and neonatal development. Epilepsy is detected in 48-96% of children with Congenital Zika Syndrome (CZS) and microcephaly. Early epilepsy surveillance is needed in children with prenatal ZIKV exposure; yet, most ZIKV-endemic regions do not have specialist epilepsy care. Here, we describe the demographic, clinical, imaging, and EEG characteristics of a 2-year-old child with CZS and microcephaly who presented with focal epileptiform activity, suboptimal growth, and severe neurodevelopmental delays. Administration of a brief seizure questionnaire by allied health professionals to the patient's caregiver helped to characterize the child's seizure semiology and differentiate focal from generalized seizure features. A telemedicine EEG interpretation platform provided valuable diagnostic information for the patient's local pediatrician to integrate into her treatment plan. This case illustrates that CZS can present with focal epilepsy features and that a telemedicine approach can be used to bridge the gap between epilepsy specialists and local care providers in resource limited ZIKV-endemic regions to achieve better seizure control in children with CZS.
Malaria is a longstanding public health problem in sub-Saharan Africa, while arthropod-borne viru... more Malaria is a longstanding public health problem in sub-Saharan Africa, while arthropod-borne viruses (arboviruses) like dengue and chikungunya cause an underrecognized burden of disease. While many human and environmental drivers affect the dynamics of vector-borne diseases, here we argue that the direct effects of warming temperatures are likely to promote greater environmental suitability for dengue and other arboviruses transmitted by Aedes aegypti while reducing the suitability for malaria transmitted by Anopheles gambiae. Environmentally-driven changes in disease dynamics will no doubt be complex and heterogeneous, but given that current public efforts are targeted to malaria control, we encourage the public health community to consider Aedes aeypgti and dengue, chikungunya, and other arboviruses as potential emerging public health threats in sub-Saharan Africa.
The goal of this study was to systematically review the published data on dengue virus (DENV) ser... more The goal of this study was to systematically review the published data on dengue virus (DENV) seroprevalence in Sudan and to estimate disease burden through meta-analysis. We searched, reviewed, and extracted online available reports on DENV in Sudan. Among 168 identified records, 19 were selected. Dengue infections were documented in 11/18 states. The overall seroprevalence of DENV in Sudan was estimated to be 27%, while the prevalence of dengue IgM was 22% and IgG was 38%. The prevalence of dengue estimated from community and hospital-based cross-sectional studies were 26% and 30% respectively. Additionally, one cohort study and a single PCR-based study reported a prevalence of 1% and 4%, respectively. Regional analysis revealed that the variation in seroprevalence in East, North, West, and Central Sudan was 23%, 24%, 36% and 43%, respectively. Interestingly, we found that DENV is circulating countrywide with a significant spatiotemporal variation in the disease seroprevalence. Fu...
Climate drives population dynamics through multiple mechanisms, which can lead to seemingly conte... more Climate drives population dynamics through multiple mechanisms, which can lead to seemingly context-dependent effects of climate on natural populations. For climate-sensitive diseases such as dengue, chikungunya, and Zika, climate appears to have opposing effects in different contexts. Here we show that a model, parameterized with laboratory measured climate-driven mosquito physiology, captures three key epidemic characteristics across ecologically and culturally distinct settings in Ecuador and Kenya: the number, timing, and duration of outbreaks. The model generates a range of disease dynamics consistent with observed Aedes aegypti abundances and laboratory-confirmed arboviral incidence with variable accuracy (28 – 85% for vectors, 44 – 88% for incidence). The model predicted vector dynamics better in sites with a smaller proportion of young children in the population, lower mean temperature, and homes with piped water and made of cement. Models with limited calibration that robus...
Background: Infectious disease epidemiology and planetary health literature often cite solid wast... more Background: Infectious disease epidemiology and planetary health literature often cite solid waste and plastic pollution as risk factors for vector-borne diseases and urban zoonoses; however, no rigorous reviews of the risks to human health have been published since 1994. This paper aims to identify research gaps and outline potential solutions to interrupt the vicious cycle of solid wastes; disease vectors and reservoirs; infection and disease; and poverty. We searched peer-reviewed publications from PubMed, Google Scholar, and Stanford Searchworks, and references from relevant articles using the search terms ("disease" OR "epidemiology") AND ("plastic pollution," "garbage," and "trash," "rubbish," "refuse," OR "solid waste"). Abstracts and reports from meetings were included only when they related directly to previously published work. Only articles published in English, Spanish, or Portuguese through 2018 were included, with a focus on post-1994, after the last comprehensive review was published. Cancer, diabetes, and food chain-specific articles were outside the scope and excluded. After completing the literature review, we further limited the literature to "urban zoonotic and biological vector-borne diseases" or to "zoonotic and biological vector-borne diseases of the urban environment." Results: Urban biological vector-borne diseases, especially Aedes-borne diseases, are associated with solid waste accumulation but vector preferences vary over season and region. Urban zoonosis, especially rodent and canine disease reservoirs, are associated with solid waste in urban settings, especially when garbage accumulates over time, creating burrowing sites and food for reservoirs. Although evidence suggests the link between plastic pollution/solid waste and human disease, measurements are not standardized, confounders are not rigorously controlled, and the quality of evidence varies. Here we propose a framework for solutions-based research in three areas: innovation, education, and policy. Krystosik et al. Solid Wastes and Disease Vectors and Reservoirs Conclusions: Disease epidemics are increasing in scope and scale with urban populations growing, climate change providing newly suitable vector climates, and immunologically naïve populations becoming newly exposed. Sustainable solid waste management is crucial to prevention, specifically in urban environments that favor urban vectors such as Aedes species. We propose that next steps should include more robust epidemiological measurements and propose a framework for solutions-based research.
Background Congenital Zika Syndrome (CZS) has a broad spectrum of clinical presentations that are... more Background Congenital Zika Syndrome (CZS) has a broad spectrum of clinical presentations that are still being described. This cohort study aimed to describe the orthopedic complications in children with microcephaly (MCP) related to Zika virus (ZIKV). Methods We evaluated 36 children with CZS up to 17 months of age followed at a pediatric rehabilitation center in the northeast of Brazil. Cohort enrollment occurred with children born between January 2015 and May 2016. We assessed their social profiles and orthopedic findings. Results Of the 36 cases, 25 were male. All of them lived in rural area. 25 had at least one congenital orthopedic alteration. Hip subluxation was the most common problem detected (n = 15); other lower limb abnormalities included knee subluxation (n = 7), clubfoot (n = 7); congenital vertical talus (n = 4); plano-valgus foot (n = 5). In relation to the upper limbs, 11 children presented with some shoulder and/or elbow abnormality and 16 had some alteration in the...
Background Infant mortality in Brazil has increased for the first time in 26 years. This study ai... more Background Infant mortality in Brazil has increased for the first time in 26 years. This study aimed to define the Zika Syndrome (ZS) perinatal case fatality rate (PCF) since the 2015 Zika outbreak in a Brazilian northeast state highly impacted by the virus. Methods Cross-sectional study conducted using data obtained through the State Health Department for cases of microcephaly (MCP) and congenital abnormalities (CA) in Rio Grande do Norte State (RN) from April 2015 to March 2, 2019. Perinatal period: commencing at 22 completed weeks (154 days) of gestation until 7 days after birth. PCF was defined as the number of deaths as a fraction of the number of sick persons with the specific disease (×100). Results There were 535 reported cases of MCP and others CA notified in RN during this period: 4 in 2014, 337 in 2015, 157 in 2016, 21 in 2017, 14 in 2018, and 2 in 2019. Of these, 151 were confirmed and 135 remain under investigation. The remaining 247 cases were ruled out by normal physi...
Background: Ambient temperature is an important determinant of malaria transmission and suitabili... more Background: Ambient temperature is an important determinant of malaria transmission and suitability, affecting the life-cycle of the Plasmodium parasite and Anopheles vector. Early models predicted a thermal malaria transmission optimum of 31 °C, later revised to 25 °C using experimental data from mosquito and parasite biology. However, the link between ambient temperature and human malaria incidence remains poorly resolved. To evaluate the relationship between ambient temperature and malaria risk, 5833 febrile children (<18 years-old) with an acute, non-localizing febrile illness were enrolled from four heterogenous outpatient clinic sites in Kenya (Chulaimbo, Kisumu, Msambweni and Ukunda). Thick and thin blood smears were evaluated for the presence of malaria parasites. Daily temperature estimates were obtained from land logger data, and rainfall from National Oceanic and Atmospheric Administration (NOAA)'s Africa Rainfall Climatology (ARC) data. Thirty-day mean temperature and 30-day cumulative rainfall were estimated and each lagged by 30 days, relative to the febrile visit. A generalized linear mixed model was used to assess relationships between malaria smear positivity and predictors including temperature, rainfall, age, sex, mosquito exposure and socioeconomic status. Results: Malaria smear positivity varied between 42-83% across four clinic sites in western and coastal Kenya, with highest smear positivity in the rural, western site. The temperature ranges were cooler in the western sites and warmer in the coastal sites. In multivariate analysis controlling for socioeconomic status, age, sex, rainfall and bednet use, malaria smear positivity peaked near 25 °C at all four sites, as predicted a priori from an ecological model. This study provides direct field evidence of a unimodal relationship between ambient temperature and human malaria incidence with a peak in malaria transmission occurring at lower temperatures than previously recognized clinically. This nonlinear relationship with an intermediate optimal temperature implies that future climate warming could expand malaria incidence in cooler, highland regions while decreasing incidence in already warm regions with average temperatures above 25 °C. These findings support efforts to further understand the nonlinear association between ambient temperature and vector-borne diseases to better allocate resources and respond to disease threats in a future, warmer world.
Nomadic pastoralists are among the worlds hardest-to-reach and least-served populations. Pastoral... more Nomadic pastoralists are among the worlds hardest-to-reach and least-served populations. Pastoralist communities are notoriously difficult to capture in household surveys due to factors including their high degree of mobility, remote terrain, fluid domestic arrangements, and cultural barriers. Most surveys utilize census-based sampling frames which do not accurately capture the demographic and health parameters of nomadic populations. As a result, pastoralists are largely invisible in population data such as the Demographic and Health Surveys (DHS). By combining remote sensing and geospatial analysis, we developed a sampling strategy designed to capture the current distribution of nomadic populations. We then implemented this sampling frame to survey a population of mobile pastoralists in southwest Ethiopia, focusing on maternal and child health (MCH) indicators. Using standardized instruments from DHS questionnaires, we surveyed this population in order to draw comparisons with reg...
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Papers by A. Labeaud