Pre-Pandemic Cross-Reactive Immunity against SARS-CoV-2 among Central and West African Populations.

For more than two years after the emergence of COVID-19 (Coronavirus Disease-2019), significant regional differences in morbidity persist. These differences clearly show lower incidence rates in several regions of the African and Asian continents. The work reported here aimed to test the hypothesis of a pre-pandemic natural immunity acquired by some human populations in central and western Africa, which would, therefore, pose the hypothesis of an original antigenic sin with a virus antigenically close to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

Nusinersen for Patients With Spinal Muscular Atrophy: 1415 Doses via an Interdisciplinary Institutional Approach.

Background: Spinal deformity and prior spinal fusion pose technical challenges to lumbar puncture (LP) for nusinersen administration for patients with spinal muscular atrophy (SMA). In this retrospective study over two study phases, we evaluated (1) factors associated with difficult LP or unscheduled requirement for image guidance and (2) effectiveness of a triage pathway for selective use of image guidance and nonstandard techniques, particularly for patients with spinal instrumentation/fusion to the sacrum.

Methods: With institutional review board approval, electronic health records, imaging, and administrative databases were analyzed for patients receiving nusinersen from January 2012 through September 2021.

Mobility evaluation by GPS tracking in a rural, low-income population in Cambodia.

Global Positioning System (GPS) technology is an effective tool for quantifying individuals' mobility patterns and can be used to understand their influence on infectious disease transmission. In Cambodia, mobility measurements have been limited to questionnaires, which are of limited efficacy in rural environments. In this study, we used GPS tracking to measure the daily mobility of Cambodian forest goers, a population at high risk of malaria, and developed a workflow adapted to local constraints to produce an optimal dataset representative of the participants' mobility.

COVID-19: Spatial analysis of hospital case-fatality rate in France.

When the population risk factors and reporting systems are similar, the assessment of the case-fatality (or lethality) rate (ratio of cases to deaths) represents a perfect tool for analyzing, understanding and improving the overall efficiency of the health system. The objective of this article is to estimate the influence of the hospital care system on lethality in metropolitan France during the inception of the COVID-19 epidemic, by analyzing the spatial variability of the hospital case-fatality rate (CFR) between French districts. In theory, the hospital age-standardized CFR should not display significant differences between districts, since hospital lethality depends on the virulence of the pathogen (the SARS-CoV-2 virus), the vulnerability of the population (mainly age-related), the healthcare system quality, and cases and deaths definition and the recording accuracy.

Does the edge effect impact on the measure of spatial accessibility to healthcare providers?

Background: Spatial accessibility indices are increasingly applied when investigating inequalities in health. Although most studies are making mentions of potential errors caused by the edge effect, many acknowledge having neglected to consider this concern by establishing spatial analyses within a finite region, settling for hypothesizing that accessibility to facilities will be under-reported. Our study seeks to assess the effect of edge on the accuracy of defining healthcare provider access by comparing healthcare provider accessibility accounting or not for the edge effect, in a real-world application.

Global Spread of Hemorrhagic Fever Viruses: Predicting Pandemics.

As successive epidemics have swept the world, the scientific community has quickly learned from them about the emergence and transmission of communicable diseases. Epidemics usually occur when health systems are unprepared. During an unexpected epidemic, health authorities engage in damage control, fear drives action, and the desire to understand the threat is greatest.

Modeling spatial variation in risk of presence and insecticide resistance for malaria vectors in Laos.

Climatic, sociological and environmental conditions are known to affect the spatial distribution of malaria vectors and disease transmission. Intensive use of insecticides in the agricultural and public health sectors exerts a strong selective pressure on resistance genes in malaria vectors. Spatio-temporal models of favorable conditions for Anopheles species' presence were developed to estimate the probability of presence of malaria vectors and insecticide resistance in Lao PDR.

Serological and molecular identification of Leptospira spp. in swine and stray dogs from Malaysia.

Leptospirosis is endemic in Malaysia with Leptospira species extensively isolated from domestic and wild animals. Rats were found to be the principal maintenance hosts followed by cattle, pigs, and dogs. The objectives of this study were to isolate and identify Leptospira serovars circulating among swine from three different farms and also from stray dogs and cats from Klang valley, Selangor, Malaysia.

Assessment of the spatial accessibility to health professionals at French census block level.

Background: The evaluation of geographical healthcare accessibility in residential areas provides crucial information to public policy. Traditional methods - such as Physician Population Ratios (PPR) or shortest travel time - offer only a one-dimensional view of accessibility. This paper developed an improved indicator: the Index of Spatial Accessibility (ISA) to measure geographical healthcare accessibility at the smallest available infra-urban level, that is, the Îlot Regroupé pour des Indicateurs Statistiques.

Determination of Leptospira borgpetersenii serovar Javanica and Leptospira interrogans serovar Bataviae as the persistent Leptospira serovars circulating in the urban rat populations in Peninsular Malaysia.

Background: Leptospirosis is an emerging infectious disease of global significance, and is endemic in tropical countries, including Malaysia. Over the last decade, a dramatic increase of human cases was reported; however, information on the primary vector, the rat, and the Leptospira serovars circulating among the rat population is limited. Therefore, the present study was undertaken to isolate Leptospira and characterise the serovars circulating in the urban rat populations from selected main cities in Peninsular Malaysia.

Epidemiology of human leptospirosis in Malaysia, 2004-2012.

Leptospirosis is an emerging disease, especially in countries with a tropical climate such as Malaysia. A dramatic increase in the number of cases has been reported over the last decade; however, information on the epidemiological trends of this disease is lacking. The objective of this study is to provide an epidemiological description of human leptospirosis cases over a 9-year period (2004-2012) and disease relationship with meteorological, geographical, and demographical information.

Spatial Pattern Detection of Tuberculosis: A Case Study of Si Sa Ket Province, Thailand.

This retrospective population-based study was conducted to analyze spatial patterns of tuberculosis (TB) incidence in Si Sa Ket province, Thailand. TB notification data from 2004 to 2008 collected from TB clinics throughout the province was used along with population data to reveal a descriptive epidemiology of TB incidences. Global clustering patterns of the occurrence were assessed by using global spatial autocorrelation techniques.

Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters.

The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover.

Long-term persistence of Chikungunya virus neutralizing antibodies in human populations of North Eastern Thailand.

Background: Chikungunya virus (CHIKV) outbreak recurrences in Thailand are unpredictable and separated by unexplained and often long silent epidemiological periods that can last for several years. These silent periods could be explained in part by the fact that infection with one CHIKV strain confers lasting natural immunity, even against other CHIKV strains. In this study we evaluated the persistence of CHIKV-specific neutralizing antibodies in the population of Chumpae District, Khon Kaen Province, nineteen years after a CHIKV outbreak occurred in the same area in 1991.

Poultry farm vulnerability and risk of avian influenza re-emergence in Thailand.

Highly pathogenic avian influenza (HPAI) remains of concern as a major potential global threat. This article evaluates and discusses the level of vulnerability of medium and small-scale commercial poultry production systems in Thailand related to avian influenza virus re-emergence. We developed a survey on 173 farms in Nakhon Pathom province to identify the global level of vulnerability of farms, and to determine which type of farms appears to be more vulnerable.

Dengue, Japanese encephalitis and Chikungunya virus antibody prevalence among captive monkey (Macaca nemestrina) colonies of Northern Thailand.

The potential of macaque Macaca nemestrina leonina in Thailand to be infected by endemic arboviruses was assessed. The prevalence of antibodies of three arboviruses actively circulating in Thailand was determined by Plaque Reduction Neutralization assay procedures using samples from captive colonies in Northern Thailand. Out of 38 macaques, 9 (24%) presented reacting antibodies against dengue virus, 5 (13%) against Japanese encephalitis virus, and 4 (10%) against Chikungunya virus.

Spatial diffusion of influenza outbreak-related climate factors in Chiang Mai Province, Thailand.

Influenza is one of the most important leading causes of respiratory illness in the countries located in the tropical areas of South East Asia and Thailand. In this study the climate factors associated with influenza incidence in Chiang Mai Province, Northern Thailand, were investigated. Identification of factors responsible for influenza outbreaks and the mapping of potential risk areas in Chiang Mai are long overdue.

Analyzing the spatio-temporal relationship between dengue vector larval density and land-use using factor analysis and spatial ring mapping.

Background: Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions and is now extending its range to temperate regions. The spread of the dengue viruses mainly depends on vector population (Aedes aegypti and Aedes albopictus), which is influenced by changing climatic conditions and various land-use/land-cover types. Spatial display of the relationship between dengue vector density and land-cover types is required to describe a near-future viral outbreak scenario.

Statistical methods for bivariate spatial analysis in marked points. Examples in spatial epidemiology.

This article presents methods to analyze global spatial relationships between two variables in two different sets of fixed points. Analysis of spatial relationships between two phenomena is of great interest in health geography and epidemiology, especially to highlight competing interest between phenomena or evidence of a common environmental factor. Our general approach extends the Moran and Pearson indices to the bivariate case in two different sets of points.

Risk factors for Zaire ebolavirus--specific IgG in rural Gabonese populations.

Background: In Gabon, several Ebolavirus outbreaks have occurred exclusively in the northeastern region. We conducted a large serosurvey to identify areas and populations at risk and potential demographic, clinical, and behavioral risk factors.

Methods: Blood samples and clinical and sociodemographic data were collected from 4349 adults and 362 children in a random sample of 220 villages in the 9 provinces of Gabon.

Epidemiologic relationship between Toscana virus infection and Leishmania infantum due to common exposure to Phlebotomus perniciosus sandfly vector.

Sand flies are recognised vectors of parasites in the genus Leishmania and a number of arthropod-borne viruses, in particular viruses within the genus Phlebovirus, family Bunyaviridae. In southern France, Toscana phlebovirus (TOSV) is recognized as a prominent cause of summer meningitis. Since Leishmania and TOSV have a common vector (Phlebotomus perniciosus), an epidemiologic link has been assumed for a long time.

Spatio-temporal diffusion pattern and hotspot detection of dengue in Chachoengsao province, Thailand.

In recent years, dengue has become a major international public health concern. In Thailand it is also an important concern as several dengue outbreaks were reported in last decade. This paper presents a GIS approach to analyze the spatial and temporal dynamics of dengue epidemics.

Acute dengue virus 2 infection in Gabonese patients is associated with an early innate immune response, including strong interferon alpha production.

Background: Dengue is now a leading cause of morbidity and mortality throughout the tropics. We conducted the first ex vivo study of dengue fever (DF) in African patients infected during the first Gabonese dengue virus 2 (DENV-2) outbreak in 2007, in order to investigate cytokine production, including the antiviral cytokine IFN-α, reported to be a potent inhibitor of DENV replication in vitro.

Methods: Levels of 50 cytokines, chemokines and growth factors were measured in plasma from 36 patients with DENV-2 infection, and in uninfected controls, using Luminex multiplex technology.