Potential climate change effects on the distribution of urban and sylvatic dengue and yellow fever vectors.

Climate change may increase the risk of dengue and yellow fever transmission by urban and sylvatic mosquito vectors. Previous research primarily focused on Aedes aegypti and Aedes albopictus. However, dengue and yellow fever have a complex transmission cycle involving sylvatic vectors. Our aim was to analyze how the distribution of areas favorable to both urban and sylvatic vectors could be modified as a consequence of climate change. We projected, to future scenarios, baseline distribution models already published for these vectors based on the favorability function, and mapped the areas where mosquitoes' favorability could increase, decrease or remain stable in the near (2041-2060) and distant (2061-2080) future. Favorable areas for the presence of dengue and yellow fever vectors show little differences in the future compared to the baseline models, with changes being perceptible only at regional scales. The model projections predict dengue vectors expanding in West and Central Africa and in South-East Asia, reaching Borneo. Yellow fever vectors could spread in West and Central Africa and in the Amazon. In some locations of Europe, the models suggest a reestablishment of Ae. aegypti, while Ae. albopictus will continue to find new favorable areas. The results underline the need to focus more on vectors Ae. vittatus, Ae. luteocephalus and Ae. africanus in West and Central sub-Saharan Africa, especially Cameroon, Central Africa Republic, and northern Democratic Republic of Congo; and underscore the importance of enhancing entomological monitoring in areas where populations of often overlooked vectors may thrive as a result of climate changes.

West Nile virus in the Iberian Peninsula: using equine cases to identify high-risk areas for humans.

BackgroundWest Nile virus (WNV) is a flavivirus with an enzootic cycle between birds and mosquitoes; humans and horses are incidental dead-end hosts. In 2020, the largest outbreak of West Nile virus infection in the Iberian Peninsula occurred, with 141 clusters in horses and 77 human cases.AimWe analysed which drivers influence spillover from the cycle to humans and equines and identified areas at risk for WNV transmission.MethodsBased on data on WNV cases in horses and humans in 2020 in Portugal and Spain, we developed logistic regression models using environmental and anthropic variables to highlight risk areas. Models were adapted to a high-resolution risk map.ResultsCases of WNV in horses could be used as indicators of viral activity and thus predict cases in humans. The risk map of horses was able to define high-risk areas for previous cases in humans and equines in Portugal and Spain, as well as predict human and horse cases in the transmission seasons of 2021 and 2022. We found that the spatial patterns of the favourable areas for outbreaks correspond to the main hydrographic basins of the Iberian Peninsula, jointly affecting Portugal and Spain.ConclusionA risk map highlighting the risk areas for potential future cases could be cost-effective as a means of promoting preventive measures to decrease incidence of WNV infection in Europe, based on a One Health surveillance approach.

An African West Nile virus risk map for travellers and clinicians.

International travellers are exposed to pathogens not commonly found in their countries of residence, including West Nile virus (WNV). Due to the difficulty of its diagnosis, little is known about its distribution in Africa. Understanding the geographic extent of risk of WNV infections is a necessity for both travellers and clinicians who advise and treat them, since there is no human vaccine. To date, there is no risk map for WNV infections in humans in Africa. Having a high-resolution risk map for the virus could be of relevance before the trip, to take preventive measures, and after the trip, for appropriate diagnosis of the disease. Virus detection in humans along the African continent were collected from official reports, and published scientific research for the period 1940 to 2020, and then geo-referenced in order to use biogeographical modelling for WNV. Models were based on fuzzy logic and machine learning algorithms and were designed to identify the environmental drivers that explain the distribution of human cases and to locate favourable areas for infections. We elaborated a high-resolution risk map for WNV infections that highlights favourable areas for infections in Africa. Although WNV infections are widely spread across Africa, the risk of the disease is not homogenously distributed. Popular tourist destinations such as Morocco, Tunisia, and South Africa, are high-risk areas for WNV infection.

Yellow fever surveillance suggests zoonotic and anthroponotic emergent potential.

Yellow fever is transmitted by mosquitoes among human and non-human primates. In the last decades, infections are occurring in areas that had been free from yellow fever for decades, probably as a consequence of the rapid spread of mosquito vectors, and of the virus evolutionary dynamic in which non-human primates are involved. This research is a pathogeographic assessment of where enzootic cycles, based on primate assemblages, could be amplifying the risk of yellow fever infections, in the context of spatial changes shown by the disease since the late 20th century. In South America, the most relevant spread of disease cases affects parts of the Amazon basin and a wide area of southern Brazil, where forest fragmentation could be activating enzootic cycles next to urban areas. In Africa, yellow fever transmission is apparently spreading from the west of the continent, and primates could be contributing to this in savannas around rainforests. Our results are useful for identifying new areas that should be prioritised for vaccination, and suggest the need of deep yellow fever surveillance in primates of South America and Africa.

Mapping the Risk for West Nile Virus Transmission, Africa.

West Nile virus (WNV) is an emergent arthropodborne virus that is transmitted from bird to bird by mosquitoes. Spillover events occur when infected mosquitoes bite mammals. We created a geopositioned database of WNV presence in Africa and considered reports of the virus in all animal components: reservoirs, vectors, and nonhuman dead-end hosts. We built various biogeographic models to determine which drivers explain the distribution of WNV throughout Africa. Wetlands of international importance for birds accounted for the detection of WNV in all animal components, whereas human-related drivers played a key role in the epizootic cases. We combined these models to obtain an integrative and large-scale perspective of the areas at risk for WNV spillover. Understanding which areas pose the highest risk would enable us to address the management of this spreading disease and to comprehend the translocation of WNV outside Africa through avian migration routes.

Worldwide dynamic biogeography of zoonotic and anthroponotic dengue.

Dengue is a viral disease transmitted by mosquitoes. The rapid spread of dengue could lead to a global pandemic, and so the geographical extent of this spread needs to be assessed and predicted. There are also reasons to suggest that transmission of dengue from non-human primates in tropical forest cycles is being underestimated. We investigate the fine-scale geographic changes in transmission risk since the late 20th century, and take into account for the first time the potential role that primate biogeography and sylvatic vectors play in increasing the disease transmission risk. We apply a biogeographic framework to the most recent global dataset of dengue cases. Temporally stratified models describing favorable areas for vector presence and for disease transmission are combined. Our models were validated for predictive capacity, and point to a significant broadening of vector presence in tropical and non-tropical areas globally. We show that dengue transmission is likely to spread to affected areas in China, Papua New Guinea, Australia, USA, Colombia, Venezuela, Madagascar, as well as to cities in Europe and Japan. These models also suggest that dengue transmission is likely to spread to regions where there are presently no or very few reports of occurrence. According to our results, sylvatic dengue cycles account for a small percentage of the global extent of the human case record, but could be increasing in relevance in Asia, Africa, and South America. The spatial distribution of factors favoring transmission risk in different regions of the world allows for distinct management strategies to be prepared.

GIS-Based and Outranking Approach to Assess Suitable Pig Farming Areas in the Mediterranean Region: Valencian Community.

The concentration of livestock production is problematic due to environmental concerns. European regulations are guiding the sector to become increasingly sustainable and, at the same time, maintaining the population in rural areas. The aim was to determine suitable areas in municipalities where livestock is presented as a market option. The methodology applied was based on the combination of multi-criteria methods and geographic information system (GIS) techniques, following three steps: removal of unsuitable zones by sectoral regulations (STEP 1); removal of unsuitable zones due to urban planning, and environmental recommendations (STEP 2); and evaluating the resulting areas depending on the importance of socio-economic, sectoral, and environmental characteristics. This study was based in a Spanish region with ongoing conflicts over land use on the coast but with a high number of rural municipalities at risk of depopulation in the interior. The results showed that 33% of the municipalities of the Valencian Community (VC) had suitable and outranking areas for the development of the swine sector. The 43 municipalities with the highest scores were because of the socio-economic factor and confirmed that suitable livestock development in municipalities with the highest risk of depopulation and low rural tourism activity was a key issue for development.

Predicting the spatio-temporal spread of West Nile virus in Europe.

West Nile virus is a widely spread arthropod-born virus, which has mosquitoes as vectors and birds as reservoirs. Humans, as dead-end hosts of the virus, may suffer West Nile Fever (WNF), which sometimes leads to death. In Europe, the first large-scale epidemic of WNF occurred in 1996 in Romania. Since then, human cases have increased in the continent, where the highest number of cases occurred in 2018. Using the location of WNF cases in 2017 and favorability models, we developed two risk models, one environmental and the other spatio-environmental, and tested their capacity to predict in 2018: 1) the location of WNF; 2) the intensity of the outbreaks (i.e. the number of confirmed human cases); and 3) the imminence of the cases (i.e. the Julian week in which the first case occurred). We found that climatic variables (the maximum temperature of the warmest month and the annual temperature range), human-related variables (rain-fed agriculture, the density of poultry and horses), and topo-hydrographic variables (the presence of rivers and altitude) were the best environmental predictors of WNF outbreaks in Europe. The spatio-environmental model was the most useful in predicting the location of WNF outbreaks, which suggests that a spatial structure, probably related to bird migration routes, has a role in the geographical pattern of WNF in Europe. Both the intensity of cases and their imminence were best predicted using the environmental model, suggesting that these features of the disease are linked to the environmental characteristics of the areas. We highlight the relevance of river basins in the propagation dynamics of the disease, as outbreaks started in the lower parts of the river basins, from where WNF spread towards the upper parts. Therefore, river basins should be considered as operational geographic units for the public health management of the disease.

Prevalence of Chronic Diseases among International Travelers Seeking Pretravel Medical Advice in 2018 at Malaga, Spain.

Travelers with preexisting diseases or chronic conditions may be more susceptible to travel-related health risks. They may, therefore, require more attention from specialist travel medicine providers. Our objective was to examine a group of international travelers in Malaga, Spain, quantify the proportion of travelers suffering from chronic conditions, and understand the characteristics of this group. A representative sample of travelers requesting pretravel medical advice at one travel clinic were asked about their preexisting chronic conditions and any immunosuppression. Additional demographic variables were used in an analysis of bivariate correlations. We used a binary logistic regression analysis to identify relationships between independent variables (age, gender, type of trip, travel duration, and destination) and the presence or absence of chronic conditions in travelers. Of the sample of 1,196 travelers, 258 (21.6%) reported having preexisting chronic conditions and 72 (6%) had two or more chronic conditions. Twenty-four of the travelers with chronic conditions (9%) were immunocompromised because of the disease or treatment. The two most common chronic conditions were cardiovascular disease and chronic respiratory conditions (36.8% and 17.1%, respectively). The chronic condition increased by 6.7% for every year of increased age. Travelers with chronic conditions are older, travel mainly to visit friends and relatives, and take shorter trips. More than half of travelers visiting (55.8%) needed more attention from the travel medicine practitioner because of their preexisting chronic conditions, age, or type of travel. Surveillance data based on the population of people traveling would be helpful to provide better advice to travelers.

Trends in the travelers' demand for pre-travel medical advice at a Spanish International Vaccination Center between 2000 and 2017.

Crises and disasters affect the numbers of people traveling either for tourism or other reasons. Many studies have been published on the effects of such events on travel, especially on tourism, and based on the arrivals or departures of travelers to or from countries. Our aim was to assess the influence of these events on the demand for pre-travel medical consultation in an International Vaccination Centre (IVC). Data on 94683 international travelers who visited 113529 international destinations attended at the IVC of Malaga (Spain) during 2000-2017 were studied. A descriptive and time series analyses was conducted. The demand to IVC was 3.47 times higher in 2017 than in 2000. The increase has not been the same for all destinations: Travel to South-East Asia and Western Pacific World Health Organization (WHO) regions has multiplied by 10, while in the same period, Africa WHO region has declined from 36% to 20% of total demand. Thailand, India and Brazil were the countries with the highest demand (21% of all pre-travel consultations). We found out three periods, concurrent with some socioeconomic or health events, in which the number of travellers attend decline with respect to the previous years, or the growth was very slow. Growth in the demand for pre-travel medical advice in parallel with a foreseeable increase in the number of travelers is expected. Pre-travel medical services must be adapted to this increase. This study of the trend of demand for pre-travel medical information should new related problems to travel to be identified and quantified, and should assist improvement of policies and programs aimed at care of travelers.

The Maritime Declaration of Health (MDH) as a tool to detect maritime traffic-related health risks: analysis of MDH forms submitted to Spanish ports, October 2014 to March 2015.

The international maritime traffic of people and goods has often contributed to the spread of pathogens affecting public health. The Maritime Declaration of Health (MDH), according to the International Health Regulations (IHR) (2005), is a document containing data related to the state of health on board a ship during passage and on arrival at port. It is a useful tool for early detection of public health risks. The main objective of our study was to evaluate compliance with the model provided in the IHR, focusing on the format and degree of completion of MDH forms received at Spanish ports. We reviewed the content of 802 MDH forms submitted to nine Spanish ports between October 2014 and March 2015. Study results show that 22% of MDH forms presented did not comply with the recommended model and 39% were incomplete. The proportion of cargo ships with correct and complete MDH forms was lower than passenger ships; thus, the nine health questions were answered less frequently by cargo ships than passenger ships (63% vs 90%, p value < 0.001). The appropriate demand and usage of MDH forms by competent authorities should improve the quality of the document as a tool and improve risk assessment.

Comparison of the stability, efficacy, and adverse effect profile of the innovator 0.005% latanoprost ophthalmic solution and a novel cyclodextrin-containing formulation.

Recently, a new latanoprost ophthalmic solution containing cyclodextrins was developed. The purpose of the present work was to compare the stability, clinical efficacy, and adverse effect profile of this formulation with the innovator product. The innovator formulation was stable at 4 degrees C but exhibited degradation at higher temperatures, whereas the cyclodextrin-containing formulation was stable at temperatures up to 40 degrees C. Formulations were assayed in a randomized double-blind clinical study in patients with primary open-angle glaucoma and/or ocular hypertension. Both latanoprost ophthalmic solutions produced comparable reduction of intraocular pressure. Conjunctival hyperemia was observed in 11.9% and 11.3% of the patients treated with the innovator and the cyclodextrin-containing formulations, respectively. There were no significant differences between the 2 ophthalmic solutions in efficacy or in the measured adverse effect. It is concluded that these 2 latanoprost ophthalmic solutions yield comparable efficacy and adverse effect outcomes. The cyclodextrin-containing formulation, however, has an improved stability.