High Dengue Incidence Research Articles

SMART DENGUE CONTROL

This research presents a novel approach to combating dengue by integrating Biological Control methods with Artificial Intelligence (AI). The objective of the study is to reduce the Aedes aegypti mosquito population and decrease dengue transmission through sustainable strategies. A comprehensive research methodology was used, involving extensive literature review, case studies, and data analysis to identify the main factors driving the high incidence of dengue in Brazil. The research applied AI tools to analyze epidemiological, meteorological, and environmental data, allowing for early outbreak predictions and targeted interventions. AI-enhanced surveillance systems were also employed to monitor mosquito populations and identify breeding sites more accurately. These strategies were combined with biological control methods, such as using natural predators and genetically modified mosquitoes, to manage mosquito populations effectively. The study demonstrate that the integration of AI and biological control can significantly improve the efficiency, accuracy, and sustainability of dengue control measures. The study concludes that this data-driven approach, when adapted to local contexts, can reduce reliance on chemical pesticides and offer a more resilient framework for long-term dengue management.

INSECTICIDE SUSCEPTIBILITY IN TWO POPULATIONS OF Aedes aegypti L. (Diptera: Culicidae) FROM GUERRERO, MEXICO, AND RECOMMENDATIONS FOR THEIR MANAGEMENT

The Aedes aegypti L. mosquito is a vector of diseases such as classic and hemorrhagic dengue (DENV), chikungunya (CHIKV), Zika (ZIKV), yellow fever (YFV), and Mayaro (MAYV). In 2019 alone, in Latin America, there were 2.7 million cases and 1206 deaths. In Mexico, government programs for managing this pest include the elimination of larval habitats and chemical control of larvae and adults. The objective of this study was to evaluate the response of two larvae and adult populations of A. aegypti from the state of Guerrero, Mexico, under laboratory conditions, to insecticides with different modes of action and to make considerations for their management. In the bioassays, larvae showed susceptibility to permethrin, malathion, deltamethrin, and Bacillus thuringiensis var. israelensis; low resistance to Temephos and propoxur; as well as moderate resistance to Spinosad. Both adult populations showed resistance to permethrin and susceptibility to deltamethrin, while the Acapulco population showed resistance to alpha-cypermethrin. For larvae, Spinosad is suggested to be used in times of high incidence of dengue. During drought, it is advisable to include rotations of B. thuringiensis var. israelensis with organophosphates. For adults, the use of imidacloprid in combination with botanical insecticides is considered a rational alternative to rotations with organophosphates and pyrethroids.

The Impact of Solid Waste Management Practices on Vector-Borne Disease Risk in Thiruvanathapuram

Vector-borne diseases (VBDs), including dengue, chikungunya, and malaria, present ongoing public health challenges, particularly in urban areas of tropical regions. Thiruvananthapuram, the capital city of Kerala, has seen a concerning rise in VBD cases, correlating with the city's rapid urbanization and inadequate solid waste management (SWM) practices. Poorly managed waste contributes to the proliferation of disease vectors, such as mosquitoes, by providing ideal breeding grounds, thereby exacerbating the risk of disease transmission. Despite the known association between inadequate SWM and VBDs, there is a paucity of localized studies that quantitatively examine this relationship in Thiruvananthapuram. This study seeks to bridge this gap by investigating the impact of existing SWM practices on the incidence of VBDs in the city. The findings aim to inform public health strategies and policy interventions that can mitigate the risk of VBDs through improved waste management. This cross-sectional study was conducted across 20 wards in Thiruvananthapuram, selected based on their varying levels of SWM effectiveness and reported VBD cases. Data collection involved field surveys to assess SWM practices, structured interviews with residents, and observational studies to identify potential breeding sites for vectors. Health records were analyzed to map the distribution of VBD cases in these wards. Statistical analyses, including correlation and regression, were employed to explore the relationship between SWM practices and VBD incidence. The study revealed a significant correlation between poor SWM practices and elevated VBD risk. Wards with inadequate waste management infrastructure exhibited a 40% higher incidence of dengue and chikungunya cases compared to areas with better-managed waste disposal systems (p < 0.01). Notably, 65% of households in the high-risk wards were found to dispose of waste improperly, contributing to the creation of vector breeding sites. Additionally, only 42% of residents were aware of the link between improper waste disposal and increased VBD risk, highlighting a critical gap in public awareness. This study concludes that inadequate SWM practices are a major contributor to the elevated risk of VBDs in Thiruvananthapuram. Addressing these challenges through improved waste management infrastructure and increased public awareness is crucial for reducing disease incidence. The outcomes of this research provide essential insights for local authorities and policymakers, emphasizing the urgent need for effective interventions to combat VBDs in urban areas.

Risk factors associated with dengue complications and death: A cohort study in Peru.

Dengue has emerged as an unprecedented epidemic in Peru, and it is anticipated that this issue will escalate further owing to climate change. This study aimed to determine the risk factors associated with death from dengue in patients treated at Hospital II in Pucallpa, Peru. This retrospective cohort study collected information from the medical records of patients with a diagnosis of dengue treated at Hospital II Pucallpa-Peru between January 2019 and March 2023. The primary outcome was death, and the secondary outcome was death, development of severe dengue, or Intensive Care Unit (ICU) admission. Cox regression models were used to determine risk factors. The clinical records of 152 patients were evaluated, with a median age of 27.5 years (interquartile range, 11-45). Among all patients, 29 (19.1%) developed severe dengue, 31 (20.4%) were admitted to the ICU, and 13 (8.6%) died during follow-up. In the survival analysis, bilirubin >1.2 mg/dL was associated with a higher risk of death aHR: 11.38 (95% CI: 1.2 106.8). Additionally, factors associated with poor prognosis included having 1 to 3 comorbidities aRR: 1.92 (1.2 to 3.2), AST ≥251 U/L aRR: 6.79 (2.2 to 21.4), history of previous dengue aRR: 1.84 (1.0 to 3.3), and fibrinogen ≥400 mg/dL aRR: 2.23 (1.2 to 4.1). Elevated bilirubin was associated with death from dengue, whereas an increase in comorbidities and a history of previous dengue were related to a poor prognosis of the disease. Early identification of severe dengue would be more feasible with improved access to laboratory testing, particularly in tropical areas with a high dengue incidence.

#862 Prevalence and surrogate predictors of acute kidney injury in tropical infections in eastern India

Abstract Background and Aims Acute kidney injury (AKI) in tropical countries is strikingly different from the other countries with a temperate climate. The epidemiology of AKI is largely influenced by environmental factors and climatic conditions and differ significantly its outcome and the surrogate predictors are not much studied. 1. To observe the spectrum and estimate the prevalence of AKI in tropical infections. 2. To evaluate the outcome and surrogate predictor of tropical AKI. Method This was a tertiary level single centre prospective observational study. All patients admitted with tropical infections associated AKI (KDIGO) were enrolled in two years and underwent complete history taking, clinical examinations and necessary laboratory investigations according to situations.. All patients were followed up more than 6 month. All data recorded were analysed in suitable statistical tool. Univariate analysis is followed by multivariate analysis was done for predictors followed by hazards ratio and Neglekers test. Results Out of 132 patients with Tropical AKI M:F was 1.5:1. Mean age was 42.3 ± 14.4 year, About 35.6% had Malaria,31.1% Dengue, 17% Scrub typhus, 10.4% Leptospira, and 5.9% patients had Typhoid fever. Malaria was the most common causative factor followed by Dengue. study reflecting the high dengue incidence occurring in the months of August, September, October & November. Among Malaria AKI (MAKI) 43.75% (21) had Falciparum malaria, 50% (24) had Vivax malaria and 6.25% (3) had dual infection. Out of 132 patients with Tropical AKI about 60% totally recovered at the time of discharge. 40% patients had Shock. Among them 60% Dengue AKI, 33.3% Malarial AKI 5 (21.7%) Scrub typhus, 4 (28.6%) Leptospira AKI & 3 (37%) Typhoid AKI patients had Shock. About 23% patients required RRT. Among them 8 (25%) patients died, 5 (15.6%) patients had CKD progression compared to non-RRT group where only 3 (2.9%) patients died, and 2 (1.94%) patients had progression to CKD. Total 11 (8.1%) patients died during hospital stay and only 7 (6.2%) patients had progressed to CKD. The mean Hospital stay was 5.51 ± 3.8 days. S hock at presentation, requirement of ICU support ( in form of ionotropic and ventilatory support), Need of RRT, prolong hospital stay, late referral was the bad prognostic predictor in terms of death. Though not statistically significant, presence of anaemia, hyponatraemia, deranged liver function & hypoalbuminemia were more in patients who died compared to survival group. Limitations: Small enrolments. non inclusion of all cause including snake bite, less biopsy in this study. Conclusion There are wide spectrum of tropical AKI with high mortality and morbidity. A greater awareness and early intervention is necessary for prompt diagnosis, treatment and favourable outcome.

Silent spread of DENV-3 in Brazil: autochthonous outbreak in São Paulo after 15years.

The high incidence of dengue in Brazil and re-emergence of DENV-3 in São Paulo after a 15-year absence, coupled with the potential risk for DENV-4, may be the results from changing climate patterns favouring Aedes mosquito proliferation, allied by the resuming of domestic and international travels.

Spatial correlation of dengue with socioeconomic status and land temperature in northwest Mexico

Objective. To characterize the geographic distribution of dengue and to evaluate the spatial autocorrelation with social and climatic determinants at the census-tract level in two medium sized cities in northwestern Mexico. Methods. In this work we apply spatial analysis ecological tools, such as the Moran’s Index and the Local Indicator of Spatial Association (LISA) method, to examine global and local spatial correlation between incidence of dengue, and socioeconomic and climatic factors at the census tract-level. For the analysis of the spatial clustering, the Getis-Ord method was used to find statistically significant hot spots in each city. Results. Overall, a global spatial autocorrelation could not be identified, although local clusters of a high dengue incidence, soil surface temperature ≤ 31 °C and high degree of social marginalization coincide. Discussion. We found that at the census-tract level in urban settings, socially disadvantaged populations showed higher clusters of dengue when compared to areas with better socioeconomic conditions. In the two study sites, a similar spatial pattern was observed when considering public health conditions and its aggregation with physical attributes using spatial analysis techniques, supporting the application of this technique for a better understanding about the dengue distribution in urban areas.

A Spatial Dengue Risk Map for the Jaffna District of Northern Sri Lanka

Dengue, a mosquito-borne disease, is a major public health concern in Sri Lanka including the northern Jaffna district. Epidemiology of dengue is associated with variations in land-use patterns and socio-economic factors. Jaffna district is one of the administrative locations with high incidence of dengue over the last two decades. The objective of the study was to identify potential dengue risk areas based on land-use patterns and socio-economic and demographic factors in Jaffna district at the Medical Officer for Health (MoH) administrative level applying spatial multi-criteria analysis using Geographic Information System Platform. The analysis also incorporated dengue cases and dengue serotypes identified in 2019 in the Jaffna district. The study reveals that the Nallur MoH division is the very high-risk area for dengue transmission. The identified risk map is expected to be useful for health authorities to prioritize control measures to identified risk areas. A detailed study considering land-use pattern, socio-economy, demography and serotypes over the years is warranted to understand the spatio-temporal patterns in dengue transmission in the Jaffna district.

Predicting dengue incidence using panel data analysis

Dengue is the most rapidly spreading infectious disease, especially in Indonesia. Dengue virus is transmitted by the bite of female Aedes mosquitoes. The high human population density and proximity to vector breeding places strengthen the interaction between the virus, vector, and humans as hosts. Using dengue incidence panel data during 2018-2019 in 34 provinces in Indonesia, this study examined the effect of human population density as a demographic variable and vector control on dengue incidence in Indonesia. The time series data were analyzed using EViews. The fixed effect model estimation showed that dengue incidence was significantly associated with demographic variables measured as human population density, with a P-value of 0.02. The vector control variable shows an insignificant association with dengue incidence. But simultaneous analysis between human population density and vector control on dengue incidence has a significant association with probability F (statistic) = 0.000. Our study demonstrated that densely populated provinces in Indonesia have a very high incidence of dengue. Improving sanitation in densely populated settlements can prevent and control dengue incidence.

Seroprevalence of dengue virus infection and its detrimental effects on pregnant women in wake of the recent floods

Dengue fever is a significant public health problem in many tropical and subtropical countries, especially those affected by severe floods as a result of global warming. The climate of these areas provides a favourable environment for the breeding vector of this disease. With Asia bearing 70% of the burden, Pakistan has been found to have a high incidence of dengue. Lack of proper healthcare facilities, rapid increase in population and substandard drainage system are a few of the problems resulting in the high number of cases. With evidence reporting the possibility of vertical transmission of this disease, it is necessary to determine the effects of dengue on the mother and the infant. Adverse effects include an increased risk of preterm birth, low birth weight, fetal loss, and maternal mortality in severe cases. The recent disastrous monsoon rainfall in Pakistan has inflicted great damage on rural areas; with the number of dengue fever cases rising to 64,000. The situation continues to worsen as the absence of proper health care and lack of action from relevant bodies has left many pregnant women vulnerable to dengue infection and unable to have safe deliveries. To combat this, the distribution of relief boxes is needed to alleviate the problems faced by victims of dengue, especially pregnant women. In order to raise awareness of this situation, this commentary has been written to describe the need for immediate action to be taken so that potential casualties of this generation and the one to come can be minimized.

Relationship between Urban Environmental Components and Dengue Prevalence in Dhaka City-An Approach of Spatial Analysis of Satellite Remote Sensing, Hydro-Climatic, and Census Dengue Data.

Dengue fever is a tropical viral disease mostly spread by the Aedes aegypti mosquito across the globe. Each year, millions of people have dengue fever, and many die as a result. Since 2002, the severity of dengue in Bangladesh has increased, and in 2019, it reached its worst level ever. This research used satellite imagery to determine the spatial relationship between urban environmental components (UEC) and dengue incidence in Dhaka in 2019. Land surface temperature (LST), urban heat-island (UHI), land-use-land-cover (LULC), population census, and dengue patient data were evaluated. On the other hand, the temporal association between dengue and 2019 UEC data for Dhaka city, such as precipitation, relative humidity, and temperature, were explored. The calculation indicates that the LST in the research region varies between 21.59 and 33.33 degrees Celsius. Multiple UHIs are present within the city, with LST values ranging from 27 to 32 degrees Celsius. In 2019, these UHIs had a higher incidence of dengue. NDVI values between 0.18 and 1 indicate the presence of vegetation and plants, and the NDWI identifies waterbodies with values between 0 and 1. About 2.51%, 2.66%, 12.81%, and 82% of the city is comprised of water, bare ground, vegetation, and settlement, respectively. The kernel density estimate of dengue data reveals that the majority of dengue cases were concentrated in the city's north edge, south, north-west, and center. The dengue risk map was created by combining all of these spatial outputs (LST, UHI, LULC, population density, and dengue data) and revealed that UHIs of Dhaka are places with high ground temperature and lesser vegetation, waterbodies, and dense urban characteristics, with the highest incidence of dengue. The average yearly temperature in 2019 was 25.26 degrees Celsius. May was the warmest month, with an average monthly temperature of 28.83 degrees Celsius. The monsoon and post-monsoon seasons (middle of March to middle of September) of 2019 sustained higher ambient temperatures (>26 °C), greater relative humidity (>80%), and at least 150 mm of precipitation. The study reveals that dengue transmits faster under climatological circumstances characterized by higher temperatures, relative humidity, and precipitation.

Electrolyte Disturbance with Severity of Dengue Infected Patient. A Study in Jhalawar Medical College & SRG Hospital, Jhalawar, Rajasthan

Background: Dengue is considered to be the most rapidly spreading mosquito borne viral disease in the world. The dengue viruses are members of the genus Flavivirus and family Flaviviridae. Electrolyte imbalance is commonly encountered in this disease. There had been only a few worldwide research studies investigated on electrolyte disturbances with severity of dengue infection. Methods: Cross sectional prospective study was carried out in medicine department of Jhalawar Medical College & SRG Hospital, Jhalawar, Rajasthan. All cases of dengue confirmed by detection of either NS1Ag or IgM/IgG by ELISA method during study period will be included in study. This study was conducted to find relation between electrolyte disturbances in patients with dengue fever. Results: Out of 90 patients, majority i.e. 48 (53.3%) patients in total had mild hyponatremia, 37 (41.1%) had normal and 3 (3.33%) and 2(2.22%) patients had moderate, severe hyponatremia respectively. The prevalence of dengue patients with hyponatremia was 58.9 % in the present study. Out of 90,77 Dengue fever patients, 32(41.6%) had normal, 45(58.4%) had mild decrease in sodium level. Out of 90, 50 (55.6%) having normal potassium,32(35.6%) were mild decrease in level,4 cases(4.5%) were moderate and 1(1.1%) were severe and 3(3.3%) had Hyperkalaemia. Conclusion: This study provides an insight regarding Electrolyte Disturbance With Severity Of Dengue Infected Patient. Considering the variations in serum electrolyte levels in patients of dengue and high incidence of dengue in India, it is necessary to have a degree of suspicion in patients of dengue about electrolyte disturbances and treat them accordingly.

Climate-driven mosquito-borne viral suitability index: measuring risk transmission of dengue, chikungunya and Zika in Mexico

BackgroundClimate variability influences the population dynamics of the Aedes aegypti mosquito that transmits the viruses that cause dengue, chikungunya and Zika. In recent years these diseases have grown considerably. Dengue is now the fastest-growing mosquito-transmitted disease worldwide, putting 40 per cent of the global population at risk. With no effective antiviral treatments or vaccines widely available, controlling mosquito population remains one of the most effective ways to prevent epidemics. This paper analyses the temporal and spatial dynamics of dengue in Mexico during 2000–2020 and that of chikungunya and Zika since they first appeared in the country in 2014 and 2015, respectively. This study aims to evaluate how seasonal climatological variability affects the potential risk of transmission of these mosquito-borne diseases. Mexico is among the world’s most endemic countries in terms of dengue. Given its high incidence of other mosquito-borne diseases and its size and wide range of climates, it is a good case study.MethodsWe estimate the recently proposed mosquito-borne viral suitability index P, which measures the transmission potential of mosquito-borne pathogens. This index mathematically models how humidity, temperature and precipitation affect the number of new infections generated by a single infected adult female mosquito in a host population. We estimate this suitability index across all Mexico, at small-area level, on a daily basis during 2000–2020.ResultsWe find that the index P predicted risk transmission is strongly correlated with the areas and seasons with a high incidence of dengue within the country. This correlation is also high enough for chikungunya and Zika in Mexico. We also show the index P is sensitive to seasonal climatological variability, including extreme weather shocks.ConclusionsThe paper shows the dynamics of dengue, chikungunya and Zika in Mexico are strongly associated with seasonal climatological variability and the index P. This potential risk of transmission index, therefore, is a valuable tool for surveillance for mosquito-borne diseases, particularly in settings with varied climates and limited entomological capacity.

Influence of hydroclimatic variability on dengue incidence in a tropical dryland area

Dengue is an endemic disease in more than 100 countries, but there are few studies about the effects of hydroclimatic variability on dengue incidence (DI) in tropical dryland areas. This study investigates the association between hydroclimatic variability and DI (2008-2018) in a large tropical dryland area. The area studied comprehends seven municipalities with populations ranging from 32,879 to 2,545,419 inhabitants. First, the precipitation and temperature impacts on interannual and seasonal DI were investigated. Then, the monthly association between DI and hydroclimatic variables was analyzed using generalized least squares (GLS) regression. The model's capability to reproduce DI given the current hydroclimatic conditions and DI seasonality over the entire time period studied were assessed. No association between the interannual variation of precipitation and DI was found. However, seasonal variation of DI was shaped by precipitation and temperature. February-July was the main dengue season period. A precipitation threshold, usually above 100 mm, triggers the rapid DI rising. Precipitation and minimum air temperature were the main explanatory variables. A two-month-lagged predictor was relevant for modeling, occurring in all regressions, followed by a non-lagged predictor. The climate predictors differed among the regression models, revealing the high spatial DI variability driven by hydroclimatic variability. GLS regressions were able to reproduce the beginning, development, and end of the dengue season, although we found underestimation of DI peaks and overestimation of low DI. These model limitations are not an issue for climate change impact assessment on DI at the municipality scale since historical DI seasonality was well simulated. However, they may not allow seasonal DI forecasting for some municipalities. These findings may help not only public health policies in the studied municipalities but also have the potential to be reproducible for other dryland regions with similar data availability.

The role of anthropogenic container habitats as mosquito oviposition habitats in rural settlements in northern Tanzania.

In many areas, the main sources of mosquito vectors are not natural habitats but small artificial water bodies that are provided unintentionally by humans. Such container habitats have been linked to outbreaks of dengue fever and other arboviral diseases. However, in many parts of the world the possible risks associated with container habitats have not been assessed. Here, we focused on a human population expansion area in northern Tanzania with a high incidence of dengue and other cases of high fever. We explored the importance of anthropogenic container habitats for mosquito production in the Lake Manyara Basin. We also assessed how biotic and physicochemical habitat characteristics limit mosquito abundance in containers. Results showed that Aedes aegypti (Linnaeus), vector of dengue and other arboviruses, and Culex quinquefasciatus (Say), vector of filarial worms, were the dominant mosquitoes ovipositing in large numbers in different containers. Old tires were the dominant and most productive container habitat for mosquitoes in the region. However, there were strong differences among villages, illustrating that the mosquito burden associated with container habitats varies locally. We concluded that in this region, removal of artificial container habitats could be a simple strategy to reduce the mosquito-mediated disease burden within the local population.

Prediction of dengue fever outbreaks using climate variability and Markov chain Monte Carlo techniques in a stochastic susceptible-infected-removed model

The recent increase in the global incidence of dengue fever resulted in over 2.7 million cases in Latin America and many cases in Southeast Asia and has warranted the development and application of early warning systems (EWS) for futuristic outbreak prediction. EWS pertaining to dengue outbreaks is imperative; given the fact that dengue is linked to environmental factors owing to its dominance in the tropics. Prediction is an integral part of EWS, which is dependent on several factors, in particular, climate, geography, and environmental factors. In this study, we explore the role of increased susceptibility to a DENV serotype and climate variability in developing novel predictive models by analyzing RT-PCR and DENV-IgM confirmed cases in Singapore and Honduras, which reported high dengue incidence in 2019 and 2020, respectively. A random-sampling-based susceptible-infected-removed (SIR) model was used to obtain estimates of the susceptible fraction for modeling the dengue epidemic, in addition to the Bayesian Markov Chain Monte Carlo (MCMC) technique that was used to fit the model to Singapore and Honduras case report data from 2012 to 2020. Regression techniques were used to implement climate variability in two methods: a climate-based model, based on individual climate variables, and a seasonal model, based on trigonometrically varying transmission rates. The seasonal model accounted for 98.5% and 92.8% of the variance in case count in the 2020 Singapore and 2019 Honduras outbreaks, respectively. The climate model accounted for 75.3% and 68.3% of the variance in Singapore and Honduras outbreaks respectively, besides accounting for 75.4% of the variance in the major 2013 Singapore outbreak, 71.5% of the variance in the 2019 Singapore outbreak, and over 70% of the variance in 2015 and 2016 Honduras outbreaks. The seasonal model accounted for 14.2% and 83.1% of the variance in the 2013 and 2019 Singapore outbreaks, respectively, in addition to 91% and 59.5% of the variance in the 2015 and 2016 Honduras outbreaks, respectively. Autocorrelation lag tests showed that the climate model exhibited better prediction dynamics for Singapore outbreaks during the dry season from May to August and in the rainy season from June to October in Honduras. After incorporation of susceptible fractions, the seasonal model exhibited higher accuracy in predicting outbreaks of higher case magnitude, including those of the 2019–2020 dengue epidemic, in comparison to the climate model, which was more accurate in outbreaks of smaller magnitude. Such modeling studies could be further performed in various outbreaks, such as the ongoing COVID-19 pandemic to understand the outbreak dynamics and predict the occurrence of future outbreaks.

FORECASTING AND ON THE INFLUENCE OF CLIMATIC FACTORS ON RISING DENGUE INCIDENCE IN BAGUIO CITY, PHILIPPINES

Dengue fever or dengue has been a concern for individuals living in Baguio City, Philippines. Every year, incidence counts rise during rainy seasons experienced from June to October. Several researches suggest that meteorological factors have great influence on the life, growth, and reproduction of dengue-carrying mosquitoes, resulting in higher dengue incidence in the area. With the continuing rise of dengue incidence in Baguio City, we aim to forecast dengue incidence in the area for the year 2019, starting from January until the end of the outbreak period in the area. Here, we use the projections package of R as it involves the serial interval distribution and 𝑅𝑡 value of dengue incidence. We also aim to use multiple linear regression analysis to determine if meteorological factors have significant effects in the rise of dengue incidence in the city. With the inclusion of time-varying reproduction number and serial interval distribution of dengue, we projected that dengue incidence may reach up to 101 cases by June 16, 2021, and without further actions, cases may rise up to 529 cases by August 29, 2021. Based on the average two-year period, such increase is attributed to relative humidity and average temperature as these are the most significant factors associated with dengue incidence based on the MLR analysis. The highest and mean maximum temperatures remain as key meteorological variables that influence dengue incidence in the city. As early as possible, local officials are recommended to uphold proper safety and health procedures in preventing the spread of dengue in Baguio City.

Trends and Spatial Pattern Analysis of Dengue Cases in Northeast Malaysia.

ObjectivesDengue remains hyperendemic in Malaysia despite extensive vector control activities. With dynamic changes in land use, urbanisation and population movement, periodic updates on dengue transmission patterns are crucial to ensure the implementation of effective control strategies. We sought to assess shifts in the trends and spatial patterns of dengue in Kelantan, a north-eastern state of Malaysia (5°15’N 102°0’E).MethodsThis study incorporated data from the national dengue monitoring system (eDengue system). Confirmed dengue cases registered in Kelantan with disease onset between January 1, 2016 and December 31, 2018 were included in the study. Yearly changes in dengue incidence were mapped by using ArcGIS. Hotspot analysis was performed using Getis-Ord Gi to track changes in the trends of dengue spatial clustering.ResultsA total of 10 645 dengue cases were recorded in Kelantan between 2016 and 2018, with an average of 10 dengue cases reported daily (standard deviation, 11.02). Areas with persistently high dengue incidence were seen mainly in the coastal region for the 3-year period. However, the hotspots shifted over time with a gradual dispersion of hotspots to their adjacent districts.ConclusionsA notable shift in the spatial patterns of dengue was observed. We were able to glimpse the shift of dengue from an urban to peri-urban disease with the possible effect of a state-wide population movement that affects dengue transmission.

Entomological risk factors for the high incidence of dengue in the forest fringe areas of Kerala, India

Incidence of dengue in Kottayam district, Kerala commences with cases reported from forest fringe areas of Kanjirappally every year. An entomological investigation was carried out to study the relative abundance of dengue vector and to delineate their breeding habitats in the forest fringe areas of Kanjirappally taluk. Four villages (Erumeli, Mundakayam, Kootikal, Koruthode) located in the forest fringe areas of Kanjirappally taluk have been selected for the study. In each study area all the breeding sources in and around 24 households covering an area of about 0.5 Sq Km were surveyed and checked for vector breeding at fortnightly intervals from February 2021 to October 2021. Immatures were collected from positive breeding site and were brought to the laboratory for emergence and species identification. Larval indices were calculated using WHO methods. Ae albopictus was found to be the most prevalent and widely distributed vector species and the primary vector Ae. aegypti was not found during the household survey. The maximum Container index and Breteau index were found to be 71.45 and 51.90 during the month of June and July which shows a linear positive correlation with rainfall and significantly higher pupal index was found during the month of May (2.96). Peridomestic water storage containers and rubber plantation associated containers were the main breeding habitat observed which accounts 64.08% and 80.29% of pupal production during the dry and wet seasons respectively. Sylvan environment of rubber plantation together with favourable climatic conditions are the key factors for the prevalence of dengue vector in the forest fringe areas of Kerala.

Geographic Partitioning of Dengue Virus Transmission Risk in Florida

Dengue viruses (DENVs) cause the greatest public health burden globally among the arthropod-borne viruses. DENV transmission risk has also expanded from tropical to subtropical regions due to the increasing range of its principal mosquito vector, Aedes aegypti. Focal outbreaks of dengue fever (dengue) in the state of Florida (FL) in the USA have increased since 2009. However, little is known about the competence of Ae. aegypti populations across different regions of FL to transmit DENVs. To understand the effects of DENV genotype and serotype variations on vector susceptibility and transmission potential in FL, we orally infected a colony of Ae. aegypti (Orlando/ORL) with low passage or laboratory DENV-1 through -4. Low passage DENVs were more infectious to and had higher transmission potential by ORL mosquitoes. We used these same DENVs to examine natural Ae. aegypti populations to determine whether spatial distributions correlated with differential vector competence. Vector competence across all DENV serotypes was greater for mosquitoes from areas with the highest dengue incidence in south FL compared to north FL. Vector competence for low passage DENVs was significantly higher, revealing that transmission risk is influenced by virus/vector combinations. These data support a targeted mosquito-plus-pathogen screening approach to more accurately estimate DENV transmission risk.