Mosquito-borne diseases in India over the past 50 years and their Global Public Health Implications: A Systematic Review.

Mosquito-borne diseases (MBDs) pose a significant public health concern globally, and India, with its unique eco-sociodemographic characteristics, is particularly vulnerable to these diseases. This comprehensive review aims to provide an in-depth overview of MBDs in India, emphasizing their impact and potential implications for global health. The article explores distribution, epidemiology, control or elimination, and economic burden of the prevalent diseases such as malaria, dengue, chikungunya, Japanese encephalitis, and lymphatic filariasis, which collectively contribute to millions of cases annually. It sheds light on their profound effects on morbidity, mortality, and socioeconomic burdens and the potential for international transmission through travel and trade. The challenges and perspectives associated with controlling mosquito populations are highlighted, underscoring the importance of effective public health communication for prevention and early detection. The potential for these diseases to spread beyond national borders is recognized, necessitating a holistic approach to address the challenge. A comprehensive literature search was conducted, covering the past five decades (1972-2022), utilizing databases such as Web of Science, PubMed, and Google Scholar, in addition to in-person library consultations. The literature review analyzed 4,082 articles initially identified through various databases. After screening and eligibility assessment, 252 articles were included for analysis. The review focused on malaria, dengue, chikungunya, Japanese encephalitis, and lymphatic filariasis. The included studies focused on MBDs occurrence in India, while those conducted outside India, lacking statistical analysis, or published before 1970 were excluded. This review provides valuable insights into the status of MBDs in India and underscores the need for concerted efforts to combat these diseases on both national and global scales through consilience.

Effectiveness of Eupatorium perfoliatum 30C in Prevention of Dengue Fever and Acute Febrile Illness during 2017 Dengue Outbreak in Urban Slums of Delhi: A Prospective, Open-Label, Community-Based, Parallel Cohort Study.

OBJECTIVE: This study was undertaken to assess the effectiveness of Eupatorium perfoliatum (EP) 30C on the incidence of dengue fever and acute febrile illness (AFI) during the 2017 dengue outbreak. METHODS: We conducted a prospective, open-label, community-based parallel cohort study involving apparently healthy individuals residing in 06 urban slums (JJ colony) of Delhi. The participants were enrolled in two cohorts - the medicine cohort (MC) and the control cohort (CC). Participants in MC were given weekly one dose of EP 30C for 10 weeks along with Information, Education and Communication (IEC) material regarding dengue. Participants in the CC were provided with the IEC material only. The primary outcome measure was the incidence of dengue fever as per case definitions notified in the national guidelines for clinical management of dengue fever by the Government of India during the 10 weeks follow-up period. The secondary outcome measures were the incidence of AFI and the hospitalization of confirmed dengue cases. RESULTS: The analysis included 40,769 participants residing in 06 slum clusters of Delhi out of which 28,321 participants were in MC and 12,448 participants were in CC. The incidence of laboratory-confirmed dengue in the MC was 2.57 per 10,000 person-weeks (95% confidence interval [CI], 2.02-3.22) in comparison with 7.55 per 10,000 person-weeks (95% CI, 6.12-9.21) in the CC. The incidence of AFI in the MC was 19.66 per 10,000 person-weeks (95% CI, 18.07-21.36) in comparison with 40.96 per 10,000 person-weeks (95% CI, 37.48-44.67) in the CC. The overall protective effect of EP against laboratory-confirmed dengue was 65.77% (95% CI, 53.37-74.87; p = 0.0001) and against AFI was 52.58% (95% CI, 46.37-58.07; p = 0.0001). Hospitalization reported in the MC was nil as against 4.35% in the CC. No dengue-related case fatalities were reported from either cohort. None of the participants from the MC reported any adverse events owing to the prophylactic intervention. CONCLUSION: The study concludes that EP 30C was able to prevent dengue significantly. Randomized controlled trials are needed to confirm or refute our findings.Das Ziel dieser Studie war die Beurteilung der Wirksamkeit von Eupatorium perfoliatum (EP) 30C auf die Inzidenz von Dengue-Fieber und akuter fiebriger Erkrankung (AFE) während des Dengue-Ausbruchs 2017.Wir führten eine prospektive, unverblindete, Bevölkerungs-Parallelgruppen-Kohortenstudie mit augenscheinlich gesunden Bewohnern von 6 städtischen Slums (JJ-Kolonie) in Delhi durch. Die Teilnehmer wurden in 2 Kohorten aufgenommen, einer Medizinkohorte (MK) und einer Kontrollkohorte (KK). Die Teilnehmer in der MK erhielten 10 Wochen lang wöchentlich eine Dosis EP 30C und dazu Aufklärungsmaterialien über Dengue. Die Teilnehmer in der KK erhielten nur die Aufklärungsmaterialien. Die primäre Zielgröße war die Dengue-Fieber-Inzidenz laut der in den nationalen Leitlinien für das klinische Management des Dengue-Fiebers von der indischen Regierung bekannt gegebenen Falldefinition in dem zehnwöchigen Beobachtungszeitraum. Die sekundären Zielgrößen waren die Inzidenz von AFE und die Anzahl hospitalisierter bestätigter Dengue-Fälle.In die Analyse wurden 40,769 Bewohner von 6 Slum-Clustern in Delhi einbezogen, davon wurden 28,321 Teilnehmer in die MK aufgenommen und 12,448 Teilnehmer in die KK. Die Inzidenz von im Labor bestätigter Dengue betrug in der MK 2,57 pro 10,000 Personen/Woche (95%-Konfidenzintervall [KI]: 2,02­3,22), verglichen mit 7,55 pro 10,000 Personen/Woche (95%-KI: 6,12­9,21) in der KK. Die Inzidenz von AFI betrug in der MK 19,66 pro 10,000 Personen/Woche (95%-Konfidenzintervall [KI]: 18,07­21,36), verglichen mit 40,96 pro 10,000 Personen/Woche (95%-KI: 37,48­44,67) in der KK. Der Schutzeffekt (SE) von EP betrug gegen im Labor bestätigte Dengue 65,77% (95%-KI: 53,37­74,87; p = 0,0001) und gegen AFI 52,58% (95%-KI: 46,37­58,07; p = 0,0001). Die Hospitalisierungsrate war in der MK gleich Null versus 4,35% in der KK. In keiner Kohorte waren Dengue-bedingte Todesfälle zu verzeichnen. Bei keinem der Teilnehmer in der MK traten jegliche unerwünschten Ereignisse infolge der prophylaktischen Maßnahme auf.Die Studie gelangt zu dem Schluss, dass Eupatorium perfoliatum 30C in signifikantem Maße Dengue vorbeugen konnte. Randomisierte kontrollierte Studien sind erforderlich, um unsere Ergebnisse zu bestätigen bzw. zu widerlegen.

Analysis of a non-integer order mathematical model for double strains of dengue and COVID-19 co-circulation using an efficient finite-difference method.

An efficient finite difference approach is adopted to analyze the solution of a novel fractional-order mathematical model to control the co-circulation of double strains of dengue and COVID-19. The model is primarily built on a non-integer Caputo fractional derivative. The famous fixed-point theorem developed by Banach is employed to ensure that the solution of the formulated model exists and is ultimately unique. The model is examined for stability around the infection-free equilibrium point analysis, and it was observed that it is stable (asymptotically) when the maximum reproduction number is strictly below unity. Furthermore, global stability analysis of the disease-present equilibrium is conducted via the direct Lyapunov method. The non-standard finite difference (NSFD) approach is adopted to solve the formulated model. Furthermore, numerical experiments on the model reveal that the trajectories of the infected compartments converge to the disease-present equilibrium when the basic reproduction number ([Formula: see text]) is greater than one and disease-free equilibrium when the basic reproduction number is less than one respectively. This convergence is independent of the fractional orders and assumed initial conditions. The paper equally emphasized the outcome of altering the fractional orders, infection and recovery rates on the disease patterns. Similarly, we also remarked the importance of some key control measures to curtail the co-spread of double strains of dengue and COVID-19.

A survey of clinical and laboratory characteristics of the dengue fever epidemic from 2017 to 2019 in Zhejiang, China.

To explore the epidemic, clinical, and laboratory characteristics of dengue patients in Zhejiang and the possible mechanism. Epidemic, clinical and laboratory data of 231 dengue patients admitted to the Second Affiliated Hospital of Zhejiang Traditional Chinese Medicine University between August 2017 and December 2019 were collected. GSE43777 dataset was downloaded from the Gene Expression Omnibus database and was used for the immune cell infiltration analysis, logistic regression analysis, and nomogram construction. Gene set enrichment analysis (GSEA) was performed to explore the possible regulatory pathways in dengue infection. Further, the receiver operating characteristic curve analysis and decision curve analysis were conducted to evaluate the value of related immune cells in predicting dengue severity. Among the 231 patients, the gender ratio was 1:1.1 (male/female). The patients in the <60 years age group, 60 to 80 years age group, and >80 years age group were 47.2%, 45.5%, and 7.3%, respectively. The major symptoms were fever (100%), weak (98.3%), anorexia (76.6%), muscle and joint pain (62.3%), and nausea (46.8%). In dengue patients, 98.7% of serum samples had decreased platelet levels, 96.5% of them had decreased white blood cell (WBC) levels, 97.8% had elevated aspartate aminotransferase levels, 82.3% had elevated lactate dehydrogenase levels, 49.4% had increased creatinine levels, and 35.5% had increased creatine kinase levels. Pneumonia, pleural effusion, and bilateral pleural reaction were observed in 16.5%, 8.2%, and 4.8%, respectively of dengue patients. Gallbladder wall roughness and splenomegaly accounted for 6.1% and 4.3% of all cases. Moreover, the levels of T cell, B cell, and dendritic cells were significantly higher in the convalescent group and they were involved in immune- and metabolism-related pathways. Of note, low levels of these 3 immune cells correlated with high dengue infection risk, while only dendritic cells exhibited satisfactory performance in predicting dengue severity. Dengue fever patients often onset with fever, accompanied by mild abnormalities of the blood system and other organ functions. Moreover, T cells, B cells, and dendritic cells might be involved in dengue infection and development.

Molecular Characterization and Identification of Potential Inhibitors for 'E' Protein of Dengue Virus.

Dengue is an arthropod-borne acute febrile illness caused by Dengue Virus (DENV), a member of Flaviviridae. Severity of the infection ranges from mild self-limiting illness to severe life-threatening hemorrhagic fever (DHF) and dengue shock syndrome (DSS). To date, there is no specific antiviral therapy established to treat the infection. The current study reports the epidemiology of DENV infections and potential inhibitors of DENV 'E' protein. Among the various serotypes, DENV-2 serotype was observed more frequently, followed by DENV-4, DENV-1, and DENV-3. New variants of existing genotypes were observed in DENV-1, 2, and 4 serotypes. Predominantly, the severe form of dengue was attributable to DENV-2 infections, and the incidence was more common in males and pediatric populations. Both the incidence and the disease severity were more common among the residents of non-urban environments. Due to the predominantly self-limiting nature of primary dengue infection and folk medicine practices of non-urban populations, we observed a greater number of secondary dengue cases than primary dengue cases. Hemorrhagic manifestations were more in secondary dengue in particularly in the pediatric group. Through different computational methods, ligands RGBLD1, RGBLD2, RGBLD3, and RGBLD4 are proposed as potential inhibitors in silico against DENV-1, -2, -3, and -4 serotypes.

Influence of Religiosity and Spirituality on the Adoption of Behaviors of Epidemiological Relevance in Emerging and Re-Emerging Diseases: The Case of Dengue Fever.

Emerging and re-emerging diseases are responsible for recurrently affecting the health of human populations. Although people are aware of these diseases, they do not seem to adopt prophylactic methods to prevent them. Here, we propose to investigate the influence of religiosity/spirituality (R/S) on the frequency of the adoption of prophylactic behaviors and the perception of risk of vulnerability to the disease. We used dengue, which is a seasonal arboviral disease in Brazil, as a model. To measure the dimensions of religiosity/spirituality, we used the Portuguese version of the Brief Multidimensional Measure of Religiosity/Spirituality questionnaire. All data were obtained through a structured questionnaire that was answered online by 204 volunteers living throughout Brazil. Our results indicate that R/S is predictive of the frequency of prophylactic behaviors (p = 0.0222, R2 = 0.025) and the perception of risk of vulnerability (p < 0.05, R2 = 0.07). We argue that the effect of R/S on health occurs through the promotion of salutogenic mechanisms promoted by socialization in religious environments. This can help understand social dynamics in epidemiological crises and mitigate the influence of these diseases.

Plant-derived alkaloids acting on dengue virus and their vectors: from chemistry to pharmacology.

Dengue is a mosquito-borne viral infection, with its prevention and control depending on effective vector control measures. At present, dengue virus (DENV) is an epidemic in more than 100 countries of Southeast Asia, Africa, Eastern Mediterranean, the Americas and the Western Pacific. Several alkaloids isolated from natural herbs can serve as a reservoir for antiDENV drug development. Traditionally, plant extracts rich in alkaloids are used for the treatment of fever and have also revealed antimicrobial activity against various pathogenic bacteria, fungi and virus. The present narrative review collates the literature-based scenario of alkaloids and derivatives acting on DENV. The mechanism of action of such alkaloids with antiDENV and vector activity is also discussed.

Climatological, virological and sociological drivers of current and projected dengue fever outbreak dynamics in Sri Lanka.

The largest ever Sri Lankan dengue outbreak of 2017 provides an opportunity for investigating the relative contributions of climatological, epidemiological and sociological drivers on the epidemic patterns of this clinically important vector-borne disease. To do so, we develop a climatologically driven disease transmission framework for dengue virus using spatially resolved temperature and precipitation data as well as the time-series susceptible-infected-recovered (SIR) model. From this framework, we first demonstrate that the distinct climatological patterns encountered across the island play an important role in establishing the typical yearly temporal dynamics of dengue, but alone are unable to account for the epidemic case numbers observed in Sri Lanka during 2017. Using a simplified two-strain SIR model, we demonstrate that the re-introduction of a dengue virus serotype that had been largely absent from the island in previous years may have played an important role in driving the epidemic, and provide a discussion of the possible roles for extreme weather events and human mobility patterns on the outbreak dynamics. Lastly, we provide estimates for the future burden of dengue across Sri Lanka using the Coupled Model Intercomparison Phase 5 climate projections. Critically, we demonstrate that climatological and serological factors can act synergistically to yield greater projected case numbers than would be expected from the presence of a single driver alone. Altogether, this work provides a holistic framework for teasing apart and analysing the various complex drivers of vector-borne disease outbreak dynamics.

Dengue fever in the Corpus Hippocraticum.

Dengue fever (DF) is a globally significant infection which causes a range of severe and non-severe clinical manifestations. It is transmitted by mosquitoes of the Aedes genus (primarily Aedes aegypti, but also Aedes albopictus). In this letter, a possible DF epidemic on Thasos Island in Greece, which is described in the Book of Epidemics I of the Corpus Hippocraticum, is presented and analyzed. To my knowledge, it is the first report of DF in the history of medicine.

Epihack Sri Lanka: development of a mobile surveillance tool for dengue fever.

BACKGROUND: Dengue is a serious problem around the globe, with 3.9 billion people at risk of the disease. Sri Lanka has recently seen unprecedented rates of dengue with 4.3 times more cases than during the same period over the previous six years. The paper discusses the development of an integrated health systems framework, aided by mobile technology, to combat and contain dengue via a health hackathon in Sri Lanka. RESULTS: The framework addresses the key functions of surveillance, health communication and civic engagement through innovations including digitisation of hospital forms; digital aid to Public Health Inspectors (PHIs); data consolidation and analytics; education for construction workers, GPs, and schools; and educating the general public. CONCLUSIONS: We present the impact of the disease burden in tropical countries, such as Sri Lanka, current technological solutions, and the process of developing the mobile application modules developed via the health hackathon.

The Polyphenol-Rich Extract from Psiloxylon mauritianum, an Endemic Medicinal Plant from Reunion Island, Inhibits the Early Stages of Dengue and Zika Virus Infection.

The recent emergence and re-emergence of viral infections transmitted by vectors, such as the Zika virus (ZIKV) and Dengue virus (DENV), is a cause for international concern. These highly pathogenic arboviruses represent a serious health burden in tropical and subtropical areas of the world. Despite the high morbidity and mortality associated with these viral infections, antiviral therapies are missing. Medicinal plants have been widely used to treat various infectious diseases since millenaries. Several compounds extracted from plants exhibit potent effects against viruses in vitro, calling for further investigations regarding their efficacy as antiviral drugs. Here, we demonstrate that an extract from Psiloxylon mauritianum, an endemic medicinal plant from Reunion Island, inhibits the infection of ZIKV in vitro without exhibiting cytotoxic effects. The extract was active against different ZIKV African and Asian strains, including an epidemic one. Time-of-drug-addition assays revealed that the P. mauritianum extract interfered with the attachment of the viral particles to the host cells. Importantly, the P. mauritianum extract was also able to prevent the infection of human cells by four dengue virus serotypes. Due to its potency and ability to target ZIKV and DENV particles, P. mauritianum may be of value for identifying and characterizing antiviral compounds to fight medically-important flaviviruses.

Dengue Knowledge, Attitudes, and Practices Among Arizona Health Care Providers, 2014-2015.

Background: Detection of local dengue transmission requires an aware and engaged medical community, as health care providers are the front line of public health surveillance. To assess the knowledge, attitude, and practice about dengue, an online survey was distributed among Arizona health care providers during 2014 and 2015. Materials and Methods: The survey consisted of a total of 10 knowledge, attitude, and practice questions divided as follows: 5 knowledge questions, 2 attitude questions, and 3 practice questions. The link to the Qualtrics survey was distributed through the Arizona Health Alert Network to a total of 4582 e-mail addresses, of which 335 participants opened the survey, and 196 completed and submitted their responses. Results: Less than half the respondents reported choosing the right dengue diagnostic test (40.4%) or understanding the epidemiology of dengue in Arizona (40.9%). Slightly more than half the respondents reported frequently asking for travel history (59%), and three-fourth of them would notify the local health department on suspicion of a dengue patient (76.1%). Survey score was associated with providers specialized in infectious diseases (1.88, 95% CI: 0.42-3.33, p = 0.01), medical doctors or doctors of osteopathic medicine (1.82, 95% CI: 0.98-2.65, p < 0.0001), and respondents who reported to have heard about the increase in dengue cases in Sonora (Mexico) in fall 2014 (1.51, 95% CI: 0.67-2.34, p = 0.0005), indicating better survey performance. Conclusions: These results indicate that education for health care providers on dengue should be improved particularly among general practice noninfectious disease providers who might be the first point of care for dengue patients. Findings suggest that additional training on clinical management, asking travel history, and notifying the local health department on suspicion of a dengue patient are needed.

Economic and epidemiological impact of dengue illness over 16 years from a public health system perspective in Brazil to inform future health policies including the adoption of a dengue vaccine.

INTRODUCTION: Dengue is a serious global health problem endemic in Brazil. Consequently, our aim was to measure the costs and disease burden of symptomatic dengue infections in Brazil from the perspective of the Brazilian Public Health System (SUS) between 2000 and 2015, using Brazilian public health system databases. Specific age group incidence estimates were used to calculate the disability-adjusted life years (DALYs) to gain a better understanding of the disease burden. Areas covered: SUS spent almost USD159 million and USD10 million to treat dengue and severe dengue, respectively, between 2000 and 2015. This is principally hospitalization costs, with the majority of patients self-treated at home with minor symptoms. The average notification rate for dengue was 273 per 100,000 inhabitants and three per 100,000 for severe dengue, with annual DALYs estimates ranging between 72.35 and 6,824.45 during the 16 years. Expert commentary: The epidemiological and morbidity burden associated with dengue is substantial in Brazil, with costs affected by the fact that most patients self-treat at home with these costs not included in SUS. The Brazilian government urgently needs to proactively evaluate the real costs and clinical benefits of any potential dengue vaccination program by the National Immunization Program to guide future decision-making.

Oviposition Deterrent Efficacy and Characteristics of a Botanical Natural Product, Ocimum gratissimum (L.) Oil-Alginate Beads, against Aedes aegypti (L.).

This study was aimed at investigating the oviposition deterrent activity of Ocimum gratissimum (L.) essential oil (O. gratissimum oil) and its product, Ocimum gratissimum (L.)- alginate beads (beads), against Aedes aegypti (Ae. aegypti) mosquitoes. Chemical analysis of O. gratissimum oil obtained by hydrodistillation, using gas chromatography-mass spectroscopy techniques, presented eugenol (67.38%) and Z-ß-ocimene (14.95 %) as major constituents. Good characteristics of beads were obtained by the orifice-ionic gelation method with calcium chloride as hardening agent and Tween®20 as emulsifier. The beads exhibited a good spherical shape and good hardness and flexibility with an average size of 1.49 ± 1.36 mm. The oil content, the yield percentage, and the entrapping efficiency were also examined. The beads (formulation code, F2) could prolong the essential oil release until the 10th d. This beads provided a remarkably longer oviposition deterrence activity against gravid Ae. aegypti with high percentage for 27 d, whereas free O. gratissimum oil showed a short period of time (8 d) in this activity. The stability study showed the stability of oil content and its compositions in storage condition. These results are very affordable approaches to control the dengue fever.

The use of longitudinal cohorts for studies of dengue viral pathogenesis and protection.

In this review, we describe how longitudinal prospective community-based, school-based, and household-based cohort studies contribute to improving our knowledge of viral disease, focusing specifically on contributions to understanding and preventing dengue. We describe how longitudinal cohorts enable measurement of essential disease parameters and risk factors; provide insights into biological correlates of protection and disease risk; enable rapid application of novel biological and statistical technologies; lead to development of new interventions and inform vaccine trial design; serve as sentinels in outbreak conditions and facilitate development of critical diagnostic assays; enable holistic studies on disease in the context of other infections, comorbidities, and environmental risk factors; and build research capacity that strengthens national and global public health response and disease surveillance.

Antibody Epitopes Identified in Critical Regions of Dengue Virus Nonstructural 1 Protein in Mouse Vaccination and Natural Human Infections.

Dengue is a global public health problem and is caused by four dengue virus (DENV) serotypes (DENV1-4). A major challenge in dengue vaccine development is that cross-reactive anti-DENV Abs can be protective or potentially increase disease via Ab-dependent enhancement. DENV nonstructural protein 1 (NS1) has long been considered a vaccine candidate as it avoids Ab-dependent enhancement. In this study, we evaluated survival to challenge in a lethal DENV vascular leak model in mice immunized with NS1 combined with aluminum and magnesium hydroxide, monophosphoryl lipid A + AddaVax, or Sigma adjuvant system+CpG DNA, compared with mice infected with a sublethal dose of DENV2 and mice immunized with OVA (negative control). We characterized Ab responses to DENV1, 2, and 3 NS1 using an Ag microarray tiled with 20-mer peptides overlapping by 15 aa and identified five regions of DENV NS1 with significant levels of Ab reactivity in the NS1 + monophosphoryl lipid A + AddaVax group. Additionally, we profiled the Ab responses to NS1 of humans naturally infected with DENV2 or DENV3 in serum samples from Nicaragua collected at acute, convalescent, and 12-mo timepoints. One region in the wing domain of NS1 was immunodominant in both mouse vaccination and human infection studies, and two regions were identified only in NS1-immunized mice; thus, vaccination can generate Abs to regions that are not targeted in natural infection and could provide additional protection against lethal DENV infection. Overall, we identified a small number of immunodominant regions, which were in functionally important locations on the DENV NS1 protein and are potential correlates of protection.

Vaccination strategies against Zika virus.

The epidemic emergence of Zika virus (ZIKV) in 2015-2016 has been associated with congenital malformations and neurological sequela. Current efforts to develop a ZIKV vaccine build on technologies that successfully reduced infection or disease burden against closely related flaviviruses or other RNA viruses. Subunit-based (DNA plasmid and modified mRNA), viral vectored (adeno- and measles viruses) and inactivated viral vaccines are already advancing to clinical trials in humans after successful mouse and non-human primate studies. Among the greatest challenges for the rapid implementation of immunogenic and protective ZIKV vaccines will be addressing the potential for exacerbating Dengue virus infection or causing Guillain-Barré syndrome through production of cross-reactive immunity targeting related viral or host proteins. Here, we review vaccine strategies under development for ZIKV and the issues surrounding their usage.

Mosquito Avoidance Practices and Knowledge of Arboviral Diseases in Cities with Differing Recent History of Disease.

As the range of dengue virus (DENV) transmission expands, an understanding of community uptake of prevention and control strategies is needed both in geographic areas where the virus has recently been circulating and in areas with the potential for DENV introduction. Personal protective behaviors such as the use of mosquito repellent to limit human-vector contact and the reduction of vector density through elimination of oviposition sites are the primary control methods for Aedes aegypti, the main vector of DENV. Here, we examined personal mosquito control measures taken by individuals in Key West, FL, in 2012, which had experienced a recent outbreak of DENV, and Tucson, AZ, which has a high potential for introduction but has not yet experienced autochthonous transmission. In both cities, there was a positive association between the numbers of mosquitoes noticed outdoors and the overall number of avoidance behaviors, use of repellent, and removal of standing water. Increased awareness and perceived risk of DENV were associated with increases in one of the most effective household prevention behaviors, removal of standing water, but only in Key West.