Increase in West Nile neuroinvasive disease after Hurricane Katrina

Retrospective Assessment of Preparedness for Mosquito Control Post-Hurricane Florence in North Carolina

OBJECTIVES

Ideally, mosquito control programs (MCPs) use surveillance to target control measures to potentially dangerous mosquito populations. In North Carolina (NC), where there is limited financial support for mosquito control, communities may suffer from mosquito-related issues post-hurricane due to lack of existing MCPs. Here, study objectives were to (1) investigate the emergency response of a subset of NC counties post-Hurricane Florence and (2) develop guidelines and policy recommendations to assist MCPs in post-hurricane mosquito control response.

METHODS

A survey was administered to a subset of eastern NC counties (an area previously impacted by hurricanes) with various levels of MCPs (from none to well-developed).

RESULTS

All respondents indicated that having Federal Emergency Management Agency (FEMA) training would be helpful in developing a post-hurricane emergency response plan for mosquito control. There was concern related to a lack of knowledge of emergency control methods (eg, aerial/ground, adulticiding/larviciding) post-hurricane. MCP structure (eg, infrastructure, resources, operational plans/policies) could facilitate response activities and help ensure necessary emergency financial support from agencies such as FEMA.

CONCLUSIONS

Mosquito control post-hurricane protects public health. Public health and other agencies can be networking resources for MCPs. Policy recommendations include implementation of routine FEMA assistance training workshops to improve an understanding of processes involved in assistance and reimbursement.

Projecting the Impacts of a Changing Climate: Tropical Cyclones and Flooding

PURPOSE OF REVIEW

There is clear evidence that the earth's climate is changing, largely from anthropogenic causes. Flooding and tropical cyclones have clear impacts on human health in the United States at present, and projections of their health impacts in the future will help inform climate policy, yet to date there have been few quantitative climate health impact projections.

RECENT FINDINGS

Despite a wealth of studies characterizing health impacts of floods and tropical cyclones, many are better suited for qualitative, rather than quantitative, projections of climate change health impacts. However, a growing number have features that will facilitate their use in quantitative projections, features we highlight here. Further, while it can be difficult to project how exposures to flood and tropical cyclone hazards will change in the future, climate science continues to advance in its capabilities to capture changes in these exposures, including capturing regional variation. Developments in climate epidemiology and climate science are opening new possibilities in projecting the health impacts of floods and tropical cyclones under a changing climate.

Exposure Assessment for Tropical Cyclone Epidemiology

PURPOSE OF REVIEW

Tropical cyclones impact human health, sometimes catastrophically. Epidemiological research characterizes these health impacts and uncovers pathways between storm hazards and health, helping to mitigate the health impacts of future storms. These studies, however, require researchers to identify people and areas exposed to tropical cyclones, which is often challenging. Here we review approaches, tools, and data products that can be useful in this exposure assessment.

RECENT FINDINGS

Epidemiological studies have used various operational measures to characterize exposure to tropical cyclones, including measures of physical hazards (e.g., wind, rain, flooding), measures related to human impacts (e.g., damage, stressors from the storm), and proxy measures of distance from the storm's central track. The choice of metric depends on the research question asked by the study, but there are numerous resources available that can help in capturing any of these metrics of exposure. Each has strengths and weaknesses that may influence their utility for a specific study. Here we have highlighted key tools and data products that can be useful for exposure assessment for tropical cyclone epidemiology. These results can guide epidemiologists as they design studies to explore how tropical cyclones influence human health.

The Complex Epidemiological Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping Review

BACKGROUND

Climate change is expected to increase the frequency of flooding events. Although rainfall is highly correlated with mosquito-borne diseases (MBD) in humans, less research focuses on understanding the impact of flooding events on disease incidence. This lack of research presents a significant gap in climate change-driven disease forecasting.

OBJECTIVES

We conducted a scoping review to assess the strength of evidence regarding the potential relationship between flooding and MBD and to determine knowledge gaps.

METHODS

PubMed, Embase, and Web of Science were searched through 31 December 2020 and supplemented with review of citations in relevant publications. Studies on rainfall were included only if the operationalization allowed for distinction of unusually heavy rainfall events. Data were abstracted by disease (dengue, malaria, or other) and stratified by post-event timing of disease assessment. Studies that conducted statistical testing were summarized in detail.

RESULTS

From 3,008 initial results, we included 131 relevant studies (dengue n = 45 , malaria n = 61 , other MBD n = 49 ). Dengue studies indicated short-term (< 1  month ) decreases and subsequent (1-4 month) increases in incidence. Malaria studies indicated post-event incidence increases, but the results were mixed, and the temporal pattern was less clear. Statistical evidence was limited for other MBD, though findings suggest that human outbreaks of Murray Valley encephalitis, Ross River virus, Barmah Forest virus, Rift Valley fever, and Japanese encephalitis may follow flooding.

DISCUSSION

Flooding is generally associated with increased incidence of MBD, potentially following a brief decrease in incidence for some diseases. Methodological inconsistencies significantly limit direct comparison and generalizability of study results. Regions with established MBD and weather surveillance should be leveraged to conduct multisite research to a) standardize the quantification of relevant flooding, b) study nonlinear relationships between rainfall and disease, c) report outcomes at multiple lag periods, and d) investigate interacting factors that modify the likelihood and severity of outbreaks across different settings. https://doi.org/10.1289/EHP8887.

Mosquitoes (Diptera: Culicidae) on the islands of Puerto Rico and Vieques, U.S.A

We conducted an island-wide survey of the Caribbean islands Puerto Rico and Vieques, U.S.A. during late 2018 and early 2019 to document the current richness of mosquitoes (Diptera: Culicidae). We used a combination of larval surveys and adult trapping using baited CDC light traps and BG-Sentinel traps across 41 of the 78 municipalities. We collected 9 genera, 12 subgenera, and 31 species, which when combined with past studies yields 44 species on the islands. We also note species occurrences across habitat types and elevations from around the islands. One new record, Aedes (Ochlerotatus) obturbator Dyar and Knab, is noted. However we found no evidence of the presence of Aedes albopictus (Skuse), an invasive found throughout the Caribbean, or Aedes (Fredwardsius) vittatus (Bigot), an exotic species recently reported in the Dominican Republic and Cuba. Habitat associations and information regarding the medical importance of species are also included. Given that the islands often experience outbreaks of several arboviruses, obtaining a complete picture of the species present is of high importance.

Traits and risk factors of post-disaster infectious disease outbreaks: a systematic review

Infectious disease outbreaks are increasingly recognised as events that exacerbate impacts or prolong recovery following disasters. Yet, our understanding of the frequency, geography, characteristics and risk factors of post-disaster disease outbreaks globally is lacking. This limits the extent to which disease outbreak risks can be prepared for, monitored and responded to following disasters. Here, we conducted a global systematic review of post-disaster outbreaks and found that outbreaks linked to conflicts and hydrological events were most frequently reported, and most often caused by bacterial and water-borne agents. Lack of adequate WASH facilities and poor housing were commonly reported risk factors. Displacement, through infrastructure damage, can lead to risk cascades for disease outbreaks; however, displacement can also be an opportunity to remove people from danger and ultimately protect health. The results shed new light on post-disaster disease outbreaks and their risks. Understanding these risk factors and cascades, could help improve future region-specific disaster risk reduction.

Assessing United States County-Level Exposure for Research on Tropical Cyclones and Human Health

BACKGROUND

Tropical cyclone epidemiology can be advanced through exposure assessment methods that are comprehensive and consistent across space and time, as these facilitate multiyear, multistorm studies. Further, an understanding of patterns in and between exposure metrics that are based on specific hazards of the storm can help in designing tropical cyclone epidemiological research.

OBJECTIVES

a) Provide an open-source data set for tropical cyclone exposure assessment for epidemiological research; and b) investigate patterns and agreement between county-level assessments of tropical cyclone exposure based on different storm hazards.

METHODS

We created an open-source data set with data at the county level on exposure to four tropical cyclone hazards: peak sustained wind, rainfall, flooding, and tornadoes. The data cover all eastern U.S. counties for all land-falling or near-land Atlantic basin storms, covering 1996-2011 for all metrics and up to 1988-2018 for specific metrics. We validated measurements against other data sources and investigated patterns and agreement among binary exposure classifications based on these metrics, as well as compared them to use of distance from the storm's track, which has been used as a proxy for exposure in some epidemiological studies.

RESULTS

Our open-source data set was typically consistent with data from other sources, and we present and discuss areas of disagreement and other caveats. Over the study period and area, tropical cyclones typically brought different hazards to different counties. Therefore, when comparing exposure assessment between different hazard-specific metrics, agreement was usually low, as it also was when comparing exposure assessment based on a distance-based proxy measurement and any of the hazard-specific metrics.

DISCUSSION

Our results provide a multihazard data set that can be leveraged for epidemiological research on tropical cyclones, as well as insights that can inform the design and analysis for tropical cyclone epidemiological research. https://doi.org/10.1289/EHP6976.

Harris County Public Health Mosquito and Vector Control Division Emergency Response to Hurricane Harvey: Vector-Borne Disease Surveillance and Control

Hurricane Harvey made a landfall on the Texas Gulf Coast on August 25, 2017, stalling over Harris County as a tropical storm for 4 days (August 26-29), dumping approximately 127 cm of rain. This tremendous amount of rainfall overwhelmed the county's natural and man-made drainage systems, resulting in unprecedented widespread flooding. Immediately following, Harris County Public Health Mosquito and Vector Control Division conducted a countywide emergency vector control response by integrating surveillance, control, and education strategies. This included landing rate counts, mosquito and avian surveillance, arbovirus testing, ground-based ultra-low volume (ULV) and aerial pesticide spraying, and community outreach. The immediate response lasted for 4 wk through September, resulting in 774 landing rates, 49,342 ha treated by ground-based ULV, 242,811 ha treated by aerial ULV, 83,241 mosquitoes collected, 1,807 mosquito pools tested, and 20 education/outreach sessions. Recovery activities of 3 additional education/outreach events continued through October while surveillance and control activities returned to routine status.

MOSQUITO CONTROL EMERGENCY PREPAREDNESS AND RESPONSE TO NATURAL DISASTERS

On February 9, 2019, the Bipartisan Budget Act of 2018 was signed into law and appropriated $200M in hurricane funding to the Centers for Disease Control and Prevention (CDC) for preparation, response, recovery, mitigation, and other expenses related to the consequences of Hurricanes Harvey, Irma, and Maria. The CDC then awarded, through CDC-RFA-TP18-1802 Cooperative Agreement for Emergency Response: Public Health Crisis Response notice of funding opportunity, $51,136,347 in extramural funding. Funding specific to vector-borne diseases, including intramural and extramural (partners and jurisdictions), was $37,628,235 to Florida, Georgia, Louisiana, Mississippi, Texas, Puerto Rico, and US Virgin Islands. State and territorial funding supported the implementation of conventional and novel mosquito control techniques, training for public health pest control applicators, replacement of mosquito surveillance and control supplies utilized in the aftermath of the 2017 hurricanes, insecticide resistance testing and training, and source reduction. Additionally, the CDC hurricane funding supported this special issue of the Journal of the American Mosquito Control Association (JAMCA) focused on mosquito control response in the wake of natural disasters. We invited hurricane relief funding grantees, mosquito control programs, academics, manufacturers, product distributors, and applicators to submit response plans or descriptive articles related to their experience with mosquito control after natural disasters. The objective of this special issue of JAMCA is to provide a comprehensive volume that includes resources to help guide mosquito control in areas affected by natural disasters. The shared experiences should serve to assist others involved in mosquito control in planning for and responding to natural disasters.

Temporal and Spatial Impacts of Hurricane Damage on West Nile Virus Transmission and Human Risk

Hurricanes have profound impacts on zoonotic pathogen ecosystems that exhibit spatial and temporal waves in both distance from and time since the event. Wind, rain, and storm surge directly affect mosquito vectors and animal hosts of these pathogens. In this analysis, we apply a West Nile virus transmission model parameterized for the Northern coast of the Gulf of Mexico to explore the effect of event timing of hurricane landfall, time since the event, and damage extent on human West Nile virus neuro-invasive disease (WNV-NID) risk. Early-season hurricanes, which make landfall prior to the peak of baseline WNV transmission activity, increase the average total WNV-infectious mosquitoes for the year by 7.8% and human WNV-NID incidence by 94.3% across all areas with hurricane damage. The indirect effects on human exposure to mosquito bites in the immediate aftermath and long-term recovery from the event have strong impacts on the risk of infection. The resultant interactive direct and indirect storm effects on the pathogen system are spatially and temporally heterogenous among the generalized time and space categories modeled.

The Impact of Hurricane Irma on Our Community and the Collier Mosquito Control District's Mission

The Collier Mosquito Control District, located in southwest Florida, is uniquely positioned in a subtropical environment between the Gulf of Mexico and Everglades National Park. The District's mission is focused on the control of disease vector and nuisance mosquitoes in Collier County, which is accomplished through integrated mosquito management. Hurricane Irma made landfall in the county on September 10, 2017, leaving in its wake tremendous property and infrastructure damage, and it also disrupted communications and airport operations. These factors greatly affected the District's operations and its ability to meet its mission. In addition, the lengthy loss of electrical power forced most residents outdoors, increasing their exposure to mosquitoes. From challenges in completing poststorm treatments to outdated policies that caught us off-guard, the event prompted a new hurricane policy and plan to ensure improved preparedness for the next natural disaster. The poststorm environment also provided a rich foundation for research into mosquito populations after tropical disturbances of this scale. Here we report the impact on the District's aerial mosquito control operations, changes to internal policies, and mosquito population abundance following Hurricane Irma.

Impacts of Hurricanes Irma and Maria on Aedes aegypti Populations, Aquatic Habitats, and Mosquito Infections with Dengue, Chikungunya, and Zika Viruses in Puerto Rico

Puerto Rico was severely impacted by Hurricanes Irma and Maria in September 2017. The island has been endemic for dengue viruses (DENV) and recently suffered epidemics of chikungunya (CHIKV 2014) and Zika (ZIKV 2016) viruses. Although severe storms tend to increase the number of vector and nuisance mosquitoes, we do not know how they influence Aedes aegypti populations and arboviral transmission. We compared the abundance of female Ae. aegypti in autocidal gravid ovitraps (AGO traps), container habitats, and presence of RNA of DENV, CHIKV, and ZIKV in this vector before and after the hurricanes in Caguas city and in four communities in southern Puerto Rico. Two of these communities were under vector control using mass AGO trapping and the other two nearby communities were not. We also investigated mosquito species composition and relative abundance (females/trap) using Biogents traps (BG-2 traps) in 59 sites in metropolitan San Juan city after the hurricanes. Mosquitoes sharply increased 5 weeks after Hurricane Maria. Ensuing abundance of Ae. aegypti was higher in Caguas and in one of the southern communities without vector control. Aedes aegypti did not significantly change in the two areas with vector control. The most abundant mosquitoes among the 26 species identified in San Juan were Culex (Melanoconion) spp., Culex quinquefasciatus, Culex nigripalpus, and Ae. aegypti. No arboviruses were detected in Ae. aegypti following the hurricanes, in contrast with observations from the previous year, so that the potential for Aedes-borne arboviral outbreaks following the storms in 2017 was low.

Complexity of the relationship between global warming and urbanization - an obscure future for predicting increases in vector-borne infectious diseases

Arthropod vectors are responsible for the transmission of many infectious diseases. Currently, more than three billion people living in endemic areas are exposed to vector-borne pathogens. Substantial differences in the biology of arthropod vectors make it extremely challenging to predict the incidence of vector-borne diseases in the future. However, global warming and urbanization both profoundly affect the ecology and distribution of arthropod vectors. Such processes often result in a biotic homogenization of species in a non-random process of biodiversity loss. The data presently available indicate a trend towards progressive increases in the presence and abundance of vectors capable of thriving in urban environments amongst humans, thus, increasing the contact between vectors and human hosts. As a consequence, we expect the incidence of vector-borne diseases to increase. In our opinion, resources should be made available and directed to strategies within the Integrated Vector Management framework, focusing on proven vector control tools. Besides, a substantial reduction of IVM costs would be achieved by observing environmental guidelines and providing basic sanitary infrastructure at early stages of its development. This could help to increase IVM effectiveness in attenuating social determinants of health and social inequities due to exposure to vectors.

Of mosquitoes and men: mitigating Zika risk via Men's family planning and male contraception

BACKGROUND

Outbreaks of mosquito-borne viral illnesses commonly occur after storms. As storms are predicted to worsen in intensity and frequency, mosquito-borne viruses, including the Zika virus are expected to spread, and with devastating consequences. While the disease is self-limited, pregnant women who contract Zika can transmit the virus to their fetuses, causing neurodevelopmental abnormalities, including microcephaly. An overlooked vector of the Zika virus, however, is men whose semen can transmit the virus at the time of sexual intercourse. Current recommendations for preventing the sexual transmission of Zika are inadequate and need to emphasize male reproductive responsibility, via expanding services for men's family planning and developing novel male contraceptives.

MAIN BODY

To prevent the sexual transmission of Zika, the World Health Organization recommends that couples use condoms or abstain from sexual activity for at least 6 months when traveling in Zika-infected areas. Strict adherence to these recommendations is neither practical nor adequate to address Zika's sexual transmission. As up to 13% of couples who use condoms experience unintended pregnancy, semen and consequent viral exposure is imminent. The use of contraception beyond just barrier methods is essential. However, the burden of contraception largely falls upon women and efforts to prevent vertical transmission are often aimed at educating women, when the outcome is equally undesirable among their male partners. These short-comings highlight the lack of attention to men's options for family planning. Educating men about the full range of contraceptive options, correcting misconceptions about the efficacy of withdrawal and barrier contraceptive methods, increasing access to vasectomy, and developing novel male contraceptive options would allow shared responsibility for the prevention of unintended pregnancy and Zika-related morbidity.

CONCLUSION

Gaps in recommendations to prevent the sexual transmission of Zika provide an opportunity to develop men's family planning initiatives and the range of accessible contraceptives to men.

Environmental and social-demographic predictors of the southern house mosquito Culex quinquefasciatus in New Orleans, Louisiana

BACKGROUND

Understanding the major predictors of disease vectors such as mosquitoes can guide the development of effective and timely strategies for mitigating vector-borne disease outbreaks. This study examined the influence of selected environmental, weather and sociodemographic factors on the spatial and temporal distribution of the southern house mosquito Culex quinquefasciatus Say in New Orleans, Louisiana, USA.

METHODS

Adult mosquitoes were collected over a 4-year period (2006, 2008, 2009 and 2010) using CDC gravid traps. Socio-demographic predictors were obtained from the United States Census Bureau, 2005-2009 American Community Survey and the City of New Orleans Department of Code Enforcement. Linear mixed effects models and ERDAS image processing software were used for statistical analysis and image processing.

RESULTS

Only two of the 22 predictors examined were significant predictors of Cx. quinquefasciatus abundance. Mean temperature during the week of mosquito collection was positively associated with Cx. quinquefasciatus abundance while developed high intensity areas were negatively associated with Cx. quinquefasciatus abundance.

CONCLUSION

The findings of this study illustrate the power and utility of integrating biophysical and sociodemographic data using GIS analysis to identify the biophysical and sociodemographic processes that increase the risk of vector mosquito abundance. This knowledge can inform development of accurate predictive models that ensure timely implementation of mosquito control interventions.

No Calm After the Storm: A Systematic Review of Human Health Following Flood and Storm Disasters

Introduction How the burden of disease varies during different phases after floods and after storms is essential in order to guide a medical response, but it has not been well-described. The objective of this review was to elucidate the health problems following flood and storm disasters.

METHODS

A literature search of the databases Medline (US National Library of Medicine, National Institutes of Health; Bethesda, Maryland USA); Cinahl (EBSCO Information Services; Ipswich, Massachusetts USA); Global Health (EBSCO Information Services; Ipswich, Massachusetts USA); Web of Science Core Collection (Thomson Reuters; New York, New York USA); Embase (Elsevier; Amsterdam, Netherlands); and PubMed (National Center for Biotechnology Information, National Institutes of Health; Bethesda, Maryland USA) was conducted in June 2015 for English-language research articles on morbidity or mortality and flood or storm disasters. Articles on mental health, interventions, and rescue or health care workers were excluded. Data were extracted from articles that met the eligibility criteria and analyzed by narrative synthesis.

RESULTS

The review included 113 studies. Poisonings, wounds, gastrointestinal infections, and skin or soft tissue infections all increased after storms. Gastrointestinal infections were more frequent after floods. Leptospirosis and diabetes-related complications increased after both. The majority of changes occurred within four weeks of floods or storms.

CONCLUSION

Health changes differently after floods and after storms. There is a lack of data on the health effects of floods alone, long-term changes in health, and the strength of the association between disasters and health problems. This review highlights areas of consideration for medical response and the need for high-quality, systematic research in this area. Saulnier DD , Brolin Ribacke K , von Schreeb J . No calm after the storm: a systematic review of human health following flood and storm disasters. Prehosp Disaster Med. 2017;32(5):568-579.

The public health planners' perfect storm: Hurricane Matthew and Zika virus

Hurricane Matthew threatened to be one of the most powerful Hurricanes to hit the United States in a century. Fortunately, it avoided making landfall on Florida, the eye of the Hurricane remaining centered 40 miles off the Florida coast. Even so it has resulted in over $7 Billion USD in damage according to initial estimates with much of the damage ongoing in severe flooding. Response to and recovery from Hurricane Matthew challenged Florida's public health services and resources just as emergency Zika-specific congressional funding to combat Zika outbreaks in Florida had become available. Hurricanes can disrupt the urban environment in a way that increases the likelihood of vector-borne illnesses and their aftermath can severely strain the very infectious disease and infection control academe needed to combat vector-borne outbreaks. This commentary attempts to examine the challenges posed by Hurricane Matthew in Florida's efforts to contain Zika.

Climate Change and Health on the U.S. Gulf Coast: Public Health Adaptation is Needed to Address Future Risks

The impacts of climate change on human health have been documented globally and in the United States. Numerous studies project greater morbidity and mortality as a result of extreme weather events and other climate-sensitive hazards. Public health impacts on the U.S. Gulf Coast may be severe as the region is expected to experience increases in extreme temperatures, sea level rise, and possibly fewer but more intense hurricanes. Through myriad pathways, climate change is likely to make the Gulf Coast less hospitable and more dangerous for its residents, and may prompt substantial migration from and into the region. Public health impacts may be further exacerbated by the concentration of people and infrastructure, as well as the region’s coastal geography. Vulnerable populations, including the very young, elderly, and socioeconomically disadvantaged may face particularly high threats to their health and well-being. This paper provides an overview of potential public health impacts of climate variability and change on the Gulf Coast, with a focus on the region’s unique vulnerabilities, and outlines recommendations for improving the region’s ability to minimize the impacts of climate-sensitive hazards. Public health adaptation aimed at improving individual, public health system, and infrastructure resilience is urgently needed to meet the challenges climate change may pose to the Gulf Coast in the coming decades.

Animal viral diseases and global change: bluetongue and West Nile fever as paradigms

Environmental changes have an undoubted influence on the appearance, distribution, and evolution of infectious diseases, and notably on those transmitted by vectors. Global change refers to environmental changes arising from human activities affecting the fundamental mechanisms operating in the biosphere. This paper discusses the changes observed in recent times with regard to some important arboviral (arthropod-borne viral) diseases of animals, and the role global change could have played in these variations. Two of the most important arboviral diseases of animals, bluetongue (BT) and West Nile fever/encephalitis (WNF), have been selected as models. In both cases, in the last 15 years an important leap forward has been observed, which has lead to considering them emerging diseases in different parts of the world. BT, affecting domestic ruminants, has recently afflicted livestock in Europe in an unprecedented epizootic, causing enormous economic losses. WNF affects wildlife (birds), domestic animals (equines), and humans, thus, beyond the economic consequences of its occurrence, as a zoonotic disease, it poses an important public health threat. West Nile virus (WNV) has expanded in the last 12 years worldwide, and particularly in the Americas, where it first occurred in 1999, extending throughout the Americas relentlessly since then, causing a severe epidemic of disastrous consequences for public health, wildlife, and livestock. In Europe, WNV is known long time ago, but it is since the last years of the twentieth century that its incidence has risen substantially. Circumstances such as global warming, changes in land use and water management, increase in travel, trade of animals, and others, can have an important influence in the observed changes in both diseases. The following question is raised: What is the contribution of global changes to the current increase of these diseases in the world?

High Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) prevalence in Triatoma sanguisuga (Hemiptera: Redviidae) in southeastern Louisiana

From May through November 2007, intensive weekly surveys at the site of a previously reported autochthonous human case of Chagas parasite infection resulted in the collection of 298 Triatoma sanguisuga (Leconte) specimens, of which 60.4% (180) were polymerase chain reaction positive for Trypanosoma cruzi Chagas. All were adults, in a ratio of approximately 1:1 female to male, indicating that the domicile was not colonized, but was a destination for these host-seeking adults. We report on seasonal activity pattern, T. cruzi prevalence in T. sanguisuga, and attempts at insect exclusion and control at the case residence.

Rapid assessment of mosquitoes and arbovirus activity after floods in southeastern Kansas, 2007

A rapid assessment was conducted in July-August 2007 to determine the impact of heavy rains and early summer floods on the mosquitoes and arbovirus activity in 4 southeastern Kansas counties. During 10 days and nights of collections using different types and styles of mosquito traps, a total of 10,512 adult female mosquitoes representing 29 species were collected, including a new species record for Kansas (Psorophora mathesoni). High numbers of Aedes albopictus were collected. Over 4,000 specimens of 4 Culex species in 235 species-specific pools were tested for the presence of West Nile, St. Louis, and western equine encephalitis viruses. Thirty pools representing 3 Culex species were positive for West Nile virus (WNV). No other arboviruses were detected in the samples. Infection rates of WNV in Culex pipiens complex in 2 counties (10.7/1,000 to 22.6/1,000) and in Culex salinarius in 1 county (6.0/1,000) were sufficiently high to increase the risk of transmission to humans. The infection rate of WNV in Culex erraticus was 1.9/1,000 in one county. Two focal hot spots of intense WNV transmission were identified in Montgomery and Wilson counties, where infection rates in Cx. pipiens complex were 26/ 1,000 and 19.9/1,000, respectively. Despite confirmed evidence of WNV activity in the area, there was no increase in human cases of arboviral disease documented in the 4 counties for the remainder of 2007.

Health of the homeless and climate change

The homeless are amongst the most vulnerable groups in developed regions, suffering from high rates of poorly controlled chronic disease, smoking, respiratory conditions, and mental illness, all of which render them vulnerable to new and resurgent disease processes associated with climate change. To date, there have been no papers reviewing the impacts of climate change on the homeless population. This paper provides a framework for understanding the nature of such an impact. We review four pathways: increased heat waves, increased air pollution, increased severity of floods and storms, and the changing distribution of West Nile Virus. We emphasize the need for further debate and research in this field.