Aedes aegypti Pharate First Instar Aseasonal Quiescence Cues Anticipatory Plasticity with Implications for Urban Vector Ecology and Control

The eggs of the dengue fever vector Aedes aegypti possess the ability to undergo an extended quiescence period hosting a fully developed first instar larvae within its chorion. As a result of this life history stage, pharate larvae can withstand months of dormancy inside the egg where they depend on stored reserves of maternal origin. This adaptation known as pharate first instar quiescence, allows A. aegypti to cope with fluctuations in water availability. An examination of this fundamental adaptation has shown that there are trade-offs associated with it. Aedes aegypti mosquitoes are frequently associated with urban habitats that may contain metal pollution. My research has demonstrated that the duration of this quiescence and the extent of nutritional depletion associated with it affects the physiology and survival of larvae that hatch in a suboptimal habitat; nutrient reserves decrease during pharate first instar quiescence and alter subsequent larval and adult fitness. The duration of quiescence compromises metal tolerance physiology and is coupled to a decrease in metallothionein mRNA levels. My findings also indicate that even low levels of environmentally relevant larval metal stress alter the parameters that determine vector capacity. My research has also demonstrated that extended pharate first instar quiescence can elicit a plastic response resulting in an adult phenotype distinct from adults reared from short quiescence eggs. Extended pharate first instar quiescence affects the performance and reproductive fitness of the adult female mosquito as well as the nutritional status of its progeny via maternal effects in an adaptive manner, i.e., anticipatory phenotypic plasticity results as a consequence of the duration of pharate first instar quiescence and alternative phenotypes may exist for this mosquito with quiescence serving as a cue possibly signaling the environmental conditions that follow a dry period. M findings may explain, in part, A. aegypti’s success as a vector and its geographic distribution and have implications for its vector capacity and control.

Natural Bagaza virus infection in game birds in southern Spain

In late summer 2010 a mosquito born flavivirus not previously reported in Europe called Bagaza virus (BAGV) caused high mortality in red-legged partridges (Alectoris rufa) and ring-necked pheasants (Phasianus colchicus). We studied clinical findings, lesions and viral antigen distribution in naturally BAGV infected game birds in order to understand the apparently higher impact on red-legged partridges. The disease induced neurologic signs in the two galliform species and, to a lesser extent, in common wood pigeons (Columba palumbus). In red-legged partridges infection by BAGV caused severe haemosiderosis in the liver and spleen that was absent in pheasants and less evident in common wood pigeons. Also, BAGV antigen was present in vascular endothelium in multiple organs in red-legged partridges, and in the spleen in common wood pigeons, while in ring-necked pheasants it was only detected in neurons and glial cells in the brain. These findings indicate tropism of BAGV for endothelial cells and a severe haemolytic process in red-legged partridges in addition to the central nervous lesions that were found in all three species.

Evidence of cryptic genetic lineages within Aedes notoscriptus (Skuse)

Aedes notoscriptus (Skuse), a mosquito from the southwest Pacific region including Australia, has been implicated as a vector of arboviruses, but its status as a species is unclear. To investigate the taxonomic situation, we assessed genetic variation and phylogenetic relationships among Ae. notoscriptus from the east coast of Australia, Western Australia and New Zealand. Phylogenetic analyses of DNA sequence data from mitochondrial markers indicate that Ae. notoscriptus is a complex of divergent genetic lineages, some of which appear geographically restricted, while others are widespread in eastern Australia. Samples from New Zealand and Western Australia were related to populations from one southern Australian lineage. Nuclear markers show no evidence of genetic isolation by geographic distance in the overall sample of mosquitoes, but strong isolation by distance is obvious within two of the lineages, supporting their status as isolated gene pools. The morphological character of wing centroid size variation is also associated with genetic lineage. These findings point to the possibility that Ae. notoscriptus is a complex of species, highlighting the need to understand physiological and ecological differences that may influence future control strategies.

Protect Your Family and Community : How Zika Spreads

Through simple illustrations, this sheet explains how the Zika virus is spread from mosquito to people.

2016 Chikungunya Virus Cases

After the bite of an infected mosquito, onset of illness occurs usually between 4 and 8 days, but can range from 2 to 12 days. Chikungunya is characterized by an abrupt onset of fever frequently accompanied by joint pain. Other common signs and symptoms include muscle pain, headache, nausea, fatigue and rash. The joint pain is often very debilitating, but usually lasts for a few days or may be prolonged to weeks. Hence the virus can cause acute, subacute, or chronic disease. Most patients recover fully, but in some cases joint pain may persist for several months, or even years. Occasional cases of eye, neurological, and heart complications have been reported, as well as gastrointestinal complaints. Serious complications are not common, but in older people, the disease can contribute to the cause of death. Often symptoms in infected individuals are mild and the infection may go unrecognized, or be misdiagnosed in areas where dengue occurs. Co-infections of dengue and chikungunya can occur.

2016 Dengue Fever Virus Cases

Dengue fever is the most common cause of fever in travelers returning from the Caribbean, Central America, and South Central Asia.* Dengue infections are commonly reported from most tropical countries of the South Pacific, Asia, the Caribbean, the Americas, and Africa. This disease is caused by four similar viruses (DENV-1, -2, -3, and -4) and is spread through the bites of infected mosquitoes. For information on current outbreaks, consult CDC’s Travelers’ Health website (http://www.cdc.gov/travel). Dengue fever is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death. Dengue should be suspected when a high fever (40°C/104°F) is accompanied by two of the following symptoms: severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands or rash. Symptoms usually last for 2–7 days, after an incubation period of 4–10 days following the bite from an infected mosquito.

2016 Eastern Equine Encephalitis Activity

Eastern equine encephalitis virus (EEEV) is transmitted to humans by the bite of an infected mosquito. Eastern equine encephalitis (EEE) is a rare illness in humans, and only a few cases are reported in the United States each year. Most cases occur in the Atlantic and Gulf Coast states. Most people infected with EEEV have no apparent illness. Severe cases of EEE (involving encephalitis, an inflammation of the brain) begin with the sudden onset of headache, high fever, chills, and vomiting. The illness may then progress into disorientation, seizures, or coma. EEE virus is one of the most severe mosquito transmitted diseases in the United States with approximately 33% mortality and significant brain damage in most survivors. There is no specific treatment for EEE; care is based on symptoms. You can reduce your risk of being infected with EEEV by using insect repellent, wearing protective clothing, and staying indoors while mosquitoes are most active.

2016 Flanders Virus Cases

Flanders virus was discovered in 1961 in the town of Flanders on Long Island, New York. The virus is in the virus family Rhabdoviridae, and it is widely distributed in Canada, the United States, and Mexico. Flanders virus does not cause disease. The virus is frequently found in birds, such as Red-winged blackbirds, House sparrows, and starlings. It is also found in bird-feeding mosquitoes, such as the black-tailed mosquito (Culiseta melanura) and the northern and southern house mosquitoes (Culex pipiens and Culex quinquefasciatus, respectively). Presence of the virus in an area serves as a sentinel or warning for West Nile virus and as a trigger for public health control and prevention interventions targeting West Nile virus.

2016 West Nile Virus Cases

Most people get infected with West Nile virus by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals. In a very small number of cases, West Nile virus has been spread through blood transfusions, organ transplants, and from mother to baby during pregnancy, delivery, or breastfeeding. Recovery from severe disease may take several weeks or months. Some of the neurologic effects may be permanent. About 10 percent of people who develop neurologic infection due to West Nile virus will die.

ZIKA PREVENTION

Zika is a disease primarily spread by mosquitoes, but it may also be spread by sexual contact with someone who is infected or from a pregnant woman to her fetus. This sheet gives Zika symptoms, how to prevent mosquito bites, how Zika is spread through sex and what to do if you suspect you have Zika.

PREVENCIÓN CONTRA EL ZIKA

Zika is a disease primarily spread by mosquitoes, but it may also be spread by sexual contact with someone who is infected or from a pregnant woman to her fetus. This sheet printed in Spanish, gives Zika symptoms, how to prevent mosquito bites, how Zika is spread through sex and what to do if you suspect you have Zika.

Distribuição espaço - temporal da malária no Piauí de 2002 a 2013.

A malária é uma doença infecciosa, aguda, febril transmitida pela picada da fêmea de mosquito do gênero Anopheles. O estudo teve como objetivo realizar análise da distribuição espaço-temporal dos casos de malária no Piauí entre 2002 a 2013. Nesta pesquisa foi utilizada a taxa de incidência cumulativa para análise dos casos e o Sistema de Informação Geográfico (SIG) para mapeamento espacial. Os resultados obtidos por meio do cálculo da taxa de Incidência Cumulativa (IC) demonstraram que os municípios de Campo Largo do Piauí, Matias Olímpio, Luzilândia, Madeiro e Porto foram os que apresentaram maior IC de malária (>15,4/100.000 hab.). As pessoas mais acometidas foram as residentes na área rural, sendo pouquíssimos os casos ocorridos na zona urbana dos municípios. Através da utilização do SIG identificou-se que o padrão de distribuição espaçotemporal dos surtos de casos de malária está concentrado na porção noroeste do estado, na fronteira com o Maranhão. Após as análises, conclui-se que todos os 74 municípios que registraram malária no Piauí na série temporal do estudo, estão localizados e aglomerados em área vulnerável e receptiva para a transmissão da doença.

GEOGRAFIA DA SAÚDE: PRESSUPOSTOS TEÓRICOS E O ESTUDO DA RELAÇÃO DA PRECIPITAÇÃO COM OS CASOS DE DENGUE NO MUNICÍPIO DE EUSÉBIO-CE-BRASIL

Esta pesquisa insere-se dentro do campo de estudo da ciência geográfica denominada Geografia da Saúde, ramo este que tem contribuído para as discussões no âmbito da Geografia. Deste modo, este estudo busca no arcabouço teórico da Geografia da Saúde sua fundamentação para relacionar a precipitação com os casos de dengue no município de Eusébio, que se localiza na Região Metropolitana de Fortaleza-CE/Brasil. A referida cidade é considerada de pequeno porte, com uma população 46.047 habitantes (IBGE, 2010). Contudo, têm crescido em ritmo acelerado e, desta forma, é necessário cuidado com os problemas socioambientais, uma vez que são nas cidades que estes riscos são mais observados. É nesta perspectiva que relaciona-se os casos de dengue no município do Eusébio com a precipitação nos últimos anos, haja vista que o município é um modelo para o Estado do Ceará de controle e combate a dengue. Esta cidade está inserida dentro de uma política cearense de combate a proliferação do Aedes Aegypti - Programa Nacional de Controle da Dengue (PNCD). Neste contexto, verifica-se a relação dos fatores climáticos - precipitação com o acréscimo dos casos de dengue no município. Entretanto, não dissociou-se os aspectos físicos que propiciam a proliferação do mosquito, da questão social, assim, averigua-se também a intervenção das políticas públicas para o controle dos casos de dengue no município.