scholarly journals Residential characteristics aggravating infestation by Culex quinquefasciatus in a region of Northeastern Brazil

2012 ◽  
Vol 46 (6) ◽  
pp. 935-941 ◽  
Author(s):  
Juliana Cavalcanti Correia ◽  
Rosângela Maria Rodrigues Barbosa ◽  
Cláudia Maria Fontes de Oliveira ◽  
Cleide Maria Ribeiro de Albuquerque

OBJECTIVE: Analyse how basic sanitation conditions, water supply and housing conditions affect the concentration of Culex quinquefasciatus METHODS: Populations of C. quinquefasciatus in 61 houses in the municipality of Olinda, PE, were monitored between October 2009 and October 2010. Observations were carried out in homes without the presence of preferred breeding sites in order to identify characteristics that may be aggravating factors for the development of the mosquito. Five aggravating factors were analysed: vegetation cover surrounding the home, number of residents/home, water storage, sewage drainage and water drainage. These characteristics were analysed in terms of presence or absence and as indicators of the degree of infestation, which was estimated through monitoring the concentration of eggs (oviposition traps - BR-OVT) and adults (CDC light traps). RESULTS: Sewage drainage to a rudimentary septic tank or to the open air was the most frequent aggravating factor in the homes (91.8%), although the presence of vegetation was the only characteristic that significantly influenced the increase in the number of egg rafts (p = 0.02). The BR-OVT achieved positive results in 95.1% of the evaluations, with the presence of at least one egg raft per month. A total of 2,366 adults were caught, with a mosquito/room/night ratio of 32.9. No significant difference was found in the number of mosquitoes caught in the homes. CONCLUSIONS: Although the sanitation and water supply influence the population density of C. quinquefasciatus, residence features that are not usually considered in control measures can be aggravating factors in sustaining the mosquito population.

2021 ◽  
Author(s):  
Ayana Gayathri ◽  
Evans DA

Abstract Plastic – derived Bisphenol A (BPA) contaminated sewages in Trivandrum, Kerala, India are mosquito breeding sites. After summer rain, BPA in the stagnant water samples ranged between 0.86 and 1.14ppm. 1.0 ppm BPA is considered as environmentally relevant concentration. Present study revealed that BPA is a developmental agonist of Culex quinquefasciatus. Embryonic and larval development are shortened by BPA but pupal development is unaffected. Under the atmospheric temperature of 26 to 310C lifecycle was completed within 312 hours but during summer it was completed within 278 hours, meanwhile atmospheric temperature ranged between 30 and 370C. Reduction in the duration of development due to BPA was 50 to 70 hours during summer and 60 to 80 hours in other seasons. Larval – pupal stadium of the mosquito has three surges of 20-hydroxy ecdysone(20-HE), at 24,32 and 48th hour of the 4th instar. BPA resulted dose-dependent advancement of 20-HE peaks, Phospholipase A2 induction and expression of Ecdysone receptor EcRA and Ecdysone inducible gene E75A, which culminated in early pupation. Adults emerging from 1.0 ppm BPA treatment did not show significant difference in sanguivory and fecundity compared to control but pupae developed in 2 and 4 ppm BPA were significantly small.


Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 182-194
Author(s):  
Paulo Sérgio Fagundes Araujo ◽  
Maria Cristiana da Silva Souto ◽  
Paulo Roberto Medeiros de Azevedo ◽  
Maria de Fatima Freire de Melo Ximenes

This study aimed to correlate sustainable development indicators with the occurrence of mosquitoes from the genus Aedes and phlebotominae sand flies, vectors of dengue fever, American visceral leishmaniasis and American tegumentary leishmaniasis, in order to establish a relationship between infestation indices and sustainability conditions in southern and northern neighborhoods of Natal, Brazil, adjacent to environmental protection zones 5 and 9, respectively. Data were obtained on Aedes aegypti and A. albopictus breeding sites and captures of phlebotominae sand flies of the genus Lutzomyia in the study area between 2006 and 2008, from the Center of Zoonosis Control of the Municipal Health Secretariat, and correlated with environmental and social indicators. Factorial analysis was applied to transform these indicators into a sustainability index for each neighborhood studied (Neighborhood Sustainability Index – NSI). Relating these indices with the occurrence of insect vectors at these sites shows a high positive correlation between SID and the Breteau index of A. aegypti (p=0.028) and with the index of household infestation by phlebotominae sand flies (p=0.01). This reveals a pattern allowing the association of sustainability conditions in the study areas with the occurrence of these insects. Analyses demonstrate the occurrence of a larger number of A. aegypti breeding sites and higher indices of household infestation by phlebotominae sand flies in neighborhoods with lower sustainability indices. Knowledge of the relationship between sustainable development indicators and the occurrence of zoonotic vectors may contribute to public health programs as well as to a restructuring of public policies in the study areas.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qing Cheng ◽  
Zeyi Liu ◽  
Guangquan Cheng ◽  
Jincai Huang

AbstractBeginning on December 31, 2019, the large-scale novel coronavirus disease 2019 (COVID-19) emerged in China. Tracking and analysing the heterogeneity and effectiveness of cities’ prevention and control of the COVID-19 epidemic is essential to design and adjust epidemic prevention and control measures. The number of newly confirmed cases in 25 of China’s most-affected cities for the COVID-19 epidemic from January 11 to February 10 was collected. The heterogeneity and effectiveness of these 25 cities’ prevention and control measures for COVID-19 were analysed by using an estimated time-varying reproduction number method and a serial correlation method. The results showed that the effective reproduction number (R) in 25 cities showed a downward trend overall, but there was a significant difference in the R change trends among cities, indicating that there was heterogeneity in the spread and control of COVID-19 in cities. Moreover, the COVID-19 control in 21 of 25 cities was effective, and the risk of infection decreased because their R had dropped below 1 by February 10, 2020. In contrast, the cities of Wuhan, Tianmen, Ezhou and Enshi still had difficulty effectively controlling the COVID-19 epidemic in a short period of time because their R was greater than 1.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdou Talipouo ◽  
Konstantinos Mavridis ◽  
Elysée Nchoutpouen ◽  
Borel Djiappi-Tchamen ◽  
Emmanouil Alexandros Fotakis ◽  
...  

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.


Author(s):  
Anand Marya ◽  
Mohmed Isaqali Karobari ◽  
Siddharthan Selvaraj ◽  
Abdul Habeeb Adil ◽  
Ali A. Assiry ◽  
...  

Objective: Healthcare workers in general are at a high risk of potential infections with COVID-19, especially those who work with aerosol generating procedures. Dentists fall in this category, as not only do they operate with aerosol generating procedures but also operate within a face-to-face contact area. Methods: A structured self-administered questionnaire was developed at Najran University and provided to the participants for data collection. The data collected included information on risk perception and incorporation of measures for protection against COVID-19 to gauge the attitude of dentists during this period. Also, clinical implementation of various protective measures was reviewed. Results: Of the n = 322 dentists that answered the questions, 50% were general dentists and 28.9% were dentists working at specialist clinics, while the remaining 21.1% of dentists were employed in academic institutions. Among the newer additions to the clinic, 36.3% of dentists answered that they had added atomizers to their practices, followed by 26.4% of dentists that had incorporated the use of UV lamps for sterilization. We found that 18.9% dentists were using HEPA filters in their clinics, while 9.9% of dentists were making use of fumigation devices to control the risk of infection. One-way ANOVA was also carried out to demonstrate that there was a statistically significant difference (p = 0.049) between groups of dentists utilizing HEPA filters, UV lamps, atomizers, and fumigation devices to prevent the spread of SARS-CoV2 across their workplaces. Conclusion: Dentists are aware of recently updated knowledge about the modes of transmission of COVID-19 and the recommended infection control measures in dental settings. A better understanding of the situation and methods to prevent it will ensure that the dental community is able to provide healthcare services to patients during the pandemic.


2014 ◽  
Vol 64 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Marcos de Miranda Leão Leite ◽  
Cynthia Yuri Ogawa ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva

The relationship between weight and size of individuals can be used to evaluate the status of a population, which is particularly useful for natural populations that are being exploited. Ucides cordatus occurs on the Atlantic coast of the American continent, from Florida (USA) to Santa Catarina (Brazil). This species is economically very important, most of all in the Northeastern area of Brazil, as well as in the Dominican Republic and Suriname. The objective of this study was to analyze life phases (‘fattening’, ‘matumba’, ‘milk-crab’, ‘maturation’ and ‘walking’) by use of the weight-length relationships, as well as temporal variations in this condition factor for each sex of U. cordatus. For this purpose, individuals were sampled monthly for twenty-four months at the Jaguaribe River estuary, Ceará State, Northeastern Brazil. The relationship between total weight and cephalothorax width was established using regression analysis, adjusted by a power equation. The dynamics of the condition factor were analyzed for each sex using the variation of its averages related to annual life cycle; this was done for each of the previously-mentioned phases. The relationship between total weight and cephalothorax width showed an isometric growth in males and negative allometric growth in females suggesting that, for the same reference size, males are heavier than females. When considering the average of the female condition factors, these were greater than those for males during the annual life cycle, except during the ‘maturation’ phase, which is the phase with a higher demand of energetic reserves for males. Annual variation of the condition factor in females presented no significant difference.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Getachew Gari ◽  
Biressaw Serda ◽  
Dejene Negesa ◽  
Fethu Lemma ◽  
Hagos Asgedom

Peste des petits ruminant (PPR) is an economically important disease of small ruminants with a rapidly expanding geographical distribution. There are fragmented reports to the occurrence and distribution of the disease in Ethiopia. A total of 700 serum samples were collected from goats and sheep to detect the presence of antibody against PPR virus using Competitive Enzyme-Linked Immunosorbent Assay (C-ELISA). An overall PPR seropositivity was reported to be 48.43% in the area. There is no statistically significant difference in the seroprevalence of the disease between sheep and goats (50.85% and 46.68%), respectively. However, there was statistically significant variation (P<0.05) in the seroprevalence of the disease in young (33.9%) and adult (55.8%) age categories. The seroprevalence in male and female was 42.07% and 50.09%, respectively, where the variation was statistically not significant (P>0.05). High seroprevalence of Peste des petites ruminants in the study area indicated the virus circulation and endemicity of the disease. The disease causes substantial economic losses by affecting the livelihood of the farmers. Therefore, control measures should be put in place to minimize the loss associated with the disease.


2014 ◽  
Vol 86 (3) ◽  
pp. 1207-1220 ◽  
Author(s):  
GUILHERME S. TOLEDO-LIMA ◽  
PHOEVE MACARIO ◽  
RACHEL M. DE LYRA-NEVES ◽  
BRUNO P. TEIXEIRA ◽  
LUIZ A.F. DE LIMA ◽  
...  

In northeastern Brazil, the reduction of the natural forest cover to a series of small, isolated fragments has had negative consequences for the local avian fauna, in particular, a loss of the more specialized species, while the populations of some generalists have tended to increase. The present study focuses on the composition and trophic groups of a bird community on a farm in the northeastern Brazilian state of Alagoas. Monthly surveys were conducted between November 2008 and October 2009, based on mist-netting and systematic observations. Overall, 112 species were recorded, of which 76 were associated with the two forest fragments surveyed, while all the others were observed exclusively in the surrounding matrix of pasture and orchards. The bird community presented a predominance of insectivorous species, followed by omnivores. However, specialized trunk-creeping and understory insectivores accounted for only around 15% of the species in this feeding category. The reduced diversity of other guilds and species with more specialized diets, and the complete absence of sensitive species such as large parrots and raptors, reflects the severe fragmentation and degradation of the local forests, which has greatly reduced the availability of dietary resources and breeding sites.


2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Danielle Nobre Santos Pinheiro ◽  
Joselito Nunes Costa ◽  
Thiago Sampaio de Souza ◽  
Vanderlan Warlington Souza Santos ◽  
Dalva Alana Azevedo ◽  
...  

ABSTRACT: This study aimed to carry out a serum epidemiological survey of goat arthritis encephalitis in the sisal region of Bahia, Brazil, and to evaluate risk factors. We evaluated 831 samples of goat blood serum among males and females older than six months, from 49 farms distributed among the municipalities of Araci, Cansanção, Conceição do Coité, Itiúba, Monte Santo, Nordestina, Queimadas, Santa Luz, São Domingos and Valente. An epidemiological questionnaire for the analysis of possible risk factors was applied. All sera were tested for immune-agar gel. The seroprevalence obtained in surveyed herds was 1.56% (13/831). There was significant difference (p<0.05) for animal racial pattern, type of farming and breeding systems. However, when considering herds with predominantly dairy breeds (Saanen and Alpine Pardo), the seropositivity in animals from Valente, Conceição do Coité and São Domingos amounted to 5.06% (12/237). In these municipalities, from 14 properties analyzed, five (38.5%) had at least one positive-testing animal. This result is extremely worrying when one considers that few control measures are adopted by farmers to prevent the goat arthritis encephalitis in the most important dairy region of Bahia state.


AoB Plants ◽  
2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Wanli Zhao ◽  
Peili Fu ◽  
Guolan Liu ◽  
Ping Zhao

Abstract Emergent aquatic plants mostly occur in shallow waters and root in bottom substrates, but their leaves emerge from the water surface and are thus exposed to air, similar to the leaves of terrestrial plants. Previous studies have found coordination between leaf water supply and demand in terrestrial plants; however, whether such a coordination exists in emergent aquatic plants remains unknown. In this study, we analysed leaf veins and stomatal characteristics of 14 emergent aquatic and 13 terrestrial monocotyledonous herb species (EMH and TMH), with 5 EMH and 8 TMH belonging to Poaceae. We found that EMH had significantly higher mean leaf area, leaf thickness, stomatal density, stomatal number per vein length and major vein diameter, but lower mean major vein length per area (VLA) and total VLA than TMH. There was no significant difference in stomatal length, minor VLA and minor vein diameter between the two groups. Stomatal density and total VLA were positively correlated among the EMH, TMH, as well as the 8 Poaceae TMH species, but this correlation became non-significant when data from both the groups were pooled. Our results showed that the differences in water supply between emergent aquatic and terrestrial plants modify the coordination of their leaf veins and stomatal traits.


Sign in / Sign up

Export Citation Format

Share Document