clove and Dengue

This review aims to describe essential oils and their constituent compounds that exhibit bioactivity against Aedes aegypti L. (Diptera: Culicidae) larvae, the immature stage of the primary vector of dengue. This review is based on original articles obtained by searching on major databases. Our literature review revealed that 361 essential oils from 269 plant species have been tested for their larvicidal activity. More than 60 % of these essential oils were considered active (LC50<100 mg/L), and the majority of these active oils were derived from species belonging to Myrtaceae, Lamiaceae, and Rutaceae. The most active essential oils exhibited effective concentrations comparable with the dosage recommended for the use of temephos in container breeding. Approximately 27 % of the plants studied for their larvicidal activity against A. aegypti were collected in Brazil. Essential oils rich in phenylpropanoids, oxygenated sesquiterpenes, and monoterpene hydrocarbons were found to be the most active. When the isolates were tested, phenylpropanoids and monoterpene hydrocarbons were the most active compound classes. We describe the plant parts used and the major constituents of the essential oils. In addition, we discuss factors affecting the activity (such as plant parts, age of the plant, chemotypes, larval source, and methods used), structure-activity relationships, and mechanisms of action of the essential oils and their compounds. Essential oils have been widely investigated and show high larvicidal activity against A. aegypti. This review reveals that the essential oils are effective alternatives for the production of larvicides, which can be used in vector-borne disease control programmes.

Topics: Aedes; Animals; Dengue; Insect Vectors; Insecticides; Lamiaceae; Larva; Myrtaceae; Oils, Volatile; Rutaceae; Structure-Activity Relationship

Arboviruses have been shown to circulate in Madagascar, including West Nile, dengue, and chikungunya viruses, though the extent of their circulation remains poorly documented. We estimated the seroprevalence of these three arboviruses in Madagascar and determined risk factors associated with seropositivity. Serum samples obtained from 1680 individuals surrounding the Sentinel Health Centers network in all regions of the country were analyzed using ELISA and hemagglutination inhibition assays for dengue, chikungunya, and West Nile viruses IgG antibodies, and multivariate logistic regression models were run. Overall, 6.5% [IC 95% 3.2-9.9] were seropositive for dengue virus, predominantly of Dengue serotype 1, 13.7% [IC 95% 6.5-20.9] for chikungunya virus, and 12.7% [IC 95% 9.0-16.5] for West Nile virus. There was no association with age, showing that dengue and chikungunya viruses were likely recently introduced. Eastern and Northern parts were more affected by dengue and chikungunya viruses, while West Nile virus seemed to circulate in all parts of the country. Dengue and chikungunya seropositivity were notably associated with high levels of vegetation, as well as frequent work in the forest, and West Nile seropositivity with the presence of cultivated areas, as well as standard of living. This analysis gives a new insight into arboviruses circulation and transmission patterns in Madagascar.

Topics: Chikungunya Fever; Chikungunya virus; Dengue; Humans; Immunoglobulin G; Madagascar; Risk Factors; Seroepidemiologic Studies; West Nile virus

Data collected by the GeoSentinel Surveillance Network for 1,415 ill travelers returning from Indian Ocean islands during 1997-2010 were analyzed. Malaria (from Comoros and Madagascar), acute nonparasitic diarrhea, and parasitoses were the most frequently diagnosed infectious diseases. An increase in arboviral diseases reflected the 2005 outbreak of chikungunya fever.

Topics: Adolescent; Adult; Aged; Alphavirus Infections; Chikungunya Fever; Communicable Diseases, Emerging; Comoros; Dengue; Female; Foodborne Diseases; Humans; Incidence; Madagascar; Malaria, Falciparum; Male; Middle Aged; Schistosomiasis; Sentinel Surveillance; Travel; Young Adult

South Western islands of the Indian Ocean are permanently threatened by dengue fever outbreaks. On the Reunion Island, two dengue outbreaks were biologically documented (1977-1978 and 2004). And since July 2004 there has been an inter-epidemic period for the island with sporadic cases and clusters. Between January 1, 2007 and October 5, 2009, the epidemiologic surveillance system detected five confirmed autochthonous cases, five confirmed imported cases (South-East Asia), and 71 probable cases. All the five autochthonous confirmed cases occurred in Saint-Louis during two consecutive clusters. In other South Western islands of the Indian Ocean, several dengue fever outbreaks have been reported. Importation of dengue virus from South-East Asia is a major risk for a new outbreak on the island. The introduction of a new serotype could lead to the emergence of new and severe clinical forms, including dengue hemorrhagic fever.

Topics: Aedes; Animals; Asia, Southeastern; Dengue; Dengue Virus; Disease Outbreaks; Guinea; Humans; Indian Ocean Islands; Insect Vectors; Madagascar; Mandatory Reporting; Population Surveillance; Reunion; Serotyping; Travel

Dengue fever is the main emerging vector-borne disease worldwide. It was estimated that 40% of the world population is at risk. A potential vector (Aedes albopictus) is present in four French departments of the southeast area of metropolitan France.. The authors tried to document the number of imported cases of dengue diagnosed from 2001 to 2006, inclusive, as well as their main features.. Between 12 and 28 cases of imported dengue were diagnosed every month during that period (eight to 18 cases per month except for years 2001-2002 during which an important dengue epidemic was documented in the French West Indies). Nearly 40% of the cases were imported between June and September during which the vector is active in the metropolitan area.. This data underlines the strong and close link between the endemic zones of the French territory (French West Indies and Guyana) and the risk of imported cases to metropolitan France. The identification of this "importation track" entails strengthening the system for detecting and managing imported dengue cases in metropolitan France when a dengue epidemic is detected in the French West Indies.

Topics: Aedes; Africa; Animals; Asia, Southeastern; Dengue; France; Humans; India; Madagascar; Seasons; South America; Sri Lanka; Travel; Urban Population

An outbreak of dengue-like syndrome occurred in Toamasina from January through March 2006. Dengue type l or chikungunya viruses were detected in 38 of 55 patients sampled. Aedes albopictus was the only potential vector collected. Of 4,242 randomly selected representative residents interviewed retrospectively, 67.5% reported a dengue-like syndrome during this period.

Topics: Aedes; Alphavirus Infections; Animals; Chikungunya virus; Cross-Sectional Studies; Dengue; Disease Outbreaks; Environmental Monitoring; Epidemiological Monitoring; Humans; Insect Vectors; Madagascar; Retrospective Studies; Seroepidemiologic Studies

Topics: Alphavirus Infections; Chikungunya virus; Comoros; Dengue; Disease Outbreaks; Humans; Indian Ocean Islands; Madagascar; Mosquito Control; Reunion; Seychelles

Starch gel electrophoresis was used to assess the polymorphism of 7 isoenzymes in single mosquitoes (field-collected F0 or F1 generation) for Aedes albopictus (8 strains) from northern Madagascar. Mosquitoes of the F2 generation (3 strains of Aedes aegypti and 10 strains of Ae. albopictus) were tested for oral susceptibility to dengue type 2 virus. Aedes aegypti was less susceptible to viral infection than Ae. albopictus. The genetic differentiation was less high between Ae. albopictus populations collected in agglomerations connected by highly frequented roads, indicating that human ground transportation favors mosquito dispersal. These results have implications for the ecology, pattern of migration, and relative importance in epidemic transmission of dengue viruses between the 2 Aedes species.

Topics: Aedes; Animals; Dengue; Female; Genetics, Population; Insect Vectors; Madagascar; Polymorphism, Genetic

Topics: Aedes; Animals; Dengue; Dengue Virus; Humans; Insect Vectors; Madagascar

Topics: Animals; Antibodies, Viral; Arbovirus Infections; Arboviruses; Arthropod Vectors; Dengue; Hemagglutination Inhibition Tests; Humans; Madagascar; Yellow Fever; Zoonoses