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1.
Bull Entomol Res ; : 1-12, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38708567

RESUMEN

The Culicidae mosquito family breeds in various natural and artificial water bodies. Phytotelmata are plant structures that hold water and are used by many mosquito species during their life cycle. Mosquitoes are disease vectors, and phytotelmata play an important role in harbouring them. Investigating these phytotelmata will facilitate to develop appropriate site specific vector control strategy. Approximately 750 phytotelmata in 16 locations on Car Nicobar Island was examined. Mosquito larvae were collected from different habitats such as tree holes, root holes, leaf axils, and bamboo stumps. On average, the number of larvae per 10 ml of water ranged from 0.003 to 3.833. Among the 16 mosquito species identified, there were vectors of malaria (Anopheles sundaicus), dengue (Aedes aegypti and Aedes albopictus) and filariasis (Culex quinquefasciatus), belonging to seven genera. The most common phytotelmata were coconut trees (17.5%) followed by Java apple trees (10.3%) and bamboo stumps (7.1%). The most widespread mosquito species was Aedes edwardsi, followed by Aedes malayensis and Ae. albopictus, and the per cent of phytotelmata that contained these species were 42.6, 22.0, and 16.8% respectively. Anopheles mosquitoes had the highest container index (6.1%) in root holes, while Aedes and Culex mosquitoes were more frequently found in bamboo stumps. The alpha biodiversity indices indicated that the mosquito population in Car Nicobar Island was highly diverse (S = 16; DMg = 36.9). Tree holes showed the highest diversity, as all 16 species were collected from them. Assessment of phytotelmata, there is a significant relationship observed between mosquito genus, village, habitat, and tree families, on the remote island of Car Nicobar. Considering the presence of disease-transmitting mosquito vectors in the phytotelmata, these habitats should be considered when implementing control measures to eliminate mosquito-borne infections.

2.
Indian J Med Res ; 156(2): 240-249, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-36629183

RESUMEN

Background & objectives: Malaria is an important public health problem in Andaman & Nicobar archipelago. Among the three districts, Nicobar is the most endemic district where API is >2. In this district, the malaria incidence in Car Nicobar Tehsil has declined steadily over the past 10 years. A renewed initiative to consolidate this gain is being made with the ultimate objective of achieving zero indigenous transmission of malaria in Car Nicobar. So, the present study undertook a close environmental monitoring of water bodies for assessing changes in the risk potential of mosquito vector breeding habitats which can augment the elimination programme. Methods: The breeding habitats of anopheline mosquitoes were sampled in 16 areas of Car Nicobar Island for eight time periods during 2017-2020. Along with anophelines, various associated water parameters (n=60) were estimated, viz. physicochemical (n=13), and biological, which included culicine mosquito immatures, insect predators (n=5), phytoplanktons (n=31) and zooplanktons (n=10). Results: In the 16 study sites, overall 1126 surface water stagnating bodies constituting 21 different habitat types were surveyed. Of these, 17 were positive for anopheline breeding. Water bodies from three villages were consistently found to be positive for anopheline breeding. However, early instars of anopheline larvae were more abundant compared to the late instars. Four anopheline species were recorded, including Anopheles sundaicus, A. barbirostris, A. insulaeflorum and A. subpictus, in which 48 per cent were A. sundaicus. Multivariable analysis indicated that anopheline density was significantly higher in permanent water bodies than in temporary habitats (P<0.05) (high risk of anophelines). The highest pH (≥8.2), dissolved solids (≥0.39) levels showed significantly (P<0.05) decreased larval densities (lower risk of breeding), adjusted with breeding sites and season. Nitrite levels increased (P=0.022) larval densities. Interpretation & conclusions: The present study facilitated estimating the productive period of a larval habitat enabling target larval sources to reduce adult populations. Implementing larviciding strategy before monsoon season is presumably the most cost-effective strategy. The output can be utilized for environmental monitoring of mosquito breeding risk in other malaria endemic areas, particularly where medium/large water bodies are the predominant breeding sites for malaria vectors.


Asunto(s)
Anopheles , Malaria , Humanos , Animales , Automóviles , Ecosistema , Malaria/epidemiología , Malaria/prevención & control , Larva , Agua , Cruzamiento
3.
Int J Infect Dis ; 113: 119-124, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34601144

RESUMEN

OBJECTIVES: Following the Public Health Emergency of International Concern declared on Zika by the World Health Organization during 2016, the Indian Council of Medical Research carried out nationwide vector surveillance for Zika and Dengue viruses (ZIKV and DENV) in India as a preparedness measure in 2016-19. METHODS: High-risk zones distributed to 49 Districts in 14 states/union territories were included in the study. Seven ICMR institutions participated, following a standard operating protocol. Aedes specimens sampled weekly were processed by multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) for ZIKV/DENV and random samples crosschecked with real-time RT-PCR for ZIKV. RESULTS: Altogether, 79 492 Aedes specimens in 6492 pools were processed; 3 (0.05%) and 63 (0.97%) pools, respectively, were found positive for ZIKV and DENV. ZIKV infections were recorded in Aedes aegypti sampled during the 2018 sporadic Zika outbreak in Jaipur, Rajasthan. However, these belonged to the Asian lineage of the virus, already circulating in the country. Both Ae. aegypti and Aedes albopictus distributed to 8 states/union territories were found to be infected with DENV. Both sexes of Ae. albopictus were infected, indicating transovarial transmission. CONCLUSION: This investigation evinced no active transmission of the American lineage-pandemic Zika virus in India during the pandemic period.


Asunto(s)
Aedes , Dengue , Infección por el Virus Zika , Virus Zika , Animales , Dengue/epidemiología , Femenino , Humanos , India/epidemiología , Masculino , Mosquitos Vectores , Pandemias , Infección por el Virus Zika/epidemiología
4.
Microb Pathog ; 96: 85-8, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27174207

RESUMEN

In this study, methanol extracts of six medicinal plants (Alstonia macrophylla, Claoxylon indicum, Dillenia andamanica, Jasminum syringifolium, Miliusia andamanica and Pedilanthus tithymaloides) traditionally used by Nicobarese tribes of Andaman and Nicobar Islands were studied for antimicrobial and antimalarial activities as well as preliminary photochemical analysis. Plants were collected from Car Nicobar of Andaman and Nicobar Islands and the ethnobotanical data were gathered from traditional healers who inhabit the study area. The methanol extracts were obtained by cold percolation method and the antimicrobial activity was found using agar well diffusion method. Among the plants tested, J. syringifolium, D. andamanica, C. indicum were most active. The antimalarial activity was evaluated against Plasmodium falciparum chloroquine-sensitive MRC-2 isolate. The crude extract of M. andamanica showed excellent antimalarial activity followed by extracts of P. tithymaloides, J. syringifolium and D. andamanica. The chemical injury to erythrocytes was also carried out and it showed that, there were no morphological changes in erythrocytes by the methanol crude extracts. The in vitro antimicrobial and antimalarial activity might be due to the presence of alkaloids, flavonoids, triterpenes, sterols, tannins and saponins in the methanol extracts of tested plants.


Asunto(s)
Antiinfecciosos/farmacología , Antimaláricos/farmacología , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Plantas Medicinales/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/toxicidad , Antimaláricos/aislamiento & purificación , Antimaláricos/toxicidad , Bacterias/efectos de los fármacos , Pruebas Antimicrobianas de Difusión por Disco , Eritrocitos/efectos de los fármacos , Hongos/efectos de los fármacos , Hemólisis , Humanos , India , Islas , Fitoquímicos/aislamiento & purificación , Fitoquímicos/toxicidad , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/toxicidad , Plasmodium falciparum/efectos de los fármacos , Grupos de Población
5.
Parasitol Res ; 115(6): 2353-62, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26969179

RESUMEN

Community-based integrated vector control (IVC) using polystyrene beads (EPS) and pyrethroid impregnated curtains (PIC) as an adjunct to mass drug administration (MDA) was implemented for lymphatic filariasis elimination, in the filaria endemic villages of Tirukoilur, south India. In all the villages, MDA was carried out by the state health machinery, as part of the national filariasis elimination programme. Thirty-six difficult-to-control villages were grouped as, viz, MDA alone, MDA + EPS and MDA + EPS + PIC arms. Implementation and monitoring of IVC was carried out by the community. After 3 years of IVC, higher reductions in filariometric indices were observed in both the community and vector population. Decline in antigenaemia prevalence was higher in MDA + IVC as compared to MDA alone arm. Vector density dropped significantly (P < 0.05) in both the IVC arms, and nil transmission was observed during post-IVC period. Almost 53.8 and 75.8 % of the cesspits in MDA + EPS and MDA + EPS + PIC arms were closed by the householders, due to the enhanced awareness on vector breeding. The paper presents the key elements of IVC implementation through social mobilization in a LF prevalent area. Thus, community-based IVC strategy can hasten LF elimination, as it reduced the transmission and filariometric indices significantly. Indices were maintained at low level with nil transmission, by the community through IVC tools.


Asunto(s)
Culicidae/efectos de los fármacos , Filariasis Linfática/prevención & control , Filaricidas/administración & dosificación , Insectos Vectores/efectos de los fármacos , Insecticidas/administración & dosificación , Control de Mosquitos/métodos , Albendazol/administración & dosificación , Animales , Brugia Malayi/fisiología , Participación de la Comunidad , Culicidae/parasitología , Dietilcarbamazina/administración & dosificación , Erradicación de la Enfermedad , Filariasis Linfática/epidemiología , Filariasis Linfática/parasitología , Femenino , Humanos , India/epidemiología , Insectos Vectores/parasitología , Microfilarias , Nitrilos/administración & dosificación , Poliestirenos , Prevalencia , Piretrinas/administración & dosificación , Wuchereria bancrofti/fisiología
7.
Parasitol Res ; 114(12): 4693-702, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26344869

RESUMEN

Dengue and chikungunya are important arboviral infections in the Andaman Islands. Competent vectors viz. Aedes aegypti and Aedes albopictus are widely prevalent. The most effective proven method for interrupting the transmission of these arboviruses is vector control, mediated through insecticides. Currently, DDT and temephos are the insecticides used for vector control in these islands. Lack of information on susceptibility necessitated assessing the susceptibility profile of A. aegypti and A. albopictus. F1 generation of adult and larvae were assayed, and LT50 and LT90 values were interpreted following the World Health Organization (WHO) protocol. Adults were found resistant to DDT-4 % while susceptible to dieldrin-0.4 %. Against organophosphates, both showed resistance to fenitrothion but susceptible to malathion-5 %. Both species showed resistance to carbamate and bendiocarb-0.1 % while susceptible to propoxur-0.1 %. Of the four synthetic pyrethroids, both were susceptible to deltamethrin-0.05 %, while resistant to permethrin-0.75 %, lambdacyhalothrin-0.05 % and cyfluthrin-0.15 %. Larvae of both species showed resistance to temephos at 0.02 mg/L but susceptible to malathion at 1 mg/L and fenthion at 0.05 mg/L. Currently, there is no prescribed WHO dose for adult-insecticide susceptibility testing. The emergence of resistance to DDT and temephos in the vector population poses a challenge to the on-going vector control measures. The results highlight the need for monitoring resistance to insecticides in the vector population. Impetus for source reduction and alternative choices of control measures are discussed for tackling future threat of arboviral infections in these islands.


Asunto(s)
Aedes/efectos de los fármacos , Fiebre Chikungunya/transmisión , Dengue/transmisión , Insectos Vectores/efectos de los fármacos , Insecticidas/farmacología , Aedes/crecimiento & desarrollo , Animales , Femenino , Humanos , India , Insectos Vectores/crecimiento & desarrollo , Islas , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Malatión/farmacología , Masculino , Nitrilos/farmacología , Permetrina/farmacología , Propoxur/farmacología , Piretrinas/farmacología , Temefós/farmacología
8.
Parasitol Res ; 114(9): 3539-46, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26220560

RESUMEN

Mosquito foraging behavior is a determinant of host-vector contact and has an impact on the risk of arboviral epidemics. Therefore, blood-feeding patterns is a useful tool for assessing the role in pathogen transmission by vector mosquitoes. Competent vectors of dengue and chikungunya viz. Aedes aegypti and Aedes albopictus are widely prevalent in the Andaman and Nicobar archipelago. Considering the vector potential, medical importance of both these mosquito species and lack of information on host-feeding patterns, blood meal analysis of both these vector mosquitoes was undertaken. Biogents Sentinel traps were used for sampling blooded mosquitoes, for identifying the source of blood meal by agar gel-precipitin test. We identified vertebrate source of 147 and 104 blood meals in Ae. aegypti and Ae. albopictus from heterogeneous landscapes in South Andaman district. Results revealed that Ae. aegypti (88 %) and Ae. albopictus (49 %) fed on human and a small proportion on mammals and fowls, indicative of predominance of anthropophilism. Ae. aegypti predominantly fed on human blood (94.2 %-densely built urban, 89.8 %-low vegetation coverage, and 78.3 %-medium vegetation coverage). Anthropophilism in Ae. albopictus was maximal in densely built urban (90.5 %) and progressively decreased from low vegetation-vegetation/forested continuum (66.7, 36.4, and 8.7 %), indicating plasticity in feeding across these landscapes. Epidemiological significance of the findings is discussed.


Asunto(s)
Aedes/fisiología , Fiebre Chikungunya/transmisión , Dengue/transmisión , Aedes/virología , Animales , Aves , Fiebre Chikungunya/virología , Dengue/virología , Conducta Alimentaria , Femenino , Humanos , India , Insectos Vectores , Islas , Mamíferos
11.
Indian J Med Res ; 141(3): 330-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25963494

RESUMEN

BACKGROUND & OBJECTIVES: One third of the world's population is infected with one or more of the most common soil-transmitted helminths (STH). Albendazole (ALB) is being administered with diethyl carbamazine (DEC) in filariasis endemic areas to eliminate lymphatic filariasis (LF) and helminth infections. In this study, the cumulative impact of seven annual rounds of mass drug administrations (MDA) of DEC and ALB on STH infection in school children in selected villages in southern India was determined. METHODS: During 2001-2010, seven MDAs were implemented by the Tamil Nadu s0 tate h0 ealth d0 epartment, India. LF and STH infections were monitored in school children from 18 villages of the two treatment arms (viz, DEC alone and DEC+ALB). Kato-Katz cellophane quantitative thick smear technique was employed to estimate STH infections at three weeks, six months and one year post MDA. RESULTS: Prior to treatment, an overall STH prevalence was 60 per cent. After each MDA, infection markedly reduced at three weeks post-treatment in both the arms. The prevalence increased at six months period, which was maintained up to one year. After seven rounds of MDA, the infection reduced from 60.44 to 12.48 per cent in DEC+ALB arm; while the reduction was negligible in DEC alone arm (58.77 to 52.70%). INTERPRETATION & CONCLUSIONS: Seven rounds of MDA with DEC+ALB reduced the infection load significantly, and further sustained low level of infection for 10 years. However, complete parasite elimination could not be achieved. To curtail STH infection in the community, MDA should be regularized and environmental sanitation measures need to be improved by effective community-based campaigns.


Asunto(s)
Albendazol/administración & dosificación , Dietilcarbamazina/administración & dosificación , Filariasis Linfática/tratamiento farmacológico , Helmintiasis/tratamiento farmacológico , Parasitosis Intestinales/tratamiento farmacológico , Animales , Niño , Esquema de Medicación , Filariasis Linfática/epidemiología , Filariasis Linfática/parasitología , Femenino , Helmintiasis/epidemiología , Helmintiasis/parasitología , Helmintos/efectos de los fármacos , Helmintos/patogenicidad , Humanos , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/parasitología , Masculino
12.
Parasitol Int ; 64(1): 1-4, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25205435

RESUMEN

The National Programme for the Elimination of Lymphatic Filariasis is underway in the endemic districts of Tamil Nadu State, South India, since 2001. Annual mass drug administration (MDA) was carried out by the state health department to all eligible individuals. The impact of MDAs on transmission parameters was evaluated in 2 revenue blocks, viz, one with DEC alone and the other with a combination of albendazole. After 10 years with 6 annual MDAs, the transmission indices reached low levels in both treatment arms, but still persisted. However, the DEC alone arm showed higher transmission rates, compared to the DEC+ALB arm. Few villages which demonstrated persistent transmission need to be targeted with an additional control measure viz, vector control, to achieve LF elimination. It is evident from the 10 year period of the study that inclusion of albendazole along with DEC has significantly reduced the transmission indices to almost nil level, as compared to DEC alone.


Asunto(s)
Albendazol/administración & dosificación , Dietilcarbamazina/administración & dosificación , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/transmisión , Filaricidas/administración & dosificación , Albendazol/uso terapéutico , Animales , Culex/parasitología , Dietilcarbamazina/uso terapéutico , Erradicación de la Enfermedad , Esquema de Medicación , Quimioterapia Combinada , Filariasis Linfática/prevención & control , Filaricidas/uso terapéutico , Humanos , India/epidemiología , Insectos Vectores/parasitología , Estudios Longitudinales , Resultado del Tratamiento
13.
J Trop Pediatr ; 60(3): 245-8, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24343822

RESUMEN

Under the Global Programme to Eliminate Lymphatic Filariasis (LF), mass drug administration (MDA) is being implemented in Tamil Nadu, south India, by the State health machinery. The impact of six annual rounds of MDA using diethylcarbamazine (DEC) with and without albendazole (ALB) on filarial infection (microfilaraemia prevalence-MFP; antigenaemia prevalence-AGP) in paediatric population of 2-9 years was determined in two revenue blocks, with a population of 321 000. After each MDA, 300-400 children were screened for filarial infection. After six MDAs, an overall MFP reduction of 84.67% and 57.95% was observed in DEC+ALB and DEC alone arms, respectively. Corresponding AGP reductions were 72.88% (p < 0.001) and 41.51% (p = 0.023). Observation of microfilaraemic children after six MDAs (0.32% in DEC+ALB; 0.75% in DEC alone), necessitates the need for supplementary control strategies (viz., vector control), in order to achieve the goal of LF elimination.


Asunto(s)
Albendazol/uso terapéutico , Dietilcarbamazina/administración & dosificación , Filariasis Linfática/tratamiento farmacológico , Filaricidas/administración & dosificación , Wuchereria bancrofti/efectos de los fármacos , Animales , Antígenos Helmínticos/sangre , Niño , Preescolar , Dietilcarbamazina/uso terapéutico , Esquema de Medicación , Quimioterapia Combinada , Filaricidas/uso terapéutico , Humanos , Incidencia , India/epidemiología , Cumplimiento de la Medicación , Prevalencia , Población Rural , Resultado del Tratamiento
14.
Trop Doct ; 43(1): 30-2, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23550201

RESUMEN

Lymphatic filariasis (LF) is endemic in the Andaman and Nicobar islands, including the lone foci for a diurnally sub-periodic form of Wuchereria bancrofti in the Nancowry group of islands. A programme to eliminate LF was launched in 2004 by the Directorate of Health Services, Andaman and Nicobar Administration which involved a single annual mass drug administration (MDA) using diethylcarbamazine (DEC) with albendazole. So far, eight rounds of MDA have been implemented through the Public Health Care network. The pattern of antifilarial drug distribution and compliance achieved in the on-going LF elimination programme in these islands has been assessed. This is the first systematic effort undertaken in these remote islands to assess the coverage and compliance with the LF elimination programme. This study covered 900 households in each of the 3 districts. There were a largest number of side effects in the Nicobar district (6.4%). Non-consumption of drugs ranged from 18.6% (Nicobar) to 42% (North and Middle Andaman). A survey revealed that almost 95.3% of the respondents had heard about MDA from the drug distributors. Therefore, the distributors should be involved in programmes designed to educate the community at risk of acquiring filarial infection and the possible side effects of the drugs.


Asunto(s)
Albendazol/administración & dosificación , Filariasis Linfática/tratamiento farmacológico , Filaricidas/administración & dosificación , Cumplimiento de la Medicación/estadística & datos numéricos , Adulto , Animales , Filariasis Linfática/prevención & control , Humanos , India , Wuchereria bancrofti
15.
J Vector Borne Dis ; 49(4): 258-61, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23428527

RESUMEN

BACKGROUND & OBJECTIVES: Wolbachia are common intracellular bacteria that are found in arthropods and nematodes. These endosymbionts are transmitted vertically through host eggs and alter host biology in diverse ways, including the induction of reproductive manipulations, such as feminization, parthenogenesis, male killing and sperm-egg incompatibility. Since they can also move horizontally across species boundaries, Wolbachia is gaining importance in recent days as it could be used as a biological control agent to control vector mosquitoes or for paratransgenic approaches. However, the study of Wolbachia requires sophisticated techniques such as PCR and cell culture facilities which cannot be affordable for many laboratories where the diseases transmitted by arthropod vectors are common. Hence, it would be beneficial to develop a simple method to detect the presence of Wolbachia in arthropods. METHOD: In this study, we described a method of staining Wolbachia endobacteria, present in the reproductive tissues of mosquitoes. The reliability of this method was compared with Gram staining and PCR based detection. RESULTS: The microscopic observation of the Gimenez stained smear prepared from the teased ovary of wild caught and Wolbachia (+) Cx. quinquefasciatus revealed the presence of pink coloured pleomorphic cells of Wolbachia ranging from cocci, comma shaped cells to bacillus and chain forms. The ovaries of Wolbachia (-) cured mosquito did not show any cell. Although Gram's staining is a reliable differential staining for the other bacteria, the bacterial cells in the smears from the ovaries of wild caught mosquitoes did not take the stain properly and the cells were not clearly visible. The PCR amplified product from the pooled remains of wild caught and Wolbachia (+) Cx. quinquefasciatus showed clear banding, whereas, no banding was observed for the negative control (distilled water) and Wolbachia (-) Cx. quinquefasciatus. INTERPRETATION & CONCLUSION: The Gimenez staining technique applied, could be used to detect the members of the endobacteria Wolbachia easily, even in a simple laboratory without any special facilities or even in the field condition and for handling large number of samples in a shorter duration.


Asunto(s)
Culex/microbiología , Reacción en Cadena de la Polimerasa/métodos , Coloración y Etiquetado/métodos , Wolbachia/genética , Wolbachia/aislamiento & purificación , Animales , Culex/clasificación , ADN Bacteriano/análisis , ADN Bacteriano/genética , Filariasis Linfática/transmisión , Femenino , Insectos Vectores/microbiología , Ovario/microbiología
16.
Trop Biomed ; 28(3): 569-76, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22433886

RESUMEN

Understanding Wolbachia mosquito interactions have been recognized as an important concept to develop novel vector control strategies. The prevalence of Wolbachia endobacteria in a natural population of the filariasis vector Culex quinquefasciatus was determined by the polymerase chain reaction method. Earlier workers had estimated the infection rates of Wolbachia with only one or very few individuals per species. In our study large number of specimens were assayed, and a total of 750 adult Culex quinquefasciatus mosquitoes were collected from three south Indian villages of Tirukoilur and Mugaiyur blocks, monthly for a period of five months (December 2006 to April 2007) and screened for the presence of Wolbachia. The percentage prevalence in adult males ranged from 88% to 96%; while in females from 84% to 100%. An overall prevalence of 91.2% was observed. There was no significant difference observed in the proportion of mosquitoes positive for Wolbachia between males and females, and also between different months of the survey; except during the month of February '07. The wsp gene sequence of the Wolbachia strain of Cx. quinquefasciatus detected was BLAST analysed and showed 99% sequence similarity with Wolbachia sp. of Culex pipiens isolated from different geographical regions. Phylogenetic analysis based on wsp gene fragments showed that the present Wolbachia isolate was closely related with Wolbachia from Culex pipens pipiens, Niphotettix virescens (Order: Hemiptera) and Cnaphalocrosis medinalis (Order: Lepidoptera).


Asunto(s)
Culex/microbiología , Filogenia , Wolbachia/clasificación , Wolbachia/aislamiento & purificación , Animales , ADN Bacteriano/química , ADN Bacteriano/genética , Enfermedades Endémicas , Femenino , Filariasis/epidemiología , Humanos , India/epidemiología , Masculino , Prevalencia , Análisis de Secuencia de ADN , Homología de Secuencia , Wolbachia/genética
17.
Tropical Biomedicine ; : 569-576, 2011.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-630097

RESUMEN

Understanding Wolbachia mosquito interactions have been recognized as an important concept to develop novel vector control strategies. The prevalence of Wolbachia endobacteria in a natural population of the filariasis vector Culex quinquefasciatus was determined by the polymerase chain reaction method. Earlier workers had estimated the infection rates of Wolbachia with only one or very few individuals per species. In our study large number of specimens were assayed, and a total of 750 adult Culex quinquefasciatus mosquitoes were collected from three south Indian villages of Tirukoilur and Mugaiyur blocks, monthly for a period of five months (December 2006 to April 2007) and screened for the presence of Wolbachia. The percentage prevalence in adult males ranged from 88% to 96%; while in females from 84% to 100%. An overall prevalence of 91.2% was observed. There was no significant difference observed in the proportion of mosquitoes positive for Wolbachia between males and females, and also between different months of the survey; except during the month of February ‘07. The wsp gene sequence of the Wolbachia strain of Cx. quinquefasciatus detected was BLAST analysed and showed 99% sequence similarity with Wolbachia sp. of Culex pipiens isolated from different geographical regions. Phylogenetic analysis based on wsp gene fragments showed that the present Wolbachia isolate was closely related with Wolbachia from Culex pipens pipiens, Niphotettix virescens (Order: Hemiptera) and Cnaphalocrosis medinalis (Order: Lepidoptera).

18.
Trop Biomed ; 27(1): 68-78, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20562816

RESUMEN

The World Health Assembly in 1997 has targeted the elimination of lymphatic filariasis (LF) by 2020, and in India the goal has been set for the year 2015 by annual single dose mass drug administration (MDA). The role of community empowerment in enhancing the drug compliance and bringing out the function of various methods used to disseminate the information on MDA to the villagers is focused. A longitudinal survey was carried out in nine villages in Tirukoilur block of Villupuram district, Tamil Nadu for filarial infection variables like microfilaraemia, antigenaemia, transmission indices before and after each MDA, to determine the drug impact. Prior to each MDA, health education campaigns with different approaches were carried out with community as the leading player. These IEC approaches were assessed after 4 MDAs for its perception in the community. After four rounds of MDA, there was a significant decline in the filarial infection variables. The microfilaraemia and antigenaemia declined by 59% and 67% respectively. The transmission indices lowered by 89% and 94% (in resting and landing catch of mosquitoes respectively). The decline in these variables, with a drug consumption rate of >80% was achieved due to the effective IEC campaigns prior to each MDA. After 4 MDAs almost 97% of the respondents were aware of lymphatic filariasis. The KAP survey in the rural villages revealed that the dissemination of MDA message through autorickshaw was the most effective, followed by school students' rally. Empowerment of community through the members of women self help groups and school students were observed to be integral to mass drug administration campaigns for the enhancement of drug compliance, thus leading to LF elimination.


Asunto(s)
Servicios de Salud Comunitaria/organización & administración , Participación de la Comunidad , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Albendazol/administración & dosificación , Albendazol/efectos adversos , Albendazol/uso terapéutico , Antihelmínticos/administración & dosificación , Antihelmínticos/efectos adversos , Antihelmínticos/uso terapéutico , Dietilcarbamazina/administración & dosificación , Dietilcarbamazina/efectos adversos , Dietilcarbamazina/uso terapéutico , Quimioterapia Combinada , Femenino , Humanos , India/epidemiología , Control de Mosquitos/métodos , Suelo/parasitología , Factores de Tiempo
19.
Indian J Med Res ; 129(3): 311-5, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19491425

RESUMEN

BACKGROUND & OBJECTIVE: The first chikungunya outbreak occurred in Kerala during 2006 affecting 14 districts, followed by another during May 2007 affecting almost whole of the State. Four of the worst affected districts viz, Pathanamthitta, Idukki, Kottayam and Thrissur were surveyed during 2007 to understand the magnitude of the problem of chikungunya fever, particularly clinical signs and symptoms. METHODS: A total of 1265 persons from 310 houses were surveyed door-to-door in 20 different localities representing four affected districts. The history and examination findings from 354 clinically diagnosed chikungunya cases were recorded. The symptoms recorded were fever, headache, myalgia, arthralgia, itch/rash, oedema, eye congestion, eye pain, oral ulcers, distaste, nausea, vomiting and haemorrhage. RESULTS: The major symptoms were fever (100%), headache (97.5%), arthralgia (99.4%) and myalgia (99.4%). A significant difference was observed in oedema, distaste, nausea and headache among different age groups and these symptoms were reported to be lower (12.2-89.8%) in younger age group than in older age group (90.4-100%). No genderwise difference was observed for any of the symptoms. In clinically diagnosed chikungunya cases higher age group (>35 years) found with higher rate of severity with symptoms of oedema, distaste, nausea and headache when compared with lower age group (1-35 yr). INTERPRETATION & CONCLUSION: Chikungunya invaded Kerala State for the first time in 2006 and continues to be a major vector borne disease in the State. The clinical symptoms in affected cases highlighted high fever, sever myalgia and prolonged arthralgia, with occasional history of skin itch/rash (petechiae).


Asunto(s)
Infecciones por Alphavirus/epidemiología , Infecciones por Alphavirus/transmisión , Virus Chikungunya , Culicidae/virología , Brotes de Enfermedades/estadística & datos numéricos , Adolescente , Adulto , Infecciones por Alphavirus/diagnóstico , Animales , Niño , Preescolar , Femenino , Humanos , India/epidemiología , Lactante , Masculino , Persona de Mediana Edad , Adulto Joven
20.
Bull World Health Organ ; 85(2): 138-45, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17308735

RESUMEN

OBJECTIVE: To determine the role of vector control in further decreasing the transmission of bancroftian filariasis achieved by mass drug administration and the long-term impact on filariometric indices. METHODS: Three rounds of annual mass drug administration, with diethylcarbamazine and ivermectin, were complemented by vector control (mainly using polystyrene beads) in villages of Tirukoilur, south India, during 1995-99. Subsequently, drug administration is being carried out with diethylcarbamazine and albendazole or diethylcarbamazine alone. We evaluated the impact of mass drug administration used alone or in conjunction with vector control (from 1995 to 2005) on vector transmission indices (such as transmission intensity index, monthly biting rate, monthly transmission potential and annual transmission potential). We analysed data on filarial infection in the community to estimate the prevalence of microfilaraemia and antigenaemia using chi2 analysis and Fisher's exact test. FINDINGS: Vector density greatly decreased in villages where vector control was used as an adjunct to mass drug administration and almost no infective mosquitoes were found in the small numbers still remaining. Filarial antigenaemia was low and continued to decrease significantly in the age group 15-25 years in villages receiving mass drug administration with vector control in contrast to villages receiving only mass drug administration. CONCLUSION: The gains of mass drug administration were sustained only with the integration of vector control measures. We advocate the incorporation of vector control in the Global Programme to Eliminate Lymphatic Filariasis as it can potentially decrease the time required for eliminating lymphatic filariasis.


Asunto(s)
Antiparasitarios/farmacología , Filariasis Linfática/prevención & control , Insectos Vectores/efectos de los fármacos , Control de Mosquitos , Evaluación de Programas y Proyectos de Salud , Práctica de Salud Pública , Wuchereria bancrofti/efectos de los fármacos , Adolescente , Adulto , Albendazol/farmacología , Animales , Culex/efectos de los fármacos , Culex/parasitología , Dietilcarbamazina/farmacología , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Enfermedades Endémicas/prevención & control , Humanos , India/epidemiología , Ivermectina , Poliestirenos , Abastecimiento de Agua
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