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1.
PLoS One ; 17(3): e0264956, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35271652

RESUMO

BACKGROUND: COVID-19 has inundated the entire world disrupting the lives of millions of people. The pandemic has stressed the healthcare system of India impacting the psychological status and functioning of health care workers. The aim of this study is to determine the burnout levels and factors associated with the risk of psychological distress among healthcare workers (HCW) engaged in the management of COVID 19 in India. METHODS: A cross-sectional study was conducted from 1 September 2020 to 30 November 2020 by telephonic interviews using a web-based Google form. Health facilities and community centres from 12 cities located in 10 states were selected for data collection. Data on socio-demographic and occupation-related variables like age, sex, type of family, income, type of occupation, hours of work and income were obtained was obtained from 967 participants, including doctors, nurses, ambulance drivers, emergency response teams, lab personnel, and others directly involved in COVID 19 patient care. Levels of psychological distress was assessed by the General health Questionnaire -GHQ-5 and levels of burnout was assessed using the ICMR-NIOH Burnout questionnaire. Multivariable logistic regression analysis was performed to identify factors associated with the risk of psychological distress. The third quartile values of the three subscales of burnout viz EE, DP and PA were used to identify burnout profiles of the healthcare workers. RESULTS: Overall, 52.9% of the participants had the risk of psychological distress that needed further evaluation. Risk of psychological distress was significantly associated with longer hours of work (≥ 8 hours a day) (AOR = 2.38, 95% CI(1.66-3.41), income≥20000(AOR = 1.74, 95% CI, (1.16-2.6); screening of COVID-19 patients (AOR = 1.63 95% CI (1.09-2.46), contact tracing (AOR = 2.05, 95% CI (1.1-3.81), High Emotional exhaustion score (EE ≥16) (AOR = 4.41 95% CI (3.14-6.28) and High Depersonalisation score (DP≥7) (AOR = 1.79, 95% CI (1.28-2.51)). About 4.7% of the HCWs were overextended (EE>18); 6.5% were disengaged (DP>8) and 9.7% HCWs were showing signs of burnout (high on all three dimensions). CONCLUSION: The study has identified key factors that could have been likely triggers for psychological distress among healthcare workers who were engaged in management of COVID cases in India. The study also demonstrates the use of GHQ-5 and ICMR-NIOH Burnout questionnaire as important tools to identify persons at risk of psychological distress and occurrence of burnout symptoms respectively. The findings provide useful guide to planning interventions to mitigate mental health problems among HCW in future epidemic/pandemic scenarios in the country.


Assuntos
Esgotamento Profissional/psicologia , COVID-19/psicologia , Pessoal de Saúde/psicologia , Adulto , Idoso , Esgotamento Profissional/epidemiologia , Esgotamento Psicológico/epidemiologia , Estudos Transversais , Depressão/epidemiologia , Feminino , Humanos , Índia/epidemiologia , Entrevistas como Assunto , Masculino , Saúde Mental/tendências , Pessoa de Meia-Idade , Pandemias , Angústia Psicológica , SARS-CoV-2/patogenicidade , Inquéritos e Questionários
3.
Epidemiol Infect ; 145(13): 2656-2665, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28768557

RESUMO

Influenza A(H1N1) viruses of the 2009 pandemic (A(H1N1)pdm09) continue to cause outbreaks in the post-pandemic period. During January to May 2015, an upsurge of influenza was recorded that resulted in high fatality in central India. Genetic lineage, mutations in the hemagglutinin (HA) gene and infection by quasi-species are reported to affect disease severity. The objective of this study is to present the molecular and epidemiological trends during the 2015 influenza outbreak in central India. All the referred samples were subjected to qRT-PCR for diagnosis. HA gene sequencing (23 survivors and 24 non-survivors) and cloning were performed and analyzed using Molecular Evolutionary Genomic Analyzer (MEGA 5·05). Of the 3625 tested samples, 1607 (44·3%) were positive for influenza A(H1N1)pdm09, of which 228 (14·2%) individuals succumbed to death. A significant trend was observed in positivity (P = 0·003) and mortality (P < 0·0001) with increasing age. The circulating A(H1N1)pdm09 virus was characterized as belonging to clade-6B. Clinically significant mutations were detected. Patients infected with the quasi-species of the virus had a greater risk of death (P = 0·009). This study proposes a robust molecular and clinical surveillance program for the detection and characterization of the virus, along with prompt treatment protocols to prevent outbreaks.


Assuntos
Surtos de Doenças , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Humanos , Índia/epidemiologia , Lactente , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Análise de Sequência de RNA , Adulto Jovem
4.
Indian J Med Res ; 141(5): 584-90, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26139775

RESUMO

BACKGROUND & OBJECTIVES: Dengue (DEN) is a rapidly spreading arboviral disease transmitted by Aedes mosquitoes. Although it is endemic in India, dengue virus (DENV) infection has not been reported from tribal areas of Madhya Pradesh. Investigations were conducted to establish the aetiology of sudden upsurge of cases with febrile illness in June 2013 from tribal villages of Mandla district of Madhya Pradesh, India. METHODS: The rapid response team of the National Institute for Research in Tribal Health, Jabalpur, conducted clinical investigations and field surveys to collect the samples from suspected cases. Samples were tested using molecular and serological tools. Collected mosquitoes were identified and tested for the presence of virus using semi nested reverse transcriptase-polymerase chain reaction (nRT-PCR). The sequences were analysed to identify serotype and genotype of the virus. RESULTS: Of the 648 samples collected from 18 villages of Mandla, 321 (49.53%) were found to be positive for dengue. The nRT-PCR and sequencing confirmed the aetiology as dengue virus type 2. Eighteen per cent of patients needed hospitalization and five deaths were attributed to dengue. The virus was also detected from Aedes aegypti mosquito, which was incriminated as a vector. Phylogenetic analysis revealed that the dengue virus 2 detected belonged to cosmopolitan genotype of the virus. INTERPRETATION & CONCLUSIONS: Dengue virus serotype 2 was detected as the aetiological agent in the outbreak in tribal villages of Mandla district of Madhya Pradesh. Conducive man-made environment favouring mosquitogenic conditions and seeding of virus could be the probable reasons for this outbreak. Urgent attention is needed to control this new threat to tribal population, which is already overburdened with other vector borne diseases.


Assuntos
Vírus da Dengue/genética , Dengue/epidemiologia , Filogenia , Grupos Populacionais , Dengue/sangue , Dengue/genética , Vírus da Dengue/isolamento & purificação , Surtos de Doenças , Feminino , Humanos , Imunoglobulina M/sangue , Índia/epidemiologia , Masculino , Sorogrupo
5.
Epidemiol Infect ; 143(2): 412-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24667083

RESUMO

Dengue is regarded as the most important arboviral disease. Although sporadic cases have been reported, serotypes responsible for outbreaks have not been identified from central India over the last 20 years. We investigated two outbreaks of febrile illness, in August and November 2012, from Korea district (Chhattisgarh) and Narsinghpur district (Madhya Pradesh), respectively. Fever and entomological surveys were conducted in the affected regions. Molecular and serological tests were conducted on collected serum samples. Dengue-specific amplicons were sequenced and phylogenetic analyses were performed. In Korea and Narsinghpur districts 37·3% and 59% of cases were positive, respectively, for dengue infection, with adults being the worst affected. RT-PCR confirmed dengue virus serotype 1 genotype III as the aetiology. Ninety-six percent of infections were primary. This is the first time that dengue virus 1 outbreaks have been documented from central India. Introduction of the virus into the population and a conducive mosquitogenic environment favouring increased vector density caused the outbreak. Timely diagnosis and strengthening vector control measures are essential to avoid future outbreaks.


Assuntos
Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , Surtos de Doenças/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Vírus da Dengue/classificação , Vírus da Dengue/isolamento & purificação , Feminino , Genótipo , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Filogenia , População Rural , Adulto Jovem
6.
Indian J Med Res ; 139(6): 940-4, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25109730

RESUMO

Hepatitis A virus (HAV) infection, a major cause of childhood hepatitis is transmitted by orofaecal route. Children mostly suffer with subclinical infection but may have serious clinical implications leading to hospitalization and mortality. IgM ELISA and nRT PCR were conducted on the blood samples collected from HAV suspected paediatric cases referred to the viral diagnostic laboratory in the Regional Medical Research Centre for Tribals at Jabalpur, Central India. The nRT PCR products were sequenced and phylogenetic analysis was done. Of the 195 samples tested, 41 (21%) were positive for HAV antibodies, among which 38 (92%) belonged to paediatric age group and 32 per cent of these were hospitalized. nRT PCR and sequencing confirmed the presence of HAV. Phylogenic analysis revealed circulation of genotype III A in central India. Regular serological and molecular monitoring would aid in understanding epidemiology of HAV and plan intervention strategies.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Hepatite A Humana/genética , Hepatite A/epidemiologia , Filogenia , Adolescente , Sequência de Bases , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Genótipo , Humanos , Imunoglobulina M/imunologia , Índia/epidemiologia , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Especificidade da Espécie
7.
Indian J Med Res ; 136(3): 491-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23041745

RESUMO

BACKGROUND & OBJECTIVES: Dengue is an important arboviral disease. All four dengue virus serotypes are reported to be circulating in India. It is also known that different serotypes, genotypes and clades of genotype determine outbreak severity. Dengue affected children are known to have serious disease outcome. We carried out this study to give reliable diagnosis of dengue infection in children and to detect circulating serotype in central India. METHODS: Samples collected from paediatric patients suspected to have dengue fever were subjected to IgM and IgG ELISA to determine dengue virus infection. Samples collected within 0-5 days of onset of illness and positive by IgM ELISA were tested by nested reverse transcription polymerase chain reaction (nRT-PCR). The PCR products were sequenced and analyzed. RESULTS: Of the 89 samples tested, 18 and 7 were positive for dengue IgM and IgG, respectively. Dengue activity was observed in both Jabalpur city and adjoining rural settings. One sample found positive by nRT-PCR was further sequenced to confirm dengue virus 4 as aetiological agent. INTERPRETATION & CONCLUSIONS: Our findings demonstrated dengue virus infection in children and adolescent in central India. Because of continuous changing epidemiology, it is important to monitor dengue virus activity at both serological and molecular level in this part of the country for better patient care and management.


Assuntos
Vírus da Dengue/isolamento & purificação , Adolescente , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Humanos , Imunoglobulina M/sangue , Índia , Lactente , Reação em Cadeia da Polimerase Via Transcriptase Reversa
8.
Vaccine ; 29(28): 4613-7, 2011 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-21549791

RESUMO

A Vero cell based vaccine candidate against Chandipura (CHP) virus (Rhabdoviridae: Vesiculovirus), was developed and evaluated for immunogenicity in mice. Virus was purified by ultracentrifugation on 30% glycerol cushion followed by differential centrifugation on 10-60% sucrose gradient and inactivated with ß-propio lactone at a concentration of 1:3500. The inactivated product was blended with aluminium phosphate (3%) and immunized 4-week-old Swiss albino mice. Neutralizing antibodies in the range of 1:10 to 160 and 1:80 to 1:320 was detected with 85% and 100% sero-conversion after 2nd and 3rd dose, respectively. All the immunized mice with antibody titer above 1:20 survived live virus challenge. The vaccine candidate has potential to be an efficient vaccine against CHP virus.


Assuntos
Vacinas de Produtos Inativados/imunologia , Vesiculovirus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Chlorocebus aethiops , Imunização , Camundongos , Infecções por Rhabdoviridae/imunologia , Infecções por Rhabdoviridae/prevenção & controle , Infecções por Rhabdoviridae/virologia , Resultado do Tratamento , Vacinas de Produtos Inativados/administração & dosagem , Células Vero , Vesiculovirus/patogenicidade , Vesiculovirus/fisiologia , Vacinas Virais/administração & dosagem
9.
Intervirology ; 52(1): 1-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19332994

RESUMO

OBJECTIVES: Mosquito densonucleosis viruses (DNVs) are known to persistently infect the insect cell line and mosquito population in nature, causing mortality in mosquitoes. Here we report the isolation and characterization of a DNV from Aedes aegypti and its distribution among different Ae. aegypti populations from India. METHODS: We screened Ae. aegypti mosquito populations from different states of India by PCR. Virus isolation and purification was performed using a cesium chloride gradient from a positive mosquito colony. Characterization of this isolate was carried out by electron microscopy, Western blot and sequencing. RESULTS: Electron microscopy showed the presence of parvovirus-like particles, and Western blot showed the presence of 2 viral proteins of 40 and 41 kDa. A total of 3,776 bases of genome were sequenced, which included a 3'UTR of 128 bases, a coding region of 3,507 bases and a 5'UTR of 141 bases. Three open reading frames (ORFs) were identified and characterized. The NIVDNV genome showed 95% similarity with Culex pipiens pallens DNV and 93% similarity with Ae. aegypti DNV. CONCLUSION: Phylogenetic analysis of all 3 ORFs showed that this new isolate falls in the lineage of Brevidensovirus along with other mosquito DNVs.


Assuntos
Aedes/virologia , Densovirus/isolamento & purificação , Animais , DNA Viral/análise , Densovirus/genética , Densovirus/ultraestrutura , Índia , Microscopia Eletrônica de Transmissão , Fases de Leitura Aberta , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
10.
Southeast Asian J Trop Med Public Health ; 36(5): 1139-44, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16438138

RESUMO

Two major factors, higher temperatures and the application of insecticides, can drastically alter the genetic structure of a vector mosquito population. Due to these two stresses, the majority of the population gets wiped out, but the ones that withstand the stress and survive are likely to pass on survivability, and have an altered physiology. Our study shows that exposures to higher temperatures and DDT during the larval stage affects their susceptibility as adult mosquitoes to the DEN-2 virus. The overall transcription and translation status of heat shock protein (Hsp70) in virus high- and low-susceptible was the same as that in other batches. In the case of a DDT-resistant (R-7) strain two bands were obtained during RT-PCRs after heat shock. These two alleles were obtained only with HY-1 in which R-7 males were used for the crosses, suggesting that the second allele is probably male sex linked. The higher expression of Hsp70 may provide DDT-resistant strains a better chance of survival high temperature environments, particularly in homozygotes and hybrids. It was also interesting to note that these strains have a significantly lower susceptibility to the virus. Wide-spread DDT-resistance and a rise in temperature above the average temperature during summer may result in a population with a low susceptibility to the virus. Several families of heat shock proteins are known to be expressed in mosquitoes, and may have a cumulative role in determining susceptibility to the virus, which itself is governed by several genes.


Assuntos
Culicidae/crescimento & desenvolvimento , DDT , Vírus da Dengue/genética , Larva/efeitos dos fármacos , Temperatura , Animais , Western Blotting , Culicidae/genética , Culicidae/virologia , Predisposição Genética para Doença , Índia , Resistência a Inseticidas , Masculino , Controle de Mosquitos
11.
Acta Virol ; 48(2): 109-13, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15462286

RESUMO

Hemagglutinin activity (HA) was studied in the midgut extracts from highly (h) and lowly susceptible strains of Aedes aegypti mosquitoes to Dengue-2 virus (DEN-2). HA in the midgut extracts from these two isofemale strains of mosquitoes was high in as compared to (h) mosquitoes. HA was found to be higher with chicken red blood cells (RBCs) than with rabbit and human RBCs of O group. Larval midgut extracts showed higher activity than those from adult female mosquitoes. Exposure of midgut extracts to 100 degrees C for 10 mins destroyed the activity. The activity was observed between pH 6 and pH 10. HA in midgut extracts was also studied using twenty different carbohydrates; five of them showed an inhibition of HA. The inhibitory carbohydrates, when incorporated into DEN-2-infected bloodmeal, showed a reduction in the susceptibility of mosquitoes to the virus as compared to the control ones fed on the virus alone. Similarly, when these carbohydrates were incorporated in the DEN-2-infected inoculum, the inoculated mosquitoes showed a reduction in the susceptibility to the virus. HA in the virus-infected midgut extracts was higher than that in the uninfected controls. These results suggest that the presence of HA in the midgut may be one of the factors that affect the susceptibility of Ae. aegypti mosquitoes to DEN-2.


Assuntos
Aedes/imunologia , Aedes/virologia , Vírus da Dengue/imunologia , Hemaglutininas/imunologia , Animais , Carboidratos/farmacologia , Galinhas/sangue , Vírus da Dengue/fisiologia , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/virologia , Hemaglutinação , Hemaglutininas/análise , Temperatura Alta , Concentração de Íons de Hidrogênio , Larva , Coelhos , Replicação Viral
12.
Acta Virol ; 48(4): 223-7, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15745045

RESUMO

An epizootic of febrile illness among the Madras red breed of sheep had occurred in 1994 in Verrapuram, Chennai, India. The epizootic was suspected as Rift Valley fever (RVF)-like sickness based on clinical features. However, its etiological agent could neither be isolated nor implicated conclusively. During the post-epizootic period a male lamb died of similar clinical features and the spleen was immediately collected. Inoculation of spleen suspension in infant mouse brain yielded a virus that was serially passaged in infant mice and rhabdomyosarcoma (RD) cells. Electron microscopic observations revealed virus particles resembling flaviviruses. RT-PCR performed on extracted total RNA from infected cells and mouse brains with flavivirus-specific or RVF-specific primers gave negative results. However, an amplicon of 280 bp was obtained with pestivirus-specific primers from the 5'-UTR. Further, a nested PCR yielded a product of 157 bp. Nucleotide sequencing of the 157 bp product showed 100% homology to BVDV-1. Western blot analysis with a flavivirus envelope protein-specific MAb revealed three proteins of 33 K, 45 K and 55 K. Further studies suggested that the 33 K and 55 K proteins were glycosylated. This is the first report of isolation of BVDV-1 from a lamb in India.


Assuntos
Vírus da Diarreia Viral Bovina Tipo 1/isolamento & purificação , Ovinos/virologia , Animais , Autopsia , Western Blotting , Vírus da Diarreia Viral Bovina Tipo 1/genética , Glicosilação , Masculino , Camundongos , Microscopia Eletrônica , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
J Eukaryot Microbiol ; 50(5): 379-82, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14563178

RESUMO

Ascogregarina culicis and Ascogregarina taiwanensis are common gregarine parasites of Aedes aegypti and Aedes albopictus mosquitoes, respectively. These mosquito species are also known to transmit dengue and Chikungunya viruses. The sporozoites of these parasites invade the midgut epithelial cells and develop intracellularly and extracellularly in the gut to complete their life cycles. The midgut is also the primary site for virus replication in the vector mosquitoes. Therefore, studies were carried out with a view to determine the possible role of these gregarines in the vertical transmission of dengue and Chikungunya viruses from larval to adult stage. Experiments were performed by exposing first instar mosquito larvae to suspensions containing parasite oocysts and viruses. Since Ascogregarina sporozoites invade the midgut of first instar larvae, the vertical transmission was determined by feeding the uninfected first instar larvae on the freshly prepared homogenates from mosquitoes, which were dually infected with viruses and the parasite oocysts. Similarly, the role of protozoan parasites in the vertical transmission of viruses was determined by exposing fresh first instar larvae to the dried pellets of homogenates prepared from the mosquitoes dually infected with viruses and the parasite oocysts. Direct vertical transmission and the vertical transmission of CHIK virus through the oocyst of the parasites were observed in the case of Ae. aegypti mosquitoes. It is suggested that As. culicis may have an important role in the maintenance of CHIK virus during the inter-epidemic period.


Assuntos
Aedes/parasitologia , Aedes/virologia , Infecções por Alphavirus/transmissão , Apicomplexa/virologia , Vírus Chikungunya/crescimento & desenvolvimento , Transmissão Vertical de Doenças Infecciosas , Insetos Vetores/virologia , Animais , Antígenos Virais/análise , Vírus Chikungunya/genética , DNA Viral/química , DNA Viral/genética , Ensaio de Imunoadsorção Enzimática , Camundongos , Reação em Cadeia da Polimerase , Replicação Viral/fisiologia
14.
Acta Virol ; 47(1): 45-7, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12828344

RESUMO

The Ades aegypti mosquito has been considered the principal vector of Chikungunya (CHIK) virus. As CHIK epidemics usually occur in urban regions and Anopheles stephensi is another highly endophilic and anthropophilic mosquito, there is a very high probability of this mosquito to feed on CHIK virus-infected patients, to pick up and transmit the virus. Therefore the present study was conducted to test the CHIK virus transmission capability for the A. stephensi mosquito. The obtained results showed that this mosquito species is capable of transmitting CHIK virus. It is surmised that during any epidemic of febrile illness CHIK virus isolation attempts should also be made from this mosquito species.


Assuntos
Infecções por Alphavirus/transmissão , Anopheles/virologia , Vírus Chikungunya , Insetos Vetores , Animais , Anopheles/crescimento & desenvolvimento , Anopheles/imunologia , Vírus Chikungunya/imunologia , Vírus Chikungunya/isolamento & purificação , Feminino , Imunofluorescência , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Indian J Med Res ; 115: 144-8, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12239836

RESUMO

BACKGROUND & OBJECTIVES: Chikungunya (CHIK) virus has caused numerous large outbreaks in India. No active or passive surveillance has been carried out since the last epidemic which occurred in 1971. For active surveillance, it is necessary to have a test, which can detect the virus from a large number of field-collected mosquitoes. METHODS: The present study describes the standardization of monoclonal antibody (MAb) based antigen capture ELISA to detect chikungunya virus antigen from the mosquitoes. CHIK virus antigen from suspension of experimentally infected mosquitoes and their progeny was captured on mouse polyclonal antibody, while biotinylated CHIK Mab was used as a probing antibody. CHIK virus antigen in the head squashes of virus inoculated mosquitoes was detected using indirect immunofluorescence antibody (IFA) test for confirmation of ELISA results. RESULTS: The ELISA test was sensitive enough to detect antigen even if a small fraction of a single infected mosquito homogenate was incorporated in the test. The IFA test failed to detect CHIK antigen in 10 and 25 microliters of suspension whereas with ELISA it was detected in all the samples. Progeny of Aedes aegypti and Ae. albopictus mosquitoes infected with chikungunya virus did not show the possibility of existence of transovarial transmission. INTERPRETATION & CONCLUSION: This test is rapid and simple since it can be completed in two days as compared to the conventional mosquito inoculation and IFA techniques, which require at least 10 days. There is an additional advantage with this test that a large number of samples can be processed, and the remaining homogenate of the mosquitoes can be used for screening other viruses. Experimental data raised using this test showed that transovarial transmission of this virus does not occur in these vector species.


Assuntos
Aedes/imunologia , Aedes/virologia , Anticorpos Monoclonais , Antígenos Virais/análise , Vírus Chikungunya/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Animais , Feminino , Camundongos
16.
Acta Virol ; 46(4): 237-40, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12693860

RESUMO

A new cell line from the embryonic tissue of Culex tritaeniorhynchus mosquito was established. Morphological studies carried out at the 45th passage level (P-45) showed four different cell types viz. epithelial-like cells, fibroblast-like cells, giant cells and vacuolated cells. Karyological studies indicated diploid (2n = 6) chromosomes in majority of cells irrespective of passage level. A twelve-fold increase of cell number was observed in 10 days at P-49. The cells could be preserved in liquid nitrogen for more than 40 months. Isoenzyme profile analysis with four enzymes clearly indicated that this cell line was derived from C. tritaeniorhynchus. This cell line was susceptible to Japanese encephalitis (JEV) and West Nile viruses (WNV) but not to Dengue 1-4 (DEN 1-4) viruses. Protein of 38 K was detected in the membrane fraction of the cells from this and the C6/36 cell line, which was found to bind DEN 1-4 viruses. These data suggest that DEN viruses bind to this membrane protein and probably enter into the cells but do not continue further in the replication process.


Assuntos
Linhagem Celular , Culex , Flavivirus/fisiologia , Animais , Membrana Celular/metabolismo , Culex/citologia , Culex/embriologia , Culex/virologia , Meios de Cultura , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Flavivirus/classificação , Virologia/métodos , Replicação Viral , Vírus do Nilo Ocidental/fisiologia
17.
Acta Virol ; 46(4): 257-60, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12693864

RESUMO

Culex quinquefasciatus mosquitoes were collected from the field and microbial flora was isolated from their midgut. Isolates belonging to 13 different genera were obtained. Four most abundant isolates viz. Pseudomonas sp., Acinetobacterjunii, Staphylococcus epidermis and Aeromonas culicicola were used to study their effect on the susceptibility of mosquitoes to Japanese encephalitis virus (JEV). Incorporation of individual isolates in the mosquito bloodmeal resulted in an increased susceptibility of mosquitoes to the virus. However, only the effects of Pseudomonas sp. and Acinetobacterjunii could be statistically evaluated but they were found insignificant.


Assuntos
Bactérias/isolamento & purificação , Culex/microbiologia , Vírus da Encefalite Japonesa (Espécie)/patogenicidade , Intestinos/microbiologia , Animais , Antibacterianos , Bactérias/efeitos dos fármacos , Culex/efeitos dos fármacos , Culex/virologia , Tetraciclina/farmacologia
18.
Acta Virol ; 45(2): 67-71, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11719984

RESUMO

Isofemale lines of Aedes aegypti mosquitoes highly and lowly susceptible to dengue type 2 (DEN-2) virus (DEN(h) and DEN(l), respectively) were established by oral feeding and individual rearing. The susceptibility at F13 generation was found to be 61% and 25% for the DEN(h) and DEN(l) line, respectively. The virus-infected mosquito females were allowed to probe on bovine albumin phosphate saline pH 7.2 (BAPS) through membrane feeders. The presence of virus in the probed BAPS was determined either by ELISA or by intrathoracic (i.t.) inoculation of mosquitoes or by both methods. The rate of oral transmission of virus was found to be 2 times higher in the DEN(h) isofemale line than in the DEN(l) one. Similarly, vertical transmission rate of the virus was found to be 7 times higher in the DEN(h) line. When batches of eggs obtained from infected female mosquitoes were allowed to hatch after two months the vertical transmission rate of the virus was very high. It is possible that, at room temperature, the virus gets an opportunity to multiply and increase its copy number in the quiescent embryos. The progeny obtained from the infected mosquitoes was found to be capable of transmitting the virus horizontally when allowed to probe on BAPS through the membrane feeder. This is the first report demonstrating horizontal transmission of DEN-2 virus by mosquitoes infected through vertical transmission. The higher vertical transmission rate of the virus in the progeny obtained from the eggs dessicated for a longer time and the horizontal transmission of the virus from the progeny is of very high epidemiological significance.


Assuntos
Aedes/virologia , Vírus da Dengue/fisiologia , Insetos Vetores , Aedes/anatomia & histologia , Aedes/fisiologia , Animais , Vírus da Dengue/patogenicidade , Embrião não Mamífero/virologia , Feminino , Larva/virologia , Masculino , Oviposição
20.
Indian J Exp Biol ; 39(8): 807-10, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12018585

RESUMO

Insecticide bioassays were carried out on larvae and adults of rosy eye mutant and wildtype strains of A. aegypti. Both the strains were equally susceptible to DDT, malathion and deltamethrin. Biochemical assays showed an increase in acetylcholinesterase enzyme (AChE) activity in all the stages of mutant strain with both the substrates i.e. acetylthiocholine iodide and S-butyrylthiocholine iodide. However, there was no difference in the percent inhibition of enzyme activity with propoxur in these two strains. Polyacrylamide gel electrophoresis performed in native conditions on the homogenates of adults of rosy eye mosquitoes showed that AChE-II allele was highly active with the substrate acetylthiocholine iodide as compared to wildtype strain. Frequency of the highly active AChE-II allele in the mutant strain was about 68%, whereas it was about 5% in the wildtype strain.


Assuntos
Acetilcolinesterase/metabolismo , Aedes/enzimologia , Isoenzimas/metabolismo , Mutação , Aedes/genética , Animais , Inibidores da Colinesterase/farmacologia , Eletroforese em Gel de Poliacrilamida , Especificidade por Substrato
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