Journal Article > ResearchAbstract Only
J Vector Borne Dis. 2021 July 1; DOI:10.4103/0972-9062.321747
Mahajan R, Nair MM, Saldanha AM, Harshana A, de Lima Pereira A, et al.
J Vector Borne Dis. 2021 July 1; DOI:10.4103/0972-9062.321747
BACKGROUND AND OBJECTIVES
There is limited evidence regarding the accuracy of dengue rapid diagnostic kits despite their extensive use in India. We evaluated the performance of four immunochromatographic Rapid Diagnostic Test (RDTs) kits: Multisure dengue Ab/Ag rapid test (MP biomedicals; MP), Dengucheck combo (Zephyr Biomedicals; ZB), SD bioline dengue duo (Alere; SD) and Dengue day 1 test (J Mitra; JM).
METHODS
This is a laboratory-based diagnostic evaluation study. Rapid tests results were compared to reference non-structural (NS1) antigen or immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) results of 241 dengue-positive samples and 247 dengue-negative samples. Sensitivity and specificity of NS1 and IgM components of each RDT were calculated separately and in combination (either NS1 or IgM positive) against reference standard ELISA.
RESULTS
A total of 238, 226, 208, and 146 reference NS1 ELISA samples were tested with MP, ZB, SD, and JM tests, respectively. In comparison to the NS1 ELISA reference tests, the NS1 component of MP, ZB, SD, and JM RDTs demonstrated a sensitivity of 71.8%, 85.1%, 77.2% and 80.9% respectively and specificity of 90.1%, 92.8%, 96.1 %, and 93.6%, respectively. In comparison to the IgM ELISA reference test, the IgM component of RDTs showed a sensitivity of 40.0%, 50.3%, 47.3% and 20.0% respectively and specificity of 92.4%, 88.6%, 96.5%, and 92.2% respectively. Combining NS1 antigen and IgM antibody results led to sensitivities of 87.5%, 82.9%, 93.8% and 91.7% respectively, and specificities of 75.3%, 73.9%, 76.5%, and 80.0% respectively.
INTERPRETATION & CONCLUSIONS
Though specificities were acceptable, the sensitivities of each test were markedly lower than manufacturers' claims. These results also support the added value of combined antigen-and antibody-based RDTs for the diagnosis of acute dengue.
There is limited evidence regarding the accuracy of dengue rapid diagnostic kits despite their extensive use in India. We evaluated the performance of four immunochromatographic Rapid Diagnostic Test (RDTs) kits: Multisure dengue Ab/Ag rapid test (MP biomedicals; MP), Dengucheck combo (Zephyr Biomedicals; ZB), SD bioline dengue duo (Alere; SD) and Dengue day 1 test (J Mitra; JM).
METHODS
This is a laboratory-based diagnostic evaluation study. Rapid tests results were compared to reference non-structural (NS1) antigen or immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) results of 241 dengue-positive samples and 247 dengue-negative samples. Sensitivity and specificity of NS1 and IgM components of each RDT were calculated separately and in combination (either NS1 or IgM positive) against reference standard ELISA.
RESULTS
A total of 238, 226, 208, and 146 reference NS1 ELISA samples were tested with MP, ZB, SD, and JM tests, respectively. In comparison to the NS1 ELISA reference tests, the NS1 component of MP, ZB, SD, and JM RDTs demonstrated a sensitivity of 71.8%, 85.1%, 77.2% and 80.9% respectively and specificity of 90.1%, 92.8%, 96.1 %, and 93.6%, respectively. In comparison to the IgM ELISA reference test, the IgM component of RDTs showed a sensitivity of 40.0%, 50.3%, 47.3% and 20.0% respectively and specificity of 92.4%, 88.6%, 96.5%, and 92.2% respectively. Combining NS1 antigen and IgM antibody results led to sensitivities of 87.5%, 82.9%, 93.8% and 91.7% respectively, and specificities of 75.3%, 73.9%, 76.5%, and 80.0% respectively.
INTERPRETATION & CONCLUSIONS
Though specificities were acceptable, the sensitivities of each test were markedly lower than manufacturers' claims. These results also support the added value of combined antigen-and antibody-based RDTs for the diagnosis of acute dengue.
Journal Article > ResearchFull Text
BMC Public Health. 2014 June 28; Volume 14 (Issue 1); DOI:10.1186/1471-2458-14-658
Lover AA, Buchy P, Rachline A, Moniboth D, Huy R, et al.
BMC Public Health. 2014 June 28; Volume 14 (Issue 1); DOI:10.1186/1471-2458-14-658
Background: Dengue is a major contributor to morbidity in children aged twelve and below throughout Cambodia; the 2012 epidemic season was the most severe in the country since 2007, with more than 42,000 reported (suspect or confirmed) cases.
Methods: We report basic epidemiological characteristics in a series of 701 patients at the National Paediatric Hospital in Cambodia, recruited during a prospective clinical study (2011-2012). To more fully explore this cohort, we examined climatic factors using multivariate negative binomial models and spatial clustering of cases using spatial scan statistics to place the clinical study within a larger epidemiological framework.
Results: We identify statistically significant spatial clusters at the urban village scale, and find that the key climatic predictors of increasing cases are weekly minimum temperature, median relative humidity, but find a negative association with rainfall maximum, all at lag times of 1-6 weeks, with significant effects extending to 10 weeks.
Conclusions: Our results identify clustering of infections at the neighbourhood scale, suggesting points for targeted interventions, and we find that the complex interactions of vectors and climatic conditions in this setting may be best captured by rising minimum temperature, and median (as opposed to mean) relative humidity, with complex and limited effects from rainfall. These results suggest that real-time cluster detection during epidemics should be considered in Cambodia, and that improvements in weather data reporting could benefit national control programs by allow greater prioritization of limited health resources to both vulnerable populations and time periods of greatest risk. Finally, these results add to the increasing body of knowledge suggesting complex interactions between climate and dengue cases that require further targeted research.
Methods: We report basic epidemiological characteristics in a series of 701 patients at the National Paediatric Hospital in Cambodia, recruited during a prospective clinical study (2011-2012). To more fully explore this cohort, we examined climatic factors using multivariate negative binomial models and spatial clustering of cases using spatial scan statistics to place the clinical study within a larger epidemiological framework.
Results: We identify statistically significant spatial clusters at the urban village scale, and find that the key climatic predictors of increasing cases are weekly minimum temperature, median relative humidity, but find a negative association with rainfall maximum, all at lag times of 1-6 weeks, with significant effects extending to 10 weeks.
Conclusions: Our results identify clustering of infections at the neighbourhood scale, suggesting points for targeted interventions, and we find that the complex interactions of vectors and climatic conditions in this setting may be best captured by rising minimum temperature, and median (as opposed to mean) relative humidity, with complex and limited effects from rainfall. These results suggest that real-time cluster detection during epidemics should be considered in Cambodia, and that improvements in weather data reporting could benefit national control programs by allow greater prioritization of limited health resources to both vulnerable populations and time periods of greatest risk. Finally, these results add to the increasing body of knowledge suggesting complex interactions between climate and dengue cases that require further targeted research.
Journal Article > ResearchFull Text
J Commun Dis. 2019 December 23; Volume 15 (Issue 3)
Kaur R, Rajvanshi H
J Commun Dis. 2019 December 23; Volume 15 (Issue 3)
INTRODUCTION
Dengue is an endemic disease in India. Epidemics occur every year with incidence rising every year. Since 2010, Chandigarh has seen Dengue epidemics every year but the toll of reported confirmed cases has been very low. A study was undertaken to assess knowledge, awareness and practices among those who had already been diagnosed with dengue and followed up multiple times by Multipurpose Health Workers (MPHWs) at their homes. This study was conducted when both authors were post-graduate scholars at the Department of Public Health at Manipal Academy of Higher Education.
OBJECTIVE
To ascertain knowledge, awareness and practices regarding dengue among incident dengue cases of 2016 in Chandigarh.
METHODS
Retrospective Cohort study was conducted among the incident cases of dengue reported in 2016. The line list of cases was obtained from health department. Each household was visited once and face to face interviews were conducted with those willing to participate from January 2017 to March 2017. Using a modified WHO (World Health Organisation) questionnaire, 149 interviews were completed and analysed using descriptive analytical tools.
RESULTS
Data from the 149 interviews (57 males and 92 females) was used for primary analysis. Only 58.4% respondents were aware about dengue before diagnosis and 63.1% knew of its vector while only 10.1% were aware of the national programme and services available to them. Use of mosquito net was negligible (3.4%), even in rural areas. Screens on doors and windows were more common in urban area of Chandigarh.
CONCLUSION
Since the study was conducted among incident cases, even after multiple visits conducted by MPHWs to the houses of these respondents, the knowledge regarding dengue was lower than expected.
Dengue is an endemic disease in India. Epidemics occur every year with incidence rising every year. Since 2010, Chandigarh has seen Dengue epidemics every year but the toll of reported confirmed cases has been very low. A study was undertaken to assess knowledge, awareness and practices among those who had already been diagnosed with dengue and followed up multiple times by Multipurpose Health Workers (MPHWs) at their homes. This study was conducted when both authors were post-graduate scholars at the Department of Public Health at Manipal Academy of Higher Education.
OBJECTIVE
To ascertain knowledge, awareness and practices regarding dengue among incident dengue cases of 2016 in Chandigarh.
METHODS
Retrospective Cohort study was conducted among the incident cases of dengue reported in 2016. The line list of cases was obtained from health department. Each household was visited once and face to face interviews were conducted with those willing to participate from January 2017 to March 2017. Using a modified WHO (World Health Organisation) questionnaire, 149 interviews were completed and analysed using descriptive analytical tools.
RESULTS
Data from the 149 interviews (57 males and 92 females) was used for primary analysis. Only 58.4% respondents were aware about dengue before diagnosis and 63.1% knew of its vector while only 10.1% were aware of the national programme and services available to them. Use of mosquito net was negligible (3.4%), even in rural areas. Screens on doors and windows were more common in urban area of Chandigarh.
CONCLUSION
Since the study was conducted among incident cases, even after multiple visits conducted by MPHWs to the houses of these respondents, the knowledge regarding dengue was lower than expected.
Journal Article > ResearchFull Text
Emerg Infect Dis. 2007 February 1; Volume 13 (Issue 2); 308-310.; DOI:10.3201/eid1302.061134
Beatty ME, Hunsperger E, Long E, Schürch J, Jain S, et al.
Emerg Infect Dis. 2007 February 1; Volume 13 (Issue 2); 308-310.; DOI:10.3201/eid1302.061134
After Hurricane Jeanne in September 2004, surveillance for mosquitoborne diseases in Gonaïves, Haiti, identified 3 patients with malaria, 2 with acute dengue infections, and 2 with acute West Nile virus infections among 116 febrile patients. These are the first reported human West Nile virus infections on the island of Hispaniola.
Journal Article > ResearchFull Text
BMC Infect Dis. 2020 November 11; Volume 20; 835.; DOI:10.1186/s12879-020-05568-5
Boyce RM, Muhindo R, Nakakande R, Ciccone EJ, Grounds S, et al.
BMC Infect Dis. 2020 November 11; Volume 20; 835.; DOI:10.1186/s12879-020-05568-5
BACKGROUND
The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. The goal of this study was to describe the epidemiology of dengue among a cohort of febrile children presenting to outpatient facilities located in areas of western Uganda with differing levels of urbanicity and malaria transmission intensity.
METHODS
Eligible children were first screened for malaria using rapid diagnostic tests. Children with a negative malaria result were tested for dengue using a combination NS1/IgM/IgG rapid test (SD Bioline Dengue Duo). Confirmatory testing by RT-PCR was performed in a subset of participants. Antigen-capture ELISA was performed to estimate seroprevalence.
RESULTS
Only 6 of 1416 (0.42%) children had a positive dengue rapid test, while none of the RT-PCR results were positive. ELISA testing demonstrated reactive IgG antibodies in 28 (2.2%) participants with the highest prevalence seen at the urban site in Mbarara (19 of 392, 4.9%, p < 0.001).
CONCLUSIONS
Overall, these findings suggest that dengue, while present, is an uncommon cause of non-malarial, pediatric febrile illness in western Uganda. Further investigation into the eocological factors that sustain low-level transmission in urban settings are urgently needed to reduce the risk of epidemics.
The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. The goal of this study was to describe the epidemiology of dengue among a cohort of febrile children presenting to outpatient facilities located in areas of western Uganda with differing levels of urbanicity and malaria transmission intensity.
METHODS
Eligible children were first screened for malaria using rapid diagnostic tests. Children with a negative malaria result were tested for dengue using a combination NS1/IgM/IgG rapid test (SD Bioline Dengue Duo). Confirmatory testing by RT-PCR was performed in a subset of participants. Antigen-capture ELISA was performed to estimate seroprevalence.
RESULTS
Only 6 of 1416 (0.42%) children had a positive dengue rapid test, while none of the RT-PCR results were positive. ELISA testing demonstrated reactive IgG antibodies in 28 (2.2%) participants with the highest prevalence seen at the urban site in Mbarara (19 of 392, 4.9%, p < 0.001).
CONCLUSIONS
Overall, these findings suggest that dengue, while present, is an uncommon cause of non-malarial, pediatric febrile illness in western Uganda. Further investigation into the eocological factors that sustain low-level transmission in urban settings are urgently needed to reduce the risk of epidemics.
Journal Article > ResearchFull Text
Viruses. 2023 August 8; Volume 15 (Issue 8); 1707.; DOI: 10.3390/v15081707
Broban A, Olive MM, Tantely ML, Dorsemans AC, Rakotomanana F, et al.
Viruses. 2023 August 8; Volume 15 (Issue 8); 1707.; DOI: 10.3390/v15081707
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.