Dengue Rapid Diagnostic Tests Research Articles

Estimating dengue burden among family contacts through cluster investigation around probable cases in 2022 and 2023 in the Central Region, Burkina Faso

BackgroundIn 2023, Burkina Faso experienced the largest dengue epidemic ever in Africa. This study aimed to estimate the prevalence of symptomatic, subclinical, and asymptomatic dengue and determine the associated factors among adult contacts of dengue in the Central Region, Burkina Faso.MethodsThis cross-sectional study included contacts of dengue probable cases through cluster sampling in 2022–2023. These suspected cases that tested positive were identified from the five health facilities (Pissy CMA, Saaba CM, Kossodo CMA, Samandin CM, and Marcoussis CSPS) that reported the highest number of cases in 2021 per district. All participants underwent dengue and malaria rapid diagnostic tests (RDT). Samples positive for non-structural 1 protein antigen (AgNS1) and/or immunoglobulin M (IgM) were tested for serotype detection by reverse transcription polymerase chain reaction (RT-PCR). Binary logistic regression was done to identify the determinants of asymptomatic, subclinical, and symptomatic dengue among contacts of probable dengue cases.ResultsA total of 484 contacts were included, mostly in 2023 (75.2%). Most participants were females (58.6%), residing (24.3%) and passing their daytime (23.1%) in Saaba. The overall prevalence of dengue was estimated at 15.1% [95% confidence interval (CI): 12.0–18.6%], representing cases not seeking care in hospitals. Asymptomatic cases represented 2.9% (95% CI: 1.6–4.8%). Subclinical and symptomatic cases accounted for 6.0% (95% CI: 4.1–8.5%) and 6.2% (95% CI: 4.2–8.7%), respectively. Of the 58 samples tested by RT-PCR, 10 were confirmed for serotype 3 in 2023. Malaria cases were estimated at 5.6% (95% CI: 3.7–8.0%). After adjustment, participants claiming that a virus transmits dengue were likelier to have asymptomatic dengue [adjusted odds ratio (aOR) = 7.1, 95% CI: 2.4–21.0]. From the multivariable analysis, subclinical dengue was statistically associated with being included in the study in 2023 (aOR = 30.2, 95% CI: 2.0–455.5) and spending the daytime at Arrondissement 4 (aOR = 11.5, 95% CI: 1.0–131.0). After adjustment, symptomatic dengue was associated with living less than 50 m away from cultivated land (aOR = 2.8, 95% CI: 1.1–6.9) and living less than 50 m from a stretch of water (aOR = 0.1, 95% CI: 0.0–0.6).ConclusionsThe overall burden of dengue among populations not seeking care in hospitals was quite high, with few asymptomatic cases. Efforts to manage dengue cases should also target non-hospital cases and raise population awareness. The 2023 epidemic could be due to dengue virus (DENV)-3.Graphical

Knowledge, attitudes, and practices of health care professionals regarding dengue fever: need for training and provision of diagnostic equipment in Togo in 2022, a cross-sectional study.

Health statistics on dengue are virtually non-existent, despite the fact that the virus is circulating in Togo. This study aimed to assess the knowledge, attitudes, and practices (KAP) of health professionals in the Kara health region. A cross-sectional study was conducted from March to June 2022 among healthcare professionals who had worked in the Kara region of northern Togo were selected using an exhaustive recruitment method. Data were collected by trained resident doctors with a face-to-face interview using a standardized, pretested questionnaire based on the WHO 2009 dengue guide. Three multivariate regression models were utilized to investigate factors associated with knowledge, attitudes and, and practices. A total of 464 respondents (37.1% female), median age 35 years, interquartile range (29-43 years) were included. Only (3.0%) of the participants had received training on dengue fever diagnosis, treatment and prevention in the last 3 years, and 10.3% had dengue rapid diagnostic tests available at their hospital. Half of the respondents (49.1%) had good knowledge of dengue fever, compared with 30.0% who had positive attitudes. Of a total of 256 professionals who had encountered a case of dengue fever in their practice, only 24 (9.4%) had appropriate practices for diagnosing and treating dengue fever. In multivariate analysis, the healthcare professionals who had taken part in ongoing training on dengue fever were more likely to have adequate dengue diagnosis and treatment practice aOR = 8.1; CI 95% = [1.7-36.0]. Strengthening healthcare professionals' dengue-related skills through ongoing training and the provision of dengue diagnostic tests could help improve early detection practices and management of dengue fever in Togo.

Rapid diagnostic tests for dengue would reduce hospitalizations, healthcare costs and antibiotic prescriptions in Spain: A cost-effectiveness analysis

BackgroundCurrent gold standard diagnostic techniques for dengue are expensive and time-consuming. Rapid diagnostic tests (RDTs) have been proposed as alternatives, although data about their potential impact in non-endemic areas is scarce. MethodsWe performed a cost-effectiveness analysis comparing the costs of dengue RDTs to the current standard of care for the management of febrile returning travelers in Spain. Effectiveness was measured in terms of potential averted hospital admissions and reduction of empirical antibiotics, based on 2015–2020 dengue admissions at Hospital Clinic Barcelona (Spain). ResultsDengue RDTs were associated with 53.6% (95% CI: 33.9–72.5) reduction of hospital admissions and were estimated to save 289.08–389.31€ per traveler tested. Moreover, RDTs would have avoided the use of antibiotics in 46.4% (95% CI: 27.5–66.1) of dengue patients. DiscussionImplementation of dengue RDTs for the management of febrile travelers is a cost-saving strategy that would lead to a reduction of half of dengue admissions and a reduction of inappropriate antibiotics in Spain.

Rapid diagnostic tests for dengue would reduce hospitalizations, healthcare costs and antibiotic prescriptions in Spain: A cost-effectiveness analysis

BackgroundCurrent gold standard diagnostic techniques for dengue are expensive and time-consuming. Rapid diagnostic tests (RDTs) have been proposed as alternatives, although data about their potential impact in non-endemic areas is scarce. MethodsWe performed a cost-effectiveness analysis comparing the costs of dengue RDTs to the current standard of care for the management of febrile returning travelers in Spain. Effectiveness was measured in terms of potential averted hospital admissions and reduction of empirical antibiotics, based on 2015–2020 dengue admissions at Hospital Clinic Barcelona (Spain). ResultsDengue RDTs were associated with 53.6% (95% CI: 33.9–72.5) reduction of hospital admissions and were estimated to save 289.08–389.31€ per traveler tested. Moreover, RDTs would have avoided the use of antibiotics in 46.4% (95% CI: 27.5–66.1) of dengue patients. DiscussionImplementation of dengue RDTs for the management of febrile travelers is a cost-saving strategy that would lead to a reduction of half of dengue admissions and a reduction of inappropriate antibiotics in Spain.

Accuracy and efficacy of pre-dengue vaccination screening for previous dengue infection with a new dengue rapid diagnostic test: a retrospective analysis of phase 3 efficacy trials

A dengue pre-vaccination test that is convenient, highly specific, and highly sensitive is still needed. The OnSite Dengue IgG rapid diagnostic test (RDT) is a new rapid diagnostic test specifically designed for pre-vaccination screening. We aimed to retrospectively assess the efficacy of a tetravalent dengue vaccine (CYD-TDV) in participants determined to be dengue seropositive by the OnSite IgG RDT and to evaluate assay performances. This was a complementary study using pre-vaccination samples from two CYD-TDV efficacy trials done in five countries in the Asia-Pacific region (NCT01373281) and five countries in Latin America (NCT01374516). Baseline dengue serostatus was determined by the OnSite IgG RDT on samples from the immunogenicity subsets of the two trials. In participants who were test positive, we calculated CYD-TDV vaccine efficacy against symptomatic virologically confirmed dengue (VCD) over 25 months, and against hospitalisation with VCD over 72 months of follow-up after the first vaccination. We used a reference algorithm to determine the reference dengue serostatus for each sample, and sensitivity and specificity of the OnSite IgG RDT were calculated. Analyses were done on the whole population (aged 2-16 years), and on those aged 6 years or older and those aged 9 years or older. Of 3983 participants in the immunogenicity subsets of the efficacy trials CYD14 and CYD15, 3962 had complete dengue reference test results enabling baseline serostatus classification and 3833 had sufficient serum samples remaining for evaluation with the OnSite IgG RDT. Of the samples tested, 2486 (64·9%) of 3833 were OnSite IgG RDT-positive. In participants aged 2-16 years who were OnSite IgG RDT-positive, vaccine efficacy was 84·1% (95% CI 71·6-91·1) against symptomatic VCD, and 69·2% (38·8-84·5) against hospitalisation with VCD, with similar findings in those aged 6 years or older and those aged 9 years or older. The OnSite IgG RDT showed very high sensitivity (91·1%, 89·9-92·1) and high specificity (92·8%, 91·2-94·2) in participants aged 2-16 years, with significantly higher specificity in those aged 9 years or older (96·6%, 94·9-97·8). The OnSite IgG RDT should provide a valuable tool for screening for previous dengue infection at the point of vaccination. In individuals who were OnSite IgG RDT-positive, the vaccine efficacy of CYD-TDV was high across all three age groups. Sanofi Pasteur.

Emergence of dengue virus serotype 2 in Mauritania and molecular characterization of its circulation in West Africa.

The number of sporadic and epidemic dengue fever cases have reportedly been increasing in recent years in some West African countries, such as Senegal and Mali. The first epidemic of laboratory-confirmed dengue occurred in Nouakchott, the capital city of Mauritania situated in the Saharan desert, in 2014. On-site diagnosis of dengue fever was established using a rapid diagnostic test for dengue. In parallel, the presence of Aedes aegypti mosquitoes in the city was confirmed. The initial diagnosis was confirmed by RT-PCR, which showed that all samples from the 2014 dengue epidemic in Nouakchott were dengue virus serotype 2 (DENV-2). The whole genome or envelope protein gene of these strains, together with other DENV-2 strains obtained from travelers returning from West African countries to France between 2016 and 2019 (including two Mauritanian strains in 2017 and 2018), were sequenced. Phylogenetic analysis suggested a recent emergence of an epidemic strain from the cosmopolitan genotype belonging to West African cosmopolitan lineage II, which is genetically distinct from African sylvatic genotype. The origin of this DENV-2 lineage is still unknown, but our data seem to suggest a recent and rapid dispersion of the epidemic strain throughout the region. More complete genome sequences of West African DENV-2 are required for a better understanding of the dynamics of its circulation. Arboviral surveillance and outbreak forecasting are urgently needed in West Africa.

Clinical evaluation of a developed paper-based Dengue NS1 rapid diagnostic test for febrile illness patients

ObjectivesThis study aimed to evaluate a microfluidic paper-based analytical device (DEN-NS1-PAD) based on a rapid NS1 antigen test for diagnosing dengue at the point of care. Methods219 serum samples from suspected dengue cases were tested with the developed DEN-NS1-PAD and commercial RDT by SD BIOLINE. The results were compared with the nested-PCR results. ResultsThe limit of detection of DEN-NS1-PAD was 0.78 ng mL−1. It showed 88.89% sensitivity, 86.67% specificity, and a substantial agreement correlation (κ = 0.7522) compared with nested-PCR. In contrast, SD BIOLINE for NS1 (SD-NS1) detection showed 87.88% sensitivity, 90.00% specificity, and had a substantial agreement correlation with nested-PCR (κ = 0.7788). ConclusionsDEN-NS1-PAD is a valuable tool for diagnosing DENV infections, especially for diagnosed patients with early acute phase samples with high viral load. DEN-NS1-PAD has better sensitivity than SD-NS1 but less specificity.

Assessment of dengue and COVID-19 antibody rapid diagnostic tests cross-reactivity in Indonesia

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic remains ongoing around the world, including in areas where dengue is endemic. Dengue and COVID-19, to some extent, have similar clinical and laboratory features, which can lead to misdiagnosis, delayed treatment and patient’s isolation. The use of rapid diagnostic tests (RDT) is easy and convenient for fast diagnosis, however there may be issues with cross-reactivity with antibodies for other pathogens.MethodsWe assessed the possibility of cross-reactivity between SARS-CoV-2 and dengue antibodies by: (1) testing five brands of COVID-19 IgG / IgM RDTs on 60 RT-PCR-confirmed dengue samples; (2) testing 95 RT-PCR-confirmed COVID-19 samples on dengue RDT; and (3) testing samples positive for COVID-19 IgG and/or IgM on dengue RDT.ResultsWe observed a high specificity across all five brands of COVID-19 RDTs, ranging from 98.3 to 100%. Out of the confirmed COVID-19 samples, one patient tested positive for dengue IgM only, another tested positive for dengue IgG only. One patient tested positive for dengue IgG, IgM, and NS1, suggesting a co-infection. In COVID-19 IgG and/or IgM samples, 6.3% of COVID-19 IgG-positive samples also tested positive for dengue IgG, while 21.1% of COVID-19 IgM-positive samples also tested positive for dengue IgG.ConclusionDespite the high specificity of the COVID-19 RDT, we observed cross-reactions and false-positive results between dengue and COVID-19. Dengue and COVID-19 co-infection was also found. Health practitioners in dengue endemic areas should be careful when using antibody RDT for the diagnosis of dengue during the COVID-19 pandemic to avoid misdiagnosis.

Travel medicine facilities: The first nationwide cross-sectional questionnaire survey in Japan

IntroductionTravel medicine has gained importance in recent years; however, there is little data regarding travel medicine departments in Japanese hospitals. MethodsThis cross-sectional study contacted 488 hospitals designated by either the Japanese government or major Japanese associations. A questionnaire comprising 11 questions pertaining to the availability of pre-travel consultation, out-of-hours service for travel-related patients, number of medical doctors engaged in travel medicine and infectious disease specialists, and the number of negative pressure rooms available for inpatients and outpatients was distributed. It also asked about the facilities available to combat specific diseases like malaria, dengue, and post-exposure prophylaxis for rabies as these are most common diseases affecting returning travelers. ResultsOf the 263 hospitals (58.7%) that responded to our questionnaire, 82 hospitals (31.2%) provided pre-travel consulting, 188 hospitals (72.0%) accepted travel-related patients out-of-hours, median (interquartile range [IQR]) number of medical doctors involved in travel medicine was 1 (0–3), and median (IQR) number of patients accepted for admission was 2 (1–4). Only 106 (41%) hospitals could diagnose malaria at any time, 56 hospitals (21%) could immediately provide oral anti-malarial medicines; rapid diagnostic test for dengue was available in 99 hospitals (39%), while 67 hospitals (26%) could immediately administer post-exposure prophylaxis for rabies. ConclusionsJapan's medical care system is concerned about illnesses—especially malaria, dengue and rabies in returned travelers. We suggest construction of a medical care system centered on designated medical facilities for category I and II infectious diseases to build capacity for early diagnosis and treatment of common tropical infectious diseases.

Performance of rapid tests in the management of dengue fever imported cases in Lazio, Italy 2014-2019

BackgroundIn Italy, dengue virus is the most frequent agent of imported viral infections. The use of rapid diagnostic tests (RDTs) may be of help as a preliminary user-friendly quick assay to facilitate dengue diagnosis, as ordinary laboratory diagnosis of dengue fever may require special efforts in terms of tools availability, interpretation of results, and skilled personnel. The performance of RDTs, however, may vary according to different epidemiological and laboratory background. MethodsWe reviewed five years of laboratory records of two dengue RDT results (Colorimetric SD-Bioline Dengue-Duo-RDT and Fluorimetric SD-Biosensor-STANDARD-F-Dengue-RDT), able to detect viral NS1 antigen and specific IgM and IgG. Diagnostic parameters were calculated using as reference the results of molecular (RT-PCR) and serological (immunofluorescence, IFA) tests. Overall performance, calculated considering the final case definition, was included in the accuracy assessment of RDTs. ResultsThe combined use of NS1 and IgM/IgG RDT for the detection of acute dengue cases resulted in an overall sensitivity and specificity of 87.2% and 97.9% for Colorimetric RDT, 96.2% and 96.2% for Fluorimetric RDT. NS1 was the most reliable marker of acute infection, while IgM resulted falsely positive in nine samples, including sera derived from 2 Zika and 4 non-arbovirus infected patients. ConclusionsThe inclusion of RDT in the diagnostic algorithm is of undeniable help in the prompt management and surveillance of dengue infection in non-endemic areas. Confirmatory tests are, however, necessary to rule in or rule out dengue fever diagnosis.

Harnessing Dengue Rapid Diagnostic Tests for the Combined Surveillance of Dengue, Zika, and Chikungunya Viruses in Laos.

.Recent expansions of vector-borne diseases highlight the need for improved surveillance, especially in resource-poor settings. Dengue virus (DENV), chikungunya virus (CHIKV), and Zika virus (ZIKV) share the same vectors as well as similar clinical presentations, suggesting that combined surveillance would be useful. We hypothesized that blood spotted on dengue rapid diagnostic tests (RDTs) could be harnessed for sample collection in remote areas for subsequent detection of DENV, CHIKV, and ZIKV by reverse transcription real-time polymerase chain reaction (RT-qPCR). CHIKV and ZIKV dilutions were spotted on dengue RDTs (SD BIOLINE Dengue DUO, Standard Diagnostics, Gyeonggi-do, Republic of Korea), dried, and extracted. As reference, aliquots of each viral dilution were directly extracted. Using specific RT-qPCR tests, both viruses were successfully detected from RDT extracts. However, the limit of detection was slightly lower in comparison to direct extracts, two logfold for CHIKV and one logfold for ZIKV. For analysis of temperature stability, DENV dilutions were spotted on RDTs and stored for up to 2 months at −80°C, 4°C, or 35°C before testing. Storage of RDTs for 2 months at 35°C did not compromise detection of RNA by RT-qPCR; only minimal degradation was observed. This proof-of-principle study demonstrates the potential of using dengue RDTs for DENV/CHIKV/ZIKV combined surveillance in areas without access to laboratory facilities. Further investigations are needed for evaluation of tri-viral surveillance under field conditions using patient samples. Large-scale implementation of surveillance for these viruses is of crucial public health importance for the early detection of epidemics. This method also has important implications for improving understanding of the molecular epidemiology of the three viruses.

Clinical and epidemiologic characteristics associated with dengue during and outside the 2016 outbreak identified in health facility-based surveillance in Ouagadougou, Burkina Faso.

BackgroundIn Africa, the magnitude of dengue virus (DENV) transmission is largely unknown. In Burkina Faso, several outbreaks have been reported and data are often based on findings from outbreak investigations.MethodsTo better understand dengue epidemiology and clinical characteristics in Burkina Faso, a fever surveillance study was conducted among patients aged 1–55 years, who presented with non-malarial febrile illness at five primary healthcare facilities in Ouagadougou, Burkina Faso from December 2014 to February 2017, encompassing a 3-month dengue outbreak in September-November 2016. Acute and convalescent blood samples were collected within an interval of 10–21 days between visits. Acute samples were tested with dengue rapid diagnostic tests (RDT) and a selected subset with RT-PCR, and all acute/convalescent samples with IgM/IgG ELISA.ResultsAmong 2929 non-malarial febrile patients, 740 (25%) were dengue–positive based on RT-PCR and/or IgM/IgG ELISA; 428 out of 777 patients (55%) and 312 out of 2152 (14%) were dengue-positive during outbreak and non-outbreak periods, respectively. There were 11% (316/2929) and 4% (129/2929) patients showing positive for NS1 and IgM, on the RDT, respectively. DENV 2 predominated during the outbreak, whereas DENV 3 predominated before the outbreak. Only 25% of dengue-positive cases were clinically diagnosed with suspected dengue. The odds of requiring observation for ≤3 days (versus routine outpatient care) were 11 times higher among dengue-positive cases than non-dengue cases. In adjusted analyses, dengue-positivity was associated with rash and retro-orbital pain (OR = 2.6 and 7.4, respectively) during the outbreak and with rash and nausea/vomiting (OR = 1.5 and 1.4, respectively) during the non-outbreak period.ConclusionDengue virus is an important pathogen in Burkina Faso, accounting for a substantial proportion of non-malarial fevers both during and outside outbreak, but is only infrequently suspected by clinicians. Additional longitudinal data would help to further define characteristics of dengue for improved case detection and surveillance.

Impact of Dengue Rapid Diagnostic Tests on the Prescription of Antibiotics and Anti-Inflammatory Drugs by Physicians in an Endemic Area in Colombia.

There is insufficient evidence on whether dengue rapid diagnostic tests (dRDTs) influence clinical decisions in endemic areas. Therefore, our objective was to evaluate the impact of dRDTs on the prescription of antibiotics and anti-inflammatory drugs by physicians in a dengue-endemic area in Colombia. A retrospective cohort study was conducted with 330 patients in Cali, Colombia, between January 2012 and December 2017. The exposure was defined by the result of the dRDT. The outcomes were prescription of antibiotics and anti-inflammatory drugs after results of dRDT. Incidence and RR with 95% CIs were estimated. Multivariate logistic regression models were fitted separately for each outcome. Antibiotics were prescribed in 3% exposed and 14% unexposed. Anti-inflammatory drugs were prescribed in 1.2% exposed and 7.9% unexposed. A positive dRDT reduced the prescription of anti-inflammatories (AdjOR: 0.06, 95% CI: 0.008-0.5) but, by itself, had no effect on antibiotics (AdjOR: 1.1, 95% CI: 0.2-6); however, in hospitalized patients, a positive result reduced the probability of antibiotic prescription (AdjOR: 0.02, 95% CI: 0.00-0.8). Despite limitations of current dRDTs, they influence treatment decisions. Further studies are needed to assess the effect of dRDTs in patient outcomes and health-care costs.

Evaluation of commercially available three dengue rapid diagnostic test kits for diagnosis of acute dengue virus infection at the point-of-care setting in Myanmar

Early and accurate diagnosis of dengue virus (DENV) infection is very important and Rapid Diagnostic Test (RDT) Kits are been used as a point-of-care test to check DENV infection. A Hospital and Laboratory-based descriptive study was conducted at 550-bedded Mandalay Children Hospital in 2018. Acute-phase serum samples were collected from 202 dengue suspected patients to evaluate the efficacy of RDT Kits for the diagnosis of DENV infection. Commercially available three test kits which include: ((i) CareUs Dengue Combo, Korea, (ii) Humasis Dengue Combo, Korea and (iii) Wondfo Dengue Combo, China) were validated against WHO-based reference standard tests. 140/202 patients (69.3%) was confirmed to have DENV infection. All four serotypes of dengue viruses (57 DENV-1, 7 DENV-2, 6 DENV-3 and 10 DENV-4) were identified from 80 dengue confirmed patients and DENV-1 was the dominant serotype. Combining the NS-1 antigen and IgM antibody results from the CareUs Dengue Combo Kit gave the best sensitivity (92.1%, 95% CI 86.4%–96.0%) and specificity (75.8%, 95%CI 63.3%–85.8%). Among the three RDT Kits, the performance of CareUS Kit was better than the other two. This study explored the evidence of the usefulness of RDT Kits at the point-of-care setting for diagnosis of acute dengue infection.

Author's response: False-positive results with rapid diagnostic test for dengue in Thailand.

Author's response: False-positive results with rapid diagnostic test for dengue in Thailand.

Outbreak of Dengue Virus Type 2 - American Samoa, November 2016-October 2018.

The U.S. territory of American Samoa has experienced recent outbreaks of illnesses caused by viruses transmitted by Aedes species mosquitoes, including dengue, chikungunya, and Zika virus. In November 2016, a traveler from the Solomon Islands tested positive for infection with dengue virus type 2 (DENV-2). Additional dengue cases were identified in the subsequent weeks through passive and active surveillance. Suspected dengue cases were tested locally with a dengue rapid diagnostic test (RDT) for DENV nonstructural protein 1 (NS1). Specimens from RDT-positive cases and patients meeting the dengue case definition were tested by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) at Hawaii State Laboratories. During November 2016-October 2018, a total of 3,240 patients were tested for evidence of DENV infection (118 by RDT-NS1 alone, 1,089 by real-time RT-PCR alone, and 2,033 by both methods), 1,081 (33.4%) of whom tested positive for dengue (19.5 per 1,000 population). All 941 real-time RT-PCR-positive specimens were positive for DENV-2. The monthly number of laboratory-confirmed cases peaked at 120 during December 2017. Among laboratory-confirmed dengue cases, 380 (35.2%) patients were hospitalized; one patient, who was transferred to American Samoa for care late in his illness, died. The public health response to this outbreak included disposal of solid waste to remove mosquito breeding sites, indoor residual spraying of pesticides in schools, reinforcement of dengue patient management education, and public education on mosquito avoidance and seeking medical care for symptoms of dengue.

Dengue rapid diagnostic tests: Health professionals' practices and challenges in Burkina Faso.

Objectives:Dengue fever remains unrecognized and under-reported in Africa due to several factors, including health professionals’ lack of awareness, important prevalence of other febrile illnesses, most of which are treated presumptively as malaria, and the absence of surveillance systems. In Burkina Faso, health centers have no diagnostic tools to identify and manage dengue, which remains ignored, despite the evidence of seasonal outbreaks in recent years. A qualitative study was conducted to analyze the use of rapid diagnostic tests in six health and social promotion centers (i.e. health-care centers, from the French Centers de Santé et de Promotion Sociale) of Ouagadougou (Burkina Faso) in an exploratory research context.Methods:Dengue rapid diagnostic tests were introduced into fever-related consultations from December 2013 to January 2014. In-depth individual interviews were conducted in May and June 2014 with 32 health professionals.Results:Prior to the introduction of the tests, dengue was not well known or diagnosed by health professionals during consultations. Most febrile cases were routinely presumed to be malaria and treated accordingly. With training and routine use of rapid diagnostic tests, health professionals became more knowledgeable about dengue, improving the diagnosis of non-malaria febrile cases and its management, and better prescription practices.Conclusions:In a context of dengue re-emergence and high prevalence of other febrile illnesses, having rapid diagnostic tools available, especially during epidemics reinforces health professionals’ diagnostic and prescribing capacities, allowing an opportune and accurate case management and facilitates diseases surveillance.

Dengue Virus Immunoglobulinaemia among Pregnant Women and Blood Donors in Nigeria: Need for Integration into Disease Management Policy

Several reports on the prevalence dengue virus antibodies among febrile subjects from different parts of Nigeria suggest that dengue fever is endemic in Nigeria. However, there are no in-country surveys or national reports on dengue disease burden or guidelines for detection, management, prevention and control of Dengue. A knowledge and policy gap is therefore identified, with the need to determine the magnitude of dengue virus immunoglobulinaemia among apparently healthy individuals as a proxy to the burden of Dengue fever infection and the need for national guidance on its management. We conducted a prospective cross sectional study to determine the seroprevalence of Dengue virus Immunoglobulinaemia among 391 voluntarily consenting Ante-Natal Clinic attendees and Blood Donors at two secondary health facilities in Dutse, Jigawa State, North west Nigeria. Serum samples from the subjects were tested for the presence of Dengue Immunoglobulin M and / or Immunoglobulin G using dengue rapid diagnostic test kit. Results showed that the seroprevalence of dengue immunoglobulinaemia was 33% among the study population comprising of; IgM 58 (14.8%), IgG 48 (12.3%) while 23 (5.9%) had both IgM & IgG immunoglobulins in their sera. We concluded that this significant level of anti-dengue antibodies among apparently healthy subjects in this study, reinforce the need to have a deliberate health policy for the clinical management and control of dengue in Nigeria.

A systematic review of the economic impact of rapid diagnostic tests for dengue

BackgroundDengue fever is rapidly expanding geographically, with about half of the world’s population now at risk. Among the various diagnostic options, rapid diagnostic tests (RDTs) are convenient and prompt, but limited in terms of accuracy and availability.MethodsA systematic review was conducted of published data on the use of RDTs for dengue with respect to their economic impact. The search was conducted with combinations of key search terms, including “((Dengue[Title]) AND cost/economic)” and “rapid diagnostic test/assay (or point-of-care)”. Articles with insufficient report on cost/economic aspect of dengue RDTs, usually on comparison of different RDTs or assessment of novel rapid diagnostic tools, were excluded. This review has been registered in the PROSPERO International prospective register of systematic reviews (registry #: CRD42015017775).ResultsEleven articles were found through advanced search on Pubmed. From Embase and Web of Science, two and 14 articles were obtained, respectively. After removal of duplicate items, title screening was done on 21 published works and 12 titles, including 2 meeting abstracts, were selected for abstract review. For full-text review, by two independent reviewers, 5 articles and 1 meeting abstract were selected. Among these, the abstract was referring to the same study results as one of the articles. After full text review, two studies (two articles and one abstract) were found to report on cost-wise or economic benefits of dengue RDTs and were selected for data extraction. One study found satisfactory performance of IgM-based Panbio RDT, concluding that it would be cost-effective in endemic settings. The second study was a modeling analysis and showed that a dengue RDT would not be advantageous in terms of cost and effectiveness compared to current practice of antibiotics prescription for acute febrile illness.ConclusionsDespite growing use of RDTs in research and clinical settings, there were limited data to demonstrate an economic impact. The available two studies reached different conclusions on the cost-effectiveness of dengue RDTs, although only one of the two studies reported outcomes from cost-effectiveness analysis of dengue and the other was considering febrile illness more generally. Evidence of such an impact would require further quantitative economic studies.

Temperature of a Dengue Rapid Diagnostic Test under Tropical Climatic Conditions: A Follow Up Study.

The Dengue Duo Rapid Diagnostic Test (SD Dengue RDT) has good specificity and sensitivity for dengue diagnosis in rural tropical areas. In a previous study, using four control sera, we demonstrated that that the diagnostic accuracy of these RDTs remains stable after long-term storage at high temperatures. We extended this study by testing sera from 119 febrile patients collected between July-November 2012 at Salavan Provincial Hospital (southern Laos) with RDTs stored for 6 months at 4°C, 35° and in a hut (miniature traditional house) at Lao ambient temperatures. The dengue NS1 antigen results from RDTs stored at 35°C and in the hut demonstrated 100% agreement with those stored at 4°C. However, lower positive percent agreements, with broad 95%CI, were observed for the tests: IgM, 60% (14.7–94.7) and 40% (5.3–85.3) for RDTs store at 35°C and in the hut, compared to those stored at 4°C, respectively. This study strenghtens the evidence of the robustness of the NS1 antigen detection RDT for the diagnosis of dengue after storage at tropical temperatures.