A prospective study on the practicality of an out-patient management protocol for dengue infection in adults was carried out during a 2-month period. Doctors were requested to follow the protocol and assessment was done on the patients' outcome, the admission rate, and the compliance to the protocol by doctors and patients. One hundred and sixty-two patients (mean age 27.3 years) were clinically diagnosed to have dengue illness. Among them, 82.7% had dengue fever (DF); 13.0% had dengue haemorrhagic fever (DHF) and 4.3% had dengue shock syndrome (DSS). Dengue aetiology was confirmed in 69.4% of the DF group and 85.7% of the DHF and DSS groups. There were no deaths among the 162 patients. The admission rate was 43.8%. A high compliance rate of 86.4% by the doctors and a low patient default rate of 16.4% showed that the protocol was practical.
Rapid diagnosis of dengue infection is essential to patient management and disease control. The development of a rapid (5 min) immunochromatographic test and a 2 h commercial capture enzyme linked immunosorbent assay (ELISA) for anti-dengue IgM and IgG antibodies may lead to more rapid and accurate testing in peripheral health settings and diagnostic laboratories.
In the present study, the construction of arrays on silicon for naked-eye detection of DNA dengue was demonstrated. The array was created by exposing a polyethylene glycol (PEG) silane monolayer to 254 nm ultraviolet (UV) light through a photomask. Formation of the PEG silane monolayer and photomodifed surface properties was thoroughly characterized by using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. The results of XPS confirmed that irradiation of ultraviolet (UV) light generates an aldehyde functional group that offers conjugation sites of amino DNA probe for detection of a specific dengue virus target DNA. Employing a gold enhancement process after inducing the electrostatic interaction between positively charged gold nanoparticles and the negatively charged target DNA hybridized to the DNA capture probe allowed to visualize the array with naked eye. The developed arrays demonstrated excellent performance in diagnosis of dengue with a detection limit as low as 10 pM. The selectivity of DNA arrays was also examined using a single base mismatch and noncomplementary target DNA.
This study describes the use of an IgM capture ELISA using cell culture derived antigens and a polyclonal rabbit antiflavivirus antisera for the detection of dengue positive cases. The IgM capture ELISA is compared with the dot enzyme immunoassay and the results are discussed in the context of dengue endemicity.
Dengue fever/Dengue haemorrhagic fever (DF/DHF) has been a public health problem in Malaysia with an endemic level of about 7 per 100,000 population per year. In 1990, Malaysia experienced its most severe outbreak of DF/DHF with a record total of 5,590 cases referred to the Division of Virology, Institute for Medical Research (IMR). Of these, 1,880 were confirmed serologically to be DF/DHF. The conventional serological procedure, the Haemagglutination Inhibition (HI) test, for the diagnosis of DF/DHF is cumbersome and causes delay in diagnosis. Another problem associated with the HI test has been that it has often been difficult to obtain a second convalescent serum sample for an accurate diagnosis. This has raised an urgent need to establish a "rapid" test for diagnosis of DF/DHF. As such the authors recently carried out an evaluation of a newly available commercial rapid test, namely, the Dengue Blot Assay (Diagnostic Biotechnology Singapore Pte Ltd). The test is intended for use in laboratory confirmation of dengue virus infection. The evaluation was to determine if the test could be utilised as a routine laboratory test and to establish its sensitivity and specificity. Over 400 samples were tested against the Dengue Blot Assay. Results were checked against an in-house Dengue IgM ELISA and HI assay. Preliminary results indicate that the sensitivity and specificity of the Dengue Blot is satisfactory. Our results also indicate that the Dengue Blot has a useful role to play in a routine laboratory especially since it provides rapid results on single serum samples thereby reducing the workload in a busy diagnostic laboratory.
The highly sensitive AFRIMS format IgM capture ELISA for the diagnosis of dengue virus infections requires the use of mouse brain derived hemagglutinins and consequently also the use of 20% acetone extracted normal human serum to eliminate high background. These reagents are not always easily available and we have thus compared the AFRIMS format with another published format which uses cell culture derived antigens (culture fluid, CF, format) in order to determine if it is reasonable to use cell culture derived antigens in situations where hemagglutinins and normal human serum are difficult to obtain. The study shows that using AFRIMS results as the reference point, the CF format described here has a sensitivity of 90% and a specificity of 96%.
Four recent cases of dengue fever with severe, unusual clinical manifestations are described. Two of these cases had features of fulminant hepatitis and encephalopathy; one of these cases was fatal. The two remaining cases showed hepatitis with renal impairment. The significance and importance of these unusual manifestations of dengue disease are discussed.
A modification of the IgM-capture ELISA which can provide an early diagnosis for dengue infection is presented. The test is technically simple compared to HI and appears to be more sensitive. It has the advantage over HIT for the detection of specific IgM in that it is more sensitive and the reading of the result is not subjective. There is the possibility of the test being able to replace HI and HIT in the future.
Biotechnological tools are being used in malaria, filariasis and dengue research. The main emphasis has been on the production of reagents for immunodiagnosis and research. In this respect monoclonal antibodies (McAbs) against various species and stages of the above pathogens have been produced. It is hoped that these McAbs will be useful not only in immunodiagnosis but also for seroepidemiological applications. A DNA probe against Brugia malayi has been tested in Malaysia and was found to be sensitive and specific.
The purpose of this study was to identify the early indicators of hemorrhage in severe dengue infections in 114 patients; 24 patients had severe hemorrhage and 92 had no hemorrhage. The platelet counts were not predictive of bleeding. The duration of shock (OR, 2.11; 95% CI, 1.13 to 3.92; P =.019) and low-normal hematocrit at the time of shock (OR, 0.72; 95% CI, 0.55 to 0.95; P =.020) were risk factors of severe hemorrhage.
We describe a child with acute fever and abdominal pain who developed rash and edema of extremities. Blood test revealed thrombocytopenia, lymphopenia, positive dengue-IgM, and hypoalbuminemia with elevated procalcitonin. Right pleural effusion revealed from chest x-ray. Diagnosed as dengue hemorrhagic fever (DHF) grade 1, however, at 7th day of illness, altered mental status, respiratory and circulatory failure occurred. Laboratory examination showed marked thrombocytopenia, transaminitis, metabolic acidosis, elevated D-dimer, decrease fibrinogen, and elevated cardiac marker (troponin I and CKMB). The patient then developed catecholamine-resistant shock and did not survive after 48 hours. Although rapid test of SARS CoV-2 infection was negative, rapid deterioration with some unusual clinical feature suggest multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 infection. This case raises an awareness of MIS-C that clinical features resemble dengue infection.
Dengue is a common infection, caused by dengue virus. There are four different dengue serotypes, with different capacity to cause severe dengue infections. Besides, secondary infections with heterologous serotypes, concurrent infections of multiple dengue serotypes may alter the severity of dengue infection. This study aims to compare the severity of single infection and concurrent infections of different combinations of dengue serotypes in-vitro. Human mast cells (HMC)-1.1 were infected with single and concurrent infections of multiple dengue serotypes. The infected HMC-1.1 supernatant was then added to human umbilical cord vascular endothelial cells (HUVEC) and severity of dengue infections was measured by the percentage of transendothelial electrical resistance (TEER). Levels of IL10, CXCL10 and sTRAIL in HMC-1.1 and IL-8, IL-10 and CXCL10 in HUVEC culture supernatants were measured by the ELISA assays. The result showed that the percentage of TEER values were significantly lower in single infections (p< 0.05), compared to concurrent infections on day 2 and 3, indicating that single infection increase endothelial permeability greater than concurrent infections. IL-8 showed moderate correlation with endothelial permeability (r > 0.4), indicating that IL-8 may be suitable as an in-vitro severity biomarker. In conclusion, this in-vitro model presented few similarities with regards to the conditions in dengue patients, suggesting that it could serve as a severity model to test for severity and levels of severity biomarkers upon different dengue virus infections.
Dengue is a major threat to public health globally. While point-of-care diagnosis of acute/recent dengue is available to reduce its mortality, a lack of rapid and accurate testing for the detection of previous dengue remains a hurdle in expanding dengue seroepidemiological surveys to inform its prevention, especially vaccination, to reduce dengue morbidity. This study evaluated ViroTrack Dengue Serostate, a biosensors-based semi-quantitative anti-dengue IgG (immunoglobulin G) immuno-magnetic agglutination assay for the diagnosis of previous and recent dengue in a single test. Blood samples were obtained from 484 healthy participants recruited randomly from two communities in Petaling district, Selangor, Malaysia. The reference tests were Panbio Dengue IgG indirect and capture enzyme-linked immunosorbent assays, in-house hemagglutination inhibition assay, and focus reduction neutralization test. Dengue Serostate had a sensitivity and specificity of 91.1% (95%CI 87.8-93.8) and 91.1% (95%CI 83.8-95.8) for the diagnosis of previous dengue, and 90.2% (95%CI 76.9-97.3) and 93.2% (95%CI 90.5-95.4) for the diagnosis of recent dengue, respectively. Its positive predictive value of 97.5% (95%CI 95.3-98.8) would prevent most dengue-naïve individuals from being vaccinated. ViroTrack Dengue Serostate's good point-of-care diagnostic accuracy can ease the conduct of dengue serosurveys to inform dengue vaccination strategy and facilitate pre-vaccination screening to ensure safety.
A 24 year-old Malay lady presented with high grade fever, myalgia, generalized rashes, severe headache and was positive for dengue serology test. Her lowest platelet count was 45 × 10(9) cells/L. She complained of sudden onset of painlessness, profound loss of vision bilaterally 7 days after the onset of fever. On examination, her right eye best corrected vision was 6/30 and left eye was 6/120. Her anterior segment examination was unremarkable. Funduscopy revealed there were multiple retinal haemorrhages found at posterior pole of both fundi and elevation at fovea area with subretinal fluid. Systemic examination revealed normal findings except for residual petechial rashes. She was managed conservatively. Her vision improved tremendously after 2 months. The retinal hemorrhages and foveal elevation showed sign of resolving. Ocular manifestations following dengue fever is rare. However, bilateral visual loss can occur if both fovea are involved.
This study presents a new approach to determine the significant prognosis factors in dengue patients utilizing the self-organizing map (SOM). SOM was used to visualize and determine the significant factors that can differentiate between the dengue patients and the healthy subjects. Bioimpedance analysis (BIA) parameters and symptoms/signs obtained from the 210 dengue patients during their hospitalization were used in this study. Database comprised of 329 sample (210 dengue patients and 119 healthy subjects) were used in the study. Accordingly, two maps were constructed. A total of 35 predictors (17 BIA parameters, 18 symptoms/signs) were investigated on the day of defervescence of fever. The first map was constructed based on BIA parameters while the second map utilized the symptoms and signs. The visualized results indicated that, the significant BIA prognosis factors for differentiating the dengue patients from the healthy subjects are reactance, intracellular water, ratio of the extracellular water and intracellular water, and ratio of the extracellular mass and body cell mass.
Thrombocytopaenia is often relied upon as an important criterion for the diagnosis of dengue infection among patients presenting with an acute non-specific febrile illness. This study was aimed to assess usefulness of thrombocytopaenia in the diagnosis of acute dengue virus infection. This was a clinic based prospective cohort study from May to November 2003. Consecutive patients presenting with acute non-specific febrile illness of less than two weeks were selected from two urban primary care centres. We did full blood count examination (FBC) on the day of visit and dengue serology on day five of illness for all patients enrolled. We repeated the FBC examination for patients who had initial normal platelet counts. Thrombocytopaenia was defined as platelet count < 150 X 10(9)/L. Eighty-seven patients enrolled in the study. Complete data was available for 73 patients. The prevalence of acute dengue virus infection was 27.6%. The sensitivity and specificity were 88% and 71% respectively. The likelihood of acute dengue infection in the presence of thrombocytopaenia was 2.52 and likelihood of not having dengue infection in normal platelet count patients was 5.22. Thrombocytopaenia has fair predictive value in diagnosing acute dengue virus infection. It was more useful to exclude than to diagnose dengue infection.
Study site: Primary Care Centre of Hospital Universiti
Kebangsaan Malaysia (HUKM) and Batu 9 Health Clinic Hulu Langat,
As well as dengue fever (DF) and dengue haemorrhagic fever-dengue shock syndrome (DHF/DSS), other atypical manifestations of dengue virus infection have also been reported. The frequency of CNS involvement in dengue remains unknown, although isolated cases with neurological manifestations have been reported in Southeast Asia, Malaysia, Burma, Puerto Rico and India. We present two cases of encephalitis associated with DF and DHF from New Delhi, India.
A commercial Dengue Duo rapid test kit was evaluated for early dengue diagnosis by detection of dengue virus NS1 antigen and immunoglobulin M (IgM)/IgG antibodies. A total of 420 patient serum samples were subjected to real-time reverse transcription-polymerase chain reaction (RT-PCR), in-house IgM capture enzyme-linked immunosorbent assay (ELISA), hemagglutination inhibition assay, and the SD Dengue Duo rapid test. Of the 320 dengue acute and convalescent sera, dengue infection was detected by either serology or RT-PCR in 300 samples (93.75%), as compared with 289 samples (90.31%) in the combined SD Duo NS1/IgM. The NS1 detection rate is inversely proportional, whereas the IgM detection rate is directly proportional to the presence of IgG antibodies. The sensitivity and specificity in diagnosing acute dengue infection in the SD Duo NS1/IgM were 88.65% and 98.75%, respectively. The assay is sensitive and highly specific. Detection of both NS1 and IgM by SD Duo gave comparable detection rate by either serology or RT-PCR.