scholarly journals Searching for the dengue virus Achilles heel

2010 ◽  
Vol 31 (2) ◽  
pp. 64
Author(s):  
Paul Young

Dengue viruses are a major public health problem throughout the tropical world, with up to 100 million people infected annually. Infection can result in acute febrile illness (dengue fever) and in severe cases is associated with abnormalities in vascular permeability and haemostasis (dengue haemorrhagic fever) that can lead to sudden and fatal hypovolemic shock (dengue shock syndrome). The incidence of dengue has steadily increased over the last two to three decades such that it is now endemic throughout much of the tropics and is the leading cause of infant mortality in some South-East Asian countries. Australia has not escaped this territorial expansion of dengue, with regular epidemic outbreaks now occurring in North Queensland. The epidemic that lasted for most of the summer of 2008?2009 involved the circulation of all four dengue virus serotypes and more than 1,000 confirmed cases. Coupled with the potential impact that climate change may have in increasing the range of its mosquito vector, there is growing concern that dengue may become endemic in Australia. Considerable challenges have accompanied the development of vaccine strategies for dengue and this has reinforced the importance of the complementary development of antiviral therapies. Part of our dengue research efforts has been focused on identifying viral targets for inhibitor design.

1990 ◽  
Vol 3 (4) ◽  
pp. 376-396 ◽  
Author(s):  
E A Henchal ◽  
J R Putnak

Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration, rash, lymphadenopathy, and leukopenia. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Four distinct serotypes of the dengue virus (dengue-1, dengue-2, dengue-3, and dengue-4) exist, with numerous virus strains found worldwide. Molecular cloning methods have led to a greater understanding of the structure of the RNA genome and definition of virus-specific structural and nonstructural proteins. Progress towards producing safe, effective dengue virus vaccines, a goal for over 45 years, has been made.


2020 ◽  
Vol 7 (3) ◽  
pp. 622
Author(s):  
Murali B. H. ◽  
Shilpa Deborah Lysander ◽  
Meghana Nannapaneni

Background: Dengue is a major public health problem throughout subtropical and tropical regions. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Dengue is endemic in more than 100 countries in tropical and subtropical regions with an estimated 390 million infections occurring worldwide, among which 96 million infections are clinically apparent. The objective of this study is to assess the usefulness of serum albumin as a prognostic factor in dengue.Method: This observational study enrolled 100 patients who were admitted in KIMS Hospital from June 2017 to June 2018 without any co morbidities as mentioned in the exclusion criteria. On day 4 of illness hemoglobin, packed cell volume, platelet and serum albumin were done, and the participants were classified into 3 groups based on clinical manifestationResults: In this study, hemoglobin was elevated on day 4 in group 3 when compared to other groups and it was statistically significant. Hemoconcentration and low platelet values were also seen in group 3 when compared to other groups showing statistical significance.Serum albumin was also low in group 3 when compared to other groups, which was strongly significant.Conclusion: Hence serum albumin can be used as a prognostic factor in dengue.


2020 ◽  
Vol 10 (1) ◽  
pp. 67-77
Author(s):  
Amos Watentena ◽  
Ikem Chris Okoye ◽  
Ikechukwu Eugene Onah ◽  
Onwude Cosmas Ogbonnaya ◽  
Emmanuel Ogudu

Mosquitoes of Aedes species are vectors of several arboviral diseases which continue to be a major public health problem in Nigeria. This study among other things, morphologically identified Aedes mosquitoes collected from Nsukka LGA and used an allele specific PCR amplification for discrimination of dengue vectors. Larval sampling, BG-sentinel traps and modified human landing catches were used for mosquito sampling in two selected autonomous communities of Nsukka LGA (Nsukka and Obimo). A total of 124 Aedes mosquitoes consisting of five (5) different species were collected from April to June, 2019 in a cross-sectional study that covered 126 households, under 76 distinct geographical coordinates. Larvae was mainly collected from plastic containers 73% (n=224), metallic containers 14% (n=43), earthen pots 9% (n=29) and used car tyres 3% (n=9), reared to adult stage 69.35% (n=86), and all mosquitoes were identified using standard morphological keys. Five (5) Aedes mosquito species were captured; Aedes aegypti 83(66.94%), Aedes albopictus 33(26.61%), Aedes simpsoni (4.48%), Aedes luteocephalus (≤1%) and Aedes vittatus (≤1%). Nsukka autonomous community had higher species diversity than Obimo. Allele specific amplification confirmed dengue vectors, Aedes aegypti and Aedes albopictus species on a 2% agarose gel. Since the most recent re-emergence of arboviral diseases is closely associated with Aedes species, findings of this study, therefore, give further evidence about the presence of potential arboviral vectors in Nigeria and describe the role of a simple PCR in discriminating some. Further entomological studies should integrate PCR assays in mosquito vector surveillance.


2010 ◽  
Vol 84 (24) ◽  
pp. 12982-12994 ◽  
Author(s):  
Long Truong Hoang ◽  
David J. Lynn ◽  
Matt Henn ◽  
Bruce W. Birren ◽  
Niall J. Lennon ◽  
...  

ABSTRACT Dengue is a pantropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. The ability to predict which patients may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host transcriptional features in 24 DSS patients and 56 sex-, age-, and virus serotype-matched uncomplicated (UC) dengue patients. In the first instance, we defined the “early dengue” profile. The transcriptional signature in acute rather than convalescent samples (≤72 h post-illness onset) was defined by an overabundance of interferon-inducible transcripts (31% of the 551 overabundant transcripts) and canonical gene ontology terms that included the following: response to virus, immune response, innate immune response, and inflammatory response. Pathway and network analyses identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB, and SP1 as key transcriptional factors mediating the early response. Strikingly, the only difference in the transcriptional signatures of early DSS and UC dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil degranulation (bactericidal/permeability-increasing protein [BPI], elastase 2 [ELA2], and defensin 1 alpha [DEF1A]). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also of the genotype of the infecting virus, as genome-length sequences of dengue virus serotype 1 (DENV-1) (n = 15) and DENV-2 (n = 3) sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2 sequences). Collectively, these data suggest a hitherto unrecognized association between neutrophil activation, pathogenesis, and the development of DSS and point to future strategies for guiding prognosis.


2021 ◽  
Vol 15 (6) ◽  
pp. e0009513
Author(s):  
Jacqueline Kyungah Lim ◽  
Pornthep Chanthavanich ◽  
Kriengsak Limkittikul ◽  
Jung-Seok Lee ◽  
Chukiat Sirivichayakul ◽  
...  

Background Dengue is a major public health problem in Thailand, but data are often focused on certain dengue-endemic areas. Methods: To better understand dengue epidemiology and clinical characteristics in Thailand, a fever surveillance study was conducted among patients aged 1–55 years, who presented with non-localized febrile illness at Bang Phae Community Hospital in Ratchaburi province, Thailand from October 2011 to September 2016. Results Among 951 febrile episodes, 130 were dengue-confirmed. Individuals aged 10–14 years were mostly affected, followed by those 15–19 years-of-age, with about 15% of dengue-confirmed cases from adults 25 years and older. There were annual peaks of dengue occurrence between June-November. Most prevalent serotype in circulation was DENV-2 in 2012, DENV-3 in 2014, and DENV-4 & -3 in 2015. Among dengue cases, 65% were accurately detected using the dengue NS1 RDT. Detection rate was similar between secondary and primary dengue cases where 66% of secondary vs. 60% of primary dengue cases had positive results on the NS1 RDT. Among dengue cases, 66% were clinically diagnosed with suspected dengue or DHF, prior to lab confirmation. Dengue was positively associated with rash, headache, hematemesis and alterations to consciousness, when compared to non-dengue. Dengue patients were 10.6 times more likely to be hospitalized, compared to non-dengue cases. Among dengue cases, 95 were secondary and 35 were primary infections. There were 8 suspected DHF cases and all were identified to be secondary dengue. Secondary dengue cases were 3.5 times more likely to be hospitalized compared to primary dengue cases. Although the majority of our dengue-positive patients were secondary dengue cases, with few patients showing manifestations of DHF, our dengue cases were mostly mild disease. Even among children < 10 years-of-age, 61% had secondary infection and the rate of secondary infection increased with age. Conclusion While the majority of dengue-confirmed cases were children, almost three-quarters of dengue-confirmed cases in this study were secondary dengue. Our study results consistent with previous data from the country confirm the hyperendemic transmission of DENV in Thailand, even in the non-epidemic years. With various interventions becoming available for dengue prevention and control, including dengue vaccines, decision-making on future implementation strategies should be based on such burden of disease data.


2015 ◽  
Vol 3 (3) ◽  
Author(s):  
Sitti S. P. Kamuh ◽  
Arthur E. Mongan ◽  
Maya F. Memah

Abstract: Dengue is a major public health problem that can be found throughout the tropical and subtropical countries around the world. Spectrum of clinical manifestations of dengue virus infection varies greatly. In addition to clinical symptoms, the diagnosis of dengue virus infection need to be supported by blood tests such as hematocrit and erythrocyte sedimentation rate. This study aimed to determine the hematocrit value and erythrocyte sedimentation rate (ESR) in children with dengue virus infection in Manado. This study used a cross-sectional design and was conducted from Desember 2014 to January 2015 at GMIM Pancaran Kasih, Advent, and Robert Wolter Mongisidi hospitals in Manado. There were 37 patients that fulfilled the inclusion criteria, consisted of 17 males and 20 females. The results showed that of 37 patients, there were 36 with hematocrit within normal limits. Moreover, of 37 patients only 6 patients performed the ESR examination; only 1 child had a rapid ESR result (> 15mm/h). Conclusion: In this study, most of the pediatric patients with dengue virus infection in Manado had normal hematocrit. Of 6 patients who had performed ESR test, only 1 had rapid ESR.Keywords: dengue, hematocrit, erythrocyte sedimentation rateAbstrak: Dengue merupakan masalah kesehatan masyarakat yang utama dan dapat ditemui diseluruh daerah tropis dan subtropis di seluruh dunia. Spektrum manifestasi klinis infeksi virus dengue sangat bervariasi. Selain gejala klinis, diagnosis infeksi virus dengue perlu ditunjang hasil uji darah di laboratorium antara lain hematokrit dan laju endap darah (LED). Penelitian ini bertujuan untuk mengetahui nilai hematokrit dan LED pada anak dengan infeksi virus dengue di Manado. Penelitian ini menggunakan desain potong lintang, dilakukan pada bulan Desember 2014 sampai Januari 2015 di RSU GMIM Pancaran Kasih Manado, RS Advent Manado, dan RSAD Robert Wolter Mongisidi Teling17 anak laki-laki dan 20 anak perempuan. Hasil penelitian memperlihatkan 36 dari 37 pasien mempunyai hematokrit normal. Dasri 37 pasien, hanya 6 anak yang menjalani pemeriksaan LED; hanya 1 anak dengan LED cepat (> 15mm/jam). Simpulan: Pada studi ini, sebagian besar pasien anak dengan infeksi virus dengue di Manado mempunyai nilai hematokrit normal. Dari 6 pasien yang dilakukan pemeriksaan LED, 1 anak mempunyai hasil LED cepat.Kata kunci: dengue, hematrokrit, laju endap darah.


Author(s):  
Henry Puerta-Guardo ◽  
Scott B. Biering ◽  
Eva Harris ◽  
Norma Pavia-Ruz ◽  
Gonzalo Vázquez-Prokopec ◽  
...  

Dengue is the most prevalent emerging mosquito-borne viral disease, affecting more than 40% of the human population worldwide. Many symptomatic dengue virus (DENV) infections result in a relatively benign disease course known as dengue fever (DF). However, a small proportion of patients develop severe clinical manifestations, englobed in two main categories known as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Secondary infection with any of the four dengue virus serotypes (DENV1, -2, -3, and -4) is a risk factor to develop severe forms of dengue disease. DSS is primarily characterized by sudden and abrupt endothelial dysfunction, resulting in vascular leak and organ impairment, which may progress to hypovolemic shock and death. Severe DENV disease (DHF/DSS) is thought to follow a complex relationship between distinct immunopathogenic processes involving host and viral factors, such as the serotype cross-reactive antibody-dependent enhancement (ADE), the activation of T cells and complement pathways, the phenomenon of the cytokine storm, and the newly described viral toxin activity of the nonstructural protein 1 (NS1), which together play critical roles in inducing vascular leak and virus pathogenesis. In this chapter that is divided in two parts, we will outline the recent advances in our understanding of DENV pathogenesis, highlighting key viral-host interactions and discussing how these interactions may contribute to DENV immunopathology and the development of vascular leak, a hallmark of severe dengue. Part I will address the general features of the DENV complex, including the virus structure and genome, epidemiology, and clinical outcomes, followed by an updated review of the literature describing the host innate immune strategies as well as the viral mechanisms acting against and in favor of the DENV replication cycle and infection.


2018 ◽  
Vol 7 (3.34) ◽  
pp. 439
Author(s):  
D Yuvaraj ◽  
P Jai Preethi ◽  
A Saravanan ◽  
K H. Smila

Lymphatic filariasis (LF), is a mosquito vector-borne disease and a major public health problem in the tropical countries. The annual mass drug administration (MDA) in India was studied in 1996-97. It was introduced with single dose of Diethylcarbamazine and was investigated  as a pilot project covering 41millon population. The study was extended to 77million population by 2002. The MDA is one of the strategies to eliminate LF in India. Liposomes, polymeric and solid lipid nanoparticles are the most promising nanopharmaceuticals which are easy to formulate, cheaper and can bring prolific consequences for filariasis management.  


2018 ◽  
Vol 9 (1) ◽  
pp. 274-277
Author(s):  
Mohammed Reaz Mobarak ◽  
Md Rafiqul Islam ◽  
AKM Tajuddin Bhuiyan ◽  
Nabila Akand ◽  
Ferdousi Begum

Background : Dengue is a mosquito-borne (Ades Agepti) infection which in recent years has become a major public health problem. It is now endemic in more than 100 countries in Africa, America, Eastern Mediterranean, South-East Asia and Western Pacific areas. According to WHO currently approximately 50 million cases of dengue fever occur every year.Objective : To evaluate the current clinical picture, outcome and serology of children suffering from dengue fever admitted in a tertiary care children hospital.Methodology : It is a hospital based prospective observational study carried out among the children having Dengue infection admitted during the period of June to December 2016 in Dhaka Shishu (Children) Hospital. After obtaining informed consent 78 suspected cases of dengue fever patients were enrolled for this study. Patient with any identified specific infection or febrile illness more than 14 days and serologically dengue negative cases were excluded from the study. A detailed history, demographic variables, clinical examination and relevant laboratory investigations were assessed. The data were collected in a predesigned structured questionnaire and were analyzedwith the help of SPSS-21.Result : Out of 78 suspected dengue cases a total of 56 cases were serologically dengue positive. Therefore 22 serologically dengue negative cases were excluded. Most common presenting symptoms were fever (100%) followed by myalgia76.79%, retro-orbital pain73.21%, and conjunctival hemorrhage 55.35%, skin rash 55.35%, with other symptoms constituting the rest. Among the serologically positive dengue cases those who presented with fever for 3 days or of lesser duration, NS1 Ag was positive in 34 cases ( 43.58%) and those who presented with fever for 6 days or more, 14 cases (17.95%) were dengue IgM positive and 8 cases (10.25%) were dengue IgG positive with accompanying low level IgM positive; platelet count 94333/mm3 (±68330), PCV 35 (±3.95) and SGPT 210 U/L(±80).Among 56 dengue positive cases 31(55.4%) were male and 25 (44.6%) were female, The age range was 1 years to 18 years with mean 6.66 ±3.69, predominant age group was 6 years to 12 years. Final diagnosis according to WHO classification were DF 42.68%, DHF-l 32.14%, DHF–ll 16.07%,DHF-lll 8.93%. Outcome of the disease were 89.3% discharge with advice (DA),7.1% discharge on request(DOR), 3.6% left against medical advice(LAMA) and no death.Conclusion : The trend of Dengue infection in Bangladesh has been changing very rapidly. In this study our observation was incidence of dengue was more in male child, peak age group being 6 years to 12 years with most admissions during the month of September. Fever with pain (body ache, retro orbital pain), headache and maculopapular rash, positive NS1Ag and dengue IgM were the main findings found in children with dengue. Most of the dengue cases were DF and DHF-l in our study.Northern International Medical College Journal Vol.9(1) July 2017: 274-277


2020 ◽  
Vol 48 (1) ◽  
Author(s):  
Rosie K. Manolas ◽  
Mike Kama ◽  
Merelesita Rainima-Qaniuci ◽  
Vinaisi D. Bechu ◽  
Samuela Tuibeqa ◽  
...  

Abstract Background Lymphatic filariasis (LF) is a major public health problem in the Pacific Region, including in Fiji. Through transmission by the mosquito vector Aedes, Fiji has suffered the burden of remaining endemic with LF despite efforts at elimination prior to 1999. In the year 1999, Fiji agreed to take part in the Pacific Programme for Elimination of LF (PacELF) and the Global Programme to Eliminate LF. Methods This study reviewed and collated past data on LF in Fiji between 1997 and 2007. Sources included published papers as well as unpublished PacELF and WHO program meeting and survey reports. Records were held at Fiji’s Department of Health and Medical Services, James Cook University and the WHO office in Suva, Fiji. Results Baseline surveys between 1997 and 2002 showed that Fiji was highly endemic for LF with an estimated 16.6% of the population antigen positive and 6.3% microfilaria positive at that time. Five rounds of annual mass drug administration (MDA) using albendazole and diethylcarbamazine commenced in 2002. Programmatic coverage reported was 58–70% per year, but an independent coverage survey in 2006 in Northern Division after the fifth MDA suggested that actual coverage may have been higher. Monitoring of the program consisted of antigen prevalence surveys in all ages with sentinel and spot check surveys carried out in 2002 (pre MDA), 2004, and 2005, together with knowledge, attitude, and practice surveys. The stop-MDA survey (C survey) in 2007 was a nationwide stratified cluster survey of all ages according to PacELF guidelines, designed to sample by administrative division to identify areas still needing MDA. The national antigen prevalence in 2007 was reduced by more than a third to 9.5%, ranging from 0.9% in Western Division to 15.4% in Eastern Division, while microfilaria prevalence was reduced by almost four-fifths to 1.4%. Having not reached the target threshold of 1% prevalence in all ages, Fiji wisely decided to continue MDA after 2007 but to move from nationwide implementation to four (later five) separate evaluation units with independent timelines using global guidelines, building on program experience to put more emphasis on increasing coverage through prioritized communication strategies, community participation, and morbidity alleviation. Conclusion Fiji conducted nationwide MDA for LF annually between 2002 and 2006, monitored by extensive surveys of prevalence, knowledge, and coverage. From a high baseline prevalence in all divisions, large reductions in overall and age-specific prevalence were achieved, especially in the prevalence of microfilariae, but the threshold for stopping MDA was not reached. Fiji has a large rural and geographically widespread population, program management was not consistent over this period, and coverage achieved was likely not optimal in all areas. After learning from these many challenges and activities, Fiji was able to build on the progress achieved and the heterogeneity observed in prevalence to realign towards a more stratified and improved program after 2007. The information presented here will assist the country to progress towards validating elimination in subsequent years.


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