Evidence of dengue and chikungunya virus co-infection and circulation of multiple dengue serotypes in a recent Indian outbreak

Beyond the Bite: Detailed findings on Chikungunya and Dengue co-detection in Punjab, North India - clinical insights and diagnostic challenges

OBJECTIVES

The co-circulation of Chikungunya virus (CHIKV) and Dengue virus (DENV) in India poses a challenge for the diagnosing clinician, as they share similar clinical signs and symptoms and geographical distribution. Both arthropod-borne viruses are maintained in the environment by the Aedes mosquito, commonly found in tropical countries including India. Here we aim to investigate the clinical and laboratory aspects of Chikungunya/Dengue suspected cases in Punjab, India during 2021-2022, focusing on the differential diagnosis of Dengue.

METHODS

All suspected cases were submitted to serological differential diagnosis approaches to arboviruses like Chikungunya and Dengue. For the detection of Chikungunya Infection, CHIK IgM Capture ELISA was employed. Whereas, for Dengue NS1 antigen ELISA and IgM Capture ELISA assays were employed.

RESULTS

A total of 370 cases suspected of arboviral infection were investigated and 38.3% (142/370) were confirmed as Chikungunya. Chikungunya cases were slightly more prevalent in males (54%) and the most frequently affected age group was adults between 16 and 30 years old (45.7%). Polyarthralgia affected 79.5% of patients, 63.3% exhibited headache and 50% presented with retro-orbital pain. 28.9% (107/370) had serological evidence of DENV exposure by detection of specific anti-DENV IgM or NS1 and 9.1% (34/370) cases of co-detection of Chikungunya and Dengue were reported. Urban populations had a higher infection rate of co-detection of Chikungunya and Dengue than rural populations with 83% versus 17%, respectively.

CONCLUSIONS

Despite an initial clinical diagnosis of Dengue, most patients with fever and arthralgia were serologically confirmed as Chikungunya cases, with a notable prevalence of CHIKV/DENV co-detection. Strengthening differential diagnosis of circulating arboviruses is crucial for improving patient care and enhancing vector control and environmental management strategies.

Molecular and serological evidence of chikungunya virus infection with high case fatality among pediatric population with acute encephalitis syndrome: first report from Eastern Uttar Pradesh, India

Acute encephalitis syndrome (AES) outbreaks in children of Eastern Uttar Pradesh (E-UP) region of India have been a longstanding public health issue, with a significant case fatality rate of 20-25%. Since past decade, a rise in chikungunya (CHIK) cases has been occurring, which is a reported etiology of AES. However, the burden of chikungunya virus (CHIKV) among pediatric AES (pAES) is unknown from E-UP. We included 238 hospitalized pAES cases. The presence of IgM antibodies for CHIKV, and Dengue virus (DENV) was tested, and RT-PCR was performed for CHIKV and DENV in serologically confirmed CHIKV and DENV pAES cases. Positive samples were sequenced using Sangers sequencing. Further, to check for co-infection, IgM antibodies for other AES etiologies including Japanese encephalitis virus (JEV), Leptospira and Orientia tsutsugamushi (OT) in serum were also investigated. IgM ELISA demonstrated 5.04% (12) positivity for CHIKV. Among CHIKV IgM positive, 3 (25%, 3/12) pAES patients died. CHIKV genome was detected in 3 pAES specimens. Among which, 2 CHIKV cases were also positive for OT DNA. Partially sequenced CHIKV were genotyped as ECSA. The overall finding indicates evidence of CHIKV infection with high case fatality among pAES patients from E-UP. This study advocates constant serological and molecular surveillance of CHIKV in AES endemic regions of India.

Importance of NFκβ, IL-10 serum levels and DC-SIGN polymorphic haplotypes in determining dengue disease severity among eastern Indian patients

OBJECTIVES

Dengue viral (DENV) infection is most prevalent arboviral infection in India resulting in wide-range of symptomatic manifestation from simple (DF) to severe dengue (SD). DENV is internalized by dendritic cell receptor, DC-SIGN, which in turn activates inflammatory cytokines: NFκβ, IL-10 as adaptive immune response. Present study focused on role of DC-SIGN polymorphisms and these cytokines in SD development among eastern Indian patients.

METHOD

DC-SIGN polymorphisms (rs735239, rs4804803, rs2287886) and NFκβ, IL-10 concentrations were analysed among 179 dengue patients and 123 healthy individuals by PCR-RFLP and sandwich ELISA, respectively. DENV copies/ml and serotype in patient-sera were measured by quantitative and qualitative real time PCR, respectively. Statistical and haplotype analysis were performed by GraphPad-Prism and SNPStat, respectively.

RESULT

Prevalence of DENV serotypes among infected patients: DENV2>DENV4>DENV3>DENV1; those with DENV3 infection reported significantly increased IL-10 level. NFκβ and IL-10 concentrations were significantly elevated among SD patients. ROC curve analysis predicted cut-off values of NFκβ>13.46 ng/ml and IL-10 > 490.5 pg/ml to detect SD among infected patients with a good sensitivity and specificity. Patients with rs735239-GG, rs2287886-GG genotypes and GGG, GAG haplotypes were significantly associated with SD development, whereas, those with rs4804803-AG exhibited high DENVcopies/ml. Patients with these haplotypes also demonstrated increased NFκβ and IL-10.

CONCLUSION

This study emphasised importance of DC-SIGN GGG and GAG haplotypes, NFκβ and IL-10 concentrations in WHO-defined severe dengue development among infected patients.

Global prevalence of dengue and chikungunya coinfection: A systematic review and meta-analysis of 43,341 participants

Dengue and chikungunya virus are important arboviruses of public health concern. In the past decades, they have accounted for numerous outbreaks of dengue and chikungunya in different parts of the world. Several cases of concurrent infection of dengue and chikungunya have been documented. However, the true burden of this concurrent infection is unknown. Here, a systematic review and meta-analysis of published data on the prevalence of dengue and chikungunya coinfection in the human population was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Six electronic databases (Web of science, Embase, PubMed, ScienceDirect, Scopus, and Google Scholar) were searched without year or language restrictions for relevant studies. The study protocol was registered with PROSPERO (CRD42020175344). Eighty-three studies involving a total of 43,341 participants were included. The random-effects model was employed to calculate the summary estimates. A pooled global prevalence of 2.5% (95% CI: 1.8-3.4) was obtained for dengue and chikungunya coinfection. Males and females appear to be coinfected at a fairly similar rate. Among the regions, Asia accounted for the highest prevalence (3.3%, 95% CI: 2.3-4.6) while North America was the least (0.8%, 95% CI: 0.3-2.4). The prevalence estimates varied across different countries. A much higher prevalence rates were obtained for Colombia (37.4%, 95% CI: 9.1-78.1), Madagascar (18.2%, 95% CI: 10.1-30.6), Laos (12.5%, 95% CI: 5.3-26.7), Maldives (4.5%, 95% CI: 1.5-13.0) and Thailand (3.7%, 95% CI: 0.4-26.3). This first extensive systematic review and meta-analysis reveals dengue and chikungunya coinfection as a global problem worthy of consideration. It is therefore pertinent that both infections be assessed during diagnosis, mosquito vector control practices be implemented, and vaccine development strides be supported globally.

Was It Chikungunya? Laboratorial and Clinical Investigations of Cases Occurred during a Triple Arboviruses’ Outbreak in Rio de Janeiro, Brazil

The co-circulation of chikungunya virus (CHIKV), dengue virus (DENV) and Zika virus (ZIKV) in Rio de Janeiro (RJ), Brazil, caused a challenging triple epidemic, as they share similar clinical signs and symptoms and geographical distribution. Here, we aimed to investigate the clinical and laboratorial aspects of chikungunya suspected cases assisted in RJ during the 2018 outbreak, focusing on the differential diagnosis with dengue and zika. All suspected cases were submitted to molecular and/or serological differential diagnostic approaches to arboviruses. A total of 242 cases suspected of arbovirus infection were investigated and 73.6% (178/242) were molecular and/or serologically confirmed as chikungunya. In RT-qPCR confirmed cases, cycle threshold (Ct) values ranged from 15.46 to 35.13, with acute cases presenting lower values. Chikungunya cases were mainly in females (64%) and the most frequently affected age group was adults between 46 to 59 years old (27%). Polyarthralgia affected 89% of patients, especially in hands and feet. No dengue virus (DENV) and Zika virus (ZIKV) infections were confirmed by molecular diagnosis, but 9.5% (23/242) had serological evidence of DENV exposure by the detection of specific anti-DENV IgM or NS1, and 42.7% (76/178) of chikungunya positive cases also presented recent DENV exposure reflected by a positive anti-DENV IgM or NS1 result. A significantly higher frequency of arthritis (p = 0.023) and limb edema (p < 0.001) was found on patients with CHIKV monoinfection compared to dengue patients and patients exposed to both viruses. Lastly, phylogenetic analysis showed that the chikungunya cases were caused by the ECSA genotype. Despite the triple arboviruses’ epidemic in the state of RJ, most patients with fever and arthralgia investigated here were diagnosed as chikungunya cases, and the incidence of CHIKV/DENV co-detection was higher than that reported in other studies.

Association of C-reactive protein polymorphisms with serum-CRP concentration and viral load among dengue-chikungunya mono/co-infected patients

India being endemic to Dengue (DENV) and chikungunya (CHIKV) infections faces high patient-mortality and morbidity with overlapping clinical features. C-reactive protein (CRP) acts as early defence system in response to these infections. This study investigated role of CRP single-nucleotide polymorphism (SNP) genotypes and protein levels towards DENV/CHIKV mono and co-infection among eastern Indian patients. 128 DENV-CHIKV co-infected, 206 DENV and 167 CHIKV mono-infected patients were subjected to genotyping of two CRP SNPs by PCR-RFLP along with 102 healthy individuals. CRP levels were determined by immunoturbidimetry. Statistical correlation of CRP genotypes with CRP concentration, DENV-CHIKV mono/co-infection and viral load was performed. Patients with rs3093059-CT and rs3091244-TT were more susceptible to DENV-CHIKV co-infection, whereas, rs3091244-CT might have imparted protection against CHIKV mono-infection. DENV-HVL was more prevalent within rs3093059-TT and rs3091244-CT co-infected patients, whereas, CHIKV-HVL among rs3091244-CC. Acute phase co-infected patients had significantly higher CRP level compared to mono-infections. Both mono and co-infected patients with aches/pain exhibited 2-3-fold higher CRP levels compared to those without. rs3093059-CT and rs3091244-CT co-infected patients had higher CRP concentration compared to rs3093059-TT and rs3091244-CC, respectively. Co-infected patients with WHO-defined warning signs had higher anti-dengue IgG/IgM ratio and serum CRP level compared to those without warning signs. Thus, patient's CRP genotype might play significant role in determining serum-CRP concentration, viral load and DENV-CHIKV mono/co-infection.

A Rapid and Easy-to-Perform Method of Nucleic-Acid Based Dengue Virus Diagnosis Using Fluorescence-Based Molecular Beacons

Detecting dengue virus (DENV) infection in patients as early as possible makes the disease management convenient. Conventionally, DENV infection is diagnosed by ELISA-based methods, but sensitivity and specificity are major concerns. Reverse-transcription-PCR (RT-PCR)-based detection confirms the presence of DENV RNA; however, it is expensive, time-consuming, and skilled personnel are required. A fluorescence-based detection system that detects DENV RNA in patient’s serum directly, without any nucleic acid amplification step, has been developed. The method uses target-specific complementary sequence in the molecular beacon, which would specifically bind to the DENV RNA. The molecular beacons are approximately 40 bases long hairpin structures, with a fluorophore-quencher system attached at the terminal ends of the stem. These probes are biotinylated in the stem region, so that they can be immobilized on the streptavidin-tagged magnetic beads. These magnetic beads, coupled with biotinylated molecular beacons, are used for the detection of the target RNA in the serum by incubating the mixture. After incubation, beads are separated and re-suspended in a buffer. The measurement of fluorescence is taken in fluorometer after 15 min incubation at 50 °C. The whole work is carried out in a single tube. This rapid method can precisely detect dengue RNA within two hours, confirming ongoing DENV replication in the patient.

Evidence of chikungunya virus infections among febrile patients at three secondary health facilities in the Ashanti and the Bono Regions of Ghana

BACKGROUND

Chikungunya is now of public health concern globally due to its re-emergence in endemic areas and introduction into new areas of the world. Worldwide, the vectors for transmission of the chikungunya virus are Aedes mosquitoes and these are prevalent in Ghana. Despite its global significance, the true burden of chikungunya virus infection in Ghana is largely unknown and the threat of outbreak remains high owing to international travel. This study sought to determine chikungunya virus infection among febrile patients suspected of having malaria infections at some selected health facilities in the Ashanti, Bono East, and Bono Regions of Ghana.

METHODOLOGY

This cross-sectional study recruited six hundred (600) febrile patients suspected of having malaria who submitted their clinical samples to the laboratories of the selected health facilities for the diagnosis of their infections. Five to ten millilitres (5-10ml) of venous blood were collected from each study participant. Sera were separated and tested for anti-chikungunya (IgM and IgG) antibodies using InBios ELISA kit following the manufacturer's instruction. Samples positive for chikungunya IgM and IgG were selected and tested for chikungunya virus RNA using Reverse Transcription-quantitative Polymerase Chain Reaction. Malaria Rapid Diagnostic Test kits were used to screen the participants for malaria. Structured questionnaires were administered to obtain demographic and clinical information of the study participants.

RESULT

Of the 600 samples tested, the overall seroprevalence of chikungunya was 6%. The seroprevalence of chikungunya IgM and IgG antibodies were 1.8% and 4.2% respectively. None of the chikungunya IgM and IgG positive samples tested positive for chikungunya RNA by RT-qPCR. Of the 600 samples, tested 32.3% (194/600) were positive for malaria parasites. Malaria and chikungunya co-infection was detected in 1.8% (11/600) of the participants.

CONCLUSION

Findings from the current study indicate low-level exposure to the chikungunya virus suggesting the virus is circulating and potentially causing morbidity in Ghana.

Management of dengue with co-infections: an updated narrative review

Dengue is a life-threatening mosquito borne viral disease. We are still in the era of supportive treatment where morbidity and mortality are a major concern. Dengue infection in presence of other co-infections makes this scenario rather worse. Timely recognition and raising alarm to be intensive is the need of the hour for primary care physicians practicing in the community and indoors. This review provides a comprehensive knowledge about the recent trends of coinfection in dengue as well as their management consideration which will be particularly helpful for physicians practicing in rural and remote areas of India.

Differential genotypic signatures of Toll-like receptor polymorphisms among dengue-chikungunya mono- and co-infected Eastern Indian patients

Dengue (DENV) and chikungunya (CHIKV) viral infections trigger high patient morbidity and mortality. Mono-/co-infection of these viruses activates innate immune response, triggering Toll-like receptor (TLR) pathways. The present study investigated the differential role of TLR3, 7 and 8 single-nucleotide polymorphisms (SNPs) between mono- and co-infected Eastern Indian patients. Interaction of TLR polymorphic variants with signal peptidase complex (SPC18) was explored which might affect immune signalling against DENV/CHIKV infections. Out of 550 febrile symptomatic patients, 128 DENV-CHIKV co-infected samples were genotyped for eight SNPs of TLR3 (rs3775290-chr4:186083063), TLR7 (rs179008-chrX:12885540, rs5741880-chrX:12869297, rs179010-chrX:12884766, rs3853839-chrX:12889539) and TLR8 (rs5744080-chrX:12919685, rs3764879-chrX:12906578, rs3764880-chrX:12906707) by PCR-RFLP along with 157 healthy individuals. Statistical analysis established genotypic association of TLR SNPs with DENV-CHIKV co-infection, and difference between mono- and co-infected patients and their role in determining high viral load (HVL) during competitive viral replication among co-infected patients. In silico protein-protein docking evaluated interactive effect of TLR variants with SPC18. The findings revealed patients with CC genotypes of TLR7 and 8 SNPs were significantly susceptible towards co-infection, whereas specific genotypes of TLR7 and 8 imparted protection against co-infection. Differential analysis between mono-/co-infected patients revealed distinct genotypic distribution of TLR3, 7 and 8 SNPs. Co-infected patients with TT-rs179010 exhibited DENV-HVL, whereas CHIKV-HVL was detected among patients with other genotypes. Molecular docking of TLR7-rs179008 Q variant and TLR8-rs3764880 V variant with SPC18 generated better free binding energy. This study underlined the importance of TLR7 and 8 SNPs towards mono-/co-infection of DENV/CHIKV, with certain genotypes associated with co-infection susceptibility. Moreover, it suggested a probable role of specific genotypes of TLR7 and 8 polymorphisms imparting high dengue/chikungunya viral load among co-infected patients.

Importance of clinical and laboratory characteristics in the diagnosis of dengue and chikungunya co-infection: Probable case report

We report the case of a 38-year-old woman who initially consulted for an undifferentiated fever. Although her clinical condition evolved with signs and symptoms compatible with dengue with alarm signs and that the anti-dengue IgM detection in a single sample indicated it was a probable case that could have happened during the previous three months, the patient kept consulting due to little improvement. On the tenth day after the onset of symptoms, she presented with painful polyarticular symmetric edema, as well as hyperpigmented lesions in the nasolabial fold. Chikungunya diagnosis was confirmed by the presence of IgM antibodies. In endemic countries for dengue and chikungunya, the possibility of co-infection exists, but it may go unnoticed. On the other hand, the co-infection may worsen the clinical course of these diseases. Therefore, physicians should evaluate the clinical and laboratory characteristics of both infections to be able to diagnose the coinfection for adequate management and to minimize complications.

Association of serum C-reactive protein level and polymorphisms with susceptibility to dengue infection and severe clinical outcome among eastern Indian patients

Dengue virus (DENV) infection is a major public health concern in India ranging from simple febrile illness to severe outcome. This study aimed to investigate association of serum CRP level and CRP gene polymorphisms towards development of dengue disease susceptibility and severity among eastern Indian patients. Blood was collected from 348 symptomatic patients. Sera was subjected to serological diagnosis for the presence of anti-dengue IgM, anti-dengue IgG antibodies and dengue NS1 antigen by ELISA. Viral RNA was extracted and the presence of DENV genome, viral load, serotypes was determined by qRT-PCR. CRP level and polymorphisms were determined by immunoturbidimetry and polymerase chain reaction-restriction fragment length polymorphism, respectively. Statistical analysis was performed by GraphPad-Prism. Among 206 dengue patients, CRP level increased significantly among patients within acute phase, and patients with qRT-PCR/NS1 antigen positivity, high viral load (HVL), secondary infection, and DENV4 and DENV2 infections. rs3091244, TT genotype positively associated with dengue susceptibility (p = 0.03). CT genotype of rs3093059 and TT genotype of rs3091244 were found to correlate with elevated CRP level and development of WHO-defined warning signs. TT genotype of rs3091244 was more prevalent among HVL patients. Thus, these CRP polymorphic variants and CRP concentration might act as potential prognostic biomarkers for predicting disease severity among acute-stage dengue patients.

Detection of coinfection with Chikungunya virus and Dengue virus serotype 2 in serum samples of patients in State of Tocantins, Brazil

BACKGROUND

The co-circulation of Chikungunya (CHIKV), Dengue (DENV) and Zika (ZIKV) viruses increased the risk of outbreaks and coinfections among them. Here, we report cases of coinfection in clinical samples from state of Tocantins, Brazil.

METHODS

In 2017, the Central Public Health Laboratory (LACEN) received samples of patients who consulted health units with symptoms compatible with arboviral infections. A total of 102 samples were sent to the Retrovirology Laboratory at the Federal University of São Paulo, where they were tested by RT-qPCR to confirm DENV, ZIKV and CHIKV infections and to detect coinfected patients.

RESULTS

We identified with CHIKV monoinfection (52), DENV serotypes 1 (28) and serotypes 2 (22). We did not detect ZIKV. Five patients were characterized with coinfection involving CHIKV and DENV serotype 2.

CONCLUSIONS

The presence of co-circulating arboviruses increases the chance of coinfection and demonstrates the importance of differential diagnosis and vector control.

Re-emergence of Chikungunya virus infection in Eastern India

Chikungunya fever is a major public health issue in India. Re-emergence of chikungunya virus (CHIKV) in West Bengal was detected after 32 years in 2006. After 2010, this infection was in apparent decline, but in 2016 a massive outbreak affected the country. Present study was carried out to understand CHIKV infection dynamics during recent outbreaks in West Bengal, Eastern India and its implication on disease manifestations. Blood was collected from 641 symptomatic patients. Patients' sera were serologically diagnosed to detect presence of anti-chikungunya-IgM antibodies. Viral RNA was extracted; presence of CHIKV genome and its respective viral load was determined by real time quantitative reverse transcription-PCR (real-time qRT-PCR). Statistical analysis was performed using EPI INFO software. CHIKV infection was detected in 24.64% of symptomatic patients. Middle-aged patients (31-40 years) were predominantly affected; clinically, both arthralgia and joint-swelling were significantly prevalent among CHIKV-infected patients. Myalgia, joint-swelling, and arthralgic manifestation were found in significantly higher frequency among patients with high chikungunya viral load (> 10,000 copies/ml). Thus, this study clearly indicated the re-emergence of CHIKV in Eastern India. Significant presence of myalgia, joint swelling, and arthralgia among chikungunya patients with high viral load implied association of disease severity with viral load; requiring vigilance for proper management of infected patients as this disease is highly morbid in nature. However, in addition to chikungunya virus, other viral, bacterial, and protozoal infections also occur during post-monsoon season in India, having overlapping symptoms. Hence, continuous monitoring of these infections is required for better clinical management of patients.

Contribution of Toll like receptor polymorphisms to dengue susceptibility and clinical outcome among eastern Indian patients

Dengue infection has been one of the major public health concerns in India causing simple dengue fever (DF) to severe dengue infection. In the present study, contribution of TLR3, 7 and 8 polymorphisms towards dengue disease susceptibility and severity among Eastern Indian patients was analysed. Genomic DNA was extracted from blood of 201 dengue infected patients and 157 healthy individuals, followed by genotyping of eight polymorphisms of TLR3 (rs3775290), TLR7 (rs5741880, rs3853839, rs179008 and rs179010) and TLR8 (rs3764879, rs3764880 and rs5744080) genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Functional analyses of the polymorphisms were predicted. Genotypic association of polymorphisms, alone and in combination, with dengue disease susceptibility and development of WHO-defined warning signs among patients was calculated by using SPSS software. TLR7-rs179008 & TLR8-rs3764880 were implicated to be non-synonymous polymorphisms. Specific genotypes of majority of the analysed TLR polymorphisms exhibited significant positive association with disease susceptibility. CC/C and AA/A of TLR7-rs179008 (p < 0.0001) and TLR8-rs3764880 (p < 0.00001) respectively were significantly associated with development of warning signs among dengue infected patients. Particular genotypic combinations of rs3853839-rs5744080 and rs179008-rs3764880 increased the risk of dengue infectivity, whereas, presence of last combination was more prevalent among dengue patients with warning signs. Thus these polymorphic variants of TLR3, 7 and 8 might act as potential prognostic biomarkers for predicting disease severity among dengue virus infected patients.

Beyond Fever and Pain: Diagnostic Methods for Chikungunya Virus

Chikungunya virus (CHIKV) is an alphavirus that is primarily transmitted by Aedes species mosquitoes. Though reports of an illness consistent with chikungunya date back over 200 years, CHIKV only gained worldwide attention during a massive pandemic that began in East Africa in 2004. Chikungunya, the clinical illness caused by CHIKV, is characterized by a rapid onset of high fever and debilitating joint pain, though in practice, etiologic confirmation of CHIKV requires the availability and use of specific laboratory diagnostics. Similar to infections caused by other arboviruses, CHIKV infections are most commonly detected with a combination of molecular and serological methods, though cell culture and antigen detection are reported. This review provides an overview of available CHIKV diagnostics and highlights aspects of basic virology and epidemiology that pertain to viral detection. Although the number of chikungunya cases has decreased since 2014, CHIKV has become endemic in countries across the tropics and will continue to cause sporadic outbreaks in naive individuals. Consistent access to accurate diagnostics is needed to detect individual cases and initiate timely responses to new outbreaks.

Dengue and Chikungunya Infections in Children : Guest Editor: Bhim S. Pandhi

Dengue and Chikungunya are two important mosquito-borne acute febrile illnesses in children. With increased urbanization and newer strains of chikungunya virus with improved transmission with Aedes albopictus, the at-risk population for these infections has greatly increased. Dengue fever has been classified by WHO as dengue with/ without warning signs and severe dengue. Severe dengue is associated with hemorrhagic manifestations, hypovolemia and hypotension secondary to third space loss due to capillary leak or severe end organ dysfunction. NS1 antigen detection and dengue polymerase chain reaction, [polymerase chain reaction (PCR during first 5 d)] and IgM for dengue (6th day of fever onwards) are commonly utilized diagnostic tests. Appropriate fluid therapy with timely tapering of intravenous fluid rate with hematocrit, treatment of hemorrhagic manifestations and clinical monitoring are the mainstay of dengue treatment. Chikungunya has less severe course with shorter febrile phase with prominent and persistent joint symptoms. PCR and IgM against chikungunya are appropriate investigations. Treatment is supportive for chikungunya infection with appropriate joint pain relief.

Simultaneous detection of IgM antibodies against dengue and chikungunya: Coinfection or cross-reactivity?

Background:

Dengue and chikungunya sharing same mosquito vector are two most important arboviruses circulating in northern India including Delhi and are responsible for frequent outbreaks. Antigen and antibodies detection ELISA kits are the major tool to diagnose these viral illnesses, and are sometimes associated with cross–reactivity, giving a false picture of coinfection, although simultaneous harboring of both the viruses is not uncommon. Various studies have reported coinfection up to 25% from the same region.

Procedure:

This study was conducted in the Department of Microbiology, Maulana Azad Medical College, New Delhi, during the month of September 2016 which included 200 blood samples from clinically suspected cases attending Medicine OPD of associated Lok Nayak Hospital, New Delhi. Diagnosis of dengue and chikungunya was made using NS-1 antigen and IgM MAC ELISA for dengue and IgM MAC ELISA for chikungunya as per manufacturer's instructions.

Results:

Out of 200 suspected cases, 34 (17%) were positive for dengue serology, 77 (38.5%) were positive for chikungunya serology, and 29.9% of positive chikungunya cases were simultaneously affected with dengue. This higher percentage of coinfection might be because of cross-reactivity of the ELISA kits.

Discussion:

India being a hyperendemic region for dengue and chikungunya, frequent outbreaks are quite common. Circulation of both the virus and huge susceptible population are the major causes for frequent outbreaks. Restricting our attention to diagnose one of them is not sufficient, and coinfection further complicates the illness.

Conclusion:

Simultaneous diagnosis of dengue and chikungunya is need of time to diagnose dual infection and prevent complications by starting supportive treatment well in time. Molecular technique if ever possible should be employed whenever the coinfection number is higher than expected to rule out cross-reactivity.

Isolation and molecular characterization of dengue virus clinical isolates from pediatric patients in New Delhi

OBJECTIVE

To characterize the in vitro replication fitness, viral diversity, and phylogeny of dengue viruses (DENV) isolated from Indian patients.

METHODS

DENV was isolated from whole blood collected from patients by passaging in cell culture. Passage 3 viruses were used for growth kinetics in C6/36 mosquito cells. Parallel efforts also focused on the isolation of DENV RNA from plasma samples of the same patients, which were processed for next-generation sequencing.

RESULTS

It was possible to isolate 64 clinical isolates of DENV, mostly DENV-2. Twenty-five of these were further used for growth curve analysis in vitro, which showed a wide range of replication kinetics. The highest viral titers were associated with isolates from patients with dengue with warning signs and severe dengue cases. Full genome sequences of 21 DENV isolates were obtained. Genome analysis mapped the circulating DENV-2 strains to the Cosmopolitan genotype.

CONCLUSIONS

The replication kinetics of isolates from patients with mild or severe infection did not differ significantly, but the viral titers varied by two orders of magnitude between the isolates, suggesting differences in replication fitness among the circulating DENV-2.

Epidemiological trends and molecular dynamics of dengue, chikungunya virus infection, coinfection, and other undifferentiated fever during 2015-2016 in Odisha, India

Chikungunya virus (CHIKV) infection is spatiotemporally related to dengue virus (DENV) infection and mostly undiagnosed due to similar primary symptoms. In 2013, a high rate (36%) of coinfection of DENV and CHIKV was reported in Odisha. Hence, the hospital-based study was continued to synthesis current epidemiological understanding of their single distribution or coinfection. Suspected DENV patients serum samples were tested for DENV and CHIKV by serology and reverse-transcription polymerase chain reaction. The positive samples were used for analysis of mutation, selection pressure, and phylogenetic relationship. Clinical information was also analyzed. Among 648 (2015 and 2016) suspected DENV patients, 141 (21.7%) were positive for DENV (serotypes 1-3), 22 (3.4%) were positive for CHIKV (ECSA) and 4 (2.8%) were coinfected with both. Sequence analysis showed four consistent mutations (M104V, V112A, K166N, and F169L) in CprM gene of DENV 2 and two consistent mutations (M269V, D284E) in E1 gene of CHIKV. Interestingly, the CHIKV- E1 A226V mutation was absent in the studied population. It was also noticed that the peak incidence of both the infections occurs in August-September in 2015-16. Moreover, Plasmodium species, Salmonella typhi, and Rickettsial typhi infections were also observed in DENV patients. Different etiology was also detected in other undifferentiated fever patients as mixed infections (malaria, S. typhi, and R. typhi ). Hence, this investigation shows the significant reduction of DENV-CHIKV coinfection as compared with previous report, the burden of arboviruses and acute undifferentiated fever in Odisha in 2015-2016, highlighting the importance of epidemiological picture of febrile patients for appropriate patient management.

Global prevalence and distribution of coinfection of malaria, dengue and chikungunya: a systematic review

BACKGROUND

Malaria, Dengue and Chikungunya are vector borne diseases with shared endemic profiles and symptoms. Coinfections with any of these diseases could have fatal outcomes if left undiagnosed. Understanding the prevalence and distribution of coinfections is necessary to improve diagnosis and designing therapeutic interventions.

METHODS

We have carried out a systematic search of the published literature based on PRISMA guidelines to identify cases of Malaria, Dengue and Chikungunya coinfections. We systematically reviewed the literature to identify eligible studies and extracted data regarding cases of coinfection from cross sectional studies, case reports, retrospective studies, prospective observational studies and surveillance reports.

RESULTS

Care full screening resulted in 104 publications that met the eligibility criteria and reported Malaria/Dengue, Dengue/Chikungunya, Malaria/Chikungunya and Malaria/Dengue/Chikungunya coinfections. These coinfections were spread over six geographical locations and 42 different countries and are reported more frequently in the last 15 years possibly due to expanding epidemiology of Dengue and Chikungunya. Few of these reports have also analysed distinguishing features of coinfections. Malaria/Dengue coinfections were the most common coinfection followed by Dengue/Chikungunya, Malaria/Chikungunya and Malaria/Dengue/Chikungunya coinfections. P. falciparum and P. vivax were the commonest species found in cases of malaria coinfections and Dengue serotype-4 commonest serotype in cases of dengue coinfections. Most studies were reported from India. Nigeria and India were the only two countries from where all possible combinations of coinfections were reported.

CONCLUSION

We have comprehensively reviewed the literature associated with cases of coinfections of three important vector borne diseases to present a clear picture of their prevalence and distribution across the globe. The frequency of coinfections presented in the study suggests proper diagnosis, surveillance and management of cases of coinfection to avoid poor prognosis of the underlying etiology.

Mother-to-child transmission of Chikungunya virus: A systematic review and meta-analysis

BACKGROUND

Chikungunya virus (CHIKV) is an emerging arboviral infection with a global distribution and may cause fetal and neonatal infections after maternal CHIKV-infections during gestation.

METHODOLOGY

We performed a systematic review to evaluate the risk for: a) mother-to-child transmission (MTCT), b) antepartum fetal deaths (APFD), c) symptomatic neonatal disease, and d) neonatal deaths from maternal CHIKV-infections during gestation. We also recorded the neonatal clinical manifestations after such maternal infections (qualitative data synthesis). We searched PubMed (last search 3/2017) for articles, of any study design, with any of the above outcomes. We calculated the overall risk of MTCT, APFDs and risk of symptomatic neonatal disease by simple pooling. For endpoints with ≥5 events in more than one study, we also synthesized the data by random-effect-model (REM) meta-analysis.

PRINCIPAL FINDINGS

Among 563 identified articles, 13 articles from 8 cohorts were included in the quantitative data synthesis and 33 articles in the qualitative data synthesis. Most cohorts reported data only on symptomatic rather than on all neonatal infections. By extrapolation also of these data, the overall pooled-MTCT-risk across cohorts was at least 15.5% (206/1331), (12.6% by REMs). The pooled APFD-risk was 1.7% (20/1203); while the risk of CHIKV-confirmed-APFDs was 0.3% (3/1203). Overall, the pooled-risk of symptomatic neonatal disease was 15.3% (203/1331), (11.9% by REMs). The pooled risk of symptomatic disease was 50.0% (23/46) among intrapartum vs 0% (0/712) among antepartum/peripartum maternal infections. Infected newborns, from maternal infections during gestation were either asymptomatic or presented within their first week of life, but not at birth, with fever, irritability, hyperalgesia, diffuse limb edema, rashes and occasionally sepsis-like illness and meningoencephalitis. The pooled-risk of neonatal death was 0.6% (5/832) among maternal infections and 2.8% (5/182) among neonatal infections; long-term neurodevelopmental delays occurred in 50% of symptomatic neonatal infections.

CONCLUSIONS/SIGNIFICANCE

Published cohorts with data on the risk to the fetus and/or newborn from maternal CHIKV-infections during gestation were sparse compared to the number of recently reported CHIKV-infection outbreaks worldwide; however perinatal infections do occur, at high rates during intrapartum period, and can be related to neonatal death and long-term disabilities.

Serological and spatial analysis of alphavirus and flavivirus prevalence and risk factors in a rural community in western Kenya

Alphaviruses, such as chikungunya virus, and flaviviruses, such as dengue virus, are (re)-emerging arboviruses that are endemic in tropical environments. In Africa, arbovirus infections are often undiagnosed and unreported, with febrile illnesses often assumed to be malaria. This cross-sectional study aimed to characterize the seroprevalence of alphaviruses and flaviviruses among children (ages 5-14, n = 250) and adults (ages 15 ≥ 75, n = 250) in western Kenya. Risk factors for seropositivity were explored using Lasso regression. Overall, 67% of participants showed alphavirus seropositivity (CI95 63%-70%), and 1.6% of participants showed flavivirus seropositivity (CI95 0.7%-3%). Children aged 10-14 were more likely to be seropositive to an alphavirus than adults (p < 0.001), suggesting a recent transmission period. Alphavirus and flavivirus seropositivity was detected in the youngest participants (age 5-9), providing evidence of inter-epidemic transmission. Demographic variables that were significantly different amongst those with previous infection versus those without infection included age, education level, and occupation. Behavioral and environmental variables significantly different amongst those in with previous infection to those without infection included taking animals for grazing, fishing, and recent village flooding. Experience of recent fever was also found to be a significant indicator of infection (p = 0.027). These results confirm alphavirus and flavivirus exposure in western Kenya, while illustrating significantly higher alphavirus transmission compared to previous studies.