Seroprevalence of dengue, Zika, chikungunya and Ross River viruses across the Solomon Islands.

Across the Pacific, and including in the Solomon Islands, outbreaks of arboviruses such as dengue, chikungunya, and Zika are increasing in frequency, scale and impact. Outbreaks of mosquito-borne disease have the potential to overwhelm the health systems of small island nations. This study mapped the seroprevalence of dengue, Zika, chikungunya and Ross River viruses in 5 study sites in the Solomon Islands. Serum samples from 1,021 participants were analysed by ELISA. Overall, 56% of participants were flavivirus-seropositive for dengue (28%), Zika (1%) or both flaviviruses (27%); and 53% of participants were alphavirus-seropositive for chikungunya (3%), Ross River virus (31%) or both alphaviruses (18%). Seroprevalence for both flaviviruses and alphaviruses varied by village and age of the participant. The most prevalent arboviruses in the Solomon Islands were dengue and Ross River virus. The high seroprevalence of dengue suggests that herd immunity may be a driver of dengue outbreak dynamics in the Solomon Islands. Despite being undetected prior to this survey, serology results suggest that Ross River virus transmission is endemic. There is a real need to increase the diagnostic capacities for each of the arboviruses to support effective case management and to provide timely information to inform vector control efforts and other outbreak mitigation interventions.

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.

Acute-Phase Levels of CXCL8 as Risk Factor for Chronic Arthralgia Following Chikungunya Virus Infection.

The immunopathogenesis of chikungunya virus (CHIKV) infection and the role of acute-phase immune response on joint pain persistence is not fully understood. We investigated the profile of serum chemokine and cytokine in CHIKV-infected patients with acute disease, compared the levels of these biomarkers to those of patients with other acute febrile diseases (OAFD) and healthy controls (HC), and evaluated their role as predictors of chronic arthralgia development. Chemokines and cytokines were measured by flow Cytometric Bead Array. Patients with CHIKV infection were further categorized according to duration of arthralgia (≤ 3 months vs >3 months), presence of anti-CHIKV IgM at acute-phase sample, and number of days of symptoms at sample collection (1 vs 2-3 vs ≥4). Patients with acute CHIKV infection had significantly higher levels of CXCL8, CCL2, CXCL9, CCL5, CXCL10, IL-1ß, IL-6, IL-12, and IL-10 as compared to HC. CCL2, CCL5, and CXCL10 levels were also significantly higher in patients with CHIKV infection compared to patients with OAFD. Patients whose arthralgia lasted > 3 months had increased CXCL8 levels compared to patients whose arthralgia did not (p<0.05). Multivariable analyses further indicated that high levels of CXCL8 and female sex were associated with arthralgia lasting >3 months. Patients with chikungunya and OAFD had similar cytokine kinetics for IL-1ß, IL-12, TNF, IFN-γ, IL-2, and IL-4, although the levels were lower for CHIKV patients. This study suggests that chemokines may have an important role in the immunopathogenesis of chronic chikungunya-related arthralgia.

Development of Nucleic Acid Lateral Flow Immunoassay for Rapid and Accurate Detection of Chikungunya Virus in Indonesia.

Chikungunya fever is an arboviral disease caused by the Chikungunya virus (CHIKV). The disease has similar clinical manifestations with other acute febrile illnesses which complicates differential diagnosis in low-resource settings. We aimed to develop a rapid test for CHIKV detection based on the nucleic acid lateral flow immunoassay technology. The system consists of a primer set that recognizes the E1 region of the CHIKV genome and test strips in an enclosed cassette which are used to detect amplicons labeled with FITC/biotin. Amplification of the viral genome was done using open-source PCR, a low-cost open-source thermal cycler. Assay performance was evaluated using a panel of RNA isolated from patients' blood with confirmed CHIKV (n = 8) and dengue virus (n = 20) infection. The open-source PCR-NALFIA platform had a limit of detection of 10 RNA copies/ml. The assay had a sensitivity and specificity of 100% (95% CI: 67.56% - 100%) and 100% (95% CI: 83.89% - 100%), respectively, compared to reference standards of any positive virus culture on C6/36 cell lines and/or qRT-PCR. Further evaluation of its performance using a larger sample size may provide important data to extend its usefulness, especially its utilization in the peripheral healthcare facilities with scarce resources and outbreak situations.

Chikungunya in Guerrero, Mexico, 2019 and Evidence of Gross Underreporting in the Region.

The local public health authorities reported nine cases of chikungunya in Mexico in 2019, none of which occurred in Guerrero, a coastal state in the southwest. To test the hypothesis that chikungunya is grossly underreported in Mexico, acute sera were collected from 639 febrile patients from low-income households in Guerrero in 2019 and serologically assayed for chikungunya virus (CHIKV). Analysis of the sera by plaque reduction neutralization test revealed that 181 (28.3%) patients were seropositive for CHIKV. To identify patients with acute CHIKV infections, a subset of serum samples were tested for CHIKV-specific IgM by ELISA. Serum samples from 21 of 189 (11.1%) patients were positive. These patients met the chikungunya case definition established by the WHO. In conclusion, we provide evidence that CHIKV remains an important public health problem in Mexico and that the true number of cases is severely underestimated.

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.

Seroprevalence of Yellow fever, Chikungunya, and Zika virus at a community level in the Gambella Region, South West Ethiopia.

Yellow fever (YF), Chikungunya (CHIK), and Zika(ZIK) are among re-emerging arboviral diseases of major public health concern. Despite the proximity of the Gambella Region to South Sudan where arboviral cases have been recorded repeatedly the current epidemiological situation is unclear in this part of southwest Ethiopia. Therefore, we conducted a community-based seroprevalence survey of YF virus (YFV), CHIK virus (CHIKV), and ZIK virus (ZIKV) infections in two selected districts. A cross-sectional study was conducted in two locations of the Gambella region (Lare and Itang) to investigate the seroprevalence of these viruses' infections. Blood samples were collected from the study participants and screened for IgG antibodies specific to YFV and CHIKV infections using enzyme-linked immunosorbent assays (ELISA). For the detection of ZIKV specific IgG antibodies, Blockade-of-binding ELISA was used. Data were analyzed using the STATA version 13.1 Softwares. A total of 150 individuals (96 males and 54 females, age ranging from 18 to 65 years, mean age ± SD = 35.92 ± 10.99) participated and provided blood samples. Among the 150 samples 135, 90, and 150 were screened for YFV, CHIKV, and ZIKV, respectively. Hence, 2.9% (95% CI: 1.1-7.7%), 15.6% (95% CI: 9.3-24.8%), and 27.3% (95% CI: 20.7-35.3%) of samples tested positive for IgG antibodies to YFV, CHIKV, and ZIKV infections, respectively. Among the individual seropositive for ZIKV, YFV and CHIKV, only six, one and three had a history of residence outside the Gambella region respectively. Agro-pastoral occupation was significantly associated with a higher prevalence of IgG against CHIKV (AOR = 14.17; 95%CI: 2.30, 87.30) and residency in the Lare district (AOR = 11; 95%CI: 3.31, 39.81) was found to be significantly associated with a higher prevalence of IgG against ZIKV. Our findings revealed the occurrence of YFV, CHIKV and ZIKV infections in the study locations.

Anti-chikungunya virus seroprevalence in Indigenous groups in the São Francisco Valley, Brazil.

BACKGROUND: Chikungunya fever (CHIKF) is a serious public health problem with a high rate of infection and chronic disabling manifestations that has affected more than 2 million people worldwide since 2005. In spite of this, epidemiological data on vulnerable groups such as Indigenous people are scarce, making it difficult to implement public policies in order to prevent this disease and assist these populations. OBJECTIVE: To describe the serological and epidemiological profile of chikungunya virus (CHIKV) in two Indigenous populations in Northeast Brazil, as well as in an urbanized control community, and to explore associations between CHIKV and anthropometric variables in these populations. METHODOLOGY/PRINCIPAL FINDINGS: This is a cross-sectional ancillary study of the Project of Atherosclerosis among Indigenous Populations (PAI) that included people 30 to 70 years old, recruited from two Indigenous tribes (the less urbanized Fulni-ô and the more urbanized Truká people) and an urbanized non-Indigenous control group from the same area. Subjects underwent clinical evaluation and were tested for anti-CHIKV IgG by enzyme-linked immunosorbent assay. Serological profile was described according to ethnicity, sex, and age. The study population included 433 individuals distributed as follows: 109 (25·2%) Truká, 272 (62·8%) Fulni-ô, and 52 (12%) from the non-Indigenous urbanized control group. Overall prevalence of CHIKV IgG in the study sample was 49.9% (216; 95% CI: 45·1-54·7). When the sample was stratified, positive CHIKV IgG was distributed as follows: no individuals in the Truká group, 78·3% (213/272; 95% CI: 72·9-83·1) in the Fulni-ô group, and 5.8% (3/52; 95% CI: 1.21-16) in the control group. CONCLUSIONS/SIGNIFICANCE: Positive tests for CHIKV showed a very high prevalence in a traditional Indigenous population, in contrast to the absence of anti-CHIKV serology in the Truká people, who are more urbanized with respect to physical landscape, socio-cultural, and historical aspects, as well as a low prevalence in the non-Indigenous control group, although all groups are located in the same area.

Large-scale outbreak of Chikungunya virus infection in Thailand, 2018-2019.

Between 2018 and 2019, the incidence of chikungunya was approximately 15,000 cases across 60 provinces in Thailand. Here, the clinical presentations in chikungunya, emergent pattern, and genomic diversity of the chikungunya virus (CHIKV) causing this massive outbreak were demonstrated. A total of 1,806 sera samples from suspected cases of chikungunya were collected from 13 provinces in Thailand, and samples were tested for the presence of CHIKV RNA, IgG, and IgM using real-time PCR, enzyme-linked immunoassay (ELISA), commercial immunoassay (rapid test). The phylogenetic tree of CHIKV whole-genome and CHIKV E1 were constructed using the maximum-likelihood method. CHIKV infection was confirmed in 547 (42.2%) male and 748 (57.8%) female patients by positive real-time PCR results and/or CHIKV IgM antibody titers. Unsurprisingly, CHIKV RNA was detected in >80% of confirmed cases between 1 and 5 days after symptom onset, whereas anti-CHIKV IgM was detectable in >90% of cases after day 6. Older age was clearly one of the risk factors for the development of arthralgia in infected patients. Although phylogenetic analysis revealed that the present CHIKV Thailand strain of 2018-2020 belongs to the East, Central, and Southern African (ECSA) genotype similar to the CHIKV strains that caused outbreaks during 2008-2009 and 2013, all present CHIKV Thailand strains were clustered within the recent CHIKV strain that caused an outbreak in South Asia. Interestingly, all present CHIKV Thailand strains possess two mutations, E1-K211E, and E2-V264A, in the background of E1-226A. These mutations are reported to be associated with virus-adapted Aedes aegypti. Taken together, it was likely that the present CHIKV outbreak in Thailand occurred as a result of the importation of the CHIKV strain from South Asia. Understanding with viral genetic diversity is essential for epidemiological study and may contribute to better disease management and preventive measures.

Biomarkers of severity and chronification in chikungunya fever: a systematic review and meta-analysis.

Currently, there are no biomarkers for Chikungunya fever (CHIK) in clinical practice that can accurately predict the severity or chronification of the disease. The aim of this study is to evaluate the existing literature on biomarkers related to the severity and chronification of CHIK. In this sense, a systematic review was conducted based on the PRISMA Statement guideline. Articles that described the association of biomarkers with the evolution of the disease (severity or chronification), published until August 20th 2019 were considered eligible. The search was carried out in the PubMed, Scopus, Virtual Health Library (VHL) and Science Direct databases. After searching the databases, 17 articles were added to the review, and after analyzing the articles, several biomarkers were associated with severity, such as increased levels of IL-6, IP-10, IL-1b, MIG, MCP-1, and reduced levels of RANTES and IL-8 or chronification, such as increased levels of IL-6, TNF-α, MCP-1, IL-12, INF-α, IL-13, INF-γ, GM-CSF, CRP, IL-1a, IL-15, Factor VII, IP-10, IL-10, IL-4, IL-1RA, IL-8, MIP-1α, MIP-1ß, ferritin, MIG, ESR, NO, malondialdehyde, and reduced levels of RANTES, ferritin, eotaxin, HGF, IL-27, IL-17A, IL-29, TGF-ß, IL-10, and thiols. IL-6, CRP and TNF-α were included in the meta-analysis to assess the relationship with chronification, although they did not reach statistical significance. It was concluded that several biomarkers showed a relationship with severity and chronification of CHIK; the search for these biomarkers can reveal prognostic factors and important therapeutic targets for the treatment of the disease.

Age-Dependent Evaluation of Immunoglobulin G Response after Chikungunya Virus Infection.

Current chikungunya antibody prevalence and titers are likely to differ based on the exposure rates before the 2006 reemergence in India. For vaccine usage, such data are of immense importance. This study addresses age-stratified IgG titers and its subtypes in Pune, India, endemic for the disease. 170 age-stratified serum pools from 791 individuals with prior chikungunya exposure, and 15 samples from acute disease phase were analyzed. An indirect ELISA based on inactivated chikungunya virus was used to determine anti-CHIKV-IgG and its subtypes. Neutralizing antibody titers (plaque reduction neutralization test [PRNT]) were compared with binding antibody titers (ELISA). Anti-CHIKV-IgG titers along with IgG1 and IgG4 increased till the age-group of until 11-15 years and remained comparable thereafter till > 65 years. IgG1 was the predominant IgG subtype detected in all the pools, whereas IgG4 was present in 151/170 pools. Strong positive correlation of IgG1 was obtained with CHIKV-PRNT50 titers. None of the sample had anti-CHIKV-IgG2, whereas five pools had IgG3 antibody. In the acute-phase serum sample, IgG1 was present in all the samples, whereas IgG4 was present in 8/15 samples. IgG4 was predominant in four samples. During acute phase and at different times postinfection, IgG1 circulated in high titers followed by IgG4. Higher antibody titers in adults reflect reexposures. The data will prove useful in assessing immune response to CHIKV vaccine in relation to IgG subtype.

Evidence of chikungunya virus infection among febrile patients in northwest Ethiopia.

BACKGROUND: Chikungunya virus (CHIKV) infection has similar clinical presentations to malaria. Hence, febrile illnesses are often misdiagnosed as malaria. Therefore, this study aimed to generate baseline data on CHIKV infection in northwest Ethiopia where malaria is endemic. METHODS: A hospital-based cross-sectional study was conducted among febrile patients presenting at the Metema and Humera Kahsay Abera hospitals from March 2016 to May 2017. Data on socio-demographic, clinical presentations, and possible risk factors were collected using a structured questionnaire. Serum samples were screened for immunoglobulin-M (IgM) and IgG antibodies to CHIKV infections using enzyme-linked immunosorbent assay. Logistic regression analysis was used to determine the strength of association. RESULTS: Of 586 samples screened, the overall seroprevalence of CHIKV infection was 23%. Of the total study participants, 22.5% had CHIKV-specific IgM, indicating recent CHIKV infection. During monsoon and post-monsoon periods, increased prevalence of anti-CHIKV IgM seropositivity was found. The most common clinical presentation observed was fever, followed by headache and joint pain. Men had twice the likelihood of CHIKV infection. The presence of stagnant water near the residence almost doubled the risk for CHIKV infection. CONCLUSIONS: Most of the study participants had recent infection with CHIKV, suggesting the need to design disease prevention and intervention strategies.

A Novel Multiplex RT-PCR Assay for Simultaneous Detection of Dengue and Chikungunya Viruses.

The goal of the study was to develop a specific, sensitive, and cost-effective molecular RT-PCR diagnostic assay for the rapid and simultaneous detection of the serotypes of dengue virus (DENV) and Chikungunya virus (CHIKV) from sera of suspected febrile patients. A single-tube, single-step multiplex RT-PCR (mRT-PCR) assay was designed for the detection of viral genomes from clinical and field samples. Specificity and sensitivity of the mRT-PCR assay were evaluated against six different combinations using two reverse transcriptases (AMV-RT and RT-Ace) and three DNA polymerases (LA-Taq, rTaq, and Tth). Among the six combinations, the AMV-RT and LA-Taq combination was more specific and sensitive than other enzyme combinations for detecting viral genomes of DENV-1, DENV-2, DENV-3, and DENV-4 (p < 0.01), and for detecting viral genomes of CHIKV (p < 0.05). The detection limits of the mRT-PCR were 10 focus forming units (FFU) for CHIKV and 1 FFU, 20 FFU, 0.1 FFU, and 10 FFU for DENV-1, DENV-2, DENV-3, and DENV-4, respectively. The primers used for the mRT-PCR did not show any cross-reactivity among the serotypes of DENV or CHIKV. Specificity and sensitivity of the newly developed mRT-PCR were validated using serum samples collected from febrile patients during dengue outbreaks in Bangladesh. The sensitivity for serotype detection of DENV and CHIKV was superior to the virus isolation method and the antigen detection method using the Dengue NS1-Ag assay. This novel mRT-PCR method can be used for molecular epidemiological surveillance of DENV and CHIKV in epidemic and endemic countries.

Neurological disease in adults with Zika and chikungunya virus infection in Northeast Brazil: a prospective observational study.

BACKGROUND: Since 2015, the arthropod-borne viruses (arboviruses) Zika and chikungunya have spread across the Americas causing outbreaks, accompanied by increases in immune-mediated and infectious neurological disease. The spectrum of neurological manifestations linked to these viruses, and the importance of dual infection, are not known fully. We aimed to investigate whether neurological presentations differed according to the infecting arbovirus, and whether patients with dual infection had a different disease spectrum or severity. METHODS: We report a prospective observational study done during epidemics of Zika and chikungunya viruses in Recife, Pernambuco, a dengue-endemic area of Brazil. We recruited adults aged 18 years or older referred to Hospital da Restauração, a secondary-level and tertiary-level hospital, with suspected acute neurological disease and a history of suspected arboviral infection. We looked for evidence of Zika, chikungunya, or dengue infection by viral RNA or specific IgM antibodies in serum or CSF. We grouped patients according to their arbovirus laboratory diagnosis and then compared demographic and clinical characteristics. FINDINGS: Between Dec 4, 2014, and Dec 4, 2016, 1410 patients were admitted to the hospital neurology service; 201 (14%) had symptoms consistent with arbovirus infection and sufficient samples for diagnostic testing and were included in the study. The median age was 48 years (IQR 34-60), and 106 (53%) were women. 148 (74%) of 201 patients had laboratory evidence of arboviral infection. 98 (49%) of them had a single viral infection (41 [20%] had Zika, 55 [27%] had chikungunya, and two [1%] had dengue infection), whereas 50 (25%) had evidence of dual infection, mostly with Zika and chikungunya viruses (46 [23%] patients). Patients positive for arbovirus infection presented with a broad range of CNS and peripheral nervous system (PNS) disease. Chikungunya infection was more often associated with CNS disease (26 [47%] of 55 patients with chikungunya infection vs six [15%] of 41 with Zika infection; p=0·0008), especially myelitis (12 [22%] patients). Zika infection was more often associated with PNS disease (26 [63%] of 41 patients with Zika infection vs nine [16%] of 55 with chikungunya infection; p≤0·0001), particularly Guillain-Barré syndrome (25 [61%] patients). Patients with Guillain-Barré syndrome who had Zika and chikungunya dual infection had more aggressive disease, requiring intensive care support and longer hospital stays, than those with mono-infection (median 24 days [IQR 20-30] vs 17 days [10-20]; p=0·0028). Eight (17%) of 46 patients with Zika and chikungunya dual infection had a stroke or transient ischaemic attack, compared with five (6%) of 96 patients with Zika or chikungunya mono-infection (p=0·047). INTERPRETATION: There is a wide and overlapping spectrum of neurological manifestations caused by Zika or chikungunya mono-infection and by dual infections. The possible increased risk of acute cerebrovascular disease in patients with dual infection merits further investigation. FUNDING: Fundação do Amparo a Ciência e Tecnologia de Pernambuco (FACEPE), EU's Horizon 2020 research and innovation programme, National Institute for Health Research. TRANSLATIONS: For the Portuguese and Spanish translations of the abstract see Supplementary Materials section.

Community-based sero-prevalence of chikungunya and yellow fever in the South Omo Valley of Southern Ethiopia.

BACKGROUND: Chikungunya (CHIK) and yellow fever (YF) are becoming major public health threats in East African countries including Ethiopia. In Ethiopia, there is no reliable information about the epidemiology of CHIK. This study aimed to assess a community-based sero-prevalence of CHIK and YF in the South Omo Valley, an endemic area for YF. METHODS: Between February and June 2018, blood samples were collected from study participants and screened for IgG antibody against CHIK virus (CHIKV) and YF virus (YFV) infections using ELISA. Data were computerized using Epi Data Software v.3.1 and analyzed using SPSS. RESULTS: A total of 360 participants (51.7% males, age range from 6 to 80, mean age ± SD = 31.95 ± 14.05 years) participated in this study. The overall sero-prevalence of IgG antibody was 43.6% (157/360) against CHIKV, while it was 49.5% (155/313) against YFV. Out of 155 samples which were positive for IgG antibody to YFV, 93 (60.0%) were positive for IgG antibody to CHIKV. Out of 158 samples which were negative for IgG antibody to YFV, 64(40.5%) were positive for IgG antibody to CHIKV. There was a significant positive correlation between IgG antibodies to CHIKV and YFV (sr = 0.82; P<0.01). Residency in the Debub Ari district (AOR = 8.47; 95% CI: 1.50, 47.74) and travel history to sylvatic areas (AOR = 2.21; 95% CI: 1.02, 4.81) were significantly and positively associated with high sero-prevalence of IgG antibody to CHIKV and YFV, respectively. CONCLUSION: High sero-prevalence of IgG antibody to CHIKV shows the circulation of the virus in the present study area. A low sero-prevalence of IgG antibody to YFV in YF vaccine received individuals is highly concerning from a public health point of view as waning of immune response to YFV infection could result in a periodic outbreaks of YF in endemic areas.Nevertheless, the present study has not investigated for possible cross-reactivity of antibody to CHIKV with other alphaviruses like O'nyong-nyong virus and antibody to YFV with other flaviviruses like Dengue fever virus and this warrants further studies in the present study area.

Development of magnetic bead based sample extraction coupled polymerase spiral reaction for rapid on-site detection of Chikungunya virus.

The molecular detection system has evolved over last two decades and is rapidly replacing the conventional confirmatory techniques in diagnostic virology. However the major limitation in implementation of available molecular detection assays is the non availability of field deployable nucleic acid isolation platform coupled with gene amplification technique. The rapid and early molecular detection is crucial for employing effective measure against many viral infections. The re-emergence of chikungunya virus (CHIKV) has led to epidemics since 2004 in several parts of the world including India. The main association of CHIKV with severe arthritis and long-lasting arthralgia and closely mimics symptoms of Dengue and Zika virus infection requiring laboratory confirmation. In this study, a simple magnetic bead based ribonucleic acid extraction method was optimized, which was coupled with isothermal polymerase spiral reaction (PSR) technique for early and rapid detection. Subsequently, the polymerase spiral reaction reagents were converted to dry down format that led to a rapid user friendly field compatible sample processing to answer method for rapid and onsite detection of Chikungunya virus. Both the methods were evaluated with a panel of clinical samples. The sensitivity of the assays were compared with available commercial viral RNA extraction platform and qRT-PCR. The in-house nucleic acid extraction system based on magnetic bead followed by dry down RT-Polymerase Spiral Reaction assay was found to be highly sensitive with 10 copies of RNA as limit of detection in CHIKV clinical specimens. With respect to other closely related viruses no cross reactivity was observed. This novel methodology has the potential to revolutionize the diagnosis of infectious agents in resource limited settings around the world.

Serological evidence of exposure to Rift Valley, Dengue and Chikungunya Viruses among agropastoral communities in Manyara and Morogoro regions in Tanzania: A community survey.

Tanzania has recently experienced outbreaks of dengue in two coastal regions of Dar es Salaam and Tanga. Chikungunya and Rift Valley Fever outbreaks have also been recorded in the past decade. Little is known on the burden of the arboviral disease causing viruses (Dengue, Rift Valley and Chikungunya) endemically in the inter-epidemic periods. We aimed at determining the prevalence of the dengue, rift valley and chikungunya among humans in two geo ecologically distinct sites. The community-based cross-sectional study was conducted in Magugu in Manyara region and Wami-Dakawa in Morogoro region in Tanzania. Venous blood was collected from participants of all age groups, serum prepared from samples and subjected to ELISA tests for RVFV IgG/IgM, DENV IgG/IgM, and CHIKV IgM/IgG. Samples that were positive for IgM ELISA tests were subjected to a quantitative RT PCR for each virus. A structured questionnaire was used to collect socio-demographic information. Data analysis was performed by using SPSSv22. A total of 191 individuals from both sites participated in the study. Only one individual was CHIKV seropositive in Magugu, but none was seropositive or positive for either RVFV or DENV. Of the 122 individuals from Wami-Dakawa site, 16.39% (n = 20) had recent exposure to RVFV while 9.83% (n = 12) were seropositive for CHIKV. All samples were negative by RVFV and CHIKV qPCR. Neither infection nor exposure to DENV was observed in participants from both sites. Being more than 5 in a household, having no formal education and having recently travelled to an urban area were risk factors associated with RVFV and CHIKV seropositivity. We report a considerable exposure to RVFV and CHIKV among Wami-Dakawa residents during the dry season and an absence of exposure of the viruses among humans in Magugu site. In both sites, neither DENV exposure nor infection was detected.

[Hemicerebellitis due to chikungunya associated with refractory status epilepticus in the paediatric age]. / Hemicerebelitis por chikungunya asociado a estado epiléptico refractario en edad pediátrica.

TITLE: Hemicerebelitis por chikungunya asociado a estado epiléptico refractario en edad pediátrica.

Increased serum levels of galectin-9 in patients with chikungunya fever.

Chikungunya fever (CHIKF) is an arboviral disease that has caused an epidemic burst of chronic inflammatory joint disease in Latin America in the last few years. Efforts are being spent in understanding the mechanisms by which it may cause such articular damage and in determining possible biomarkers of the disease. Galectins (GAL) are a family of animal lectins with an affinity for beta-galactosides. They have multiple functions including working as receptors in innate immunity and as a control for inflammatory responses in both innate and adaptive immunity. They regulate functions of immune cells, such as lymphocytes and macrophages, which have a main role in the chikungunya inflammatory process. Galectins are also involved in chronification of viral diseases, participate in the immunopathogenesis of chronic joint diseases such as rheumatoid arthritis, and have a role in inflammation in other arboviral diseases, such as dengue. Thus, we intended to determine the serum levels of galectin-1, -3, -4, -7, and -9 in patients with subacute and chronic articular manifestations of CHIKF and to evaluate their associations with clinical manifestations. We evaluated 44 patients with clinical manifestations of CHIKF and serological confirmation with IgM and/or IgG chikungunya virus (CHIKV) antibodies. Forty-nine age- and gender-matched healthy individuals served as controls. Anti-CHIKV IgM and IgG antibodies and galectins serum levels were measured by ELISA. We found higher levels of GAL-9 (patients median 2192 [1500-2631] pg/mL, controls median 46.88 [46.88-46.88] pg/mL, p < 0.0001) and lower levels of GAL-3 (patients median 235.5 [175.5-351.8] pg/mL, controls median 2236.0 [1256.0-2236.0] pg/mL, p < 0.0001) in patients than in controls. There was no statistical difference in levels of GAL-1, -4 and -7 between patients and control groups. There was no difference in GAL-9 serum levels between patients with subacute or chronic symptoms (median 2148 [1500-2722] pg/mL x 2212 [1844-2500] pg/mL, p = 0.3626). A significant association of GAL-9 with joint stiffness, both in its duration and intensity, was found. These results may reflect the participation of GAL-9 in the immunopathogenesis of the inflammatory process in chikungunya fever, as morning stiffness may reflect the systemic inflammatory process.