scholarly journals Chikungunya Outbreak in Kedougou, Southeastern Senegal in 2009–2010

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Abdourahmane Sow ◽  
Oumar Faye ◽  
Mawlouth Diallo ◽  
Diawo Diallo ◽  
Rubing Chen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Virus Isolation ◽  
Clinical Manifestations ◽  
Serum Samples ◽  
Chikv Infection ◽  
Sylvatic Cycle ◽  
Transmission Cycle ◽  
Significant Difference ◽  
Domestic Cycle

Abstract Background In Senegal, Chikungunya virus (CHIKV), which is an emerging mosquito-borne alphavirus, circulates in a sylvatic and urban/domestic cycle and has caused sporadic human cases and epidemics since 1960s. However, the real impact of the CHIKV sylvatic cycle in humans and mechanisms underlying its emergence still remains unknown. Methodology One thousand four hundred nine suspect cases of CHIKV infection, recruited from 5 health facilities located in Kedougou region, south-eastern Senegal, between May 2009 to March 2010, together with 866 serum samples collected from schoolchildren from 4 elementary schools in May and November 2009 from Kedougou were screened for anti-CHIKV immunoglobulin (Ig)M antibodies and, when appropriate, for viral nucleic acid by real-time polymerase chain reaction (rPCR) and virus isolation. In addition, mosquitoes collected in the same area from May 2009 to January 2010 were tested for CHIKV by rPCR and by virus isolation, and 116 monkeys sera collected from March 2010 to May 2010 were tested for anti-CHIKV IgM and neutralizing antibodies. Results The main clinical manifestations of the CHIKV suspect cases were headache, myalgia, and arthralgia. Evidence for CHIKV infection was observed in 1.4% (20 of 1409) of patients among suspect cases. No significant difference was observed among age or sex groups. In addition, 25 (2.9%) students had evidence of CHIKV infection in November 2009. Chikungunya virus was detected in 42 pools of mosquitoes, mainly from Aedes furcifer, and 83% of monkeys sampled were seropositive. Conclusions Our findings further documented that CHIKV is maintained in a sylvatic transmission cycle among monkeys and Aedes mosquitoes in Kedougou, and humans become infected by exposure to the virus in the forest.

scholarly journals Reassessing the Role of the Active TGF-β1 as a Biomarker in Systemic Sclerosis: Association of Serum Levels with Clinical Manifestations

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Andréa Tavares Dantas ◽  
Sayonara Maria Calado Gonçalves ◽  
Anderson Rodrigues de Almeida ◽  
Rafaela Silva Guimarães Gonçalves ◽  
Maria Clara Pinheiro Duarte Sampaio ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Clinical Manifestations ◽  
Serum Levels ◽  
Vascular Involvement ◽  
Digital Ulcers ◽  
Serum Samples ◽  
Peripheral Blood Mononuclear ◽  
Pbmc Culture ◽  
Significant Difference ◽  
Skin Biopsies

Objective. To determine active TGF-β1 (aTGF-β1) levels in serum, skin, and peripheral blood mononuclear cell (PBMC) culture supernatants and to understand their associations with clinical parameters in systemic sclerosis (SSc) patients.Methods. We evaluated serum samples from 56 SSc patients and 24 healthy controls (HC). In 20 SSc patients, we quantified spontaneous or anti-CD3/CD28 stimulated production of aTGF-β1 by PBMC. The aTGF-β1 levels were measured by ELISA. Skin biopsies were obtained from 13 SSc patients and six HC, and TGFB1 expression was analyzed by RT-PCR.Results. TGF-β1 serum levels were significantly higher in SSc patients than in HC (p< 0.0001). Patients with increased TGF-β1 serum levels were more likely to have diffuse subset (p= 0.02), digital ulcers (p= 0.02), lung fibrosis (p< 0.0001), positive antitopoisomerase I (p= 0.03), and higher modified Rodnan score (p= 0.046). Most of our culture supernatant samples had undetectable levels of TGF-β1. No significant difference in TGFB1 expression was observed in the SSc skin compared with HC skin.Conclusion. Raised active TGF-β1 serum levels and their association with clinical manifestations in scleroderma patients suggest that this cytokine could be a marker of fibrotic and vascular involvement in SSc.

ANTIBODY RESPONSES OF YOUNG INFANTS TO NATURALLY OCCURRING VIRAL INFECTIONS

PEDIATRICS ◽  
1966 ◽  
Vol 38 (4) ◽  
pp. 564-570
Author(s):  
Hugh L. Moffet ◽  
Henry G. Cramblett
Keyword(s):  
Neutralizing Antibodies ◽  
Virus Isolation ◽  
Viral Infections ◽  
Low Frequency ◽  
Severity Of Illness ◽  
Antibody Responses ◽  
Older Children ◽  
Young Infants ◽  
Naturally Occurring ◽  
Significant Difference

A fourfold rise in neutralizing antibodies was demonstrated for 45% of infants 1 through 6 months of age compared to 63% of older children or adults from whom an adenovirus or an enterovirus was recovered. This difference appeared to be related to severity of illness rather than to age, as there was no significant difference between young infants and older patients when only clinically severe illnesses were analyzed. The isolation of virus from more than one specimen increased the probability of a significant response in either age group. Infants with minor symptoms had a low frequency of significant fourfold antibody responses after virus isolation, but this was not significantly different from older children with minor symptoms. Failure to develop an increase in antibody titer could not be related to the presence of maternal antibodies.

Serological Responses in Patients Infected with Mayaro Virus and Evaluation of Cross-Protective Responses against Chikungunya Virus

2021 ◽  
Author(s):  
Nathen E. Bopp ◽  
Kara J. Jencks ◽  
Crystyan Siles ◽  
Carolina Guevara ◽  
Stalin Vilcarromero ◽  
...  
Keyword(s):  
Latin America ◽  
South America ◽  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Neutralization Test ◽  
Close Relative ◽  
Previous Exposure ◽  
Chikv Infection ◽  
The Caribbean ◽  
Mayaro Virus

Mayaro virus (MAYV) is an alphavirus endemic to both Latin America and the Caribbean. Recent reports have questioned the ability of MAYV and its close relative, Chikungunya virus (CHIKV), to generate cross-reactive, neutralizing antibodies to one another. Since CHIKV was introduced to South America in 2013, discerning whether individuals have cross-reactive antibodies or whether they have had exposures to both viruses previously has been difficult. Using samples obtained from people infected with MAYV prior to the introduction of CHIKV in the Americas, we performed neutralizing assays and observed no discernable neutralization of CHIKV by sera from patients previously infected with MAYV. These data suggest that a positive CHIKV neutralization test cannot be attributed to prior exposure to MAYV and that previous exposure to MAYV may not be protective against a subsequent CHIKV infection.

scholarly journals Effects of Chikungunya virus immunity on Mayaro virus disease and epidemic potential

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Emily M. Webb ◽  
Sasha R. Azar ◽  
Sherry L. Haller ◽  
Rose M. Langsjoen ◽  
Candace E. Cuthbert ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Semliki Forest Virus ◽  
Virus Disease ◽  
Cross Protection ◽  
Health Concern ◽  
Antigenic Relationship ◽  
Wild Type ◽  
Chikv Infection ◽  
Mayaro Virus

AbstractMayaro virus (MAYV) causes an acute febrile illness similar to that produced by chikungunya virus (CHIKV), an evolutionary relative in the Semliki Forest virus complex of alphaviruses. MAYV emergence is typically sporadic, but recent isolations and outbreaks indicate that the virus remains a public health concern. Given the close phylogenetic and antigenic relationship between CHIKV and MAYV, and widespread distribution of CHIKV, we hypothesized that prior CHIKV immunity may affect MAYV pathogenesis and/or influence its emergence potential. We pre-exposed immunocompetent C57BL/6 and immunocompromised A129 or IFNAR mice to wild-type CHIKV, two CHIKV vaccines, or a live-attenuated MAYV vaccine, and challenged with MAYV. We observed strong cross-protection against MAYV for mice pre-exposed to wild-type CHIKV, and moderately but significantly reduced cross-protection from CHIKV-vaccinated animals. Immunity to other alphavirus or flavivirus controls provided no protection against MAYV disease or viremia. Mechanistic studies suggested that neutralizing antibodies alone can mediate this protection, with T-cells having no significant effect on diminishing disease. Finally, human sera obtained from naturally acquired CHIKV infection cross-neutralized MAYV at high titers in vitro. Altogether, our data suggest that CHIKV infection can confer cross-protective effects against MAYV, and the resultant reduction in viremia may limit the emergence potential of MAYV.

scholarly journals Occurrence of Antibodies against SARS-CoV-2 in the Domestic Cat Population of Germany

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 772
Author(s):  
Anna Michelitsch ◽  
Donata Hoffmann ◽  
Kerstin Wernike ◽  
Martin Beer
Keyword(s):  
Neutralizing Antibodies ◽  
Large Scale ◽  
Close Contact ◽  
Companion Animals ◽  
Cross Reactivity ◽  
Human Infection ◽  
Domestic Cat ◽  
Domestic Cats ◽  
Serum Samples ◽  
Transmission Cycle

Domestic cats (Felis catus) are popular companion animals that live in close contact with their human owners. Therefore, the risk of a trans-species spreading event between domestic cats and humans is ever-present. Shortly after the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread around the world, the role of domestic cats in the transmission cycle was questioned. In the present study, the first large-scale survey of antibody occurrence in the domestic cat population in Germany was conducted, in order to assess the incidence of naturally occurring human to cat transmission of SARS-CoV-2. A total of 920 serum samples, which were collected from April to September of 2020, were screened by an indirect multispecies ELISA. Positive samples were verified using an indirect immunofluorescence test (iIFT) and additionally tested for neutralizing antibodies. Furthermore, serum samples were screened for antibodies against feline coronavirus (FCoV), in order to rule out cross-reactivity in the described test systems. Overall, 0.69% (6/920) of serum samples were found to be positive for antibodies against SARS-CoV-2 by ELISA and iIFT. Two of these reactive sera also displayed neutralizing antibodies. No cross-reactivity with FCoV-specific antibodies was observed. The finding of SARS-CoV-2 antibody-positive serum samples in the domestic cat population of Germany, during a period when the incidence of human infection in the country was still rather low, indicates that human-to-cat transmission of SARS-CoV-2 happens, but there is no indication of SARS-CoV-2 circulation in cats.

scholarly journals First Imported Case of Chikungunya Virus Infection in a Travelling Canadian Returning from the Caribbean

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Christian Therrien ◽  
Guillaume Jourdan ◽  
Kimberly Holloway ◽  
Cécile Tremblay ◽  
Michael A. Drebot
Keyword(s):  
Virus Infection ◽  
Dengue Virus ◽  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Joint Stiffness ◽  
Clinical Feature ◽  
Chikv Infection ◽  
Imported Case ◽  
The Caribbean ◽  
Hands And Feet

This is the first Canadian case of Chikungunya virus (CHIKV) infection reported in a traveller returning from the Caribbean. Following multiple mosquito bites in Martinique Island in January 2014, the patient presented with high fever, headaches, arthralgia on both hands and feet, and a rash on the trunk upon his return to Canada. Initial serological testing for dengue virus infection was negative. Support therapy with nonsteroidal anti-inflammatory drugs was administered. The symptoms gradually improved 4 weeks after onset with residual arthralgia and morning joint stiffness. This clinical feature prompted the clinician to request CHIKV virus serology which was found to be positive for the presence of IgM and neutralizing antibodies. In 2014, over four hundred confirmed CHIKV infection cases were diagnosed in Canadian travellers returning from the Caribbean and Central America. Clinical suspicion of CHIKV or dengue virus infections should be considered in febrile patients with arthralgia returning from the recently CHIKV endemic countries of the Americas.

scholarly journals Studies on the level of neutralizing antibodies produced by inactivated COVID-19 vaccines in the real world

2021 ◽  
Author(s):  
Haiying Zhang ◽  
Yuyuan Jia ◽  
Ying Ji ◽  
Xu Cong ◽  
Yan Liu ◽  
...  
Keyword(s):  
Real World ◽  
Linear Correlation ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Igg Antibodies ◽  
Serum Samples ◽  
The Real ◽  
Significant Difference ◽  
Positive Rate ◽  
High Linear Correlation

Background Although effective vaccines have been developed against COVID-19, the level of neutralizing antibodies (Nabs) induced after vaccination in the real world is still unknown. To evaluate the level and persistence of NAbs induced by two inactivated COVID-19 vaccines in China. Methods and findings Serum samples were collected from 1,335 people aged 18 and over who were vaccinated with COVID-19 inactivated vaccine in Peking University People's Hospital from January 19 to June 23, 2021, for detection of COVID-19 antibodies. The WHO standard of SARS-CoV-2 NAbs was detected. The coefficients of variation between the detection results and the true values of the NAbs detected by the WHO standard were all lower than the WHO international standard 3% after the dilution of the original and the dilution of the theoretical concentrations of 500 IU/mL, 250 IU/mL, 125 IU/mL, 72.5 IU/mL, 36.25 IU/mL and 18.125 IU/mL. On day 11-70, the positive rate of NAbs against COVID-19 was 82% to 100%; From day 71 to 332, the positive rate of NAbs decreased to 27%. The level of NAbs was significantly higher at 3-8 Weeks than at 0-3 Weeks. There was a high linear correlation between NAbs and IgG antibodies in 1335 vaccinated patients. NAbs levels were decreased in 31 of 38 people (81.6%) at two time points after the second dose of vaccine. There was no significant difference in age between the group with increased and decreased neutralizing antibody levels (x2 =-0.034, P>0.05). The positive rate of NAbs in the two-dose vaccine group (77.3%) was significantly higher than that in the one-dose group (18.1%), with statistical difference (x2=312.590, P<0.001). A total of 206 people who were 11-70 days after receiving the second dose were tested and divided into three groups: 18-40 years old, 41-60 years old and >60 years old. The positive rates of NAbs in three groups (18-40 years old, 41-60 years old and >60 years old) were 95.14%, 78.43% and 81.8%, respectively. The positive rate of NAbs was significantly higher in 18-40 years old than in 41-60 years old (x2=12.547, P <0.01). The titer of NAbs in 18-40 years old group was significantly higher than that in 41-60 years old group (t=-0.222, P <0.01). The positive rate of NAbs in male group (89.32%) was lower than in female (91.26%), but there was no significant difference (x2=0.222, P >0.05). Conclusions The positive rate of NAbs was the highest from 10 to 70 days after the second dose of vaccine, and the positive rate gradually decreased as time went by. There was a high linear correlation between COVID-19 NAbs and IgM/IgG antibodies in vaccinators, suggesting that in cases where NAbs cannot be detected, IgM/IgG antibodies can be detected instead. The level of NAbs produced after vaccination was affected by age, but not by gender. The highest levels of NAbs were produced between shots 21 to 56 days apart, suggesting that 21 to 56 days between shots is suitable for vaccination.

scholarly journals Serological Evidence for the Circulation of Ebolaviruses in Pigs From Sierra Leone

2018 ◽  
Vol 218 (suppl_5) ◽  
pp. S305-S311 ◽  
Author(s):  
Kerstin Fischer ◽  
Juliet Jabaty ◽  
Roland Suluku ◽  
Thomas Strecker ◽  
Allison Groseth ◽  
...  
Keyword(s):  
Sierra Leone ◽  
Neutralizing Antibodies ◽  
Ebola Virus ◽  
The Philippines ◽  
Serum Samples ◽  
Susceptible Host ◽  
Transmission Cycle ◽  
Porcine Serum ◽  
Three Samples ◽  
Ebov Infection

Abstract Many human ebolavirus outbreaks have been linked to contact with wildlife including nonhuman primates and bats, which are assumed to serve as host species. However, it is largely unknown to what extent other animal species, particularly livestock, are involved in the transmission cycle or act as additional hosts for filoviruses. Pigs were identified as a susceptible host for Reston virus with subsequent transmission to humans reported in the Philippines. To date, there is no evidence of natural Ebola virus (EBOV) infection in pigs, although pigs were shown to be susceptible to EBOV infection under experimental settings. To investigate the potential role of pigs in the ecology of EBOV, we analyzed 400 porcine serum samples from Sierra Leone for the presence of ebolavirus-specific antibodies. Three samples reacted with ebolavirus nucleoproteins but had no neutralizing antibodies. Our results (1) suggest the circulation of ebolaviruses in swine in Sierra Leone that are antigenically related but not identical to EBOV and (2) could represent undiscovered ebolaviruses with unknown pathogenic and/or zoonotic potential.

scholarly journals Treatment of Chikungunya Virus (CHIKV) Using Targeted Immunotherapy

2021 ◽  
Author(s):  
Fleury Augustin Nsole Biteghe ◽  
Chalomie Nyangone Ekome Toung ◽  
Jean De La Croix Ndong ◽  
Neelakshi Mungra ◽  
Tahir B. Dar ◽  
...  
Keyword(s):  
Animal Studies ◽  
Chikungunya Virus ◽  
Clinical Manifestations ◽  
Chikv Infection ◽  
Prophylactic Efficacy ◽  
Multiple Factors ◽  
Therapeutic Benefits ◽  
Infection Dynamics ◽  
Human And Mouse ◽  
Targeted Immunotherapy

Chikungunya virus (CHIKV) is the most common mosquito-borne Alphavirus infecting humans worldwide. Up to date, there are no antiviral treatments or vaccines approved to treat or prevent CHIKV for which treatments remain symptomatic based on clinical manifestations. Hence, designing effective therapies to either prevent or treat CHIKV infection is of paramount importance. Interestingly, monoclonal antibodies (mAbs) are known to be significantly important in mediating protective immunity in CHIV infection. During the last decades, numerous animal studies have reported the protective and prophylactic efficacy of human and mouse anti-CHIKV mAbs isolated from convalescent patients. However, the therapeutic benefits of these anti-CHIKV mAbs can be limited by multiple factors. Thus, it becomes pertinent to better understand the CHIKV infection dynamics, mitigate the undesired mAbs-associated effects and improve therapies. In this review, we critically discuss CHIKV antiviral infectious mechanisms and address how the improved understanding of the latter may pave the way to better targeted immunotherapies.

scholarly journals Evidence of Chikungunya virus seroprevalence in Myanmar among dengue-suspected patients and healthy volunteers in 2013, 2015, and 2018

2021 ◽  
Vol 15 (12) ◽  
pp. e0009961
Author(s):  
Elizabeth Ajema Chebichi Luvai ◽  
Aung Kyaw Kyaw ◽  
Nundu Sabiti Sabin ◽  
Fuxun Yu ◽  
Saw Wut Hmone ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Clinical Symptoms ◽  
Febrile Illness ◽  
Neutralization Assay ◽  
Confirmatory Test ◽  
Serum Samples ◽  
Igm Elisa ◽  
Focus Reduction

Introduction Chikungunya virus (CHIKV) is a mosquito-borne virus known to cause acute febrile illness associated with debilitating polyarthritis. In 2019, several institutions in Myanmar reported a CHIKV outbreak. There are no official reports of CHIKV cases between 2011 and 2018. Therefore, this study sought to determine the seroprevalence of CHIKV infection before the 2019 outbreak. Methods A total of 1,544 serum samples were collected from healthy volunteers and patients with febrile illnesses in Yangon, Mandalay, and the Myeik district in 2013, 2015, and 2018. Participants ranged from one month to 65 years of age. Antibody screening was performed with in-house anti-CHIKV IgG and IgM ELISA. A neutralization assay was used as a confirmatory test. Results The seroprevalence of anti-CHIKV IgM and anti-CHIKV IgG was 8.9% and 28.6%, respectively, with an overall seropositivity rate of 34.5%. A focus reduction neutralization assay confirmed 32.5% seroprevalence of CHIKV in the study population. Age, health status, and region were significantly associated with neutralizing antibodies (NAbs) and CHIKV seropositivity (p < 0.05), while gender was not (p = 0.9). Seroprevalence in 2013, 2015, and 2018 was 32.1%, 28.8%, and 37.3%, respectively. Of the clinical symptoms observed in participants with fevers, arthralgia was mainly noted in CHIKV-seropositive patients. Conclusion The findings in this study reveal the circulation of CHIKV in Myanmar’s Mandalay, Yangon, and Myeik regions before the 2019 CHIKV outbreak. As no treatment or vaccine for CHIKV exists, the virus must be monitored through systematic surveillance in Myanmar.

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