Virus IgG Research Articles

P-2351. Assumptions and Realities: Unraveling Varicella Zoster Virus Immunity in Unvaccinated Populations

Abstract Background In countries without universal vaccination for chickenpox in childhood, a very high seroprevalence for varicella zoster virus (VZV) IgG in adults is often assumed. Consequently, some suggest vaccinating at-risk adults against herpes zoster, even if they lack a documented history of chickenpox, under the assumption of immunity. However, this presumption may not accurately reflect today's epidemiological landscape. Neglecting the risk of primary infection post-childhood could lead to severe outcomes in vulnerable adults, pregnant patients, and increase the likelihood of exposure for caregivers, potentially resulting in secondary transmission. Graphic 1. Sample distribution by gender and age group. Methods A retrospective study was conducted on VZV serology among individuals aged 11 and above, from February 2014 to March 2024, who were unvaccinated and lacked known chickenpox history, within a Portuguese hospital. Graphic 2. Varicella Zoster Virus IgG seroprevalence by gender and age group. Results Analysis of 613 patients (68% women, median age 39 years), all with high VZV infection risk due to comorbidities or immunosuppression, revealed an 83.6% VZV IgG positivity rate, increasing with age. Among working age individuals aged 21-60,12% were seronegative for VZV and 19.2% of women of childbearing age 16-40 showed no immunity. Conclusion Although common, the presence of antibodies against VZV is not universal after childhood in unvaccinated populations. Vaccination for herpes zoster is not indicated for the prevention of primary infection, so assuming immunity may fail to prevent it in a population at risk. Prevention of chickenpox relies on specific vaccination, or the use of immunoglobulin when the former is contraindicated, which implies recognition of this susceptibility. Serology remains a useful tool, especially for at-risk individuals and caregivers, and should be considered in women of reproductive age and immunocompromised individuals. Disclosures All Authors: No reported disclosures

Cytokine Profile in Patients with Herpes Zoster

Background. In recent years, increasing attention has been paid to studying cytokine levels in the blood of virus carriers and patients, as cytokines are mediators of intercellular interactions within the immune system. They influence herpes virus-infected endothelial cells, promoting enhanced expression of cellular adhesion molecules and initiating inflammatory reactions in the vascular walls. This study focuses on investigating the levels of major pro- and anti-inflammatory cytokines in patients with herpes zoster to reveal key immunopathogenetic features of inflammatory process exacerbations caused by the Varicella Zoster virus (VZV). Purpose – to assess serum cytokine levels and IgG antibody levels against VZV in patients with herpes zoster. Materials and Methods. Serum cytokine profiles (IL-1β, IL-4, IL-6, IL-10, IL-17a, IL-23) were analyzed using ELISA (Elabscience, USA), along with IgG antibody levels against VZV (Varicella Zoster Virus IgG ELISA, DRG Diagnostics Germany) in 30 patients with herpes zoster. Results. The incidence of herpes zoster was age-dependent, with patients over 61 years being the most affected. Significant imbalances between pro- and anti-inflammatory cytokines were observed during the first day of hospitalization, likely due to functional imbalance in T-helper lymphocytes. VZV IgG antibody titers were significantly higher (P < 0.0001) in patients with herpes zoster compared to the control group. Strong correlations between cytokine and antibody levels were observed. High IL-17 levels were notable in the patient group, while IL-4 levels negatively correlated with disease severity. Conclusions. Elevated cytokine levels associated with cellular and humoral immunity were identified, confirming immune system activation. Vaccination for individuals aged 60 and above is recommended to prevent VZV reactivation.

Development of a Luciferase Immunosorbent Assay for Detecting Crimean-Congo Hemorrhagic Fever Virus IgG Antibodies Based on Nucleoprotein.

Crimean-Congo hemorrhagic fever (CCHF) is a serious tick-borne disease with a wide geographical distribution. Classified as a level 4 biosecurity risk pathogen, CCHF can be transmitted cross-species due to its aerosol infectivity and ability to cause severe hemorrhagic fever outbreaks with high morbidity and mortality. However, current methods for detecting anti-CCHFV antibodies are limited. This study aimed to develop a novel luciferase immunosorbent assay (LISA) for the detection of CCHFV-specific IgG antibodies. We designed specific antigenic fragments of the nucleoprotein and evaluated their sensitivity and specificity in detecting IgG in serum samples from mice and horses. In addition, we compared the efficacy of our LISA to a commercial enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that the optimal antigen for detecting anti-CCHFV IgG was located within the stalk cut-off domain of the nucleoprotein. The LISA exhibited high specificity for serum samples from indicated species and significantly higher sensitivity (at least 128 times) compared with the commercial ELISA. The proposed CCHFV-LISA has the potential to facilitate serological diagnosis and epidemiological investigation of CCHFV in natural foci, providing valuable technical support for surveillance and early warning of this disease.

Serotype-Specific Dengue Virus IgG Assay Using EDIII-Based Recombinant Proteins and Its Application in an Endemic Population in Northeast Brazil.

Dengue is the most prevalent arboviral disease globally, with Brazil currently experiencing a significant rise in cases. Dengue virus (DENV) typically co-circulates with other clinically and antigenically similar flaviviruses, such as Zika virus (ZIKV). The clinical diagnosis is difficult and accurate serological analysis represents an unmet challenge. Traditionally, serological analysis of DENV infection focuses on the acute phase via detection of NS1 or IgM. Developing IgG DENV-specific assays has been defiant due to the co-circulation of four antigenically distinct serotypes and a strong cross-reactivity with other arboviruses, particularly with ZIKV. The goal of this study was to produce recombinant domain III of the Envelope (EDIII) proteins of each DENV serotype and ZIKV and evaluate the ability to detect specific IgG antibodies. The antigens were tested on the ELISA platform to measure DENV-specific IgG in mice and patients infected with ZIKV and DENV. The assay differentiated serotype-specific IgG responses in susceptible mice (AG129) experimentally infected with DENV or ZIKV. In addition, the test demonstrated a robust performance achieving 87.8% sensitivity and 91.4% specificity when tested against 648 well-characterized sera collected from humans infected with DENV and/or ZIKV. The test was further applied to serum samples collected from 318 healthy individuals from an endemic region in Northwest/Central Brazil, without a previous diagnosis of DENV, and revealed that 65% of the samples reacted with at least one DENV serotype antigen, including 123 monotypic samples (88 for DENV-1) and 90 samples reacting with multiple antigens. Collectively, these results indicate that the IgG DENV-EDIII ELISA is a valuable tool for assessing the serological status of populations in endemic areas, particularly in regions where other flaviviruses, particularly ZIKV, co-circulate and offer support to establish public health policies against the disease.

Double umbilical artery converging into a single umbilical artery: A case report.

The normal structure and Doppler parameters of the umbilical cord are closely related to many diseases, including fetal infection, chromosomal abnormalities, hypoxia, and growth and development restrictions. We report a case of bilateral umbilical artery confluence resulting in the formation of a single umbilical artery in the free segment of the fetal umbilical cord, diagnosed at 24 weeks and 4 days gestation. The fetus was born prematurely after premature membrane rupture at 31 weeks and 3 days gestation. The Toxoplasma, Others, Rubellavirus, Cytomegalovirus, Herpesvirus test showed positive results for Toxoplasma gondii, rubella virus, and herpes simplex virus IgG antibodies. A 36-year-old woman had vaginal discharge for > 1 hour at 31 weeks + 3 days gestation and came to our obstetrics department for treatment. The pregnant woman sought treatment due to premature membrane rupture and vaginal discharge for > 1 hour. The vaginal discharge was caused by Escherichia coli. After cesarean section, the Toxoplasma, Others, Rubellavirus, Cytomegalovirus, Herpesvirus test revealed positive results for the following: T gondii, rubella virus, and herpes simplex virus IgG antibodies. The patient underwent 2 ultrasound examinations and was diagnosed with umbilical artery malformation (the free segment of the umbilical cord on the fetal side converged into a single umbilical artery), which may have been related to fetal infection. The patient received anti-inflammatory and fetal lung maturation treatment for 2 days before undergoing a cesarean section. The mother and newborn received anti-inflammatory, symptomatic, and supportive treatment and were discharged after 1 week of improvement. After 1 month, 6 months, and 1 year of follow-up after birth, the growth and development of the infant (height and weight) were significantly lower than those of her peers, and her responses to sound and light were slightly delayed. Umbilical artery malformation is extremely rare and may be related to intrauterine parasitic and viral infections. Ultrasound has the advantages of being noninvasive and cost-effective and can be used to dynamically observe umbilical artery structure. An abnormal change in umbilical artery structure found during ultrasound examination can indicate intrauterine infection risk, which provides clinical guidance for further examination of pregnant women, early diagnosis, timely targeted treatment, and fetal prognosis improvement.

Comparison of the sensitivity and specificity of commercial anti-dengue virus IgG tests to identify persons eligible for dengue vaccination.

The Advisory Committee on Immunization Practices (ACIP) has set forth recommendations that dengue pre-vaccination screening tests must exhibit at least 98% specificity and 75% sensitivity. Our research rigorously assesses the performance of various commercial tests against these benchmarks using well-characterized specimens from Puerto Rico. The findings from our study are particularly relevant given FDA approval and ACIP recommendation of Sanofi Pasteur's Dengvaxia vaccine, highlighting the need for accurate pre-vaccination screening tools.

Prevalence of Chikungunya Virus IgG and IgM Antibodies among Febrile Patients Presumptively Diagnosed with Malaria in Ogun State, Nigeria

Prevalence of Chikungunya Virus IgG and IgM Antibodies among Febrile Patients Presumptively Diagnosed with Malaria in Ogun State, Nigeria

Antibody immune responses and causal relationships in four immune skin diseases: Evidence from Mendelian randomization and Bayesian Weighting (Antibody Responses in Skin Diseases: MR & Bayesian).

Recent studies increasingly suggest that microbial infections and the immune responses they elicit play significant roles in the pathogenesis of chronic inflammatory skin diseases. This study uses Mendelian randomization (MR) and Bayesian weighted Mendelian randomization (BWMR) to explore the causal relationships between immune antibody responses and four common skin diseases: psoriasis, atopic dermatitis (AD), rosacea, and vitiligo. We utilized summary statistics from genome-wide association studies (GWAS) for antibody responses to 13 infectious pathogens and four skin diseases. Single nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs) to assess causal relationships using multiple MR methods, including inverse variance weighted (IVW), MR Egger, and weighted median. BWMR was also employed to confirm findings and address potential pleiotropy. The IVW analysis identified significant associations between specific antibody responses and the skin diseases studied. Key findings include protective associations of anti-Epstein-Barr virus (EBV) IgG seropositivity and Helicobacter pylori UREA antibody levels with psoriasis and AD. anti-chlamydia trachomatis IgG seropositivity, anti-polyomavirus 2 IgG seropositivity, and varicella zoster virus glycoprotein E and I antibody levels were negatively associated with rosacea, while EBV Elevated levels of the early antigen (EA-D) antibody levels and HHV-6 IE1B antibody levels were positively associated with rosacea. H. pylori Catalase antibody levels were protectively associated with vitiligo, whereas anti-herpes simplex virus 2 (HSV-2) IgG seropositivity was positively associated with vitiligo. The BWMR analysis confirmed these associations. This study underscores the significant role of H. pylori and other pathogens in these skin diseases, suggesting both protective and exacerbating effects depending on the specific condition. Understanding these pathogen-immune interactions can lead to the development of more effective, personalized treatments and preventative strategies, ultimately improving patient outcomes and quality of life.

A Cross-Sectional Study of Measles-Specific Antibody Levels in Australian Blood Donors-Implications for Measles Post-Elimination Countries.

Passive immunisation with normal human immunoglobulin (NHIG) is recommended as post-exposure prophylaxis (PEP) for higher-risk measles contacts where vaccination is contraindicated. However, the concentration of measles-specific antibodies in NHIG depends on antibody levels within pooled donor plasma. There are concerns that measles immunity in the Australian population may be declining over time and that blood donors' levels will progressively decrease, impacting levels required to produce effective NHIG for measles PEP. A cross-sectional study of Australian plasmapheresis donors was performed using an age-stratified, random sample of recovered serum specimens, collected between October and November 2019 (n = 1199). Measles-specific IgG antibodies were quantified by ELISA (Enzygnost anti-measles virus IgG, Siemens), and negative and equivocal specimens (n = 149) also underwent plaque reduction neutralisation testing (PRNT). Mean antibody levels (optical density values) progressively decreased from older to younger birth cohorts, from 2.09 [±0.09, 95% CI] to 0.58 [±0.04, 95% CI] in donors born in 1940-1959 and 1990-2001, respectively (p < 0.0001). This study shows that mean measles-specific IgG levels are significantly lower in younger Australian donors. While current NHIG selection policies target older donors, as younger birth cohorts become an increasingly larger proportion of contributing donors, measles-specific antibody concentrations of NHIG will progressively reduce. We therefore recommend monitoring measles-specific antibody levels in future donors and NHIG products in Australia and other countries that eliminated measles before the birth of their youngest blood donors.

Metagenomic Next-Generation Sequencing for the Diagnosis of Viral Infectious Uveitis and Its Mimics

ABSTRACT Purpose To investigate the value of metagenomic next-generation sequencing (mNGS) for virus detection in patients with suspected viral infectious uveitis. Methods In this retrospective, multicenter case series study, 70 patients with suspected viral infectious uveitis were recruited. All patients underwent mNGS test using intraocular fluid samples and serological screening tests for pathogens. Twelve cases also underwent a PCR panel test for herpetic viruses using intraocular fluid samples; 7 cases also underwent aqueous anti-herpetic viral IgG level tests. Results Among 70 patients with suspected viral infectious uveitis, 34 cases were female, mean age was 45.3 years with a range from 6 to 78 years; 53 cases (75.7%) were diagnosed as infectious uveitis, 17 cases (24.3%) diagnosed as non-infectious uveitis. Among 53 cases with infectious uveitis, herpetic viruses, Bartonella henselae, Toxoplasma gondii, and Treponema pallidum were detected in 43, 6, 4, and 1 case, respectively. Among 43 cases with viral infectious uveitis, herpetic virus was detected in 39 cases by mNGS, the other 4 cases showed negative results in mNGS test, but positive results in 2 cases in serological screening tests, in 1 case in PCR, and in 1 case in aqueous anti-herpetic viral IgG level test, respectively. The sensitivity, specificity, positive predictive value, negative predictive value of mNGS in detecting viruses were 90.7%, 100%, 100%, and 81.0%, respectively. Conclusions mNGS is a sensitive and valuable method to detect viruses in intraocular fluid samples, and an alternative for pathogen detection in cases with suspected viral infectious uveitis but negative test results in PCR.

Prevalence of Hepatitis D in People Living with HIV: A National Cross-Sectional Pilot Study.

This study assesses the prevalence of hepatitis D virus (HDV) in people living with HIV (PLWHIV) in Greece. Given the compounding effects of HDV and hepatitis B (HBV) on liver disease progression, as well as the emergence of new therapeutic options such as bulevirtide, understanding regional disparities and the epidemiological impact of such co-infections is vital. A cross-sectional analysis was conducted utilizing 696 serum samples from PLWHIV attending five major university hospitals. The methodology included HDV antibody detection by ELISA and HDV RNA confirmation. Of the 30 HBsAg-positive samples analyzed, the study population was primarily male (93%), with a median age of 54 years. Participants had been on antiretroviral therapy for a median of 10 years, and the median CD4 count was 738 (539-1006) copies/mL. Additional serological findings revealed a 7% prevalence of hepatitis C virus (HCV) IgG antibodies and a 55% prevalence of hepatitis A virus (HAV) IgG antibodies. Seroreactivity for syphilis (RPR/VDRL/TPHA positive) was identified in 33% of the participants. The results indicated a low HDV prevalence, with only one individual (3%) testing positive for anti-HDV IgG antibodies and none for HDV RNA. This indicates a lower prevalence of HDV among PLWHIV with chronic HBV in Greece compared to global data.

Cytomegalovirus, Epstein-Barr Virus, Herpes Simplex Virus, and Varicella Zoster Virus Infection Dynamics in People with Multiple Sclerosis from Northern Italy.

Previous exposure to Epstein-Barr virus (EBV) is strongly associated with the development of multiple sclerosis (MS). By contrast, past cytomegalovirus (CMV) infection may have no association, or be negatively associated with MS. This study aimed to investigate the associations of herpesvirus infections with MS in an Italian population. Serum samples (n = 200) from Italian people with multiple sclerosis (PwMS) classified as the relapsing-and-remitting clinical phenotype and (n = 137) healthy controls (HCs) were obtained from the CRESM Biobank, Orbassano, Italy. Both PwMS and HCs samples were selected according to age group (20-39 years, and 40 or more years) and sex. EBV virus capsid antigen (VCA) IgG, EBV nucleic acid-1 antigen (EBNA-1) IgG, CMV IgG, herpes simplex virus (HSV) IgG, and varicella zoster virus (VZV) IgG testing was undertaken using commercial ELISAs. EBV VCA IgG and EBNA-1 IgG seroprevalences were 100% in PwMS and 93.4% and 92.4%, respectively, in HCs. EBV VCA IgG and EBNA-1 IgG levels were higher (p < 0.001) in PwMS compared with HCs. For PwMS, the EBNA-1 IgG levels decreased with age, particularly in females. The CMV IgG seroprevalence was 58.7% in PwMS and 62.9% in HCs. CMV IgG seroprevalence increased with age. The HSV IgG seroprevalence was 71.2% in PwMS and 70.8% in HCs. HSV IgG levels were lower (p = 0.0005) in PwMS compared with HCs. VZV IgG seroprevalence was 97.5% in PwMS and 98.5% in HCs. In the population studied, several herpesvirus infections markers may have been influenced by the age and sex of the groups studied. The lack of a negative association of MS with CMV infection, and the observation of lower levels of HSV IgG in PwMS compared with HCs are findings worthy of further investigation.

First Broad-Range Serological Survey of Crimean-Congo Hemorrhagic Fever among Hungarian Livestock.

(1) Background: Crimean-Congo hemorrhagic fever (CCHF) is an emerging tick-borne disease endemic in Africa, Asia, the Middle East, and the Balkan and Mediterranean regions of Europe. Although no human CCHF cases have been reported, based on vector presence, serological evidence among small vertebrates, and the general human population, Hungary lies within high evidence consensus for potential CCHF introduction and future human infection. Thus, the aim of our pilot serosurvey was to assess CCHF seropositivity among cattle and sheep as indicator animals for virus circulation in the country. (2) Methods: In total, 1905 serum samples taken from free-range cattle and sheep in 2017 were tested for the presence of anti-CCHF virus IgG antibodies using commercial ELISA and commercial and in-house immunofluorescent assays. (3) Results: We found a total of eleven reactive samples (0.58%) from five administrative districts of Hungary comprising 8 cattle and 3 sheep. The most affected regions were the south-central and northwestern parts of the country. (4) Conclusions: Based on these results, more extended surveillance is advised, especially in the affected areas, and there should be greater awareness among clinicians and other high-risk populations of the emerging threat of CCHF in Hungary and Central Europe.

A Luciferase Immunosorbent Assay Based on Attachment Glycoprotein for the Rapid and Easy Detection of Nipah Virus IgG Antibodies.

Nipah virus (NiV) is a virulent zoonotic disease whose natural host is the fruit bat (Pteropus medius), which can coexist with and transmit the virus. Due to its high pathogenicity, wide host range, and pandemic potential, establishing a sensitive, specific, and rapid diagnostic method for NiV is key to preventing and controlling its spread and any outbreaks. Here, we established a luciferase immunosorbent assay (LISA) based on the NiV attachment glycoprotein (G) to detect NiV-specific immunoglobulin G by expressing a fusion protein of nanoluciferase (NanoLuc) and the target antigen. Sensitivity analysis was performed and compared to an indirect enzyme-linked immunosorbent assay (ELISA), and specificity and cross-reactivity assessments were performed using NiV-positive horse serum and Ebola virus-, Crimean-Congo hemorrhagic fever virus-, and West Nile virus-positive horse sera. The optimal structural domain for NiV detection was located within amino acids 176-602 of the NiV G protein head domain. Moreover, the LISA showed at least fourfold more sensitivity than the indirect ELISA, and the cross-reactivity results suggested that the LISA had good specificity and was capable of detecting NiV-specific immunoglobulin G in both mouse and horse serum. In conclusion, the establishment of a rapid, simple NiV LISA using the G protein head domain provides a resource for NiV monitoring.

Severe Tick-Borne Encephalitis (TBE) in a Patient with X-Linked Agammaglobulinemia; Treatment with TBE Virus IgG Positive Plasma, Clinical Outcome and T Cell Responses

PurposeA patient with X-linked agammaglobulinemia (XLA) and severe tick-borne encephalitis (TBE) was treated with TBE virus (TBEV) IgG positive plasma. The patient’s clinical response, humoral and cellular immune responses were characterized pre- and post-infection.MethodsELISA and neutralisation assays were performed on sera and TBEV PCR assay on sera and cerebrospinal fluid. T cell assays were conducted on peripheral blood the patient and five healthy vaccinated controls.ResultsThe patient was admitted to the hospital with headache and fever. He was not vaccinated against TBE but receiving subcutaneous IgG-replacement therapy (IGRT). TBEV IgG antibodies were low-level positive (due to scIGRT), but the TBEV IgM and TBEV neutralisation tests were negative. During hospitalisation his clinical condition deteriorated (Glasgow coma scale 3/15) and he was treated in the ICU with corticosteroids and external ventricular drainage. He was then treated with plasma containing TBEV IgG without apparent side effects. His symptoms improved within a few days and the TBEV neutralisation test converted to positive. Robust CD8+ T cell responses were observed at three and 18-months post-infection, in the absence of B cells. This was confirmed by tetramers specific for TBEV.ConclusionTBEV IgG-positive plasma given to an XLA patient with TBE without evident adverse reactions may have contributed to a positive clinical outcome. Similar approaches could offer a promising foundation for researching therapeutic options for patients with humoral immunodeficiencies. Importantly, a robust CD8+ T cell response was observed after infection despite the lack of B cells and indicates that these patients can clear acute viral infections and could benefit from future vaccination programs.

Detection of intrathecal IgG antibody for varicella and measles diagnosis by evaluation and comparison of a commercial IgG chemiluminescent immunoassay with two ELISAs.

Analyse alternative methods of intrathecal antibody detection by comparing chemiluminescent immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) techniques to determine if CLIA can replace ELISA in the diagnosis of CNS infections. A panel of 280 paired samples-cerebrospinal fluid (CSF) and serum-with known antibody reactivities (Varicella, n = 60; Measles, n = 120) and negative samples (n = 100) were used to evaluate the performance of six serological test kits (Enzygnost, VirClia®, and Serion ELISA (Measles and Variella). For Measles virus IgG, the VirClia® IgG monotest revealed 97% and 94% positive and negative agreement to the Enzygnost as reference test,respectively. In contrast, Serion ELISA kits yielded values of 18% and 90%. For theVaricella Zoster virus (VZV) IgG, the VirClia® IgG monotest showed 97% and 90% positive and negative agreement compared to Enzygnost. The Serion ELISA kits showed values of 55% and 86%, respectively. ROC analysis revealed that the areas under the curve for Measles and VZV IgGs were 0.7 and 0.852, respectively, using the Serion kit, and 0.963 and 0.955, for Vircell S.L CLIA technique. VirClia® monotest values were calculated using an antibody index cut-off of 1.3. The findings indicate that CLIA testing can improve antibody detection in CSF samples, aiding the diagnosis of infectious neurological impairments.

Rodent control strategies and Lassa virus: some unexpected effects in Guinea, West Africa

ABSTRACT The Natal multimammate mouse (Mastomys natalensis) is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10–30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village. We also captured rodents both before and after the intervention period to assess their effectiveness by examining alterations in trapping success and infection rates (Lassa virus RNA and IgG antibodies). We found that both interventions reduced the rodent population by 74–92% but swiftly rebounded to pre-treatment levels, even already six months after the last snap-trapping control. Furthermore, while we observed that chemical control modestly decreased Lassa virus infection rates annually (a reduction of 5% in seroprevalence per year), the intensive trapping unexpectedly led to a significantly higher infection rate (from a seroprevalence of 28% before to 67% after snap trapping control). After seven years, we conclude that annual chemical control, alone or with intensive trapping, is ineffective and sometimes counterproductive in preventing Lassa virus spillover in rural villages. These unexpected findings may result from density-dependent breeding compensation following culling and the survival of a small percentage of chronically infected rodents that may spread the virus to a new susceptible generation of mice.

Cryptic circulation of chikungunya virus in São Jose do Rio Preto, Brazil, 2015-2019.

Chikungunya virus (CHIKV) has spread across Brazil with varying incidence rates depending on the affected areas. Due to cocirculation of arboviruses and overlapping disease symptoms, CHIKV infection may be underdiagnosed. To understand the lack of CHIKV epidemics in São José do Rio Preto (SJdRP), São Paulo (SP), Brazil, we evaluated viral circulation by investigating anti-CHIKV IgG seroconversion in a prospective study of asymptomatic individuals and detecting anti-CHIKV IgM in individuals suspected of dengue infection, as well as CHIKV presence in Aedes mosquitoes. The opportunity to assess two different groups (symptomatic and asymptomatic) exposed at the same geographic region aimed to broaden the possibility of identifying the viral circulation, which had been previously considered absent. Based on a prospective population study model and demographic characteristics (sex and age), we analyzed the anti-CHIKV IgG seroconversion rate in 341 subjects by ELISA over four years. The seroprevalence increased from 0.35% in the first year to 2.3% after 3 years of follow-up. Additionally, we investigated 497 samples from a blood panel collected from dengue-suspected individuals during the 2019 dengue outbreak in SJdRP. In total, 4.4% were positive for anti-CHIKV IgM, and 8.6% were positive for IgG. To exclude alphavirus cross-reactivity, we evaluated the presence of anti-Mayaro virus (MAYV) IgG by ELISA, and the positivity rate was 0.3% in the population study and 0.8% in the blood panel samples. In CHIKV and MAYV plaque reduction neutralization tests (PRNTs), the positivity rate for CHIKV-neutralizing antibodies in these ELISA-positive samples was 46.7%, while no MAYV-neutralizing antibodies were detected. Genomic sequencing and phylogenetic analysis revealed CHIKV genotype ECSA in São José do Rio Preto, SP. Finally, mosquitoes collected to complement human surveillance revealed CHIKV positivity of 2.76% of A. aegypti and 9.09% of A. albopictus (although it was far less abundant than A. aegypti) by RT-qPCR. Our data suggest cryptic CHIKV circulation in SJdRP detected by continual active surveillance. These low levels, but increasing, of viral circulation highlight the possibility of CHIKV outbreaks, as there is a large naïve population. Improved knowledge of the epidemiological situation might aid in outbreaks prevention.

A Proposed Approach to Screening and Surveillance Labs for Patients With Multiple Sclerosis on Anti-CD20 Therapy.

Anti-CD20 therapies have proven to be highly effective and safe therapies for multiple sclerosis (MS) and have had rapid uptake in the MS community. However, no clear consensus has arisen regarding an approach to screening or surveillance lab monitoring. Based on current evidence, for screening labs before anti-CD20 initiation, we propose checking liver function test (LFT), complete blood count with differential (CBC), absolute B-cell count, quantitative immunoglobulins, hepatitis B virus serologies, varicella zoster virus IgG, John Cunningham virus (JCV) status, and age-appropriate vaccination history. For surveillance monitoring in an otherwise asymptomatic individual, we propose biannual LFTs and CBC, quantitative immunoglobulins annually after year 3, absolute B-cell count at month 6 and in the setting of relapse, and JCV only if clinical or radiographic features of progressive multifocal leukoencephalopathy arise. For ublituximab, pregnancy testing is additionally recommended before each infusion. We propose evidence-based screening and safety surveillance labs which take into account likelihood of changing management in an otherwise stable or asymptomatic individual.

Influenza A virus antibodies in horses and pigs in Nigeria: The need for One Health approach

Influenza A viruses are a great threat to human health because of their heterogeneity in its host range and the propensity of reassortment to novel viruses with pandemic potential. There is risk of zoonotic transmission of influenza A between humans and livestock due to close interactions. Due to the paucity of data on influenza A viruses among domesticated animals, we investigated the presence of nucleocapsid of influenza A virus antibodies using ID screen® influenza A antibody competitive multi-species enzyme linked immunosorbent assay. A total of 184 pigs were sampled from Benue state, and 92 horses were sampled from three local government areas of Kaduna state, Nigeria. Of the animals sampled, an estimated 25% (95% CI: 18.92, 31.90) of pigs and 93.48% (95% CI: 86.34, 97.57) of horses tested positive for influenza A virus IgG. The results indicate exposure of domestic animals to influenza A virus, thereby raising concern of potential epidemics in both animals and humans. There is need for increased surveillance in both domestic animals and humans who are in close interaction.