In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

Over the past several decades, significant advances have been made in identifying factors that contribute to the pathogenesis of multiple sclerosis (MS) and have culminated in the approval of some effective therapeutic strategies for disease intervention. However, the mechanisms by which environmental factors, such as infection, contribute to the pathogenesis and/or symptom exacerbation remain to be fully elucidated. Relapse frequency in MS patients contributes to neurological impairment and, in the initial phases of disease, serves as a predictor of poor disease prognosis. The purpose of this review is to examine the evidence that supports a role for peripheral infection in modulating the natural history of this disease. Evidence supporting a role for infection in promoting exacerbation in animal models of MS is also reviewed. Finally, a few mechanisms by which infection may exacerbate symptoms of MS and other neurological diseases are discussed. Those who comprise the majority of MS patients acquire approximately two upper-respiratory infections per year; furthermore, this type of infection doubles the risk for MS relapse, underscoring the contribution of this relationship as being potentially important and particularly detrimental.
infection as an environmental trigger of multiple sclerosis disease exacerbation

Background: Rift Valley fever (RVF) is endemic to the tropical regions of eastern and southern Africa. The seroprevalence of RVF was investigated among the human population in Borno State, Nigeria to determine the occurrence of the disease in the study area in comparison with that of Lassa fever and Crimean-Congo Hemorrhagic fever. Methods: Recombinant nucleoprotein (rNP)-based IgG-ELISAs for the detection of serum antibodies against RVF virus (RVFV), Lassa fever virus (LASV), and Crimean-Congo hemorrhagic fever virus (CCHFV) were used to test human sera in Borno State, Nigeria. The presence of neutralizing antibody against the RVFV-glycoprotein-bearing vesicular stomatitis virus pseudotype (RVFVpv) was also determined in the human sera. Of the 297 serum samples tested, 42 (14.1%) were positive for the presence of RVFV-IgG and 22 (7.4%) and 7 (2.4%) of the serum samples were positive for antibodies against LASV and CCHFV, respectively. There was a positive correlation between the titers of neutralizing antibodies obtained using RVFVpv and those obtained using the conventional neutralization assay with the attenuated RVFV-MP12 strain. Conclusions: The seroprevalence of RVF was significantly higher than that of LASV and CCHF in Borno State, Nigeria. The RVFVpv-based neutralization assay developed in this study has the potential to replace the traditional assays based on live viruses for the diagnosis and seroepidemiological studies of RVF.
Development and validation of serological assays for viral hemorrhagic fevers and determination of the prevalence of Rift Valley fever in Borno State, Nigeria

The worldwide prevalence of chronic hepatitis C virus (HCV) infection is estimated to be approaching 200 million people 1 . Current therapy relies upon a combination of pegylated interferon-a and ribavirin, a poorly tolerated regimen typically associated with less than 50% sustained virological response rate in those infected with genotype 1 virus 2,3 . The development of direct-acting antiviral agents to treat HCV has focused predominantly on inhibitors of the viral enzymes NS3 protease and the RNA-dependent RNA polymerase NS5B 4 . Here we describe the profile of BMS-790052, a small molecule inhibitor of the HCV NS5A protein that exhibits picomolar half-maximum effective concentrations (EC 50 ) towards replicons expressing a broad range of HCV genotypes and the JFH-1 genotype 2a infectious virus in cell culture. In a phase I clinical trial in patients chronically infected with HCV, administration of a single 100-mg dose of BMS-790052 was associated with a 3.3 log 10 reduction in mean viral load measured 24 h post-dose that was sustained for an additional 120 h in two patients infected with genotype 1b virus. Genotypic analysis of samples taken at baseline, 24 and 144 h post-dose revealed that the major HCV variants observed had substitutions at amino-acid positions identified using the in vitro replicon system. These results provide the first clinical validation of an inhibitor of HCV NS5A, a protein with no known enzymatic function, as an approach to the suppression of virus replication that offers potential as part of a therapeutic regimen based on combinations of HCV inhibitors. We designed a mechanistically unbiased approach based on chemical genetics to identify chemical starting points for interfering with HCV replication. Our differentiating strategy centred on the identification of compounds functionally distinct from those acting on the traditional targets of antiviral research in this field, the NS3 protease and the NS5B RNA-dependent RNA polymerase 5-7 . Using a Con-1 genotype 1b replicon replicating in Huh-7 liver cells 8 , we screened over one million compounds from the Bristol-Myers Squibb proprietary collection in high throughput mode. We used a dual assay format that simultaneously evaluated replication of the related flavivirus bovine viral diarrhoea virus (BVDV) and host cell cytotoxicity as an efficient means of preliminarily eliminating compounds without specificity for HCV 9 . Active inhibitors were further triaged by evaluation in biochemical assays for NS3 protease, NS3 helicase and NS5B polymerase in addition to screening against a panel of unrelated viruses. The iminothiazolidinone BMS-858 (Fig. 1) emerged as a weak but, more importantly, specific inhibitor of HCV RNA replication (EC 50 5 0.57 mM, halfmaximum cytotoxic concentration (CC 50 ) 5 .50 mM) for which resistance was mapped to a tyrosine to histidine substitution at residue 93 in the NS5A protein (Y93H or Y2065H in the HCV polyprotein) 10 . BMS-858 formed the basis of an extensive series of chemical refinements that focused on improving antiviral potency, broadening inhibitory activity to encompass the HCV 1a genotype, and optimizing for oral bioavailability and sustained pharmacokinetic properties. After defining symmetry as an important contributor to antiviral activity 10 , a discovery that preceded the disclosure of structural information (see below), we subsequently identified BMS-790052 (Fig. 1 ) as a development candidate for advancement into clinical trials 11 . (The studies leading to the identification of BMS-790052 and its preclinical profiling will be the subject of a series of separate publications.) This compound is the most potent HCV replication inhibitor reported so far, with mean EC 50 values of 50 and 9 pM against genotype 1a and 1b replicons, respectively (data summarized in Table 1 ). BMS-790052 displays a therapeutic index (CC 50 /EC 50 ) of at least 100,000 in vitro and is inactive towards a panel of 10 RNA and DNA viruses, with EC 50 values greater than 10 mM, which confirms specificity for HCV (Supplementary Tables 1  and 2 ).

Chemical genetics strategy identifies an HCV NS5A inhibitor with a potent clinical effect