Hepatitis B virus infection among illegal drug users in Enugu State, Nigeria: prevalence, immune status, and related risk factors.

INTRODUCTION: Hepatitis B virus infection poses a global health challenge, particularly in low- and middle-income African countries. Illicit drug use exacerbates the problem, with drug users having a higher HBV infection risk and maintaining a quiet transmission pool. This study aimed to determine HBV infection prevalence, immune status, and risk factors among illegal drug users in Enugu State, Nigeria. MATERIALS AND METHODS: A cross-sectional study was conducted in Enugu State, using privileged access interviewer methods to enroll drug users. Pre-tested structured questionnaires were administered after informed consent was obtained. Blood samples were tested for HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb using immunochromatographic rapid test kits. Statistical analysis was performed using SPSS version 25. RESULTS: One hundred drug users were recruited into the study. Overall, 7% of the drug users had HBV infection. 61% were found to be susceptible to HBV infection, 15% showed serological evidence of immunity from HBV vaccination and 1% developed natural immunity from HBV exposure. Significant risk factors for HBV infection were age less than 20 years, young age (≤ 20 years) at drug initiation, being single, injecting drugs more than or equal to 20 times per month and injecting with used syringes. CONCLUSION: This study shows high intermediate endemicity of HBV infection among drug users, low vaccination uptake, and high susceptibility to HBV infection. This calls for the urgent inclusion of drug users in national HBV vaccination campaigns and the adoption of the World Health Organization's recommendations on the prevention of viral hepatitis among people who inject drugs.

Juxtaposing Caenorhabditis elegans-Pathogenic Mould Model with Other Models; How Reliable Is This Nematode Model? A Mini Review.

The application of Caenorhabditis elegans as a pathogenic model has spanned decades. Its use for pathogenic mould modeling has been attracting some attention lately, though not without some reservations. Several studies have shown C. elegans to be a reliable model for evaluating moulds' virulence factors and patterns as well as for screening the pathogenicity of mutant strains alongside their parental/wild type and revertant/complementary strains. There is a very high degree of reported similarities between the virulence patterns demonstrated in C. elegans and those of other invertebrate and vertebrate models. We have here presented several works in which this nematode model was adopted for virulence evaluation, and other comparative research in which virulence in C. elegans model were juxtaposed with other models. We have further presented possible reasons why there might have been variations of virulence in a few cases, thereby validating C. elegans to be an effective and reliable tool in the study of pathogenic moulds.

Caenorhabditis elegans as an Infection Model for Pathogenic Mold and Dimorphic Fungi: Applications and Challenges.

The threat burden from pathogenic fungi is universal and increasing with alarming high mortality and morbidity rates from invasive fungal infections. Understanding the virulence factors of these fungi, screening effective antifungal agents and exploring appropriate treatment approaches in in vivo modeling organisms are vital research projects for controlling mycoses. Caenorhabditis elegans has been proven to be a valuable tool in studies of most clinically relevant dimorphic fungi, helping to identify a number of virulence factors and immune-regulators and screen effective antifungal agents without cytotoxic effects. However, little has been achieved and reported with regard to pathogenic filamentous fungi (molds) in the nematode model. In this review, we have summarized the enormous breakthrough of applying a C. elegans infection model for dimorphic fungi studies and the very few reports for filamentous fungi. We have also identified and discussed the challenges in C. elegans-mold modeling applications as well as the possible approaches to conquer these challenges from our practical knowledge in C. elegans-Aspergillus fumigatus model.

Towards Improved Use of Vaccination in the Control of Infectious Bronchitis and Newcastle Disease in Poultry: Understanding the Immunological Mechanisms.

Infectious bronchitis (IB) and Newcastle disease (ND) are two important diseases of poultry and have remained a threat to the development of the poultry industry in many parts of the world. The immunology of avian has been well studied and numerous vaccines have been developed against the two viruses. Most of these vaccines are either inactivated vaccines or live attenuated vaccines. Inactivated vaccines induce weak cellular immune responses and require priming with live or other types of vaccines. Advanced technology has been used to produce several types of vaccines that can initiate prime immune responses. However, as a result of rapid genetic variations, the control of these two viral infections through vaccination has remained a challenge. Using various strategies such as combination of live attenuated and inactivated vaccines, development of IB/ND vaccines, use of DNA vaccines and transgenic plant vaccines, the problem is being surmounted. It is hoped that with increasing understanding of the immunological mechanisms in birds that are used in fighting these viruses, a more successful control of the diseases will be achieved. This will go a long way in contributing to global food security and the economic development of many developing countries, given the role of poultry in the attainment of these goals.

Coinfection of Tuberculosis and HIV in Nigeria: A Systematic Review and Meta-analysis.

Tuberculosis (TB) and HIV/AIDS are major public health issues globally. The burden of these diseases is particularly significant in Nigeria due to the high TB and HIV/AIDS prevalence. This meta-analysis for the 1st time addressed the TB/HIV coinfection prevalence in Nigeria at the regional level. A total of 58 relevant publications comprising 80 studies (n = 44,508) were obtained from PUBMED, ScienceDirect, African Journals Online, and Cochrane Library databases using carefully constructed keywords combinations. The PRISMA guideline was followed for this meta-analysis. Two independent reviewers conducted the publication screening, data extraction and methodological quality appraisal with a third reviewer serving as arbitrator. The pooled estimates were calculated using the random effects model. Heterogeneity was assessed using Cochran's Q and I 2 statistic. Univariate and multivariate meta-regressions were done to predict sources of between-study heterogeneity. Overall, the pooled prevalence of TB/HIV coinfection was 25.8%. The highest coinfection prevalence of 34.3% was recorded among the North Central States of Nigeria, while the least prevalence of 19.3% was recorded among the Southeastern states of Nigeria. There was a paucity of published articles from the Northeastern states of Nigeria. There was a significant heterogeneity between studies (I2 > 90%, p < 0.001), but meta-regression analysis only explained < 10% of it. This study has shown that the prevalence of TB/HIV coinfection remains significantly high in Nigeria. Constant surveillance should be rigorously implemented with special attention given to the Northeast due to the ongoing crises that are compounding the problem.

Marine Bioactive Compounds against Aspergillus fumigatus: Challenges and Future Prospects.

With the mortality rate of invasive aspergillosis caused by Aspergillus fumigatus reaching almost 100% among some groups of patients, and with the rapidly increasing resistance of A. fumigatus to available antifungal drugs, new antifungal agents have never been more desirable than now. Numerous bioactive compounds were isolated and characterized from marine resources. However, only a few exhibited a potent activity against A. fumigatus when compared to the multitude that did against some other pathogens. Here, we review the marine bioactive compounds that display a bioactivity against A. fumigatus. The challenges hampering the discovery of antifungal agents from this rich habitat are also critically analyzed. Further, we propose strategies that could speed up an efficient discovery and broaden the dimensions of screening in order to obtain promising in vivo antifungal agents with new modes of action.

Immune Response to Herpes Simplex Virus Infection and Vaccine Development.

Herpes simplex virus (HSV) infections are among the most common viral infections and usually last for a lifetime. The virus can potentially be controlled with vaccines since humans are the only known host. However, despite the development and trial of many vaccines, this has not yet been possible. This is normally attributed to the high latency potential of the virus. Numerous immune cells, particularly the natural killer cells and interferon gamma and pathways that are used by the body to fight HSV infections have been identified. On the other hand, the virus has developed different mechanisms, including using different microRNAs to inhibit apoptosis and autophagy to avoid clearance and aid latency induction. Both traditional and new methods of vaccine development, including the use of live attenuated vaccines, replication incompetent vaccines, subunit vaccines and recombinant DNA vaccines are now being employed to develop an effective vaccine against the virus. We conclude that this review has contributed to a better understanding of the interplay between the immune system and the virus, which is necessary for the development of an effective vaccine against HSV.

Seroprevalence of herpes simplex virus types 1 and 2 in Nigeria: a systematic review and meta-analyses.

A source of comprehensive information on the prevalence of herpes simplex virus type 1 and 2 (HSV-1 and HSV-2) can help researchers and policymakers address HSV related burden in the society. At the moment, this is not readily available. This study aims to fill this gap by attempting to estimate the seroprevalence of HSV-1 and HSV-2 infections in Nigeria on the basis of published data. A systematic review and meta-analysis including cross-sectional studies on HSV-1 and HSV-2 in Nigeria was conducted. Electronic databases including PubMed/MEDLINE, CENTRAL, African Journals Online (AJOL), ScienceDirect, WHO-Afro Library, WHO-IRIS and African Index Medicus were searched for English Language publications on HSV-1 and HSV-2. Seven relevant publications were identified. Seroprevalence measures of 3 and 23 for HSV-1 and HSV-2, respectively, were extracted. The pooled mean seroprevalences for HSV-1 and HSV-2 were 74.0% (37.4-99.4%) and 63.4% (56.1-70.4%) respectively. The mean seroprevalence of HSV-1 was higher among females, 82.4% (n = 509, CI, 36.6-100.0%), than males, 54.5% (n = 198, CI, 47.6-61.4%). The mean seroprevalence of HSV-2 were 51.8% (n = 1414, CI: 39.4-64.0%) and 86.5% (n = 162, CI: 80.8-91.3%) among healthy and clinical populations, respectively. The study was limited by the paucity of quality studies, variations in diagnostic methods and high heterogeneity in seroprevalence estimates. In conclusion, the seroprevalence of HSV-1 and HSV-2 remain high in Nigeria. Large and representative national epidemiological surveys covering all regions and specific groups are recommended.

Persistence of avian influenza viruses in lake sediment, duck feces, and duck meat.

The persistence of 3 low-pathogenicity avian influenza viruses (LPAIV) (H4N6, H5N1, and H6N8) and one human influenza virus (H1N1) as well as Newcastle disease virus (NDV) and enteric cytopathogenic bovine orphan (ECBO) virus was investigated in lake sediment, duck feces, and duck meat at 30, 20, 10, and 0°C using a germ carrier technique. Virus-loaded germ carriers were incubated in each substrate, and residual infectivity of the eluted virus was quantified on cell culture after regular intervals for a maximum of 24 weeks. Data were analyzed by a linear regression model to calculate T(90) values (time required for 90% loss of virus infectivity) and estimated persistence of the viruses. In general, the persistence of all of the viruses was highest in lake sediment, followed by feces, and was the lowest in duck meat at all temperatures. For the avian influenza virus subtypes, T(90) values in sediment ranged from 5 to 11, 13 to 18, 43 to 54, and 66 to 394 days at 30, 20, 10, and 0°C, respectively, which were 2 to 5 times higher than the T(90) values of the viruses in the feces and meat. Although the individual viruses vary in tenacity, the survival time of influenza viruses was shorter than that of NDV and ECBO virus in all substrates. The results of this study suggest that lake sediment may act as a long-term source of influenza viruses in the aquatic habitat, while the viruses may remain infectious for extended periods of time in duck feces and meat at low temperatures, allowing persistence of the viruses in the environment over winter.

Detection and characterization of sapoviruses in outbreaks of gastroenteritis in southwest Germany.

BACKGROUND: Sapovirus (SV) has been reported from many countries as one of the major causes of gastroenteritis in infants, but its importance for a broader age range is not well appreciated. While previous studies in our regional laboratory and other parts of Germany have identified Norovirus (NV) as a major cause of gastroenteritis in Germany, the prevalence of SV has not been recorded. OBJECTIVES: To investigate the prevalence of SV in outbreaks of gastroenteritis in Baden-Württemberg, Germany. STUDY DESIGN: Stool specimens from 34 outbreaks of gastroenteritis collected in Baden-Württemberg, Germany in 2002 and 2003, which tested negative for other enteric pathogens were tested for SV by RT-PCR. Positive samples were sequenced and typed using phylogenetic analysis. RESULTS: SV was identified in two of 157 (1.3%) specimens. These two viruses belonged to different genotypes of SV and had a nucleotide similarity of only 57%. CONCLUSIONS: SV circulates within the study area, but is not an important cause of gastroenteritis in the area.

Molecular epidemiology of norovirus in outbreaks of gastroenteritis in southwest Germany from 2001 to 2004.

The identification and molecular epidemiology of norovirus in outbreaks of gastroenteritis were studied during a 3-year period in Germany. Specimens (n = 316) from 159 nonbacterial gastroenteritis outbreaks from March 2001 to June 2004 were analyzed for the presence of noroviruses by reverse transcriptase PCR. Outbreaks were most frequent in elderly people's homes and care centers (43%), followed by hospitals (24%). Molecular analyses of strains from 148 outbreaks showed that there were up to 12 genotypes involved in the outbreaks. Genogroup II noroviruses were responsible for 95% of the outbreaks. Cocirculation of more than one strain in the same outbreak and cocirculation of genogroup I and II strains in the same place were observed. Genogroup II4 (Grimsby-like) was the most prevalent strain, accounting for 48% and 67% of the outbreaks in 2002 and 2003, respectively. The genogroup IIb (Castell/Suria) genotype was observed in all the years of the study. Epidemiological and molecular data indicated that there was a major shift of the predominant strain that coincided with the appearance of a new variant of genogroup II4 in 2002. By the application of reverse transcriptase PCR, this study has demonstrated the importance and dynamism of noroviruses in Germany.