This chapter primarily focuses on two human viruses as a means to explore the conserved similarities and unique differences of DNA viruses. Human papilloma viruses (HPV) and Kaposi's sarcoma-associated herpes virus (KSHV), also known as human herpesvirus-8, are of particular interest because both viruses are causative agents of several human cancers, and therefore represent a subset of DNA viruses that are highly relevant to human disease. The chapter highlights the common viral themes of all DNA viruses including: members of Geminiviridae, Herpesviridae, Nanoviridae, Papillomaviridae, Poxviridae, Parvoviridae, Polyomaviridae, Adenoviridae and Circoviridae, specifically T4 bacteriophage, various large nucleocytoplasmic large DNA viruses, torque teno virus, Hepatitis B virus, Epstein–Barr virus, pox viruses, Simian virus-40 and variola virus. DNA viruses are everywhere, on animals, plants, soil, and fresh and salt water. KSHV is the most recent of the eight human Herpes viridae known family members to be identified.
Herpesviruses are prevalent throughout the animal kingdom, and they have coexisted and coevolved along with their host species for millions of years. Herpesviruses carry a large (120-230 kb) double-stranded DNA genome surrounded by a protein capsid, a tegument layer consisting of viral and host proteins, and a lipid bilayer envelope with surface glycoproteins. A key characteristic of these viruses is their ability to enter a latent state following primary infection, allowing them to evade the host’s immune system and persist permanently. Herpesviruses can reactivate from their dormant state, usually during times of stress or when the host’s immune responses are impaired. While herpesviruses can cause complications with severe disease in immune-compromised people, most of the population experiences few ill effects from herpesvirus infections. Indeed, herpes simplex virus 1 (HSV-1) in particular has several features that make it an attractive tool for therapeutic gene delivery. Herpes simplex virus 1 targets and infects specific cell types, such as epithelial cells and neurons. The HSV-1 genome can also accommodate large insertions of up to 14 kb. The HSV-1-based vectors have already achieved success for the oncolytic treatment of melanoma. In addition to serving as a vehicle for therapeutic gene delivery and targeted cell lysis, comparative genomics of herpesviruses HSV-1 and 2 has revealed valuable information about the evolutionary history of both viruses and their hosts. This review focuses on the adaptability of HSV-1 as an instrument for gene delivery and an evolutionary marker. Overall, HSV-1 shows great promise as a tool for treating human disease and studying human migration patterns, disease outbreaks, and evolution.
BACKGROUND:Worldwide, approximately 257 million people have chronic hepatitis B virus (HBV) infection, with the highest infection rates recorded in Africa and Asia. Although HBV infection has been associated with dyslipidemia, which may lead to death via liver related complications, the effect of the virus on the lipid profile of patients remain unclear. This study was designed to evaluate the effect of chronic hepatitis B virus infection on lipid profile of sero-positive individuals from Ghana.METHODS:Blood samples were collected from chronic HBV infected patients who were recruited from the Korle-Bu Teaching Hospital, Accra, and HBV sero-negative healthy volunteers who were used as controls. Demographic and clinical data were obtained using a structured questionnaire. Blood pressure and body mass index were determined, and HBV profile markers and lipid profiles of the patients were determined using a commercially available kit and a chemistry analyzer, respectively.RESULTS:Triglycerides, low density lipoproteins (LDL), high density lipoproteins (HDL), very low density lipoproteins (VLDL), and total cholesterol were used as indices of lipid metabolism disorder. Body mass index and diastolic blood pressures were significantly elevated in patients compared to healthy volunteers.CONCLUSION:The observed high total cholesterol and LDL, with a significantly lower HDL levels compared to healthy controls suggest an increased cardiovascular disease risk index in the patients. There is therefore the need to regularly monitor HBV infected patients for signs of cardiovascular diseases.
Filoviruses cause outbreaks which lead to high fatality in humans and non-human primates, thus tagging them as major threats to public health and species conservation. In this review, we give account of index cases responsible for filovirus disease outbreaks that have occurred over the past 52 years in a chronological fashion, by describing the circumstances that led to the outbreaks, and how each of the outbreaks broke out. Since the discovery of Marburg virus and Ebola virus in 1967 and 1976, respectively, more than 40 filovirus disease outbreaks have been reported; majority of which have occurred in Africa. The chronological presentation of this review is to provide a concise overview of filovirus disease outbreaks since the discovery of the viruses, and highlight the patterns in the occurrence of the outbreaks. This review will help researchers to better appreciate the need for surveillance, especially in areas where there have been no filovirus disease outbreaks. We conclude by summarizing some recommendations that have been proposed by health and policy decision makers over the years.
Background: Cytomegalovirus (CMV) infection risk in the first month after transplantation is felt to be minimal; however, the epidemiology has not been specifically investigated, particularly in the modern era of potent immunosuppressive regimens and universal CMV prophylaxis. Objective: The aim of this study was to describe the incidence of and risk factors associated with CMV occurring less than 30 days after transplant and evaluate the effect of very early CMV on outcomes. Methods: Retrospective, single-center study of adult renal transplant (RTX) recipients between January 1, 1994 and December 31, 2014. Results: A total of 5225 patients who received a renal transplant in the study time period were reviewed for the presence of CMV infection occurring less than 30 days after transplant. Of these, only 14 patients demonstrated this finding for an overall incidence of 0.27%. Half of these patients were considered to be at heightened risk due to being a recipient of a non-primary transplant or on chronic immunosuppression. This left seven patients without known risk factors for very early CMV to evaluate. In this group, time from transplant to CMV infection was 13.5 ± 7 days. The majority (57.1%, n = 4) were high-risk serostatus (CMV D+/R−) and occurred in the valganciclovir era (71.4%, n = 5). Lymphocyte-depleting induction predominated (57.1%, n = 4). Average cold ischemic time (CIT) was 19.7 ± 7.7 hours. Three patients had post-operative complications, two required exploratory-laparotomy for hemorrhage. When evaluating outcomes, 43% (n = 3) had subsequent episodes of CMV infection, 28.6% (n = 2) developed rejection, and 28.6% (n = 2) died. Outcomes between patients with CMV infection less than 30 days and those with CMV infection more than 30 days after transplant were not significantly different. Conclusions: In our review of over 5000 kidney transplants, the incidence of CMV infection in the first 30 days after renal transplant is 0.2%. Notable common patient characteristics include hemorrhage requiring re-operation and prolonged CIT. Outcomes were similar to CMV occurring more than 30 days after transplant. This study should provide the clinician with some reassurance; despite potent immunosuppressive therapy, CMV infection in the first 30 days is unlikely.
