Endemic Worldwide Research Articles

Host-virus interactions in hepatitis B and hepatitis C infection.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are among the most endemic pathogens worldwide, with more than 500 million people globally currently infected with these viruses. These pathogens can cause acute and chronic hepatitis that progress to liver cirrhosis or hepatocellular carcinoma. Both viruses utilize multifaceted strategies to evade the host surveillance system and fall below the immunological radar. HBV has developed specific strategies to evade recognition by the innate immune system and is acknowledged to be a stealth virus. However, extensive research has revealed that HBV is recognized by dendritic cells (DCs) and natural killer (NK) cells. Indoleamine-2, 3-dioxygenase is an enforcer of sequential immune reactions in acute hepatitis B, and this molecule has been shown to be induced by the interaction of HBV-infected hepatocytes, DCs, and NK cells. The interleukin-28B genotype has been reported to influence HCV eradication either therapeutically or spontaneously, but the biological function of its gene product, a type-III interferon (IFN-λ3), remains to be elucidated. Human BDCA3(+)DCs have also been shown to be a potent producer of IFN-λ3 in HCV infection, suggesting the possibility that BDCA3(+)DCs could play a key role in developing therapeutic HCV vaccine. Here we review the current state of research on immune responses against HBV and HCV infection, with a specific focus on innate immunity. A comprehensive study based on clinical samples is urgently needed to improve our understanding of the immune mechanisms associated with viral control and thus to develop novel immune modulatory therapies to cure chronic HBV and HCV infection.

Severe Acute Cytomegalovirus Infection Complicated by Disseminated Intravascular Coagulation and Pneumonitis in a Healthy Female

Cytomegalovirus (CMV) is an endemic infection worldwide. Among healthy individuals, infections are usually asymptomatic. An infectious mononucleosis-type syndrome is classically described. More serious manifestations, such as pneumonitis, hepatitis, and meningoencephalitis have been described in otherwise healthy populations. Disseminated intravascular coagulation is a life-threatening complication that is extremely rare in competent hosts. We describe a case of pneumonitis and DIC associated with acute CMV infection that resolved with antiviral therapy.

Effect of adenosine deaminase activity on lipid profile in patients of type 2 diabetes mellitus

Background: Type 2 diabetes mellitus is a worldwide endemic disease. Dyslipidemia is also a frequent disorder associated with diabetic patients. The present study is an attempt to link that elevated levels of adenosine deaminase in Type 2 diabetes mellitus patients augment hyperlipidemia. Material and Methods: The subjects included in this study were divided into 3 groups. Group A consisted of 30 normal healthy individuals who served as controls with no history of DM. Group B consisted of 30 patients of Type 2 Diabetes Mellitus both males & females in the age group of 40-65 years on oral hypoglycaemic drugs with HbA1c 7 %. Serum levels of fasting blood sugar, HbA1c, ADA and lipid profile were estimated in all the subjects under study. Results: All the three parameters, FBS, HbA1c and ADA levels were found to be increased in the patients of Type 2 DM as compared to controls. The mean S. Triglyceride and S. VLDL-C levels were significantly elevated in group C as compared to Group A. The mean serum levels of S. HDL-C showed a decreasing trend with increase in levels of HbA1c. Conclusion: From the present study, it was concluded that dyslipidemia was found to be higher in diabetic patients with respect to healthy controls. The lipid abnormality (dyslipidemia) associated with type 2 diabetes typically consists of elevated triglyceride and decreased HDL-C levels. Keywords: Diabetes Mellitus type 2, Adenosine deaminase (ADA), Glycated haemoglobin (HbA1c), Fasting blood Sugar (FBS)

Brugia malayi in Cervical Lymph Node Aspirate: A Rare Case Report

ABSTRACT Filariasis is endemic worldwide with the main focus in the tropical areas. Reported cases of filarial lymphadenopathy are caused by Wuchereria bancrofti, which is limited to the groin, the femoral triangle, and axilla, causing lymphedema of lower and upper limbs, and is usually diagnosed clinically and by the presence of microfilaria in peripheral blood smear. We are reporting an unusual case of cervical lymphadenitis, which on fine needle aspiration cytology (FNAC) showed microfilaria of a rare species, Brugia malayi. The purpose of this article is to make clinicians aware of this rare disease as one of the differential diagnoses of cervical lymphadenopathy in an endemic country like India. How to cite this article Srivastava A, Mohan C, Kumar S, Agarwal R. Brugia malayi in Cervical Lymph Node Aspirate: A Rare Case Report. Int J Adv Integ Med Sci 2016;1(2):79-80.

Assessing the economic burden of avian infectious bronchitis on poultry farms in Brazil.

Avian infectious bronchitis (IB), caused by avian infectious bronchitis virus (IBV), is a worldwide endemic disease of chickens that affects all branches of the poultry industry. Multiple geno/serotypes occur, and lowvaccine cross-protection results from the highly divergent IBV types. In view of the lack of consistent data on the economic losses caused by IB and the poor protection resulting from the use of the Massachusetts type as a live vaccine in Brazil, this survey aimed to estimate the losses per 1000 birds in broiler and breeder flocks positive for IBV. Thirty-two different IBV genetic types were found. In breeders, the total loss per 1,000 birds was US $3567.4 and US $4210.8 at 25-26 and 42 weeks old, respectively, whereas in broilers (48 days old), the estimated loss was US $266.3 per 1,000 birds. Taken together, the results show a significant and measurable economic impact on the broiler and breeder industries, with an age-dependent increasing trend and an association with multiple genetic types of the virus.

The health impacts of dietary sodium and a low-salt diet

High salt intake is now endemic worldwide. It contributes to the generation and maintenance of high blood pressure, which is now the biggest risk factor for global disease. There is now compelling evidence to support salt reduction in hypertensives and a substantial body of evidence to support salt reduction in the general population to reduce risk of death from cardiovascular disease. In specific diseases such as heart failure and chronic kidney disease, guidelines support the World Health Organization target for reduced salt intake at 5g daily. Achieving a diet that is lower in salt has challenges, but is more likely to be achieved through salt reduction strategies particularly focused on processed food and through educational programs. To be effective, these interventions require collaboration between industry, health agencies and governments.

Naiveté is not forever: responses of a vulnerable native rodent to its long term alien predators

Alien predators have wreaked havoc on isolated endemic and island fauna worldwide, a phenomenon generally attributed to prey naiveté, or a failure to display effective antipredator behaviour due to a lack of experience. While the failure to recognise and/or respond to a novel predator has devastating impacts in the short term after predators are introduced, few studies have asked whether medium to long term experience with alien predators enables native species to overcome their naiveté. In Australia, introduced dogs Canis lupus familiaris, foxes Vulpes vulpes and cats Felis catus have caused rapid extinctions and declines in small–medium sized native mammals since they were introduced ∼150 years ago. However, native wildlife have had ∼4000 years experience with another dog – the dingo Canis lupus dingo. Native bush rats Rattus fuscipes remain common despite predation from these predators. We predicted that prior experience with dingoes would mean that bush rats recognise and respond to dogs, but suspect that hundreds of years experience may not be enough for effective responses to cats and foxes. To test these predictions, we combined the giving‐up density (GUD) with analysis of remote camera footage to measure bush rat foraging and behavioural responses to body odour from dogs, foxes, cats and native spotted‐tail quolls Dasyurus maculatus. Bush rats responded strongly to dogs with increased GUDs, increased vigilance and decreased foraging. However, mixed responses to foxes and cats suggest that at least some individuals remain naïve towards these predators. Naiveté is not necessarily forever: alien predators devastate many native prey species, but others may learn or adapt to the new threat.

Estimating the Future Impact of a Multi-Pronged Intervention Strategy on Ocular Disease Sequelae Caused by Trachoma: A Modeling Study

Purpose: Trachoma control programs are underway in endemic regions worldwide. They are based on the SAFE strategy (Surgery for trichiasis, Antibiotic distribution, Facial cleanliness, and Environmental improvement). Although much is known about the effect of community-wide treatment with antibiotics on the prevalence of Chlamydia trachomatis, the impact of the SAFE strategy on severe ocular disease sequelae (the main focus of the Global Elimination of blinding Trachoma by 2020 program) remains largely unknown.Methods: We use a mathematical model to explore the impact of each of the components of the SAFE strategy, individually and together, on disease sequelae, arising from repeat infection and subsequent conjunctival scarring. We ask whether two elimination goals, to reduce the prevalence of trachomatous trichiasis to 1 per 1000 persons, and the incidence of corneal opacity to 1 per 10,000 persons per annum, are achievable, and which combinations of interventions have the greatest impact on these indicators.Results: In high prevalence communities (here, >20% infection of children aged 1–9 years), a combination of efforts is needed to bring down sustainably the prevalence and incidence of ocular disease sequelae.Conclusion: The mass delivery of antibiotics is highly beneficial for the clearance of infection, inflammation and prevention of subsequent scarring, but needs to be supplemented with sustained reductions in transmission and surgery to consider realistically the elimination of blindness by the year 2020.

Antileishmanial Activity of Compounds Derived from the Medicines for Malaria Venture Open Access Box Against Intracellular Leishmania major Amastigotes.

Leishmaniasis is a complex tropical disease caused by kinetoplastid parasitic protozoa of the genus Leishmania and is transmitted by the sand fly insect vector. Cutaneous leishmaniasis (CL) is the most common form of this disease, and CL infections often result in serious skin lesions and scars. CL remains a public health problem in many endemic countries worldwide because of the absence of effective, safe, and cost-effective drugs for treatment. One of the strategies we chose to use to find novel chemical entities worthy of further development as antileishmanials involved screening synthetic and natural products libraries. In our study, we developed a Leishmania major intracellular amastigote assay that uses the activity of luciferase as a measure of parasite proliferation and used this assay to screen a collection of 400 compounds obtained from Medicines for Malaria Venture (MMV) for their antileishmanial activity. Our results showed that 14 compounds identified by MMV as antimalarial drugs have antileishmanial activity and can potentially be optimized for CL drug development.

Coxiella burnetii Endocarditis and Aortic Vascular Graft Infection: An Underrecognized Disease

Q fever is considered endemic worldwide, and endocarditis, or aortic vascular infection, or both caused by Coxiella burnetii can be a fatal disease. The importance of surgical intervention has not yet been defined. We performed a descriptive retrospective study to assess indications for surgical treatment, timing of treatment, and outcome. We studied all patients from the cardiac surgery department of a large tertiary hospital who underwent valve surgical procedure due to endocarditis or aortic surgical procedure due to graft infection. Throughout a 10-year period, we performed a total of 171 procedures due to valve endocarditis and/or vascular infection. In 16 patients (9.36%) Coxiella burnetii infection was diagnosed. Ten patients had previous cardiac surgical procedures, 3 had previous aortic surgical procedures, 2 had preexisting valvular disease, and 1 patient had no previous valve disorder. All patients received prolonged oral-specific antibiotic therapy under serologic guidance. In 9 patients antibiotic treatment (doxycycline and hydroxychloroquine) was started before the surgical procedure (12.4 ± 37.5 days), and in 7 patients after the surgical procedure (5.1 ± 13.5 days). We observed one in-hospital death (6.25%) and no long-term mortality. The mean follow-up period was 50.5 ± 34.7 months (range, 2 to 104 months). In this series surgical treatment yielded good results for both Q fever endocarditis and vascular graft infection. No association was found between timing of the surgical procedure and patients' outcomes.

Intestinal Parasitic Infections among School Children.

Introduction: Intestinal parasitic infections are endemic worldwide and constitute a major public health problem and considered as ‘cancers of developing countries. Nepal is small improvised country where 70.0% of morbidity and mortality are associated with infectious diseases. Giardiasis, ascariasis, amoebiasis, ancyclostomiasis and taeniasis are common intestinal parasitic infections in Nepal. Thus, in this paper we report the prevalence of intestinal parasitic infection among school going children of Eastern part of Nepal. Mathods: A total of 300 stool samples were collected from school children of Eastern part of Nepal in random basis. An informed consent was taken from both students and school teachers. The samples were examined for the presence of parasites both macroscopically and microscopically. Standard parasitological examination methods were followed. Results: Out of total 300 school going children included in the study, 195 were male and 105 were female. A total of 97 (29.1%) were positive for one or more parasites. Out of total parasites detected, 35 (36.1%) were protozoan, 39 (40.2%) were helminthes and 23(23.7%) were mixed type. Giardia intestinalis 30 (30.9%) and Hookworm 18 (18.6%) were the commonest protozoan and helminthes respectively. The other parasites detected were A. lumbricoides 15(15.5%), H. nana 6 (6.2%) and Entamoeba histolytica 5(5.2%). Multiple parasitism was detected in 23(23.7%) children. Conclusion: The incidence of intestinal parasite infection was 29%. The commonest infestation was Helminthe. Regular deworming program in association to other preventive measures may help reduce the prevalence.doi: http://dx.doi.org/10.3126/mjsbh.v13i1.12994

Occult Hepatitis B Virus Infection in Nigerian Blood Donors and Hepatitis B Virus Transmission Risks.

BackgroundOccult hepatitis B virus infection (OBI) characterized by the absence of detectable HBsAg remains a potential threat in blood safety. We investigated the actual prevalence, viral factors and genotype of OBI infections in Nigerian blood donors.MethodsSerum collected from two blood banks were reconfirmed as HBsAg seronegative by ELISA. Forty HBsAg positive samples were employed as controls. HBV-DNA was amplified from all donors and viral loads were determined using quantitative real-time PCR. Antibodies to the HBV core, surface and HBe antigen (anti-HBc,anti-HBs,HBeAg) were measured. The PreS/S and PreC/C regions of the HBV genome were sequenced.ResultsOf the 429 blood donors, 72(17%) were confirmed as OBI by DNA detection in different reference labs and excluded the concern of possible contamination. Of the 72 OBI samples, 48(67%) were positive for anti-HBc, 25(35%) positive for anti-HBs, and 2(3%) positive for HBeAg. Of the 72 OBI samples, 31(43%) were seropositive for either anti-HBc, anti-HBs or HBeAg, 21 (30%) positive for both anti-HBc and anti-HBs,one positive for both anti-HBc and HBeAg. None of the OBI samples were positive for all three serological markers. The viral load was <50copies/ml in the OBI samples and genotype E was predominant. The L217R polymorphism in the reverse transcriptase domain of the HBV polymerase gene was observed significantly higher in OBI compared with HBsAg positive individuals (P<0.0001).ConclusionHigh incidence of OBI is relevant in high endemic areas worldwide and is a general burden in blood safety. This study signifies the high prevalence of OBI and proposes blood donor samples in Nigeria should be pre-tested for OBI by nucleic acid testing (NAT) and/or anti-HBc prior to transfusion to minimize the HBV infection risk.

Taenia solium Human Cysticercosis: A Systematic Review of Sero-epidemiological Data from Endemic Zones around the World.

Background Taenia solium cysticercosis is a zoonotic neglected disease responsible for severe health disorders such as seizures and death. Understanding the epidemiology of human cysticercosis (HCC) in endemic regions will help to expose critical information about the transmission of the disease, which could be used to design efficient control programs. This review gathered serological data on apparent prevalence of T. solium circulating antigens and/or seroprevalence of T. solium antibodies, apparent prevalence of human taeniasis and risk factors for HCC from endemic communities in order to understand the differences in exposure to the parasite and active infections with T. solium metacestodes in endemic areas around the world.MethodsThree databases were used to search sero-epidemiological data from community-based studies conducted between 1989 and 2014 in cysticercosis endemic communities worldwide. The search focused on data obtained from T. solium circulating antigen detection by monoclonal antibody-based sandwich ELISA and/or T. solium antibody seroprevalence determined by Enzyme-linked Immunoelectrotransfer Blot (EITB). A meta-analysis was performed per continent.Principal FindingsA total of 39,271 participants from 19 countries, described in 37 articles were studied. The estimates for the prevalence of circulating T. solium antigens for Africa, Latin America and Asia were: 7.30% (95% CI [4.23–12.31]), 4.08% (95% CI [2.77–5.95]) and 3.98% (95% CI [2.81–5.61]), respectively. Seroprevalence estimates of T. solium antibodies were 17.37% (95% CI [3.33–56.20]), 13.03% (95% CI [9.95–16.88]) and 15.68% (95% CI [10.25–23.24]) respectively. Taeniasis reported prevalences ranged from 0 (95% CI [0.00–1.62]) to 17.25% (95% CI [14.55–20.23]).SignificanceA significant variation in the sero-epidemiological data was observed within each continent, with African countries reporting the highest apparent prevalences of active infections. Intrinsic factors in the human host such as age and immunity were main determinants for the occurrence of infections, while exposure was mostly related to environmental factors which varied from community to community.

Molecular characterization of clinical isolates of Cyclospora cayetanensis from patients with diarrhea in India

Purpose:Cyclospora cayetanensis is an intestinal coccidian protozoan that has emerged as an important cause of both epidemic and endemic protracted diarrhea worldwide. Though humans appear to be the only natural hosts; the role of animals as natural reservoir is uncertain but of increasing concern. The present study aimed to study the prevalence of coccidian in different groups such as immunocompromised, clinically apparent immunocompetent and healthy individuals. Also, the study isolates were assessed for heterogeneity among the sequences. Materials and Methods: Stool samples from different groups of patients were collected. The parasite was detected in stool by different diagnostic tools such as light microscopy and nested PCR-restriction fragment length polymorphism using 18S ribosomal RNA as the target gene. Results: The prevalence of C. cayetanensis was 2.4% (19/800) in the present study. The PCR assay amplified Cyclospora cayetanensis DNA in only 89% (17/19) isolates. Further, sequencing revealed no significant difference among the study isolates and the non-primates. Phylogenetic analysis of the study isolates however, formed two clusters. While one cluster showed close evolutionary association with the C. cayetanensis strains, the other cluster showed evolutionary association with the two non-primate species. Conclusion: The methods described here for detection of C. cayetanensis oocysts are simple, efficient, specific, and sensitive and therefore can be effectively applied for laboratory diagnosis and environmental assessment of fresh produce and water sources. Clinicians should include Cyclospora infection in the differential diagnosis of prolonged or relapsing diarrheal illness even in clinically apparent immunocompetent individuals.

The Effect of Solar Irradiated Vibrio cholerae on the Secretion of Pro-Inflammatory Cytokines and Chemokines by the JAWS II Dendritic Cell Line In Vitro.

The use of solar irradiation to sterilize water prior to its consumption has resulted in the reduction of water related illnesses in waterborne disease endemic communities worldwide. Currently, research on solar water disinfection (SODIS) has been directed towards understanding the underlying mechanisms through which solar irradiation inactivates the culturability of microorganisms in water, enhancement of the disinfection process, and the health impact of SODIS water consumption. However, the immunological consequences of SODIS water consumption have not been explored. In this study, we investigated the effect that solar irradiated V. cholerae may have had on the secretion of cytokines and chemokines by the JAWS II dendritic cell line in vitro. The JAWS II dendritic cell line was stimulated with the different strains of V. cholerae that had been: (i) prepared in PBS, (ii) inactivated through a combination of heat and chemical, (iii) solar irradiated, and (iv) non-solar irradiated, in bottled water. As controls, LPS (1 μg/ml) and CTB (1 μg/ml) were used as stimulants. After 48 hours of stimulation the tissue culture media from each treatment was qualitatively and quantitatively analysed for the presence of IL-1α, IL-1β, IL-6, IL-7, IL-10, IL-12p40, IL-12p70, IL-15, MIP-1α, MIP-1β, MIP-2, RANTES, TNF-α, IL-23 and IL-27. Results showed that solar irradiated cultures of V. cholerae induced dendritic cells to secrete significant (p<0.05) levels of pro-inflammatory cytokines in comparison to the unstimulated dendritic cells. Furthermore, the amount of pro-inflammatory cytokines secreted by the dendritic cells in response to solar irradiated cultures of V. cholerae was not as high as observed in treatments involving non-solar irradiated cultures of V. cholerae or LPS. Our results suggest that solar irradiated microorganisms are capable of inducing the secretion of pro-inflammatory cytokines and chemokines. This novel finding is key towards understanding the possible immunological consequences of consuming SODIS treated water.

Development of the Brazilian Anti Schistosomiasis Vaccine Based on the Recombinant Fatty Acid Binding Protein Sm14 Plus GLA-SE Adjuvant

Data herein reported and discussed refer to vaccination with the recombinant fatty acid binding protein (FABP) family member of the schistosomes, called Sm14. This antigen was discovered and developed under a Brazilian platform led by the Oswaldo Cruz Foundation, from the Health Ministry in Brazil, and was assessed for safety and immunogenicity in healthy volunteers. This paper reviews past and recent outcomes of developmental phases of the Sm14-based anti schistosomiasis vaccine addressed to, ultimately, impact transmission of the second most prevalent parasitic endemic disease worldwide.

Whole genome analysis to detect potential vaccine-induced changes on Shigella sonnei genome

Shigellosis or bacillary dysentery is endemic worldwide and is a significant cause of death in children less than five years of age in developing countries. There are no licensed Shigella vaccines and glycoconjugates are among the leading candidate vaccines against shigellosis today.We used whole genome sequence analysis (WGA) to find out whether immunization, with an investigational Shigella sonnei glycoconjugate, could induce selective pressure leading to changes in the genome of S. sonnei. An outbreak of culture-proven S. sonnei shigellosis which occurred immediately after vaccination in one of the cohorts of volunteers participating in a phase III trial of the vaccine in Israel created a unique condition in which the epidemic agent “co-existed” with the developing immune responses induced by the vaccine and natural infection among vaccinees who developed S. sonnei shigellosis. By comparing the whole genomes of S. sonnei isolated from vaccinees and from volunteers in the control group, we show at a very high sensitivity that a potent S. sonnei glycoconjugate that conferred 74% protective efficacy against the homologous disease did not induce changes in the genome of S. sonnei and in particular on the O-antigen gene cluster.

Sero-epidemiological survey of human cystic echinococcosis in Kashmir, North India.

BackgroundEchinococcosis is a human and animal health problem in many endemic areas worldwide. There are numerous reports and hospital-based studies from Kashmir, North India, yet there has been no epidemiological study conducted in Kashmir, the apparently endemic area for human hydatidosis. This study was designed to determine the seroprevalence of hydatid infection in Kashmir Valley and to find out association of risk factors for acquisition of this infection.MethodologyFourteen hundred and twenty-nine samples were collected from different districts in the Kashmir region (North India) using systematic random sampling. The 130 control samples included were from apparently healthy blood donors (100), patients with other parasitic infections (20), surgically confirmed hydatidosis patients (5), and apparently healthy subjects excluded for hydatidosis and intestinal parasitic infections (5). Hydatid-specific IgG antibody was detected by enzyme-linked immunosorbent assay, and seropositive samples were analysed further by Western blotting.ResultsOut of 1,429 samples, 72 (5.03%) were IgG positive by ELISA. The percentage occurrence of the highly immunoreactive antigenic fractions in IgG ELISA positive samples was 57 kDa (72.2%) followed by 70 kDa (66.7%) and 39kDa (58.3%) by immunoblotting. Samples with other parasitic infections were reactive with the cluster of 54-59 kDa antigenic fractions. Age <15 years, male gender, contact with dog, and rural residence were the most significant factors associated with the seropositivity.ConclusionThe study revealed that 72 (5.03%) out of 1,429 subjects asymptomatic for hydatidosis were seropositve to E.granulosus antigen by ELISA. Western blot analysis of 72 ELISA seropositive samples showed that 66.7% and 58.3% of samples were immunoreactive with 70 and 39kDa specific antigenic fractions, respectively. The seropositivity was significantly higher (5.79%) in the younger age group (<15 years) as compared to the 16-55 years (4.07%) and > 55 years (3.05%) age groups, suggesting ongoing transmission of this infection in the younger age group. The number of seropositive males was significantly higher as compared to females. The risk factors identified were rural residence and contact with dogs. The study suggests the presence of asymptomatic infection in subjects in Kashmir, North India, and efforts need to be made for implementation of effective prevention measures to reduce the infection burden, which may otherwise lead to symptomatology and complications in the infected subjects.

Hepatitis B reactivation in the setting of chemotherapy and immunosuppression - prevention is better than cure.

Due to the inherent relationship between the immune system and the hepatitis B virus (HBV) in exposed and infected individuals, immunomodulation associated with the treatment of solid tumours, haematological malignancies and inflammatory disorders has been linked to HBV reactivation (HBVr). Reactivation of HBV infection in the setting of chemotherapy and immunosuppression may lead to fulminant liver failure and death, but there is a cumulative body of evidence that these are potentially preventable adverse outcomes. As chronic hepatitis B is largely asymptomatic but also endemic worldwide, clinicians caring for patients requiring chemotherapy or immunosuppression need to be vigilant of the potential for HBVr in susceptible individuals. Serological screening and prophylactic and pre-emptive antiviral treatment with a nucleos(t)ide analogue should be considered in appropriate settings. Hepatitis B prevalence is examined in this review article, as are the risks of HBVr in patients receiving chemo- and immunosuppressive therapy. Recommendations regarding screening, monitoring and the role of antiviral prophylaxis are outlined with reference to current international associations' guidelines and the best available evidence to date.

Pathogenesis of varicelloviruses in primates.

Varicelloviruses in primates comprise the prototypic human varicella-zoster virus (VZV) and its non-human primate homologue, simian varicella virus (SVV). Both viruses cause varicella as a primary infection, establish latency in ganglionic neurons and reactivate later in life to cause herpes zoster in their respective hosts. VZV is endemic worldwide and, although varicella is usually a benign disease in childhood, VZV reactivation is a significant cause of neurological disease in the elderly and in immunocompromised individuals. The pathogenesis of VZV infection remains ill-defined, mostly due to the species restriction of VZV that impedes studies in experimental animal models. SVV infection of non-human primates parallels virological, clinical, pathological and immunological features of human VZV infection, thereby providing an excellent model to study the pathogenesis of varicella and herpes zoster in its natural host. In this review, we discuss recent studies that provided novel insight in both the virus and host factors involved in the three elementary stages of Varicellovirus infection in primates: primary infection, latency and reactivation.