No abstract

Recently, the first case of HIV and SARS-CoV-2 infection was reported in the literature. With this letter, we proposed a hypothesis that could explain the interaction between HIV infection and the clinical course of SARS-CoV-2 infection.

Hepatitis C virus (HCV) affects about 3% of the world's population and peaks in subjects aged over 40 years. Its prevalence in pregnant women is low (1%-2%) in most western countries but drastically increases in women in developing countries or with high risk behaviors for blood-transmitted infections. Here we review clinical, prognostic and therapeutic aspects of HCV infection in pregnant women and their offspring infected through vertical transmission. Pregnancy-related immune weakness does not seem to affect the course of acute hepatitis C but can affect the progression of chronic hepatitis C. In fact, postpartum immune restoration can exacerbate hepatic inflammation, thereby worsening the liver disease, particularly in patients with liver cirrhosis. HCV infection increases the risk of gestational diabetes in patients with excessive weight gain, premature rupture of membrane and caesarean delivery. Only 3%-5% of infants born to HCV-positive mothers have been infected by intrauterine or perinatal transmission. Maternal viral load, human immunodeficiency virus coinfection, prolonged rupture of membranes, fetal exposure to maternal infected blood consequent to vaginal or perineal lacerations and invasive monitoring of fetus increase the risk of viral transmission. Cesarean delivery and breastfeeding increases the transmission risk in HCV/human immunodeficiency virus coinfected women. The consensus is not to offer antiviral therapy to HCV-infected pregnant women because it is based on ribavirin (pregnancy category X) because of its embryocidal and teratogenic effects in animal species. In vertically infected children, chronic C hepatitis is often associated with minimal or mild liver disease and progression to liver cirrhosis and hepatocarcinoma is lower than in adults. Infected children may be treated after the second year of life, given the adverse effects of current antiviral agents.

About 3-5 % of the world's population is chronically infected by hepatitis B virus (HBV) and is at risk of developing liver cirrhosis or hepatocellular carcinoma. The risk of dying prematurely because of chronic HBV infection is higher in younger people. The current strategies to prevent HBV infection involve immunization (active and/or passive) and antiviral chemoprophylaxis. The vaccines available for active immunization, containing hepatitis B surface antigen, are safe and confer long-term immunity in most healthy subjects. Since the vaccination is unsatisfactory in some patients, e.g., those with chronic kidney disease, human immunodeficiency virus infection, type I diabetes mellitus, and celiac disease, new strategies of vaccination are required. The neonatal, infant, and adolescent routine program vaccination in about 180 countries has greatly decreased the disease burden. Passive immunization with specific HBV immunoglobulins is recommended after single acute exposure, in infants born to infected mothers, and in HBV-infected patients undergoing liver transplantation combined with nucleoside/nucleotide analogues (chemoprophylaxis). Chemoprophylaxis is also indicated in HBV carrier candidates for immunosuppressive treatment and in patients with occult B infection undergoing immunosuppressive therapy or hematopoietic stem cell transplantation. Since HBV is not eradicable by an immune response or by antiviral drugs developed so far, the only preventive strategy remains global neonatal vaccination in all countries, firstly in HBV-endemic countries.

In Italy, the incidence of hepatitis A has progressively declined over the last 30 years, though not homogeneously throughout the country. In Campania, Southern Italy, high annual incidence rates have been reported and several periodic outbreaks have occurred. To investigate the phylogenetic and epidemiologic relationships among HAV strains circulating in Campania over the period 1997-2015, 87 hepatitis A cases were investigated. The most frequent risk factor was the consumption of raw/undercooked shellfish (75/87, 86.2%). During 1997-2002 most viral strains were subtype IA (16/23, 70%); the phylogenetic pattern suggests that the incidence peaks observed in 2000-2001 had likely been caused by multiple strains. During a large 2004 outbreak, almost all viral variants were subtype IB (38/41, 93%); most of them (22/38, 58%) were recognized to be one of two main strains (differing for just a single nucleotide), the remaining sequences were strictly related variants. In 2014/2015, only IA strains were observed; two phylogenetically related but distinct strains were responsible, respectively, for a small cluster in 2014 and an outbreak in 2015. In each outbreak, several strains unrelated to those responsible for most cases were detected in a minority of patients, documenting a background of sporadic cases occurring even in the course of outbreaks; some of them proved to be identical to strains detected 11-14 years previously. Overall, the data suggest that several related and unrelated HAV strains have endemically circulated over the last 15 years in Campania, with some strains gaining epidemic transmission likely because of a local combination of multiple factors, including inadequate waste water purification and dietary habits.