Herpes simplex virus (HSV) infections are very common in the general population and among immunocompromised patients. Acyclovir (ACV) is an effective treatment which is widely used. We deemed it essential to conduct a wide and coordinated survey of the emergence of ACV-resistant HSV strains . We have formed a network of 15 virology laboratories which have isolated and identified, between May 1999 and April 2002, HSV type 1 (HSV-1) and HSV-2 strains among hospitalized subjects. The sensitivity of each isolate to ACV was evaluated by a colorimetric test (C. Danve, F. Morfin, D. Thouvenot, and M. Aymard, J. Virol. Methods 105:207-217, 2002). During this study, 3,900 isolated strains among 3,357 patients were collected; 55% of the patients were immunocompetent. Only six immunocompetent patients excreted ACV-resistant HSV strains (0.32%), including one female patient not treated with ACV who was infected primary by an ACV-resistant strain. Among the 54 immunocompromised patients from whom ACV-resistant HSV strains were isolated (3.5%), the bone marrow transplantation patients showed the highest prevalence of resistance (10.9%), whereas among patients infected by human immunodeficiency virus, the prevalence was 4.2%. In 38% of the cases, the patients who excreted the ACV-resistant strains were treated with foscarnet (PFA), and 61% of them developed resistance to PFA. The collection of a large number of isolates enabled an evaluation of the prevalence of resistance of HSV strains to antiviral drugs to be made. This prevalence has remained stable over the last 10 years, as much among immunocompetent patients as among immunocompromised patients.Herpes simplex virus (HSV) infections are very common; they are localized on the face and torso in the case of HSV type 1 (HSV-1) and in the genital region in the case of HSV-2. HSV-1 infections in the genital region are on the increase (40). Ocular herpes is less frequent, and neonatal herpes and herpetic meningoencephalitis are very rare but have a severe functional and vital prognosis (37).Since acyclovir (ACV) {9-[(2-hydroxyethoxy)methyl)guanine]} was introduced to the market in 1983, it has been used primarily in the prevention and treatment of HSV infections. ACV-resistant HSV strains have been observed in vivo since the first large therapeutic trials (5, 10, 36). These resistant strains are detected in vitro by phenotypic tests which determine the antiviral concentration inhibiting viral replication by 50%. Several methods have been used to evaluate the sensitivity of the HSV strains to ACV, including techniques to detect the intensity of the cytopathic effect, such as the plaque reduction (17, 31) and colorimetric (11,22,26) techniques, but also the detection of DNA replication by hybridization (39) or antigen production by flow cytometry (30).Previous surveys among immunocompetent patients have shown a prevalence of resistance to ACV varying between 0 and 0.6%, whereas among immunocompromised patients, the prevalence varied between 3 and 6% (9,16,29). The use of ACV is co...

Intravenous administration of anti-B-cell antibodies may be effective in controlling diffuse, severe, oligoclonal B-cell proliferation not involving the central nervous system.

Fourteen cases of severe acyclovir-resistant herpes simplex virus type 1 (HSV-1) infection, 7 of which showed resistance to foscarnet, were diagnosed among 196 allogeneic stem cell transplant recipients within a 29-month period. Recipients of unrelated stem cell transplants were at higher risk. All patients received foscarnet; 8 subsequently received cidofovir. Strains were initially foscarnet-resistant in 3 patients and secondarily so in 4 patients. In vitro resistance to acyclovir or foscarnet was associated with clinical failure of these drugs; however, in vitro susceptibility to foscarnet was associated with complete response in only 5 of 7 patients. No strain from any of the 7 patients was resistant in vitro to cidofovir; however, only 3 of 7 patients achieved complete response. Therefore, acyclovir- and/or foscarnet-resistant HSV-1 infections after allogeneic stem cell transplantation have become a concern; current strategies need to be reassessed and new strategies must be evaluated in this setting.

Since its discovery, human parvovirus B19 (B19V), now termed erythrovirus, has been associated with many clinical situations (neurological and myocardium infections, persistent B19V DNAemia) in addition to the prototype clinical manifestations, i.e., erythema infectiosum and erythroblastopenia crisis. In 2002, the use of new molecular tools led to the characterization of three different genotypes of human B19 erythrovirus. Although the genomic organization is conserved, the geographic distribution of the different genotypes varies worldwide, and the nucleotidic divergences can impact the molecular diagnosis of B19 virus infection. The cell cycle of the virus remains partially unresolved; however, recent studies have shed light on the mechanism of cell entry and the interactions of B19V proteins with apoptosis pathways.Before the recent descriptions of human bocavirus (2) and human parvovirus 4 (PARV4) (41), parvovirus B19 ([B19V] or erythrovirus B19) was the only known member of the Parvoviridae family to infect humans. The Erythrovirus genus contains B19V, erythroviruses that infect several simian species, and the parvovirus from Manchurian chipmunks (87a). These viruses share the remarkable property of replicating in and destroying erythroid progenitors. This strong in vitro tropism explains the difficulties in studying the replicative cycle of these viruses; indeed, the in vitro production and culture of erythroid progenitor cells remain delicate. An infectious B19V clone was described only recently (102), and its use, although mostly limited and allowing only a small amount of progeny production, led to constructions of recombinant viruses that were helpful in understanding the steps of the virus life cycle and the toxicity of the virus. Discovered in 1975 (19), B19V can cause a wide range of mild and self-limiting clinical manifestations, such as erythema infectiosum (fifth disease) and oligoarthritis (98). B19V infection can also cause acute anemia by aplastic crisis in patients whose red blood cells have shortened survival times (i.e., patients with sickle cell disease, thalassemia, spherocytosis, or any disorder of hemoglobin gene expression or red cell membrane constitution), chronic anemia in patients with congenital immunodeficiencies or human immunodeficiency virus (HIV) infection or who are undergoing chemotherapy for malignancies or organ transplants (48, 58), and hydrops fetalis or intrauterine death in infected fetuses (86). Recently, cases of neurological manifestations have been associated with B19V infection (22), as have myocardium infections (4,5,47,83), and the spectrum of B19V-linked diseases may further increase. CLINICAL MANIFESTATIONSThe primary route of transmission of B19V is the respiratory tract (via aerosol droplets), with a majority of infections occurring during childhood, but the infection may also be transmitted by organ transplantation and especially by transfusion of blood components, in particular by packed red cells from blood collected during the short preseroconversion vi...

We report three cases of systemic lupus erythematosus (SLE) associated with necrotizing histiocytic lymphadenitis (Kikuchi's disease) and immunologically proven human parvovirus B19 infection. Simultaneous occurrence of SLE and Kikuchi's disease was a characteristic of the three cases. Kikuchi's disease is an uncommon disease that usually affects young women and is characterized by painless unilateral cervical lymph-node enlargement. T-cell regions of affected lymph nodes are exclusively involved with patchy paracortical necrosis surrounded by a polymorphous cell population of histiocytes and macrophages. However, lymphadenopathy in patients with SLE may be histologically indistinguishable from Kikuchi's necrotizing lymphadenitis. The cause of Kikuchi's disease remains uncertain, although infectious agents have been proposed. A positive IgM-specific anti-human parvovirus B19 antibody test in our three cases suggests that B19 can induce a necrotizing histiocytic lymphadenitis and possibly a clinical SLE flare. High-dose (1 mg/kg/day) and medium-dose (0.5 mg/kg/day) oral prednisone was an effective treatment for constitutional and visceral symptoms of Kikuchi's and SLE diseases.