Infection and immunity for human parvovirus B19 in patients with febrile exanthema.

The contribution of parvovirus B19 (B19V) as a causative agent of febrile exanthema (FE) in Cordoba, Argentina, was analysed by detection of viral DNA, and specific IgM and IgG. Serum from 141 patients with FE who were negative for measles and rubella, collected during 2005-2009, plus serum from 31 healthy individuals, were assayed. B19V was the aetiological agent in 14·9% of all FE cases, and in 39·1% in an epidemic year (2007). B19V DNA was detected in 47·6% of IgM-positive FE patients, 30·2% of IgM-negative/IgG-positive FE patients, and 9·7% of healthy controls, indicating B19V long-term infection in ~10% of immunocompetent individuals. Persistent B19V DNA was significantly more frequent in children than adults and in males than females. All patients with acute B19V infection had rash and fever, 85·7% had adenopathy, and only 14·3% had arthropathy. This is the first follow-up study of markers of infection and immunity for B19V infection in Argentina.

[Prevalence of anti-rubella and anti-parvovirus B19 antibodies in pregnant women in the city of Córdoba, and in women of fertile age in the city of Villa Mercedes, province of San Luis]. / Prevalencia de anticuerpos antirrubéola y antiparvovirus B19 en embarazadas de la ciudad de Córdoba y en mujeres en edad fértil de la ciudad de Villa Mercedes, San Luis.

We determined the prevalence of anti-rubella antibodies in 100 serum samples from pregnant women who attended routine examination at a private institution in the city of Córdoba, and in 100 serum samples from women of gestational age, 42 of whom were pregnant, attending health centres in the city of Villa Mercedes, province of San Luis. IgG antibodies against parvovirus 819 were also determined in the serum samples from Córdoba. Using the hemmagglutination inhibition test, we found a 98% prevalence of anti-rubella antibodies among pregnant women in Córdoba and of 96% among the women in Villa Mercedes, whereas the prevalence of anti-parvovirus 819 was 66% in the serum samples from Cordoba. These results coincide with those reported for other cities in the world, and establish an interest in continuing similar studies in order to monitor the immunization plan, which in Argentina has been going on since 1997. They also suggest the importance of the determination of IgM anti-parvovirus B19 in pregnant women who are symptomatic but with a negative result for rubella.

Prevalencia de anticuerpos antirrubéola y antiparvovirus B19 en embarazadas de la ciudad de Córdoba y en mujeres en edad fértil de la ciudad de Villa Mercedes, San Luis / Prevalence of anti-rubella and anti-parvovirus B19 antibodies in pregnant women in the city of Córdoba, and in women of fertile age in the city of Villa Mercedes, province of San Luis

Se determinó la prevalencia de anticuerpos contra virus rubéola en 100 muestras de suero de mujeres embarazadas que concurrían a chequeos de rutina en una institución privada de la ciudad de Córdoba y en 100 muestras de suero de mujeres en edad fértil (42 de ellas embarazadas) que concurrían a dispensarios de la ciudad de Villa Mercedes, provincia de San Luis. En las muestras tomadas en la ciudad de Córdoba también se determinaron anticuerpos IgG contra parvovirus B19. Por inhibición de la hemoaglutinación, los resultados de los sueros de Córdoba mostraron una prevalencia de anticuerpos antirrubéola del 98%; en las muestras de Villa Mercedes se observó una prevalencia del 96%. La prevalencia de anticuerpos antiparvovirus B19 en los sueros de Córdoba fue del 66%. Estos datos se asemejan a los de la bibliografía mundial y fundamentan el interés en continuar estudios de este tipo para monitorear el plan de inmunización para rubéola, que en Argentina se lleva a cabo desde 1997, como así también la relevancia de la determinación de IgM antiparvovirus B19 en aquellas embarazadas sintomáticas con resultado negativo para rubéola, a fin de elaborar un diagnóstico diferencial.

We determined the prevalence of anti-rubella antibodies in 100 serum samples from pregnant women who attended routine examination at a private institution in the city of Córdoba, and in 100 serum samples from women of gestational age, 42 of whom were pregnant, attending health centres in the city of Villa Mercedes, province of San Luis. IgG antibodies against parvovirus B19 were also determined in the serum samples from Córdoba. Using the hemmagglutination inhibition test, we found a 98 % prevalence of anti-rubella antibodies among pregnant women in Córdoba and of 96 % among the women in Villa Mercedes, whereas the prevalence of anti-parvovirus B19 was 66% in the serum samples from Córdoba. These results coincide with those reported for other cities in the world, and establish an interest in continuing similar studies in order to monitor the immunization plan, which in Argentina has been going on since 1997. They also suggest the importance of the determination of IgM anti-parvovirus B19 in pregnant women who are symptomatic but with a negative result for rubella.

Detection of rubella-virus-induced apoptosis in Vero cell cultures with hematoxylin and eosin staining.

In order to facilitate the detection of apoptotic cells (Apo C) in Rubella virus (RV) infected cultures in settings of low resources, we compared hematoxylin and eosin staining (H&E) with the conventional TUNEL technique, and confirmed our findings with DNA electrophoresis and transmission electron microscopy. H&E allowed to distinguish Apo C from non-apoptotic cells. The proportion of Apo C in infected cultures was proportional to the multiplicity of infection (MOI). At a MOI of 10, the percent of Apo C at 3, 4 and 5 days post infection (pi) were 26, 45 and 47%, respectively, which were significantly reduced when the caspase inhibitor z-VAD-fmk was present in the supernatant. By the TUNEL assay, the percent of Apo C in RV-infected cultures were lower (0.8, 1.2 and 1.2% at 3, 4 and 5 days pi, respectively). Our results have shown that H&E staining is an easy, rapid, economic and reproducible method to detect Apo C in RV infected Vero cells cultures. It is possible that H&E makes evident early stages of apoptosis, when an apoptotic cell shows chromatin condensation, nuclear and cytoplasmic contraction (but is still attached to the monolayer), while TUNEL detects later stages of apoptosis because it needs an extensive DNA fragmentation, when apoptotic cells are about to or have already detached from the substratum.

Detection of rubella-virus-induced apoptosis in Vero cell cultures with hematoxylin and eosin staining

In order to facilitate the detection of apoptotic cells (Apo C) in Rubella virus (RV) infected cultures in settings of low resources, we compared hematoxylin and eosin staining (H&E) with the conventional TUNEL technique, and confirmed our findings with DNA electrophoresis and transmission electron microscopy. H&E allowed to distinguish Apo C from non-apoptotic cells. The proportion of Apo C in infected cultures was proportional to the multiplicity of infection (MOI). At a MOI of 10, the percent of Apo C at 3, 4 and 5 days post infection (pi) were 26, 45 and 47

, respectively, which were significantly reduced when the caspase inhibitor z-VAD-fmk was present in the supernatant. By the TUNEL assay, the percent of Apo C in RV-infected cultures were lower (0.8, 1.2 and 1.2

at 3, 4 and 5 days pi, respectively). Our results have shown that H&E staining is an easy, rapid, economic and reproducible method to detect Apo C in RV infected Vero cells cultures. It is possible that H&E makes evident early stages of apoptosis, when an apoptotic cell shows chromatin condensation, nuclear and cytoplasmic contraction (but is still attached to the monolayer), while TUNEL detects later stages of apoptosis because it needs an extensive DNA fragmentation, when apoptotic cells are about to or have already detached from the substratum.

Detection of rubella-virus-induced apoptosis in Vero cell cultures with hematoxylin and eosin staining.

In order to facilitate the detection of apoptotic cells (Apo C) in Rubella virus (RV) infected cultures in settings of low resources, we compared hematoxylin and eosin staining (H&E) with the conventional TUNEL technique, and confirmed our findings with DNA electrophoresis and transmission electron microscopy. H&E allowed to distinguish Apo C from non-apoptotic cells. The proportion of Apo C in infected cultures was proportional to the multiplicity of infection (MOI). At a MOI of 10, the percent of Apo C at 3, 4 and 5 days post infection (pi) were 26, 45 and 47

, respectively, which were significantly reduced when the caspase inhibitor z-VAD-fmk was present in the supernatant. By the TUNEL assay, the percent of Apo C in RV-infected cultures were lower (0.8, 1.2 and 1.2

at 3, 4 and 5 days pi, respectively). Our results have shown that H&E staining is an easy, rapid, economic and reproducible method to detect Apo C in RV infected Vero cells cultures. It is possible that H&E makes evident early stages of apoptosis, when an apoptotic cell shows chromatin condensation, nuclear and cytoplasmic contraction (but is still attached to the monolayer), while TUNEL detects later stages of apoptosis because it needs an extensive DNA fragmentation, when apoptotic cells are about to or have already detached from the substratum.