Rotavirus. I. Hemagglutination and complement fixation inhibitor antibodies in individuals of Mexico city.

Hemagglutination inhibiting antibodies were studied in 1,278 sera of individuals of different ages in Mexico City representative of four different socioeconomic levels. It was found that 1,261 (98.7 per cent) had antibodies against the Nebraska strain (calf rotavirus). An unusual finding was that more than 95 per cent of children from one to four years of age, had antibodies. For this reason five year old children were studied utilizing two viral strains as antigens in hemagglutination inhibition tests. It was found that in 918 sera, 821 (89.4 per cent) had antibodies against SA-11 samples (monkey rotavirus); percentage increased from 87.2 per cent in neonates to 97.5 percent in children from four to five years of age. A similar phenomenon was observed when Nebraska strain hemagglutinin was utilized. Also complement fixation antibodies against SA-11 strain in 583 sera were studied finding that 260 (44.6 per cent) had antibodies. Utilization of this technique showed that seropositivity percentage decreased from 47.6 per cent in the neonate group to 14.5 per cent in the one ot three month old children increasing progressively until reaching 65.1 per cent in children three to four years of age. These results show that rotavirus infection takes place at early ages, as has been confirmed by other authors that have used electron microscopy techniques, RNA electrophoresis, etc., regardless of the presence of transplacental antibodies.

Rotavirus. II. Viruses associated with acute gastroenteritis in children.

Rotavirus was investigated in the feces of 232 children under five years of age with acute infectious gastroenteritis by means of viral RNA electrophoretic technique. 15.1 per cent of cases were positive and no predominance was observed regarding age or seasonal period. Approximately 50 per cent corresponded to one of the two rotavirus types, byt type 2 (2 L) was predominant in the first six months of the year and type 1 (2 S) in the other six. Results are consistent with those obtained by other authors for it is considered that approximately 20 per cent of acute diarrheas during infancy are caused by viral agents.

Rotavirus. II. Virus relacionados con la gastroenteritis aguda en el nino. / Rotavirus. II. Viruses associated with acute gastroenteritis in children

Se estudio la presencia de rotavirus en la materia fecal de 232 ninos menores de cinco anos con gastroenteritis infecciosa aguda por medio de la tecnica de electroforesis del RNA viral. Se encontraron 15.1 por ciento de casos positivos, no observandose predominio en relacion con la edad o la epoca del ano.Aproximadamente 50 por ciento correspondieron a cada uno de los dos tipos de rotavirus, pero el tipo 2 (2 L) predomino en los seis primeros meses del ano y el tipo 1 (2 S) en los otros seis. Los resultados concuerdan con los obtenidos por otros autores, ya que se considera que aproximadamente 20 por ciento de las diarreas agudas de la infancia son causadas por estos agentes virales

[Assessment of five laboratory tests for differential diagnosis in bacterial and viral meningoencephalitides]. / Evaluación de cinco pruebas de laboratorio para el diagnóstico diferencial entre meningoencefalitis purulenta y viral.

The usefulness of five different laboratory tests for differential diagnosis in bacterial and viral meningoencephalitides was assessed. The clinical manifestations and cytochemical alterations of cerebrospinal fluid (CSF) were used as criteria for diagnostic selection. The causal agent was identified by means of CSF cultures in 47.8 per cent of bacterial meningoencephalitis cases; Gram stain was postive in CSF smear in 34.8 per cent and protein electrophoresis in CSF did not show significant differences when compared to cases of bacterial or viral etiology and the control group. PH and CSF lactate determinations allowed diagnosis of all cases of bacterial meningoencephalitis and was not modified in those cases where this disease was of a viral origin. We suggest to add these determinations to the initial cytochemical study of CSF in all cases where meningoencephalitis is suspected.

[Antiviral antibodies in acute laryngotracheobronchitis]. / Anticuerpos antivirales en laringotraqueobronquitis aguda.

Antibodies to influenza A2, influenza B, parainfluenza 2 and 3, adenovirus and respiratory syncytial viruses were determined in thirty nine children with acute laryngotracheobronchitis; nine cases were not included in the analysis because of the presence of anticomplementary sera; 40% of cases were positive, 20% to influenza A2, 10% to influenza B (one case of double infection with influenza B and parainfluenza 2 viruses), 6.7% to respiratory syncytial virus and 3.3% to parainfluenza 2. Results are compared with previous studies done in Mexico.