Héctor Guiscafré

Diagnostic value of tachypnoea in pneumonia defined radiologically

OBJECTIVE To evaluate whether sensitivity and specificity of tachypnoea for the diagnosis of pneumonia change with age, nutritional status, or duration of disease. METHODS Diagnostic testing of 110 children with acute respiratory infection, 51 of whom presented with tachypnoea. The gold standard was a chest roentgenogram. Thirty five children had a radiological image of pneumonia; 75 were diagnosed as not having pneumonia. Sensitivity, specificity, and percentage of correct classification of tachypnoea, by itself or in combination with other clinical signs for all children, by age groups, nutritional status, and disease duration were calculated. RESULTS Tachypnoea as the sole clinical sign showed the highest sensitivity (74%) and a specificity of 67%; 69% of cases were classified correctly. Sensitivity was reduced when other clinical signs were combined with tachypnoea, and there was no significant increase in correct classification, although specificity increased to 84%. In children with a disease duration of less than three days, tachypnoea had a lower sensitivity and specificity (55% and 64%, respectively), and a lower percentage of correct classification (62%). In children with low weight for age (< 1 Z-score), tachypnoea had a sensitivity of 83%, a specificity of 48%, and 60% correct classification. Sensitivity and specificity did not vary with age groups. CONCLUSIONS Tachypnoea used as the only clinical sign is useful for identifying pneumonia in children, with no significant variations for age. In children with low weight for age, tachypnoea had higher sensitivity, but lower specificity. However, during the first three days of disease, the sensitivity, specificity, and percentage of correct classification were significantly lower.

Antibiotic noncompliance and waste in upper respiratory infections and acute diarrhea.

A prospective cohort study was conducted to analyze factors associated with antibiotic noncompliance and waste among patients suffering acute respiratory infection (ARI) and acute diarrhea (AD). The study took place in four primary health care clinics in Mexico City, two belonging to the Ministry of Health (MoH) and two to the Mexican Social Security Institute (IMSS). Two hundred twenty-two patients with ARI and 155 with AD were included. Data about study variables and the assessment of compliance were obtained through patient interviews and direct observation. Factors associated with noncompliance were assessed through a multiple logistic regression procedure. Noncompliance was 60% for ARI and 55.5% for AD in both health care systems. Prescription of an antibiotic was justified only in 13.5% of cases. Associated factors were: increased duration of illness (OR 2.95; 95% CI, 1.17-7.41); complexity of the treatment: 3 or more doses per day (OR 2.47; 95% CI, 1.56-3.92), and treatment for more than 7 days (OR 1.94; 95% CI, 1.16-3.26); younger age of patient (OR 1.89; 95% CI, 1.18-3.02); and an inadequate physician-patient relationship (OR 1.87; 95% CI, 1.16-3.02). Antibiotic waste was higher in IMSS (ARI 39.3%, AD 32.6%), than in the MoH (ARI 21.2%, AD 16.4%). Educational strategies to modify physician prescribing practices and strengthen physician-patient relationships might improve compliance and decrease drug waste.

Prevalence and Genetic Diversity of Human Astroviruses in Mexican Children with Symptomatic and Asymptomatic Infections

ABSTRACT The prevalence and type diversity of human astroviruses (HAstV) in children with symptomatic and asymptomatic infections were determined in five localities of Mexico. HAstV were detected in 4.6 (24 of 522) and 2.6% (11 of 428) of children with and without diarrhea, respectively. Genotyping of the detected strains showed that at least seven (types 1 to 4 and 6 to 8) of the eight known HAstV types circulated in Mexico between October 1994 and March 1995. HAstV types 1 and 3 were the most prevalent in children with diarrhea, although they were not found in all localities studied. HAstV type 8 was found in Mexico City, Monterrey, and Mérida; in the last it was as prevalent (40%) as type 1 viruses, indicating that this astrovirus type is more common than previously recognized. A correlation between the HAstV infecting type and the presence or absence of diarrheic symptoms was not observed. Enteric adenoviruses were also studied, and they were found to be present in 2.3 (12 of 522) and 1.4% (6 of 428) of symptomatic and asymptomatic children, respectively.

Reversible Hearing Loss after Meningitis Prospective Assessment using Auditory Evoked Responses

Hearing loss (HL) was prospectively studied in 236 children with meningitis using brainstem auditory evoked responses. Hearing loss was detected in 38 (16.1%) in the acute phase of the disease and in 10 (5.2%) of 193 patients who were tested 6 months later. Hearing loss was more frequent and more severe in patients with bacterial meningitis (25.4% in the acute phase, and 8% 6 months later) than in patients with viral and tuberculous meningitis. In half of the affected cases the auditory lesion was bilateral. Follow-up was possible in 32 patients with early postmeningitic HL. Ten (31.2%) had permanent HL while the remaining 22 (68.7%) recovered normal hearing. Severe initial losses tended to be permanent, whereas minimal and intermediate losses were generally reversible and patients recovered completely in 1 to 6 months. The high incidence of HL in bacterial meningitis suggests that any one of the existing methods of auditory screening should be performed in all patients during the convalescent period.

Validation of the verbal autopsy method to ascertain acute respiratory infection as cause of death.

The validity of the Verbal Autopsy (VA) in death due to acute respiratory infection (ARI), Was tested in 36 children who died by any acute infectious disease as stated by the necropsy diagnosis, at two public hospitals in Mexico City; the illness started at home. Clinical data obtained through VA were compared with diagnoses of necropsies, which were considered as “gold standard”. The presence of dyspnoea for more than one day showed sensitivity of 0.69 and Specificity of 0.74, while history of coughing showed a sensitivity of 0.61 and a specificity of 0.73. Combination of both clinical data improved specificity (0.83), but decreased sensitivity (0.54). Additional sources of diagnosis (a panel of assessors, the clinical record and the death certificate), also showed good sensitivity (0.69–0.77) and specificity (0.74–7.8). Focus on history of dyspnea and/or cough in children with an infectious syndrome should be emphasized, as a useful epidemiologic tool to determine children’s mortality due to ARI in areas where diagnosis resources are constrained.

Hearing Loss after Hemophilus Influenzae Meningitis Follow-up Study with Auditory Brainstem Potentials

Hearing loss was studied prospectively using auditory brainstem potentials in 34 children with Hemophilus influenzae meningitis treated with chloramphenicol and in 36 children with purulent meningitis caused by microorganisms other than H influenzae treated with ampicillin. Our results indicate that high doses of ampicillin are not associated with permanent hearing loss. Moreover, no statistically significant difference was found in the incidence of hearing loss following H influenzae meningitis and that following meningitis caused by other microorganisms, either during the acute phase or in the convalescent period. Neurological damage, when present, was probably located in the inner ear or in the auditory nerve. Finally, early hearing loss in purulent meningitis does not always constitute an irreversible lesion.

The relative contribution of case management and inadequate care-seeking behaviour to childhood deaths from diarrhoea and acute respiratory infections in Hidalgo, Mexico

Objective  To investigate the contribution of poor case management and care‐seeking behaviour to childhood deaths from acute respiratory infections (ARI) and diarrhoeal diseases in rural Mexico.

La mortalidad por enfermedad diarreica en México: ¿problema de acceso o de calidad de atención?

Objetivo. Evaluar el proceso de atencion y el acceso a servicios de salud en menores de cinco anos fallecidos por enfermedad diarreica (ED), en cuatro estados de la Republica mexicana. Material y metodos. Se realizo un estudio transversal que incluyo defunciones ocurridas durante un ano; mediante autopsia verbal se obtuvo informacion de caracteristicas clinicas, atencion durante la enfermedad y acceso a los servicios de salud; se realizo un analisis descriptivo y comparativo de acuerdo con el tamano de la localidad. Resultados. De 553 defunciones, la mayoria ocurrio en ninos sin derecho a seguridad social o residentes en localidades rurales; la muerte en el hogar, la edad menor a un ano y la corta evolucion de la enfermedad caracterizaron a mas de la mitad de los casos. Se proporciono terapia de hidratacion oral por decision de la madre a casi 75% de los ninos; 20% recibio atencion no medica, principalmente de curanderos. La atencion medica fue otorgada en 60% de los casos; a una elevada proporcion le fue indicado algun medicamento y no se le envio a hospital ni se recomendo regresar ante la presencia de signos de alarma; la indicacion de hidratacion oral fue mayor por medicos de servicios publicos y en localidades rurales; en estas, el acceso geografico y economico fue menor. Conclusiones. Si bien se confirmo el problema de acceso a los servicios de salud, se identificaron fallas importantes en la atencion medica primaria. Se propone la creacion de unidades docente-asistenciales como una estrategia para la reduccion de la mortalidad por ED.

Frequency and Determinants of Vitamin A Deficiency in Children Under 5 Years of Age with Pneumonia

BACKGROUND Vitamin A deficiency (VAD) has been closely related to acute respiratory infections (ARI), although information is still incomplete; for example, the frequency of VAD in children <5 years of age with pneumonia is not known, and the conditions associated with VAD have not been identified. This study was conducted to gain insight into the status of vitamin A in children with pneumonia. A secondary objective was to identify the sociodemographic, individual, and nutritional factors associated with VAD in these children. METHODS A cross-sectional study was conducted in the Mexican state of Hidalgo, one of the poorest in the country. Children with community-acquired pneumonia treated at nine public hospitals were included. Information was obtained by interviewing mothers, and ascertainment of vitamin A status was performed with relative-dose-response (RDR) test. RESULTS A total of 422 cases were included. VAD was identified in 17.8% of children; 50.3% showed normal results, 24.6% had liver reserve depletion, and 7.3% showed results attributable to the infectious process. Variables associated with VAD were as follows: age <2 months (OR 3.44, 95% CI: 1.84-9.24); children >6 months of age fed with formula (OR 0.37, 95% CI: 0.15-0.91), and affiliation with the Mexican Social Security Institute (IMSS) health system (OR 0.40, 95% CI: 0.22-0.72). CONCLUSIONS The frequency of VAD in children with community-acquired pneumonia confirms that the problem of deficiency persists in Mexico. The associated factors for VAD found in this study can be taken into account when planning and evaluating vitamin A supplementation activities in populations with high risk for deficiency.

The impact of a clinical training unit on integrated child health care in Mexico

This study had two aims: to describe the activities of a clinical training unit set up for the integrated management of sick children, and to evaluate the impact of the unit after its first four years of operation. The training unit was set up in the outpatient ward of a government hospital and was staffed by a paediatrician, a family medicine physician, two nurses and a nutritionist. The staff kept a computerized database for all patients seen and they were supervised once a month. During the first three years, the demand for first-time medical consultation increased by 477% for acute respiratory infections (ARI) and 134% for acute diarrhoea (AD), with an average annual increase of demand for medical care of 125%. Eighty-nine per cent of mothers who took their child for consultation and 85% of mothers who lived in the catchment area and had a deceased child received training on how to recognize alarming signs in a sick child. Fifty-eight per cent of these mothers were evaluated as being properly trained. Eighty-five per cent of primary care physicians who worked for government institutions (n = 350) and 45% of private physicians (n = 90) were also trained in the recognition and proper management of AD and ARI. ARI mortality in children under 1 year of age in the catchment area (which included about 25,000 children under 5 years of age) decreased by 43.2% in three years, while mortality in children under 5 years of age decreased by 38.8%. The corresponding figures for AD mortality reduction were 36.3% and 33.6%. In this same period, 11 clinical research protocols were written. In summary, we learned that a clinical training unit for integrated child care management was an excellent way to offer in-service training for primary health care physicians.