Large Retropharyngeal Abscesses in an Immunocompetent Adult Patient with Disseminated Tuberculosis.

BACKGROUND The retropharyngeal abscess is a rare presentation of head and neck tuberculosis. The pathogenesis of the abscess formation in the retropharyngeal space in the adult is controversial. CASE REPORT We report a case of large retropharyngeal abscesses in a 46-year-old man with disseminated tuberculosis. The patient had severe progressive dysphagia, weight loss, and a slowly enlarging bilateral cervical mass during a period of three months. His posterior pharynx wall was bulging and red, and both tonsils were enlarged and congested. The neck had an abscess of 5 cm in diameter that was firm, tender, and warm along the left sternocleidomastoid muscle. Palpable bilateral lymphadenitis was detected in the submandibular, cervical, axillary, and inguinal regions. A computed tomographic (CT) scan of the neck revealed large bilobulated retropharyngeal abscesses. A liver ultrasound showed multiple hypoechoic lesions. A Ziehl-Neelsen smear for acid-fast bacilli was positive from different abscess samples, and mycobacterial cultures subsequently yielded Mycobacterium tuberculosis. Antituberculous therapy was begun and the retropharyngeal abscesses were aspirated by external incision with complete drainage and relief of symptoms. CONCLUSIONS Large retropharyngeal abscess is a rare entity in which Mycobacterium tuberculosis etiology should be considered, especially in endemic countries, and the diagnosis may be difficult because symptoms and signs are influenced by abscess size and time of onset, or if the etiology is not suspected.

Seasonal variation of enteropathogens in infants and preschoolers with acute diarrhea in western Mexico.

The present study estimates the prevalence of some enteropathogens in infants and preschoolers with acute diarrhea. From 2006 to 2007, 5459 consecutive stool samples were evaluated. Cryptosporidium parvum was the parasite identified with the higher frequency (5.1%), followed by Giardia lamblia (1.2%). Campylobacter jejuni was isolated in 858 cases (15.7%) and was the most frequent enteropathogen overall. The rates of C parvum, Shigella, and Salmonella were higher in the summer. Rotavirus had the expected winter peak and it was the third enteropathogen because of its frequency. Overall frequency of stool-reducing substances was 15.6% and was associated with a rotavirus-positive test.

Serotypes and susceptibility of Streptococcus pneumoniae strains isolated from children in Mexico.

OBJECTIVE: To identify serotypes and susceptibility of S. pneumoniae strains from 48 children with invasive infections and 50 carriers. MATERIAL AND METHODS: Typing was performed by the Quellung reaction and susceptibility by Kirby-Bauer and Etest according to CLSI standards. RESULTS: Of 31 meningeal strains, serotypes 19F, 3, 6B, 14 and 23F were predominant. Resistance to penicillin and STX was 16 and 58%, respectively; of 17 invasive non-meningeal strains, serotypes 19F and 3 were predominant and resistance to penicillin and SXT was 0 and 82%, respectively; of carrier strains, serotypes 6A, 6B, 19F and 23F were predominant. CONCLUSIONS: A 10-valent conjugate vaccine could offer a better coverage for meningeal strains.

Serotypes and susceptibility of Streptococcus pneumoniae strains isolated from children in Mexico / Serotipos y susceptibilidad de cepas de Streptococcus pneumoniae aisladas de niños en México

Objective. To identify serotypes and susceptibility of S. pneumoniae strains from 48 children with invasive infections and 50 carriers. Material and Methods. Typing was performed by the Quellung reaction and susceptibility by Kirby-Bauer and Etest according to CLSI standards. Results. Of 31 meningeal strains, serotypes 19F, 3, 6B, 14 and 23F were predominant. Resistance to penicillin and STX was 16 and 58 percent, respectively; of 17 invasive non-meningeal strains, serotypes 19F and 3 were predominant and resistance to penicillin and SXT was 0 and 82 percent, respectively; of carrier strains, serotypes 6A, 6B, 19F and 23F were predominant. Conclusions. A 10-valent conjugate vaccine could offer a better coverage for meningeal strains.

Objetivo. Identificar serotipos y susceptibilidad en cepas aisladas de 48 niños con infecciones invasivas y de 50 portadores. Material y métodos. Serotipificación mediante reacción de Quellung y susceptibilidad mediante Kirby-Bauer y E-test. Resultados. De 31 cepas meníngeas, predominaron serotipos 19F, 3, 6B, 14 y 23F y la resistencia a penicilina (P) y trimetoprim-sulfametoxazol (SXT) fue de 16 y 58 por ciento. En 17 cepas invasivas no meníngeas, predominaron serotipos 19F y 3 y la resistencia a P y SXT fue de 0 y 82 por ciento, en cada caso. En portadores predominaron serotipos 6A, 6B, 19F y 23F. Conclusiones. La resistencia es similar a otros informes. La vacuna conjugada 10-valente podría ofrecer mejor cobertura para serotipos asociados a meningitis.

Molecular analysis of hepatitis B virus isolates in Mexico: predominant circulation of hepatitis B virus genotype H.

AIM: To determine the genotypes in Mexican hepatitis B virus (HBV) isolates and characterize their precore and core promoter mutations. METHODS: Forty-nine HBV isolates of Mexico obtained from sera of 15 hepatitis patients, 6 hemodialysis patients, 20 men seeking HIV testing, and 8 AIDS patients were analyzed. HBV isolates were amplified by PCR, and genotyped by line probe assay (INNO-LiPA HBV Genotyping; INNOGENETICS N V, Ghent, Belgium). HBV genotype confirmation was performed by DNA sequencing part of the sAg region. Precore and core promoter mutation characterization was performed by line probe assay (INNO-LiPA HBV PreCore; INNOGENETICS N V, Ghent, Belgium). RESULTS: Overall, HBV genotype H was found in 37 (75.5%) out of the 49 isolates studied. HBV genotypes G, A, and D were found in 5 (10.2%), 4 (8.2%), and 3 (6.1%) isolates, respectively. HBV genotype H was predominant in isolates from hemodialysis patients (100%), hepatitis patients (80%), and men seeking HIV testing (75%), and accounted for half of infections in AIDS patients (50%). Six (12.2%) out of the 49 HBV isolates showed both wild type and mutant populations at precore codon 28. These mixed wild type and precore mutant populations were observed in one HBV genotype A isolate and in all HBV genotype G isolates. A dual variant core promoter mutation was observed in 1 (2%) of the isolates, which was genotype H. CONCLUSION: HBV genotype H is highly predominant in HBV isolates of Mexico followed by genotypes G, A and D. A low frequency of precore and core promoter mutations is observed in HBV Mexican isolates.

Genotypic resistance to lamivudine among hepatitis B virus isolates in Mexico.

BACKGROUND: Drug resistance of hepatitis B virus (HBV) is an increasing clinical problem. Resistance to lamivudine in HBV isolates in Mexico has been poorly explored. OBJECTIVES: To characterize the mutation patterns associated with genotypic resistance to lamivudine and their prevalence among HBV isolates in Mexico. MATERIAL AND METHODS: Thirty-nine Mexican HBV isolates were analysed by PCR and line probe assay for detection of genetic variants in the polymerase open reading frame domains B and C (INNO-LiPA HBV DR; INNOGENETICS N. V., Ghent, Belgium). This assay detects wild-type and mutations at codons 180, 204 and 207 of the HBV polymerase gene, and at codon positions 171, 172, 195, 196, 198 and 199 of the HBV surface antigen (HBsAg). HBV isolates were obtained from HBsAg-positive serum samples of 15 chronic hepatitis patients, two haemodialysis patients with chronic HBV carriage, 20 men found positive for HBsAg when seeking HIV testing and two AIDS patients with chronic HBV infection. None of the participants had received antiviral therapy. RESULTS: Overall, HBV wild-type was found in 37 (94.9%) out of the 39 isolates studied. Two (5.1%) out of the 39 isolates showed mixed wild-type and mutant populations. These mutations occurred in isolates from one hepatitis patient and one haemodialysis patient. The isolate from the hepatitis patient showed a double mutation at codon positions 180 (L180M) and 204 (M204V), thus a 2.6% prevalence of genotypic resistance to lamivudine was found. The isolate from the haemodialysis patient showed a single mutation at codon position 180 (L180M). The two HBV mutant isolates were further analysed for genotype and both isolates were genotype H. CONCLUSIONS: HBV genotypic resistance to lamivudine exists in Mexican isolates. The results highlight the importance of testing for HBV resistance before treatment and have implications for a more rational use of drugs.

Changing trends in prevalence, morbidity, and lethality in persistent diarrhea of infancy during the last decade in Mexico.

BACKGROUND: Persistent diarrhea (PD) of infancy has incurred high morbidity and lethality. However, decrease in its prevalence, morbidity, and lethality appeared to occur progressively throughout the last decade of the twentieth century. Our objective in this study was to compare prevalence, lethality, and morbidity of infants and children with PD managed in a pediatric referral hospital. METHODS: We conducted a comparative cross-sectional study. A total of 546 patients with PD managed during three different periods (1988-1991, 1993-1994, and 1997-1999) were described and analyzed. Prevalence x 100 admissions, prevalence rates of nutritional status, sepsis, pneumatosis intestinalis, carbohydrate and protein intolerance, and lethality were calculated. We used Student t and chi2 tests (alpha = 0.05). RESULTS: Mean age on admission was 13.8 +/- 24.3 months; 296 (54.2%) patients were males. Prevalence of admissions for PD decreased gradually from 31.7 to 13.8%; rates of lethality and mortality remained unchanged. Malnutrition had high prevalence throughout the three periods evaluated. Rate of carbohydrate intolerance diminished but protein intolerance increased; proportion of pneumatosis intestinalis and bowel perforation did not change. Isolation of Salmonella spp. and small bowel bacterial overgrowth decreased significantly from the 1988-1991 series when compared with later series. CONCLUSIONS: Although these observations were made at a pediatric referral hospital, they may suggest that prevalence of PD is diminishing. However, its lethality and mortality rates remain unchanged. Malnutrition persists as a relevant associated factor. Decrease of carbohydrate intolerance and increase in protein intolerance rates resemble rates of children with PD of developed countries. These observations may reflect an epidemiologic transition of PD in Mexico.

[Utility of studying feces for the diagnosis and management of infants and preschool children with acute diarrhea]. / Utilidad del estudio de las heces para el diagnóstico y manejo de lactantes y prescolares con diarrea aguda.

OBJECTIVE: To analyze the results of a stool work-up protocol in a series of infants and preschoolers with acute diarrhea. MATERIAL AND METHODS: A cross-sectional descriptive study was conducted between April 1999 and March 2000, among 288 children seen at a pediatric office in Guadalajara, Mexico. The mean age (+/-/SD) was 23.1 +/- 13.9 months; 43% were females. Data were collected on demographic and clinical characteristics. The stool work-up consisted of fresh smear and methylene blue and Kinyoun smears, as well as determination of pH and reducing substances. Stool culture was performed in samples with > or = 3 leukocytes/microscopic field and rotavirus antigen detection only in selected cases. Data were analyzed using descriptive statistics, chi 2, odds ratios, and 95% confidence intervals. RESULTS: Enterophatogens (%) identified were: rotavirus 47.1, Campylobacter jejuni 27.4, Salmonella spp. 5.1, Shigella spp. 4.3, Cryptosporidium parvum 2.8, Giardia lamblia 2.4, Blastocystis hominis 1.4, Entamoeba histolytica 0.7. An OR of 5.7 was obtained for isolation of enteroinvasive bacteria in the presence of fecal leukocytes. Lactose intolerance was detected in 19.1%. The frequencies of rotavirus antigen identification and lactose intolerance were significantly higher in infants; the OR for lactose intolerance in infants with rotavirus was 21. Mucus and blood in the stools were associated to enteroinvasive bacteria and Cryptosporidium parvum. CONCLUSIONS: The current stool work-up protocol allowed the identification of enteropathogenic parasites, rotavirus and lactose intolerance in a short period of time. Leukocytes in stools were associated to the isolation of enteroinvasive bacteria. The frequency of agents associated to diarrheal disease was similar to that from other national studies. This stool work-up protocol could be useful as a tool to limit the unnecessary prescription of drugs and to follow universal recommendations for dietary management of these patients. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Utilidad del estudio de las heces para el diagnóstico y manejo de lactantes y prescolares con diarrea aguda / Utility of studying feces for the diagnosis and management of infants and preschool children with acute diarrhea

OBJECTIVE: To analyze the results of a stool work-up protocol in a series of infants and preschoolers with acute diarrhea. MATERIAL AND METHODS: A cross-sectional descriptive study was conducted between April 1999 and March 2000, among 288 children seen at a pediatric office in Guadalajara, Mexico. The mean age (+/-/SD) was 23.1 +/- 13.9 months; 43 were females. Data were collected on demographic and clinical characteristics. The stool work-up consisted of fresh smear and methylene blue and Kinyoun smears, as well as determination of pH and reducing substances. Stool culture was performed in samples with > or = 3 leukocytes/microscopic field and rotavirus antigen detection only in selected cases. Data were analyzed using descriptive statistics, chi 2, odds ratios, and 95 confidence intervals. RESULTS: Enterophatogens () identified were: rotavirus 47.1, Campylobacter jejuni 27.4, Salmonella spp. 5.1, Shigella spp. 4.3, Cryptosporidium parvum 2.8, Giardia lamblia 2.4, Blastocystis hominis 1.4, Entamoeba histolytica 0.7. An OR of 5.7 was obtained for isolation of enteroinvasive bacteria in the presence of fecal leukocytes. Lactose intolerance was detected in 19.1. The frequencies of rotavirus antigen identification and lactose intolerance were significantly higher in infants; the OR for lactose intolerance in infants with rotavirus was 21. Mucus and blood in the stools were associated to enteroinvasive bacteria and Cryptosporidium parvum. CONCLUSIONS: The current stool work-up protocol allowed the identification of enteropathogenic parasites, rotavirus and lactose intolerance in a short period of time. Leukocytes in stools were associated to the isolation of enteroinvasive bacteria. The frequency of agents associated to diarrheal disease was similar to that from other national studies. This stool work-up protocol could be useful as a tool to limit the unnecessary prescription of drugs and to follow universal recommendations for dietary management of these patients.

Asymptomatic bacteriuria and inflammatory response urinary tract infection of elderly ambulatory women in nursing homes

Background. Bacteriuria = 10 to fifth CFU/ml is evidence of urinary tract infection in the absence of associated signs or symptoms. The presence of pyuria with asymptomatic bacteriuria established the response of elderly women against microorganisms capable of causing invasiveness or tissue injury of the urinary tract. Methods. The association between bacteriuria and pyuria was determined in 178 elderly, ambulatory women without symptoms of urinary tract infection in seven nursing homes. Urine culture results were subsequently analyzed in conjunction with absolute leukocyte count in urine. In this cross-sectional study, asymptomatic bacteriuria in elderly women was classified with and without pyuria. Results. The prevalence of asymptomatic bacteriuria was found in 44 (24.7 percent) elderly women. The presence of pyuria had a sensitivity of 63.6 percent for bacteriuria and a specificity of 91 percent. The positive predictive value for the presence of pyuria predicting those with bacteriuria was 70 percent, and the negative predictive value for the absence of pyuria predicting those without bacteriuria was 88.4 percent. Escherichia coli was the most common organism isolated in 81.8 percent of the women. Conclusions. bacteriuria = 10 to fifth CFU/ml associated with pyuria was detected in 77 percent of elderly women with asymptomatic urinary tract infections bacteriuria of < 10 to fifth CFU/ml with pyuria proves less sensitive as an indicator of urinary tract infection. Elderly women with pyuria but without bacteriuria should be studied for other causes of urinary tractinflammation

Prevalencia de marcadores de virus de hepatitis B y C en personal médico de un hospital de tercer nivel / Prevalance of hepatitis B and C virus markers in physicians working in a third level hospital

Objetivo: Evaluar la prevalancia de marcadores de infección por virus de hepatitis B y C en muestras de suero de médicos del Hospital de Especialidades del Centro Médico Nacional de Occidente (HE-CMNO). Material y métodos: Se determinó el antígeno de superficie del virus de la hepatitis B (AgsVHB) y el anticuerpo contra el antígeno corre a través de inmunoanálisis de hepanostika. También se realizó la detección de anticuerpos contra el virus de la hepatitis C (anti VHC) por la técnica de ELISA de segunda generación. Resultados: Se incluyeron 62 médicos que ejercían su profesión en servicios médicos o quirúrgicos, de los cuales 51 eran del sexo masculino (82 por ciento) y 11 del sexo femenino (18 por ciento). La edad promedio fue de 28 años (intervalo de 25 a 66), el tiempo de ejercicio en promedio fue de ocho años (intervalo 2 a 44 años). En cuatro médicos (6 por ciento) se encontraron marcadores serológicos con evidencia de infección por virus de hepatitis B (VHB), todos tuvieron anticuerpos anticore del VHB negativo (AccVHB), en un caso se encontró anti VHC positivo (2 por ciento). La prevalancia en médicos con antecedentes de exposición percutánea múltiple fue del 25 por ciento, en médicos de servicios quirúrgicos fue del 14 por ciento y en aquellos con más de 10 años de actividad profesional fue del 24 por ciento. Conclusiones: la prevalancia mayor de infección por virus de hepatitis se observó en aquellos médicos con más de 10 años de actividad clínica en servicio quirúrgico y en médicos con lesiones percutáneas múltiples

Etiología de sepsis neonatal y sensibilidad a los antibióticos en el Nuevo Hospital Civil de Guadalajara / Ethiology of neonatal sepsis and sensitivity to antibiotics in the New Civil Hospital of Guadalajara

Objetivo: Identificar las bacterias causantes de sepsis neonatal y sus patrones de sensibilidad a diversos antibióticos en el Nuevo Hospital Civil de Guadalajara. Material y métodos: El estudio se realizó en la unidad de cuidados intensivos neonatales de un hospital de segundo nivel de atención en guadalajara, Jalisco, México. Se analizaron 74 neonatos con sospecha clínica y/o paraclínica de sepsis, bajo un diseño prospectivo, transversal, observacional y comparativo. Se consideró como infectados a los neonatos que en dos hemocultivos tomados de sitios diferentes de venopunción, tuvieron el mismo aislamiento. Los antibiogramas se realizaron por el método de kirby-Bauer, con los puntos recomendados por la NCCLS. Resultados: Hubo 41 (55.4 por ciento) pacientes con hemocultivos positivos. De los aislamientos, 30 (73 por ciento) correspondieron a K. pneumoniae y 8 (19 por ciento) a S. epidermidis. Todas las cepas de K. pneumoniae fueron resistentes a ampicilina, pero 93 por ciento fueron sensibles a los aminoglucósidos y las cefalosporinas de tercera generación probados. Todas las cepas de estafilococos fueron sensibles a vancomicina y sólo dos fueron resistentes a dicloxacilina. Conclusiones: El 98 por ciento de las cepas de K. pneumoniae presentó el mismo patrón de sensibilidad a los antibióticos, lo que sugiere una transmisión horizontal intrahospitalaria. La gran mayoría de los aislamientos fueron sensibles a los antimicrobianos de uso común, por lo que sugerimos que el tratamiento empírico inicial debe incluir a aminoglucósidos como gentamicina o amikacina, asociados a dicloxacilina o en casos específicos vancomicina y dejar como alternativa el uso de cefalosporinas de tercera generación.

Estudio de un brote de brucelosis y valoración diagnóstica de las pruebas de laboratorio / Study of a brucellosis outbreak and diagnostic evaluation of laboratory

En 1991, en la zona de Villa Corona, Jalisco, se registró un número anormal de casos con fiebre de origen desconocido, con múltiples diagnósticos clínicos. Se revisaron todos los casos estableciéndose la sospecha de un brote de brucelosis. Se consideró caso a cualquier persona entre cinco y 60 años, que desde enero de 1991 presentó fiebre, calosfríos de más de tres días de evolución más cefalea y/o artralgias. Se hizo un muestreo por conglomerado de las viviendas; cada caso se comparó con tres controles, dos convivientes y un vecino del mismo grupo de edad; se realizaron pruebas seriadas y hemocultivo, para comparar la validez y confiabilidad diagnóstica. Se detectaron 31 casos probables y se estudiaron 85 controles (68.5 por ciento de la muestra de controles esperada). Se aisló Brucella melitensis por hemocultivo en un caso. Se definieron 18 casos con brucelosis activa. Se obtuvo una razón de momios (RM) de 12.6 (IC 95 por ciento = 30-56.1); XMH, p<0.000 para la ingesta habitual de lácteos crudos y una RM de 10.0 (IC 95 por ciento=2.5-43.5); Xmh, p<0.000 para la ingesta continua durante seis meses. Este riesgo se ajustó a 3.0 para los pares discordantes que ingerían regularmente leche cruda. Las pruebas seriadas mostraron: Hudlesson, sensibilidad = 50 por ciento y especificidad = 84.6 por ciento; rosa de Bengala, sensibilidad = 94.4 por ciento y especificidad 84.6 por ciento. Los resultados sugieren que la prueba de Hudlesson tiene una baja confiabilidad. La aglutinación en tubo y la prueba de 2 mercaptoetanol tienen resultados serológicos más satisfactorios

Aspergilosis pulmonar / Pulmonar aspergillosis

Se resenta un paciente de 15 años de edad con tres formas clínicas de aspergilosis. Adolescente masculino con asma bronquial de difícil control desde los cinco años de edad; a los 12 años se le diagnosticó tuberculosis pulmonar, siendo manejado con varios esquemas terapéuticos. Fue referido a nuestro hospital para estudio de hemoptisis, confirmándose aspergilosis en su forma de aspergiloma; después de practicar lobectomía superior izquierda se comprobó la forma invasiva; posteriormente presentó cuadro respiratorio obstructivo recurrente, diagnósticándose la forma alérgica. Tuvo IgE sérica elevada que disminuyó al recibir tratamiento con corticoides; simultáneamente tuvo mejoría clínica el tratamiento se suspendió al obtener estabilidad clínica y nivel normal de IgE. Se discute la ruta de diagnóstico y el tratamiento: Aspergilosis

Aislamiento de Histoplasma capsulatum en el suelo de los alrededores de Ciudad Guzman, Jalisco / Isolation of Histoplasma capsulatum in soils of the vecinity of Ciudad Guzman, Jalisco, México

La histoplasmosis, micosis profunda grave, se presenta en México tanto en forma primaria aguda pulmonar, como en forma secundaria crónica-diseminada. La forma primaria pulmonar aguda se presenta principalmente en brotes epidémicos y gracias a ellos ha sido detectada en más de 10 Estados de la República Mexicana. La demostración de H. capsulatum en el suelo de los alrededores de Ciudad Guzmán, Jalisco, exitiende la zona de endemicidad de esta micosis en nuestro país