Meningovascular neurosyphilis with basilar artery thrombosis in HIV patient.

Currently, neurosyphilis is an uncommon disease and may occur at any stage of syphilis. Co-infection of syphilis with HIV can affect the clinical course. We report a case of meningovascular neurosyphilis in a patient with HIV in whom basilar artery thrombosis and reactive VDRL in CSF were detected. Treatment with penicillin was instituted with adequate response showing clinical improvement. Neurosyphilis is a differential diagnosis in young patients with cerebral infarction, especially in HIV patients.

[Methicillin resistance and vancomycin susceptibility pattern among blood isolates of Staphylococcus aureus]. / Resistencia a meticilina y susceptibilidad a vancomicina de Staphylococcus aureus aislados de sangre.

BACKGROUND: Staphylococcus aureus is capable of acquiring resistance against all antimicrobial agents. Vancomycin has been the cornerstone therapy for serious methicillin-resistant S. aureus infections. However, vancomycin treatment failures have been reported. METHODS: From March to August 2010, S. aureus blood isolates were included to determine methicillin-resistance and the vancomycin susceptibility by using a standard microdilution method. To detect methicillin-resistance, a Mueller-Hinton agar plate added with oxacillin 4 µg/mL and 2 % NaCl, and an agglutination test were used. Growth of S. aureus on the agar plate and/or reactive agglutination defined a methicillin-resistant organism. Vancomycin susceptibility was assessed by determining the minimal inhibitory concentration (MIC) in Muelller-Hinton agar plates prepared with dilutions ranging from 16 to 0.5 µg/mL. RESULTS: A total of 25 blood-isolates of S. aureus were included. A 60 % was methicillin-resistant. All isolates were vancomycin-susceptible (MIC ≤ 2 µg/mL) showing the next MICs distribution: 48 % ≤ 0.5 µg/mL; 44 % 1 µg/mL, and 8 % 2 µg/mL. CONCLUSION: The high proportion of methicillin-resistance among S. aureus and the presence of vancomycin susceptible phenotypes (MIC of 2 µg/mL) not only claim for an enforcement of standard precautions and antimicrobial control, but also for a regular surveillance of vancomycin susceptibility pattern using a reference method.

Introducción: el Staphylococcus aureus es capaz de desarrollar resistencia a todos los antimicrobianos. La vancomicina es clave para tratar infecciones graves causadas por S. aureus meticilino-resistente. Sin embargo, últimamente se reportan fallas terapéuticas. El objetivo fue establecer la resistencia a la meticilina y el perfil de susceptibilidad a la vancomicina del S. aureus. Métodos: de marzo a agosto del 2010, se determinó la meticilino-resistencia y la susceptibilidad a vancomicina de S. aureus aislados de hemocultivos, mediante el método estándar de microdilución. Para la meticilino-resistencia se utilizó una placa de agar Mueller-Hinton con 4 µg/mL de oxacilina, más NaCl al 2 % y una prueba de aglutinación. El desarrollo bacteriano o la aglutinación positiva identificaron al microorganismo meticilino-resistente. Para la susceptibilidad a vancomicina se determinó la concentración mínima inhibitoria (CMI) en placas de agar Mueller-Hinton con dilución de 16 a 0.5 µg/mL. Resultados: en total se incluyeron 25 S. aureus. El 60 % fue meticilino-resistente; el 100 % sensible a vancomicina (CMI ≤ 2 µg/mL), con las siguientes CMI: el 48 %, ≤ 0.5 µg/mL; 44 %, 1 µg/mL; y el 8 %, 2 µg/mL. Conclusión: la proporción alta de meticilino-resistencia y la evidencia de fenotipos sensibles a la vancomicina, pero asociados a falla terapéutica (CMI 2 µg/mL), demandan no solo el reforzamiento continuo de las precauciones estándar y el control de antimicrobianos sino también la vigilancia sistemática del patrón de susceptibilidad a la vancomicina con un método de referencia.

[Nosocomial outbreak of scabies from a Norwegian scabies case]. / Brote intrahospitalario de escabiasis, a partir de un caso de sarna noruega.

OBJECTIVE: To describe a nosocomial outbreak of scabies occurred in August 1999, resulting from exposure to an undiagnosed Norwegian scabies case, in Mexico City. MATERIAL AND METHODS: After reviewing the index case, we isolated the patient and identified secondary scabies cases among employees working in the affected ward, their relatives, and inpatients. Only individuals complaining from skin lesions and pruritus were included as infested cases. Control measures as contact isolation, proper handling of contaminated clothes, and topical treatment were implemented. RESULTS: A patient with AIDS (index case) with a severe water and electrolyte imbalance was admitted to the Hospital de Infectologia (Infectious Diseases Hospital) of the Centro Medico Nacional La Raza (La Raza National Medical Center) in Mexico City from July 19 to August 20, 1999. Twenty-eight days after the index case admission, scabies cases occurred among health workers. Norwegian scabies was suspected and confirmed by microscopic evidence of the mites on a specimen of scabs from the index case. We identified 48 secondary cases with clinical scabies: 71% health workers, mainly nurses (79%); 23% health workers' relatives; and 6% inpatients. The mean incubation period was 15 days (range 12 to 27). Skin rashes commonly involved the upper extremities (60%) but not the hands. CONCLUSIONS: This paper highlights the difficulties in diagnosing Norwegian scabies in an immunosuppressed host, as well as the importance of ensuring that health workers follow standard precautions at all times. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Brote intrahospitalario de escabiasis, a partir de un caso de sarna noruega / Nosocomial outbreak of scabies from a Norwegian scabies case

OBJETIVO: Describir un brote intrahospitalario de escabiasis ocurrido en la Ciudad de México, en agosto de 1999, como resultado de exposición a un caso de sarna noruega no diagnosticado oportunamente. MATERIAL Y MÉTODOS: Después de revisar el caso índice, instituimos aislamiento del paciente e identificamos casos secundarios de escabiasis entre pacientes hospitalizados, empleados que laboraban en el área afectada y sus familiares. Sólo individuos que padecían lesiones dérmicas y prurito fueron incluidos como casos infestados. Se establecieron medidas de control, como aislamiento de contacto, manejo apropiado de ropas contaminadas y tratamiento tópico. RESULTADOS: Un paciente con SIDA (caso índice de sarna noruega) que cursaba con desequilibrio hidroelectrolítico severo fue admitido en el Hospital de Infectología, del Centro Médico Nacional La Raza, del Instituto Mexicano del Seguro Social, del 19 de julio al 20 de agosto de 1999, en la Ciudad de México. Veintiocho días después de su admisión emergieron casos de escabiasis entre los trabajadores de la salud; entonces, se sospechó de escabiasis noruega, lo que se confirmó por evidencia microscópica de los parásitos en una preparación de escamas del caso pista. Identificamos 48 casos secundarios con sarna clínica: 71% trabajadores de la salud, principalmente enfermeras (79%), 23% familiares de trabajadores y 6% pacientes. El periodo de incubación promedio fue de 15 días (intervalo 12 a 27). Aunque con mayor frecuencia las lesiones involucraron extremidades superiores (60%), las manos fueron respetadas. CONCLUSIONES: Este trabajo demuestra no sólo las dificultades para diagnosticar la escabiasis noruega en el hospedero inmunosuprimido, sino también la importancia de estar seguros de que los trabajadores de la salud cumplan con las precauciones estándar en todo momento.

Epidemiological and biological characteristics of Methicillin-Resistant staphylococcal infections in a Mexican Hospital

Background. Methicillin-resistant Staphylococcus aureus (MRSA) has spread worldwide since 1960. However, there is little information concerning methicillinresistant coagulase-negative staphylococci (MRCNS) infections. Methods. In order to study the clinical and epidemiological characteristics of methicillinresistant staphylococci (MRS) infections and to determine the relationship between MRS and both synergistic hemolysis (SH) and slime production (SP), a laboratory-based survey and non-matched case-control study were carried out at a tertiary-care center in Mexico City. In regard to patients, from May 1991 to October 1992, 46 cases of MRS infection and 86 patients (controls) infected by methicillin-susceptible staphylococci (MSS) were included. Clinical and epidemiologic variables were analyzed. The isolates were identified and tested for antimicrobial susceptibility by standard method. An MIC of oxacillin = 8 µg/mL was defined as an MRS. Results. During the study. 94 nosocomial staphyloccocal infections were diagnosed: S. aureus, 35 and CNS, 59; 43 (45.7 percent) by MRS (rate of MRS infections was 1.12 per 100 inpatients); 2 MRSA; 41 MRCNS, and only 19 were symptomatic. Three infections were community-acquired, including one MRSA and two MRCNS. After multivariate analysis, the significant risk factors were previous antimicrobial therapy (p= 0.013) and catheterelated (p= 0.009) and urinary-tract source (p = 0.0001). Forty-nine percent of MRS showed SH while only 15 percent of MSS (p < 0.001) showed SH, especially in 10/10 MR-S. hemolyticus. additionally, 48 percent of MRCNS showed SP, as did 18 percent of MSCNS (p = 0.019), particularly in 15/20 MR-S. epidermis. Of all MRS isolates, 38 percent showed a homogeneous phenotype, a trait associated with multi-durg resistance (p < 0.01) and SH (p< 0.001). Conclusions. CNS predominanted as the cause of MRS infections in our setting. The homogeneous phenotype was associated with SH and multi-drug resistance