Rapid spread of an ongoing outbreak of Zika virus disease in pregnant women in a Mexican hospital

Abstract In the first nine weeks of implementation of a Zika Virus Preparedness Plan in a Mexican Public Hospital, we cared for 221 pregnant women with any signal or symptom suggesting Zika virus infection and 99 (44.8%) patients were found to be positive for Zika virus.The median age of patients was 25.3 years (range 13-49). Symptoms in PCR-positive patients were rash (91.4%) followed by headache (53.1%), myalgia (46.9%), arthralgia (45.7%), pruritus (35.8%), retroocular pain (29.6%), conjunctivitis (21%), and fever (21%). The women's epidemiologic exposure history indicates local transmission and a community outbreak.

Increasing rates of Clostridium difficile infection in Mexican hospitals

Abstract Introduction The epidemiology of Clostridium difficile infection (CDI) has changed in the last two decades. There is a lack of information regarding incidence and severity of CDI, especially in the developing world. Methods This was a retrospective and observational study from four hospitals of three Mexican cities. Patients were diagnosed with CDI when presented with loose stools and had at least one of the following tests positive: toxins assay, real-time PCR, or an endoscopic image compatible with pseudomembranous colitis. CDI was classified according to international guidelines. Demographic and clinical data as well as information regarding total hospital admissions, total length-of-hospital stay, and other variables related to hospitalization were gathered from the epidemiology and administration departments of each hospital. Results A total of 2050 hospital beds were analyzed with 288,171 patients hospitalized accumulating 1,576,446 days of hospitalization during the study period. The average rate of CDI per 1000 hospital-days was lower than the rates reported in the US and Europe, although in 2015 CDI rates were almost persistently above the mean rate for the study period. More than half of PCR positive patients were ribotype 027. Conclusion Hospital rates of CDI are increasing in Mexican hospitals with a predominance of infections caused by ribotype 027.

Molecular epidemiology of coagulase-negative bloodstream isolates: detection of Staphylococcus epidermidis ST2, ST7 and linezolid-resistant ST23

Abstract The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p < 0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence.

Sexually transmitted pathogens, coinfections and risk factors in patients attending obstetrics and gynecology clinics in Jalisco, Mexico / Patógenos de transmisión sexual, coinfecciones y factores de riesgo en pacientes que asisten a clínicas de obstetricia y ginecología en Jalisco, México

Abstract: Objective: To determine the frequency of nine sexually transmitted pathogens, coinfections and risk factors in patients attending obstetrics and gynecology clinics in Jalisco, Mexico. Materials and methods: Samples from 662 patients attending obstetrics and gynecology clinics were analyzed. Treponema pallidum, HIV, and HCV were detected by serology. HPV was detected by Polimerase Chain Reaction (PCR), and its genotype was determined by Restriction Fragment Length Polymorphism (RFLP). Trichomonas vaginalis, HSV-1, HSV-2, Mycoplasma genitalium, Neisseria gonorrhoeae and T. pallidum were detected by multiplex PCR. Results: By serology, HIV frequency was 6.8%, T. pallidum was 2.26%, and HCV was 0.15%. By PCR, HPV frequency was 13.9%, (more frequent genotype was 16, 33.7%), followed by T. vaginalis (14.2%), HSV-1 (8.5%), M. genitalium (2,41%), N. gonorrhoeae (2.11%), HSV-2 (1.8%), and T. pallidum (1.05%). Patients infected with T. vaginalis were more likely to have multiple coinfections (p = 0.01). Conclusion: The frequency of HPV, HVS-1, HSV-2, M. genitalium and T. vaginalis was lower than that reported. However, a high frequency of HIV, T. pallidum, and N. gonorrhoeae was detected.

Resumen: Objetivo: Determinar la frecuencia de nueve patógenos de transmisión sexual, coinfecciones y factores de riesgo en pacientes que acudieron a una consulta de ginecología y obstetricia en Jalisco, México. Material y métodos: Se analizaron muestras de 662 pacientes que asistieron a la consulta de ginecología y obstetricia. Se detectaron Treponema pallidum, VIH y VHC mediante serología. Se detectó VPH por Reacción de Cadena de Polimerasa (PCR) y sus genotipos se detectaron por Polimorfismos de Longitud de Fragmentos de Restricción (RFLP). Se detectaron Trichomonas vaginalis, VHS-1,VHS-2, Mycoplasma genitalium, Neisseria gonorrhoeae y T. pallidum por PCR múltiple. Resultados: Por serología, la frecuencia deVIH fue 6.8%, de T. pallidum fue 2.26% y deVHC fue 0.15%. Por PCR, la frecuencia más alta fue deVPH (13.9%, el genotipo más frecuente fue el 16, 33.7%), seguida deT. vaginalis (14.2%), VHS-1 (8.5%), M. genitalium (2.41%), N. gonorrhoeae (2.11%), VHS-2 (1.8%) y T. pallidum (1.05%). Los pacientes infectados con T. vaginalis presentaron más probabilidades de tener múltiples coinfecciones (p = 0.01). Conclusiones: La frecuencia de infección por VPH, VHS-1,VHS-2, M.genitalium y T. vaginalis fue menor a lo reportado. Sin embargo, se detectó una alta frecuencia de VIH, T. pallidum, y N. gonorrhoeae.

Clostridium difficile outbreak caused by NAP1/BI/027 strain and non-027 strains in a Mexican hospital

Abstract Background Clostridium difficile infections caused by the NAP1/B1/027 strain are more severe, difficult to treat, and frequently associated with relapses. Methods A case–control study was designed to examine a C. difficileinfection (CDI) outbreak over a 12-month period in a Mexican hospital. The diagnosis of toxigenic CDI was confirmed by real-time polymerase chain reaction, PCR (Cepheid Xpert C. difficile/Epi). Results During the study period, 288 adult patients were evaluated and 79 (27.4%) patients had confirmed CDI (PCR positive). C. difficilestrain NAP1/B1/027 was identified in 31 (39%) of the patients with confirmed CDI (240 controls were included). Significant risk factors for CDI included any underlying disease (p < 0.001), prior hospitalization (p < 0.001), and antibiotic (p < 0.050) or steroid (p < 0.001) use. Laboratory abnormalities included leukocytosis (p < 0.001) and low serum albumin levels (p < 0.002). Attributable mortality was 5%. Relapses occurred in 10% of patients. Risk factors for C. difficileNAP1/B1/027 strain infections included prior use of quinolones (p < 0.03). Risk factors for CDI caused by non-027 strains included chronic cardiac disease (p < 0.05), chronic renal disease (p < 0.009), and elevated serum creatinine levels (p < 0.003). Deaths and relapses were most frequent in the 027 group (10% and 19%, respectively). Conclusions C. difficile NAP1/BI/027 strain and non-027 strains are established pathogens in our hospital. Accordingly, surveillance ofC. difficile infections is now part of our nosocomial prevention program.

Application of the ATLAS score for evaluating the severity of Clostridium difficile infection in teaching hospitals in Mexico

Background: For clinicians, a practical bedside tool for severity assessment and prognosis of patients with Clostridium difficileinfection is a highly desirable unmet medical need.Setting: Two general teaching hospitals in northeast Mexico.Population: Adult patients with C. difficileinfection.Methods: Prospective observational study.Results: Patients included had a median of 48 years of age, 54% of male gender and an average of 24.3 days length of hospital stay. Third generation cephalosporins were the antibiotics most commonly used prior to C. difficileinfection diagnosis. Patients diagnosed with C. difficileinfection had a median ATLAS score of 4 and 56.7% of the subjects had a score between 4 and 7 points. Patients with a score of 8 through 10 points had 100% mortality.Conclusion: The ATLAS score is a potentially useful tool for the routine evaluation of patients at the time of C. difficileinfection diagnosis. At 30 days post-diagnosis, patients with a score of ≤3 points had 100% survival while all of those with scores ≥8 died. Patients with scores between 4 and 7 points had a greater probability of colectomy with an overall cure rate of 70.1%.

Drug resistance and molecular epidemiology of Mycobacterium tuberculosis in Mexico: a systematic review / Farmacorresistencia y epidemiología molecular de Mycobacterium tuberculosis en México: una revisión sistemática

Objective. To compare drug resistance (DR) rates and genetic diversity of Mycobacterium tuberculosis strains from different states of Mexico. Materials and methods. A systematic review of English and Spanish-language articles using MEDLINE and Google Scholar. Search terms included Mycobacterium tuberculosis, Mexico, resistance, mutation and epidemiology. Results. Fifteen studies for phenotypic DR rates (n=2 694), twelve studies for genotypic DR (n=748) and eleven studies for genetic diversity (n=2 044) met our inclusion criteria. Mean DR and multidrug resistance (MDR) rates were 37.5% and 20.6%, respectively. The most frequent mutations were rpoB531 (53.1%), katG315 (50.6%), embB306 (32.1%), rpsL43 (14.6%) and pncA359 (16.7%) in DR strains. Novel mutations were found. Predominant shared types were SIT53 (T1, n=188, 3.9%), SIT119 (X1, n=125, 6.9%), SIT19 (EAI2-Manila, n=80, 6.3%) and SIT42 (LAM9, n=77, 3.0%). SIT1 Beijing genotype has been reported in six states from Mexico. Conclusions. DR and MDR rates continue to increase. Genetic diversity of M. tuberculosis strains in Mexico is high. Reports of Beijing strains are increasing.

Objetivo. Comparar los niveles de farmacorresistencia (FR) y la diversidad genética de cepas de Mycobacterium tuberculosis de diferentes estados de México. Material y métodos. Una revisión sistemática de artículos en inglés y español usando MEDLINE y Google Scholar. Los términos de búsqueda incluyeron Mycobacterium tuberculosis, México, resistencia, mutación y epidemiología. Resultados. Quince estudios de niveles de FR fenotípica (n=2 694), doce estudios de FR genotípica (n=748) y once estudios de diversidad genética (n=2 044) concordaron con nuestros criterios de inclusión. El promedio de los niveles de FR y multifarmacorresistencia (MFR) fue 37.5 y 20.6%, respectivamente. Las mutaciones más frecuentes fueron rpoB531 (53.1%), katG315 (50.6%), embB306 (32.1%), rpsL43 (14.6%) y pncA359 (16.7%) en cepas FR. Se encontraron nuevas mutaciones. Los tipos compartidos predominantes fueron SIT53 (T1, n=188, 3.9%), SIT119 (X1, n=125, 6.9%), SIT19 (EAI2-Manila, n=80, 6.3%) y SIT42 (LAM9, n=77, 3.0%). El genotipo Beijing SIT1 se ha reportado en seis estados de México. Conclusiones. Las tasas de FR y MFR siguen incrementando. La diversidad genética de las cepas de M. tuberculosis es alta. Los reportes de cepas Beijing están aumentando.

Changes in Staphylococcus aureus susceptibility across Latin America between 2004 and 2010

The Tigecycline Evaluation and Surveillance Trial is a global surveillance study monitoring the efficacy of tigecycline and comparators against clinically important pathogens. Between 2004 and 2010, 3126 isolates of Staphylococcus aureus were collected from 66 centers in 13 countries in Latin America; of these, 1467 (46.9%) were resistant to methicillin. The main contributors of S. aureus isolates were Mexico (n = 846), Argentina (n = 740), and Colombia (n = 445). The methicillin-resistant S. aureus rate was greater than 50% in five countries, the highest reported in Puerto Rico (73.9%). Methicillin-resistant S. aureus rates across Latin America ranged from 40.1% to 50.6% over the study period. All S. aureus isolates were susceptible to linezolid and vancomycin, while 100% of methicillin-susceptible S. aureus isolates and 99.8% of methicillin-resistant S. aureus isolates were susceptible to tigecycline. Both methicillin-susceptible S. aureus and methicillin-resistant S. aureus were highly susceptible to minocycline (99.2% and 97.0%, respectively). Latin American methicillinsusceptible S. aureus were highly susceptible to levofloxacin (94.6%) while only 16.2% of methicillin-resistant S. aureus were levofloxacin-susceptible. This study shows that linezolid, vancomycin, and tigecycline are all highly active against S. aureus from Latin America, regardless of methicillin resistance.

Prevención de la infección por el complejo Mycobacterium avium. ¿Una necesidad en nuestros pacientes con SIDA? / Prevention of infection due to Mycobacterium avium complex. A need in our AIDS patients?

Antecedentes: el complejo Mycobacterium avium (CMA) está compuesto por dos especies que poseen poca virulencia en el huésped normal, ya que la inmunidad celular da protección. Objetivo: conocer la frecuencia de la infección diseminada por el complejo Mycobacterium avium en nuestra población de pacientes con SIDA. Material y métodos: se estudiaron todos los pacientes que tuvieron cuadro clínico sugestivo y linfocitos CD4 < 200 células/mm3; también se les efectuó cultivo de médula ósea para procesarse en medio de Lowenstein Jensen. El grupo total estuvo constituido por 33 pacientes. Resultados: en ningún caso se aisló la micobacteria después de doce semanas de incubación. Dos enfermos (6 por ciento) fallecieron debido a sarcoma de Kaposi y otras infecciones oportunistas, y 31 individuos (94 por ciento) se encontraban en buenas condiciones después de seis meses de seguimiento. Conclusiones: la infección diseminada por el complejo Mycobacterium avium no es común en nuestro medio, por lo cual, al parecer, la profilaxis rutinaria no es imprescindible.

Identification of mycobacteria by mycolic acid pattern

Background. Tuberculosis caused by Mycobacterium tuberculosis is a public health problem which has increased in importance during the last 12 years, due in part to the increasing number of cases cuased by the association of acquired immunodeficiency syndrome (AIDS) and the appearance of multiple drug-resistant strains. Other mycobacteria which are often indistinguishable from tuberculosis have also increased. Methods. Mycolic acid patterns were obtained from 53 clinical isolated of sputum, cerebrospinal fluid, bronchial washing, corneal ulcer, and bone marrow, as well as from 11 acid-fast stain smear-positive clinical specimens. Standardized mycolic acid extraction method was used to ensure the maximal extraction of mycolic acid derivates to enhace the sensitivity of the method. A chromatographic column different from what others have employed and a different gradient elution from those reported in the literature were used, making a correlation between retention times of the chromatographic peaks obtained in this study and those previously reported for mycolic acid patterns from a strain of Mycobacterium avium necessary. Then, a comparison of retention times of mycolic acid pattern obtained in this study and those previously reported in the literature was carried out. Strains were identified as Mycobacterium tuberculosis complex, Mycobacterium avium complex, Mycobacterium fortuitum, Mycobacterium chelonae and Mycobacterium kansasii in less than 24 hours. Results. In direct analysis of acid-fast stain smearpositive from 1+ to 4+ specimens, mycolic acid patterns were identified as Mycobacterium tuberculosis complex, Mycobacterium avium complex, Mycobacterium chelonae, and Mycobacterium kansasii, with a strong signal even in light 1+ positive samples. conclusions: The results showed that identification of mycobacteria through mycolic acid pattern is a rapid, sensitive, and very useful method for identification of mycobacteria in the early diagnosis of the mycobacteriosis