Immediate treatment of acute HIV in a tertiary healthcare center: bridging gaps in communication using smartphones.

OBJECTIVES: Early initiation of antiretroviral therapy (ART) during acute HIV infection is associated with favourable clinical and epidemiological outcomes. Barriers to prompt treatment initiation limit the benefits of universal access to ART in Mexico. We sought to create an algorithm for the immediate detection and treatment of patients with acute HIV infection. METHODS: A nationwide cohort of patients with acute HIV infection was created in 2015. In order to identify cases and treat them promptly at our centre, an interdisciplinary group coordinated through an instant-messaging tool using smart phones was established. When a probable case was detected, a discussion was initiated to confirm the diagnosis and facilitate the administrative processes to initiate ART as soon as possible. We compared time to ART initiation with that in a comparison group of patients with chronic HIV infection enrolled during the same period (May 2015 to February 2017) through routine care, using survival analysis estimators and log-rank tests. RESULTS: We recruited 29 patients with acute HIV infection. The median time to ART initiation was 2 days in these patients, in contrast to 21 days for patients with chronic infection. There were no significant differences in the percentages of patients engaged in care, on treatment or virologically suppressed at 1 year of follow-up. CONCLUSIONS: Implementing immediate ART initiation programmes is feasible in Mexico, in spite of the substantial administrative barriers that exist in the country. More extensive replication of this model in other centres and in patients with chronic infection is warranted to evaluate its effect on the continuum of care.

Effects of thalidomide on HIV-associated wasting syndrome: a randomized, double-blind, placebo-controlled clinical trial.

OBJECTIVE: To evaluate the efficacy of thalidomide in treating wasting syndrome in patients with advanced HIV disease, and to assess the effects of thalidomide on circulating CD4+ T cells, and on HIV viral burden in peripheral blood mononuclear cells (PBMC). DESIGN: Randomized, double-blind placebo-controlled clinical trial. SETTING: Public tertiary care hospital in Mexico City. PATIENTS: Twenty-eight adults with advanced HIV disease being treated with antiretroviral therapy, and who had received antiretrovirals for at least 6 months, who did not have an active opportunistic infection, and who had 10% weight loss in the previous 6 months. INTERVENTIONS: Patients received thalidomide (100 mg by mouth, four times daily) or a matching placebo for the duration of the study (12 weeks). MAIN OUTCOME MEASURES: The main clinical endpoint for efficacy of thalidomide was weight gain or no progression of wasting. Secondary endpoints were Karnofsky performance status, CD4+ cell counts, and HIV viral burden in PBMC. RESULTS: Both groups were comparable in their baseline status. Therapeutic failure occurred in 10 out of 14 patients from the placebo group and in three out of 14 from the thalidomide group (P = 0.021). Weight gain occurred in one patient on placebo and in eight given thalidomide. The Karnofsky index was significantly higher by the end of the study in the thalidomide group (P = 0.003). Mild and transient somnolence and erythematous macular skin lesions were significantly more common in the thalidomide group. CD4+ T cell counts and HIV viral burden in PBMC did not change in either group. CONCLUSIONS: Results suggest that thalidomide not only impeded but also reverted the wasting syndrome, preserving the Karnofsky index in patients with advanced HIV disease. Thalidomide, at the dosage used in this study, had no effect on peripheral CD4+ T cells nor on HIV viral burden in PBMC.

Control of emergence of multi-resistant gram-negative bacilli by exclusive use of amikacin.

Results of a three-year prospective study of amikacin as the only aminoglycoside used at the Instituto Nacional de la Nutrición "Salvador Zubirán" are presented. During the initial three-month baseline period, resistance to amikacin, gentamicin, and tobramycin among 870 gram-negative bacterial isolates was 3.2 percent, 17.4 percent, and 11.2 percent, respectively. In this period, the overall consumption of aminoglycosides was 69 percent for gentamicin, 30.5 percent for amikacin, and 0.5 percent for tobramycin. In the following period of exclusive amikacin use, sensitivity patterns of 9,344 gram-negative strains isolated over three years were recorded. During this period, amikacin constituted 99.3 percent of all aminoglycosides used. The percentage of gentamicin-resistant gram-negative strains declined to 7.4 percent (p less than 0.0001), whereas the percentage of amikacin-resistant strains did not change significantly. Quarterly trend analysis of aminoglycoside-resistant strains also demonstrated a significant decrease in gentamicin resistance (p less than 0.005) and an overall steady state of amikacin resistance. It is concluded that the exclusive use of amikacin was not accompanied by a significant increase in amikacin resistance during a three-year period, and may even lead to a decrease in resistance to gentamicin and tobramycin among most gram-negative organisms.

Antibiotic misuse in diarrhea. A household survey in a Mexican community.

A survey of 1659 households in a periurban community in Mexico City was carried out to assess the frequency of and risk factors for inappropriate antimicrobial therapy in acute diarrhea. The housewife was interviewed to obtain information of the occurrence of diarrhea or use of an antibiotic in the previous 2 weeks by any member of the family. An antibiotic was used in 37% or 287 diarrheal episodes although only in 5% of all episodes was this therapy indicated, based on the presence of gross blood in stools. Patients seen by a physician were 6 times more likely to be treated with an antibiotic compared to those who did not consult a physician (p < 0.001). Self-medication was associated with a higher risk of using an inadequate drug or dose (in 72% of treated episodes) and of following treatment for less than 5 days (in 66% of treated episodes). Other risk factors significantly and independently associated with antibiotic misuse were: an increased number of stools (odds ratio [OR] = 1.21; 95% confidence interval [CI] = 1.04, 1.41), bloody diarrhea (OR = 19.04; 95% CI = 2.52, 160.90) and family crowding (OR = 2.07; 95% CI = 1.17, 3.63). These findings support future community-oriented educational interventions aimed at improving physician prescribing practices and patient compliance behavior in order to achieve a more rational use of antibiotics.

Cohort study of rotavirus serotype patterns in symptomatic and asymptomatic infections in Mexican children.

A cohort of 200 Mexican children from a low income periurban community was monitored from birth to the age of 2 years to determine the serotype-specific incidence, morbidity and seasonal pattern of symptomatic and asymptomatic human rotavirus (HRV) infections. A total of 177 HRV infections occurred in 134 (67%) children; 50% of these infections were asymptomatic. The incidence of all HRV infections was 0.6 episode/child year and was inversely related to age (r = -0.93; P < 0.01). The incidence of HRV-associated diarrhea was 0.3 episode/child year, with the highest frequency and severity occurring in infants between 4 and 6 months of age. HRV infections were more frequent each autumn, with a changing sequential pattern of predominant serotypes. Overall serotype 3 (34%) was the most frequent, followed by serotypes 1 (16%), 2 (15%) and 4 (6%). The 4 serotypes were associated with a similar risk for diarrhea and severity of diarrhea. In 23 (26%) HRV diarrhea-associated infections, an additional enteropathogen was identified; these mixed infections were more frequent in older children (chi square, 4.45; P < 0.05) but were not more severe (chi square, 0.02; P > 0.05). Our data indicate that HRV infections were common early in life, seasonal, frequently asymptomatic and caused by a variety of serotypes, none of which was a risk factor for diarrhea or severity of diarrhea.

Asymptomatic Shigella infections in a cohort of Mexican children younger than two years of age.

The proportion of Shigella infections that occur asymptomatically in young children has not been established. A community-based cohort study of 367 infants was followed prospectively by weekly home visits from January, 1990, through December, 1991. Stool samples were collected weekly and when diarrhea occurred and were tested for Shigella and other enteropathogens. There were 2925 child months of observation and 65 episodes of Shigella infection. There were 3.1 episodes/100 child months during the warm season (May through September) and 0.97 episode/100 child months during the cold season. Shigella infections were rare during the first 6 months of life but increased with age (P < 0.0001). Overall 55% of detected infections were asymptomatic. The proportion of infections that were asymptomatic increased as age increased (P < 0.01). Symptom status was not significantly associated with Shigella species or season. All isolates from symptomatic and asymptomatic children had the 120- to 140-megadalton virulence plasmid. We conclude that infections with virulent strains of Shigella are commonly asymptomatic in Mexican children during the first 2 years of life.

PIP: During January 1990-December 1991, each week, field workers visited the home of 367 children aged 0-24 months from a periurban area southwest of Mexico City (San Pedro Martir and San Andres Totoltepec, Tlalpan) and collected stool specimens from them to determine whether Shigella infections are often asymptomatic. The crude incidence rate of diarrhea, regardless of etiology, was 29 episodes/100 child months during the warmer and rainy months (May-September), while it was 21 episodes/100 child months for the rest of the year (October-April) (relative risk [RR] =1.38). 53 of all children (l4%) had 65 Shigella infections. The overall monthly incidence of symptomatic and asymptomatic Shigella infection was higher during May-September than October-April (3.13 vs. 0.97 episodes/100 children; RR = 3.22). 55% of all Shigella infections (36) were asymptomatic. 32% developed secretory-type diarrhea and 13% had blood present in the stool. The incidence of Shigella infections grew as did the age (0.4-8.2 episodes/100 child months for 0-6 month olds to 18-24 month olds; p 0.0001). The proportion of asymptomatic Shigella infections also increased with age (33% for 0-6 month olds, 40% for 7-12 month olds, 46% for 13-18 month olds, and 78% for 18-24 month olds; p 0.01). Shigella sonnei, S. flexneri, and S. boydii were the only species detected. The 120-140 megadalton virulence plasmid was present in all isolates from asymptomatic and symptomatic children. Mixed infections were rather common in both asymptomatic (47%) and symptomatic (45%) children. Among infants aged less than 12 year months, breast feeding infants were less likely to be infected with Shigella than nonbreast feeding infants (RR = 2.41). On the other hand, among children aged 12-24 months, nonbreast feeding was associated with a lower risk of Shigella infection (RR = 0.69). These findings show that Shigella infections in Mexican children aged 0-24 months range from asymptomatic infections to secretory diarrhea to bloody diarrhea.

A prospective study of astrovirus diarrhea of infancy in Mexico City.

AIM: To describe the epidemiologic and clinical characteristics of astrovirus-associated diarrhea in a cohort of young children from a periurban community in Mexico City. METHODS: From November, 1988, through December, 1991, a total of 214 children were enrolled in a longitudinal study of diarrhea and monitored from birth to 18 months of age. A stool specimen was collected during each episode of diarrhea. Specimens from a total of 510 diarrhea episodes were tested for astrovirus by enzyme immunoassay and examined for other enteric pathogens. The antigenic types of astrovirus were determined by a typing enzyme immunoassay. RESULTS: Astrovirus was detected in 26 (5%) of 510 diarrhea episodes, with an incidence rate of 0.1 episode/child year; the highest rate was in children 13 to 18 months of age. Astrovirus-associated diarrhea was characterized by a median of 4 stools (range, 2 to 10) during the first 24 h, a median duration of 3 days (range, 1 to 21), vomiting (20%), and fever (7%). No cases of dehydration or repeat symptomatic infections were observed. Coinfection with another pathogen was detected in 11 of the 26 episodes (42%). Serotype 2 (35%) was most common, followed by serotypes 4 (15%), 3 (11%), and 1 and 5 (4% each); 31% were nontypable. Astrovirus-associated diarrhea was less severe, as measured by the number of stools (4.3 +/- 1.9), than diarrhea caused by rotavirus (7.1 +/- 2.8) or when coinfections occurred (5.5 +/- 1.6; P = 0.008). CONCLUSIONS: Astrovirus was associated with 5% of the episodes of diarrhea in this cohort of young Mexican children and presented as a mild secretory diarrhea. Five predominant antigenic types were detected with type 2 being the most common.

Hospital-acquired diarrhea in adults: a prospective case-controlled study in Mexico.

OBJECTIVE: To know the incidence, etiology, risk factors, morbidity, and mortality of nosocomial diarrhea in adults. DESIGN: Nested case-control study, matched by service, length of stay, date of admission, and presence of leukopenia and/or the acquired immunodeficiency syndrome (AIDS). Cases were those who developed nosocomial diarrhea. Controls were those who did not develop nosocomial diarrhea during a comparative period nor during the next ten days. Stool samples were processed in search for parasites, yeasts, bacteria, and rotavirus. SETTING: Third-level referral center, in Mexico City, Mexico, for general internal medicine and surgical problems. PATIENTS: Eligible subjects were all new admissions to the hospital from November 1987 to September 1988. Reasons for exclusion were presence of chronic diarrheal disease or melena. There were 115 cases and 111 controls. RESULTS: Overall risk of acquiring nosocomial diarrhea was 5.5%, or 1.8 episodes per 100 patient-weeks. A potential pathogen was found in 59%. Yeasts and Entamoeba histolytica were the most frequently isolated pathogens. Mortality in cases was 18%, as compared with 5% in controls (p less than .01). Multivariate analysis showed enteral feeding, recent enemas, presence of Candida species, use of antacids/H2-blockers, and presence of nasogastric tubes as significant risk factors for nosocomial diarrhea. CONCLUSIONS: Diarrhea is a common complication in hospitalized patients. It occurs more often than previously suspected and is linked with a substantial mortality. The spectrum of etiologic agents is different from that reported in pediatric hospitals. Given that nosocomial diarrhea may constitute, at least, a marker of severity of illness, it should receive more attention in general hospitals.

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 methicillin-resistant coagulase-negative staphylococci (MRCNS) infections. METHODS: In order to study the clinical and epidemiological characteristics of methicillin-resistant 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 methods. An MIC of oxacillin > or = 8 micrograms/mL was defined as an MRS. RESULTS: During the study, 94 nosocomial staphylococcal infections were diagnosed: S. aureus, 35 and CNS, 59; 43 (45.7%) by MRS (rate of MRS infections was 1.12 per 100 in-patients); 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 catheter-related (p = 0.009) and urinary-tract source (p = 0.0001). Forty-nine percent of MRS showed SH while only 15% of MSS (p < 0.001) showed SH, especially in 10/10 MR-S. hemolyticus. Additionally, 48% of MRCNS showed SP, as did 18% of MSCNS (p = 0.019), particularly in 15/20 MR-S. epidermidis. Of all MRS isolates, 38% showed a homogeneous phenotype, a trait associated with multi-drug resistance (p < 0.01) and SH (p < 0.001). CONCLUSIONS: CNS predominated as the cause of MRS infections in our setting. The homogenous phenotype was associated with SH and multi-drug resistance.

Helicobacter pylori in water systems for human use in Mexico City.

Helicobacter pylori infection is associated with peptic ulcers and gastric cancer in humans. Transmission of H. pylori is still not certain with some epidemiological data suggesting water as a possible transmission route. The objective of this study was to detect H. pylori 16S rRNA gene in five water systems in the Mexico City area. Samples were taken between 1997 and 2000 from extraction wells (system 1), from dams used as water sources, both pre- and post-treatment (systems 2 and 3), treated wastewater (system 4) and non-treated wastewater (system 5). Detection of the H. pylori 16S rRNA gene in water samples was carried out using nested PCR in 139 water samples and confirmed by using cagA gene detection by PCR-hybridisation. The results showed the presence of H. pylori in 58 (42%) of the water samples in total with a prevalence of 68% in system 1, 100% in system 2, 0% in system 3, 17% in system 4 and 20% in system 5. This first stage showed the presence of H. pylori in the tested water systems; nevertheless, viability of the microorganism in water and vegetables needs to be confirmed as well as demonstration of a relationship between human and environmental strains.

[Utility of thoracic teleradiography in hospitalized patients]. / Utilidad de la telerradiografía de tórax en pacientes hospitalizados.

AIM: To assess the utility of the chest roentgenogram (CR) in hospitalized patients in terms of its diagnostic and therapeutic influence on the clinician. DESIGN: A survey in a group of residents of internal medicine at a tertiary care teaching hospital was carried out. Two questionnaires were applied: one when a follow-up CR was ordered (inquiring about reasons for ordering the film, the likelihood that the CR would show changes and physician's therapeutic plan); the second questionnaire was applied after the CR was obtained (inquiring about how unexpected the CR finding was and its degree of influence on therapy). Both questionnaires were analyzed in regard to the CR interpretation by a radiologist. RESULTS: One hundred surveys were analyzed. CR ruled out the suspicion of a new pulmonary event (55% of cases) or of the worsening of a known lung disease (50%) as predicted by the physician. In turn, CR confirmed the absence of a new pulmonary event (92%), or the improvement/stabilization of the course of a known lung disease (92%), as predicted by the physician. Sixty-one percent of these CR had a definite influence on patients' treatment. CONCLUSION: CR in hospitalized patients is of practical benefit to physicians, mainly in avoiding overdiagnosis and unnecesary treatment to their patients.

[Antibiotic therapy in secondary peritonitis: towards a definition of its optimal duration]. / Antibioticoterapia en peritonitis secundaria: hacia una definición de su duración óptima.

BACKGROUND: The optimal time period of antibiotic treatment in secondary peritonitis is still unknown. AIM: To prospectively evaluate: 1) The preferred time period of antibiotic treatment in secondary peritonitis by means of a survey applied to a sample of surgeons, and 2) The outcome of a series of patients with secondary peritonitis in whom the length of antibiotic treatment was based on clinical and laboratory indicators. PATIENTS AND METHODS: A survey presenting the case of a patient with acute appendicitis and secondary peritonitis was applied to 100 Mexican surgeons. The optimal length of antibiotic treatment in that particular patient was asked. Results were tabulated and analyzed. Subsequently, 35 patients with secondary peritonitis were prospectively evaluated. Antibiotics were discontinued when fever relapsed and the white blood count normalized. Clinical characteristics, diagnosis, surgical treatment and outcome were analyzed. Recurrence of sepsis was investigated as the main outcome variable. RESULTS: The survey revealed that 96% surgeons recommended antibiotic treatment for a period longer than one week. In our study group median age was 33 years, 21 were male and 14 female. All patients had a surgical abdominal condition associated to secondary peritonitis. Median period of antibiotic treatment was 3 days. In a follow-up of one month there was no persistent or recurrent sepsis in any patient. CONCLUSIONS: This information may impact in determining the total length of antibiotic therapy if our results are reproduced in studies with more patients.

[Antibiotic resistance of Helicobacter pylori in an infectious disease referral center]. / Resistencia a antimicrobianos de Helicobacter pylori en un centro de referencia infectológico.

OBJECTIVE: To estimate the frequency of H. pylori clinical isolates resistant to six commonly used antimicrobials. DESIGN: Cross-sectional observational study. SETTING: A tertiary-referral health care institution in Mexico City. PARTICIPANTS: 31 isolates of H. pylori from 31 patients with chronic antral gastritis were obtained from gastric mucosal biopsy specimens. MAIN OUTCOME MEASURE: The Minimum Inhibitory Concentration (MIC) to ampicillin, amoxycillin, tetracycline, doxycycline, metronidazole and to colloidal bismuth subcitrate was determined by the agar plate dilution test. RESULTS: All isolates showed to be susceptible to the former four antibiotics but only in 46% and 55% growth was inhibited by 8 micrograms/mL and 16 micrograms/mL of metronidazole, respectively. All isolates were inhibited by < or = 128 micrograms/mL of bismuth. A 50% increase in the percentage of metronidazole-resistant isolates (MIC > or = 8 micrograms/mL) between 1988 to 1992 was observed. CONCLUSION: There is a need of future studies in our setting aimed at assessing the cost/effectiveness of diverse H. pylori-associated peptic ulcer treatment options.

[Usefulness and risks of transtracheal aspiration in the diagnosis of pulmonary infections]. / Utilidad y riesgos del aspirado transtraqueal en el diagnóstico de infecciones pulmonares.

OBJECTIVE: To define the diagnostic usefulness and the risks of the transtracheal aspirate in a group of patients studied at the National Institute of Nutrition in Mexico City. DESIGN: It is a retrospective and descriptive analysis of a group of patients in whom a transtracheal aspiration (TTA) was performed due to suspicion of pulmonary infection. The study period was from 1983 to 1987. PATIENTS: On the study period 137 patients were submitted to a TTA; the clinical files of 126 of the cases were considered suitable for analysis. RESULTS: The procedure was performed because of a suspected bacterial pneumonia in 80% of the cases, and to study an interstitial infiltrate or pulmonary nodules in 14% and 6%, respectively. In the cases in which a bacterial pneumonia was suspected, the TTA had a sensitivity of 77% and a specificity of 95% when compared against a group of clinical, radiologic and microbiological data. Sensitivity increased to 84% when the patients who received antibiotics prior to the procedure were excluded. The specificity of the sputum's culture was sensibly less in this same group of patients. The TTA proved to be of value in five of nine pulmonary tuberculosis, two of three pulmonary mycoses and three of seven P. carinii pneumonias. Adverse events were noted in 6.3% of the cases; none of them was fatal, and specific corrective measures were necessary in only two patients. CONCLUSIONS: Our results agree with previous reports related to the usefulness of the TTA on patients with a suspected bacterial pneumonia. Our specificity is higher than that seen by other authors: we believe this is due to the low incidence of chronic respiratory diseases in the patients who attend our hospital. Transtracheal aspirate can be a valuable alternative in the diagnosis of non-bacterial pulmonary infections when the elective procedures cannot be performed. A modification on the technique is proposed to increase its usefulness in patients with interstitial pneumonia.

Diagnostic laparotomy in fever of unknown origin.

Twenty five consecutive patients with fever of unknown origin (FUO) who underwent diagnostic laparatomy (DL) are reviewed. There were 14 females and 11 males, with a mean age of 34 years. The main symptoms and signs besides fever were malaise, weight loss, varied abdominal complaints, peripheral lymph nodes enlargement, hepatomegaly and splenomegaly. The main laboratory abnormalities were: anemia, leukocytosis, and mild alterations in liver function tests. CT scan was performed in 14 patients: hepatomegaly, splenomegaly and or retroperitoneal nodes were found in 10 of them. During laparotomy, an extensive exploration of intra-abdominal organs was performed, taking multiple biopsies for histopathologic and microbiologic analysis. Splenectomy was performed in 17 patients, prophylactic appendectomy in four, and cholecistectomy in one. Laparotomy was useful to establish a diagnosis in 64 percent of cases. The most frequently diagnosed pathologies were lymphoma and tuberculosis. Postoperative morbidity was 12% and mortality was 4%. Mean follow-up was 29 months. When preoperative data were analyzed, no predictive factors were found for a laparotomy with diagnostic success. It is concluded that DL is a useful last-step procedure in the diagnostic work-up for patients with FUO.