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.

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.

[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.

Geographic differences in bone mineral density of Mexican women.

The aim of this study was to generate standard curves for normal spinal and femoral neck bone mineral density (BMD) in Mexican women using dual-energy X-ray absorptiometry (DXA), to analyze geographic differences and to compare these with 'Hispanic' reference data to determine its applicability. This was a cross-sectional study of 4460 urban, clinically normal, Mexican women, aged 20-90 years, from 10 different cities in Mexico (5 in the north, 4 in the center and 1 in the southeast) with densitometry centers. Women with suspected medical conditions or who had used drugs affecting bone metabolism, were excluded. Lumbar spine BMD was significantly higher (1.089 +/- 0.18 g/cm2) in women from the northern part of Mexico, with intermediate values in the center (1.065 +/- 0.17 g/cm2) and lower values (1.013 +/- 0.19 g/cm2) in the southeast (p < 0.0001). Similarly, femoral neck BMD was significantly higher in women from the north (0.895 +/- 0.14 g/cm2), intermediate in the center (0.864 +/- 0.14 g/cm2) and lower (0.844 +/- 0.14 g/cm ) in the southeast part of Mexico (p < 0.0001). Northern Mexican women tend to be taller and heavier than women from the center and, even more, than those from the southeast of Mexico (p < 0.0001). However, these differences in BMD remained significant after adjustment for weight (p < 0.0001). A significant loss (p < 0.0001) in BMD was observed from 40 to 69 years of age at the lumbar spine and up to the eighth decade at the femoral neck. Higher and lower lumbar spine values, as compared with the 'Hispanic' population, were observed in Mexican mestizo women from the northern and southeastern regions, respectively. In conclusion, there are geographic differences in weight and height of Mexican women, and in BMD despite adjustment for weight.

Serum antibody as a marker of protection against natural rotavirus infection and disease.

To determine whether naturally acquired serum IgA and IgG antibodies were associated with protection against rotavirus infection and illness, a cohort of 200 Mexican infants was monitored weekly for rotavirus excretion and diarrhea from birth to age 2 years. Serum samples collected during the first week after birth and every 4 months were tested for anti-rotavirus IgA and IgG. Children with an IgA titer >1:800 had a lower risk of rotavirus infection (adjusted relative risk [aRR], 0.21; P<.001) and diarrhea (aRR, 0. 16; P=.01) and were protected completely against moderate-to-severe diarrhea. However, children with an IgG titer >1:6400 were protected against rotavirus infection (aRR, 0.51; P<.001) but not against rotavirus diarrhea. Protective antibody titers were achieved after 2 consecutive symptomatic or asymptomatic rotavirus infections. These findings indicate that serum anti-rotavirus antibody, especially IgA, was a marker of protection against rotavirus infection and moderate-to-severe diarrhea.

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.

Rapid ethnographic assessment of breastfeeding practices in periurban Mexico City.

Before carrying out a breastfeeding promotion programme in a periurban area of Mexico City, we conducted a rapid ethnographic study to determine the factors associated with absence of exclusive breastfeeding. The responses to pilot interviews were used to develop a standardized questionnaire regarding reasons for infant feeding choice, sources of advice, and barriers to breastfeeding. We interviewed a random sample of 150 mothers with a child < 5 years of age; 136 (91%) of them had initiated breastfeeding; but only 2% exclusively breastfed up to 4 months. The mothers consistently stated that the child's nutrition, health, growth, and hygiene were the main reasons for the type of feeding selected; cost, comfort, and the husband's opinion were less important. Physicians were ranked as the most important source of advice. Reduction or cessation of breastfeeding occurred on the doctor's advice (68%); or when the mothers encountered local folk illnesses such as "coraje" (52%) or "susto" (54%), which are associated with anger or fright; or had "not enough milk" (62%) or "bad milk" (56%); or because of illness of the mother (56%) or child (43%). During childhood illnesses and conditions, breastfeeding was reduced and the use of supplementary foods was increased. This study emphasizes the importance of cultural values in infant feeding choices, defines specific barriers to breastfeeding, and provides a basis for interventions to promote exclusive breastfeeding in the study population.

PIP: Prior to initiating a community-based intervention program to promote exclusive breast feeding in San Pedro Martir, Mexico, a 2-month (1994) rapid ethnographic assessment was conducted. 150 mothers whose youngest child was under 5 years of age were interviewed. 136 mothers (91%) had breast-fed their infant, for a median duration of 6 months, but only 2% exclusively breast-fed for up to 4 months. Mothers consistently described breast feeding as the best nutrition for their infant. However, the dominant feeding pattern was mixed breast and bottle-feeding. Formula, tea, and water were introduced during the first postpartum day. By the end of the third month, 63% of mothers had introduced solid food to promote growth. It was common practice to reduce breast feeding and increase feeding of supplementary foods when a child was ill. Physicians were the most respected source of knowledge on breast feeding. 42% of mothers reported that, at some point when they were breast feeding, a doctor had advised them to stop and half these mothers complied. The data collected in this rapid survey were used to guide a peer counseling program to promote exclusive breast feeding in the community.

Efficacy of home-based peer counselling to promote exclusive breastfeeding: a randomised controlled trial.

BACKGROUND: Exclusive breastfeeding is recommended worldwide but not commonly practised. We undertook a randomised controlled study of the efficacy of home-based peer counselling to increase the proportion of exclusive breastfeeding among mothers and infants residing in periurban Mexico City. METHODS: Two intervention groups with different counselling frequencies, six visits (44) and three visits (52), were compared with a control group (34) that had no intervention. From March, 1995, to September, 1996, 170 pregnant women were identified by census and invited to participate in the study. Home visits were made during pregnancy and early post partum by peer counsellors recruited from the same community and trained by La Leche League. Data were collected by independent interview. Exclusive breastfeeding was defined by WHO criteria. FINDINGS: 130 women participated in the study. Only 12 women refused participation. Study groups did not differ in baseline factors. At 3 months post partum, exclusive breastfeeding was practised by 67% of six-visit, 50% of three-visit, and 12% of control mothers (intervention groups vs controls, p<0.001; six-visit vs three-visit, p=0.02). Duration of breastfeeding was significantly (p=0.02) longer in intervention groups than in controls, and fewer intervention than control infants had an episode of diarrhoea (12% vs 26%, p=0.03). INTERPRETATION: This is the first reported community-based randomised trial of breastfeeding promotion. Early and repeated contact with peer counsellors was associated with a significant increase in breastfeeding exclusivity and duration. The two-fold decrease in diarrhoea demonstrates the importance of breastfeeding promotion to infant health.

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.

[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.

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.

Rotavirus infection in infants as protection against subsequent infections.

BACKGROUND: Rotavirus is the leading cause of severe diarrhea in infants. To provide a base line for assessing the efficacy of rotavirus vaccines, we evaluated the protection that is conferred by natural rotavirus infection. METHODS: We monitored 200 Mexican infants from birth to two years of age by weekly home visits and stool collections. A physician assessed the severity of any episodes of diarrhea and collected additional stool specimens for testing by enzyme immunoassay and typing of strains. Serum collected during the first week of life and every four months thereafter was tested for antirotavirus IgA and IgG. RESULTS: A total of 316 rotavirus infections were detected on the basis of the fecal excretion of virus (56 percent) or a serologic response (77 percent), of which 52 percent were first and 48 percent repeated infections. Children with one, two, or three previous infections had progressively lower risks of both subsequent rotavirus infection (adjusted relative risk, 0.62, 0.40, and 0.34, respectively) and diarrhea (adjusted relative risk, 0.23, 0.17, and 0.08) than children who had no previous infections. No child had moderate-to-severe diarrhea after two infections, whether symptomatic or asymptomatic. Subsequent infections were significantly less severe than first infections (P=0.024), and second infections were more likely to be caused by another G type (P=0.054). CONCLUSION: In infants, natural rotavirus infection confers protection against subsequent infection. This protection increases with each new infection and reduces the severity of the diarrhea.

Antimicrobial resistance in fecal flora: longitudinal community-based surveillance of children from urban Mexico.

We assessed the colonization patterns, over time, of three sentinel drug-resistant enteric bacterial genera in samples from a cohort of 20 healthy small children in a periurban community in Mexico. The children were monitored during a 13-week period by means of weekly home visits and examinations of stool collections. These specimens were tested for the presence of Escherichia coli, Klebsiella species, and Shigella species resistant to one or more of seven antimicrobial agents. Ninety, 77, and 62% of the stool specimens had E. coli isolates resistant to ampicillin, trimethoprim, and tetracycline, respectively. Simultaneous resistance to more than one antibiotic by an E. coli isolate was observed in 88.5% of stool samples. Persistent fecal shedding of ampicillin-, trimethoprim-, and tetracycline-resistant E. coli occurred during the study period in the majority of children. We detected colonization by E. coli resistant to chloramphenicol, gentamicin, nitrofurantoin, or norfloxacin, as well as by Klebsiella species and Shigella species resistant to one of these antibiotics, in fewer children and for shorter periods. These data suggest the common and persistent intestinal shedding of multidrug-resistant E. coli strains by small healthy children.

Polymerase chain reaction for the detection of Mycobacterium tuberculosis DNA in tissue and assessment of its utility in the diagnosis of hepatic granulomas.

A polymerase chain reaction (PCR) assay for the rapid identification of Mycobacterium tuberculosis, based on amplification of the IS6110 insertion sequences, was tested in paraffin-embedded tissue from 64 biopsy samples with either positive or negative cultures for Mycobacterium tuberculosis. The utility of this PCR assay in the diagnosis of tuberculosis among patients with hepatic granulomas (HGs) was then tested by examining 43 liver biopsy samples. They were classified as either having definitive or probable tuberculosis or as being of nontuberculous origin, on the basis of clinical and microbiologic data and on their response to antituberculous treatment. PCR was 100% sensitive in the diagnosis of culture-positive M. tuberculosis infection in the lymph node, lung, and liver. The sensitivity of the PCR in the diagnosis of HG of definitive tuberculous origin was 58%, and the specificity was 96%. PCR is a valuable test for the demonstration of mycobacterial DNA in tissues. Although it is not highly sensitive, the DNA amplification method may also be more sensitive than culture in the diagnosis of M. tuberculosis-associated HG.

Study of Norwalk-related viruses in Mexican children.

Two-hundred Mexican children monitored from birth to 2 years of age in a cohort study of diarrhea were tested for Norwalk virus (NV) and Norwalk-related virus infection. Blood was collected quarterly and tested by an enzyme immunoassay (EIA) using the recombinant NV (rNV) particles as antigen. Stool was collected weekly and tested by an EIA using hyperimmune anti-sera from animals immunized with rNV and a reverse transcription-polymerase chain reaction (RT-PCR) with primers in the RNA polymerase region of NV. A high prevalence of serum antibody to NV (85% at age 2 years) was found by the antibody EIA. In 54 stool specimens selected from children who developed a high titer of serum antibody to rNV, none was positive for NV by the antigen EIA, but 6 yielded products by the RT-PCR. One stool specimen (MX virus) yielded a 3.3 kb RT-PCR product from the 3' end of the viral genome. The MX virus cDNA has a genomic organization like other caliciviruses. Sequence comparison showed that MX virus shares 80% nucleic acid and 91% amino acid sequence identity with Snow Mountain agent (SMA), but only 62% and 60% identity, respectively, with NV in the RNA polymerase region, suggesting that MX virus is a SMA-like virus.