The effect of exposure to antibiotics on incidence and spontaneous clearance of childhood Helicobacter pylori infection

It is claimed often in the H. pylori literature that spontaneous clearance (infection loss without attempts to treat) is uncommon, though little evidence supports this claim. Emerging evidence suggests that spontaneous clearance may be frequent in young children; however, factors that determine persistence of untreated H. pylori infection in childhood are not well understood. The author hypothesized that antibiotics taken for common infections cause spontaneous clearance of H. pylori infection in children. The Pasitos Cohort Study (19982005) investigated predictors of acquisition and persistence of H. pylori infection in children from El Paso, Texas, and Juarez, Mexico, enrolled prenatally at maternal-child clinics. Children were screened for infection at target intervals of 6 months from 6-84 months of age by the 13C-urea breath test corrected for body-size-dependent variation in CO2 production. This dissertation aimed to estimate the risk of spontaneous clearance at the next test following an initial detected H. pylori infection (first detected clearance), estimate the effect of antibiotic exposure on the risk of first detected clearance (risk difference), and estimate the effect of antibiotic exposure on the rate of first detected infection (rate ratio). Data on infection status and medication history were available for 608 children followed for a mean of 3.5 years. Among 265 subjects with a first detected infection, 218 had a subsequent test, and among them, the risk of first detected clearance was 68% (95% CI: 61-74%). Children who took antibiotics during the interval between first detected infection and next test had an increased probability (risk difference of 10 percentage points) of a first detected clearance. However, there was also a similar effect of average antibiotic use >0 courses across all intervals preceding the next test. Average antibiotic exposure across all intervals preceding the first detected infection appeared to have a much stronger protective effect than interval/specific exposure when estimating incidence rate ratios (0.45 vs. 1.0). Incidental antibiotic exposure appears to influence the acquisition and duration of childhood H. pylori infection, however, given that many exposed children acquired the infection and many unexposed children cleared the infection, antibiotic exposure does not explain all infection events. ^

Respiratory syncytial virus infection in hematopoietic stem cell transplant patients

Respiratory Syncytial Virus (RSV) is a major cause of respiratory tract infections in immunocompromised patients such as children less than 2 years, premature infants with congenital heart disease and chronic lung disease, elderly patients and patients who have undergone hematopoietic stem cell transplant (HSCT). HSCT patients are at high risk of RSV infection, at increased risk of developing pneumonia, and RSV-related mortality. Immunodeficiency can be a major risk factor for severe infection & mortality. Therapy of RSV infection with Ribavirin, Palivizumab and Immunoglobulin has shown to reduce the risk of progression to LRI and mortality, especially if initiated early in the disease. Data on RSV infection in HSCT patients is limited, especially at various levels of immunodeficiency. 323 RSV infections in HSCT patients have been identified between 1/1995 and 8/2009 at University of Texas M D Anderson Cancer Center (UTMDACC). In this proposed study, we attempted to analyze a de-identified database of these cases and describe the epidemiologic characteristics of RSV infection in HSCT patients, the course of the infection, rate of development of pneumonia and RSV-related mortality in HSCT patients at UTMDACC.^ Key words: RSV infections, HSCT patients ^

Reducing liver cancer disparities: a community-based hepatitis-B prevention program for Asian-American communities

OBJECTIVES: Several Asian-American groups are at a higher risk of dying of liver diseases attributable to hepatitis-B infection. This culturally diverse community should be well informed of and protected against liver diseases. The present study assesses the knowledge of hepatitis B before and after a hepatitis-B educational program and determines the infection status of an Asian community. METHODS: Nine Asian communities of Montgomery County, MD, enrolled in the hepatitis-B prevention program between 2005 and 2006. They attended culturally tailored lectures on prevention, completed self-administered pre- and posttests, and received blood screening for the disease. RESULTS: More than 800 Asian Americans participated in the study. Knowledge of prevention was improved after educational delivery. The average infection rate was 4.5%, with Cambodian, Thai, Vietnamese, Chinese and Korean groups having higher infection rates. The age group of 36-45 had the highest percentage of carriers (9.1%). CONCLUSION: Many Asian groups, particularly those of a southeast Asian decent, were subject to a higher probability of hepatitis-B infection. At an increased risk are first-generation Asian immigrants, groups with low immunization rates and those aged 36-45. The findings provide potential directions for focusing preventive interventions on at-risk Asian communities to reduce liver cancer disparities.

A METAGENOMIC STUDY OF THE TICK MIDGUT

A Metagenomic Study of the Tick Midgut Daniel Yuan, B.S. Supervisory Professor : Steven J. Norris, Ph.D. Southern tick–associated rash illness (STARI) or Master’s disease is a Lyme-like illness that occurs following bites by Amblyomma americanum, the lone-star tick. Clinical symptoms include a bull’s eye rash similar to the erythema migrans lesions of Lyme disease, as well as fever and joint pains. Lyme disease is caused by Borrelia burgdorferi and related spirochetes. However, B. burgdorferi has not been detected in STARI patients, or in ticks in the South Central U.S. The causative agent of STARI has not been identified, although it was once thought to be caused by another Borrelia species, Borrelia lonestari. Furthermore, while adult A. americanum have up to a 5.6% Borrelia lonestari infection rate, the prevalence of all Borrelia species in Texas ticks as a whole is not known. Previous studies indicate that 6%-30% of Northern Ixodes scapularis ticks are infected by Borrelia burgdorferi while only 10% of Northern A. americanum and I. scapularis ticks are infected by Borrelia species. The first specific aim of this project was to determine the bacterial community that inhabits the midgut of Texas and Northeastern ticks by using high throughput metagenomic sequencing to sequence bacterial 16S rDNA. Through the use of massively parallel 454 sequencing, we were able to individually sequence hundreds of thousands of 16S rDNA regions of the bacterial flora from 133 ticks from the New York, Missouri and Texas. The presence of previously confirmed endosymbionts, specifically the Rickettsia spp. and Coxiella spp., that are commonly found in ticks were confirmed, as well as some highly prevalent genera that were previously undocumented. Furthermore, multiple pathogenic genera sequences were often found in the same tick, suggesting the possibility of co-infection of multiple pathogenic species. The second specific aim was to use Borrelia specific primers to screen 344 individual ticks from Missouri, Texas and the Northeast to determine the prevalence of Borrelia species in ticks. To screen for Borrelia species, two housekeeping genes, uvrA and recG, were selected as well as the 16S-23S rDNA intergenic spacer. Ticks from Missouri, Texas and New York were screened. None of the Missouri or Texas ticks tested positive for Borrelia spp. The rate of I. scapularis infection by B.burgdorferi is dependent on tick feeding activity as well as reservoir availability. B. burgdorferi is endemic in the Northeast, sometimes reported as highly present in over 50% of all I. scapularis ticks. 11.6% of all New York ticks were positive for a species of Borrelia, however only 6.9% of all New York ticks were positive for B. burgdorferi. Despite being significantly lower than 50%, the results still fall in line with previous reports of about the prevalence of B. burgdorferi. 1.5% of all Texas ticks were positive for a Borrelia species, specifically B. lonestari. While this study was unable to identify the causative agent for STARI, 454 sequencing was able to provide a tremendous insight into the bacterial flora and possible pathogenic species of both the I. scapularis and the A. americanum tick.

Effectiveness of an early postoperative feeding protocol

Background. The increasing emphasis on medical outcomes and cost containment has made it imperative to identify patient populations in which aggressive nutritional care can improve quality of care. The aim of this prospective study was to implement a standardized early jejunal feeding protocol for patients undergoing small and large bowel resection, and to evaluate its effect on patient outcome and cost.^ Methods. Treatment patients (n = 81) who met protocol inclusion criteria had a jejunal feeding tube inserted at the time of surgery. Feeding was initiated at 10 cc/hour within 12 hours after bowel resection and progressed if hemodynamically stable. The control group (n = 159) received usual care. Outcome measures included postoperative length of stay, total direct cost, nosocomial infection rate and health status (SF-36) scores.^ Results. By postoperative day 4, the use of total parenteral nutrition (TPN) was significantly greater in the control group compared to the treatment group; however, total nutritional intake was significantly less. Multiple regression analysis indicated an increased likelihood of infection with the use of TPN. A reduction of 3.5 postoperative days (p =.013) with 4.3 fewer TPN days per patient (p =.001) and a 9.6% reduction in infection rate (p =.042) was demonstrated in the treatment group. There was no difference in health status scores between groups at discharge and 3 months post-discharge.^ Conclusion. These positive outcomes and an average total cost savings of $4,145 per treatment patient indicate that the treatment protocol was effective. ^

SOCIO-ENVIRONMENTAL FACTORS ASSOCIATED WITH THE DISTRIBUTION OF DRACUNCULUS MEDINENSIS (GUINEA WORM DISEASE) AND SUGGESTED METHODS FOR CONTROL, IBARAPA, NIGERIA, 1982 (AFRICA)

A population-based cross-sectional survey of socio-environmental factors associated with the prevalence of Dracunculus medinensis (guinea worm disease) was conducted in Idere, a rural agricultural community in Ibarapa, Oyo state, Nigeria, during 1982.^ The epidemiologic data were collected by household interview of all 501 households. The environmental data were collected by analysis of water samples collected from all domestic water sources and rainfall records.^ The specific objectives of this research were to: (a) Describe the prevalence of guinea worm disease in Idere during 1982 by age, sex, area of residence, drinking water source, religion and weekly amount of money spent by the household to collect potable drinking water. (b) Compare the characteristics of cases with non-cases of guinea worm in order to identify factors associated with high risk of infection. (c) Investigate domestic water sources for the distribution of Cyclops. (d) Determine the extent of potable water shortage with a view to identifying factors responsible for such shortage in the community. (e) Describe the effects of guinea worm on school attendance during 1980/1982 school years by class and location of school from piped water supply.^ The findings of this research indicate that during 1982, 31.8 percent of Idere's 6,527 residents experienced guinea worm infection, with higher prevalence of infection recorded in males in their most productive years and females in their teenage years. The role of sex and age to risk of higher infection rate was explained in the context of water related exposure and water intake due to dehydration from physical occupational actitives of subgroups.^ Potable water available to residents was considerably below the minimum recommended by WHO for tropical climates, with sixty-eight percent of water needs of the residents coming from unprotected surface water which harbour Cyclops, the obligatory intermediate host of Dracunculus medinensis. An association was found between periods of relative high density of Cyclops in domestic water and rainfall.^ Impact of guinea worm infection on educational activities was considerable and its implications were discussed, including the implications of the research findings in relation to control of guinea worm disease in Ibarapa. ^

The prevention of catheter related bloodstream infections in a pediatric population

Catheter related bloodstream infections are a significant barrier to success in many inpatient healthcare facilities. The goal of this study was to analyze and determine if an evidence based methodology to reduce the number of catheter related bloodstream infections in a pediatric inpatient healthcare facility had significant impact on the infection rate. Catheter related bloodstream infection rates were compared before and after program implementation. The patient population was selected based upon a recommendation in the 2010 National Healthcare Safety Network report on device related infections. This report indicated a need for more data on pediatric populations requiring admission to a long term care facility. The study design is a retrospective cohort study. Catheter related bloodstream infection data was gathered between 2008 and 2011. In October of 2008 a program implementation began to reduce the number of catheter related bloodstream infections. The key components of this initiative were to implement a standardized catheter maintenance checklist, introduce the usage of a chlorhexadine gluconate based product for catheter maintenance and skin antisepsis, and a multidisciplinary education plan that focused on hand hygiene and aseptic technique. The catheter related bloodstream infection rate in 2008 was 21.21 infections per 1000 patient-line days. After program implementation the 2009 catheter related bloodstream infection rate dropped to 1.11 per 1000 patient-line days. The infection rates in 2010 and 2011 were 2.19 and 1.47 respectively. Additionally, this study demonstrated that there was a potential cost savings of $620,000 to $1,240,000 between 2008 and 2009. In conclusion, an evidence based program based upon CDC guidelines can have a significant impact on catheter related bloodstream infection rates. ^

Risk factors for spinal surgical site infection

Background. Surgical site infections (SSI) are one of the most common nosocomial infections in the United States. This study was conducted following an increase in the rate of SSI following spinal procedures at the study hospital. ^ Methods. This study examined patient and hospital associated risk factors for SSI using existing data on patients who had spinal surgery performed at the study hospital between December 2003 and August 2005. There were 59 patients with SSI identified as cases; controls were randomly selected from patients who had spinal procedures performed at the study hospital during the study period, but did not develop infection. Of the 245 original records reviewed, 5% were missing more than half the variables and were eliminated from the data set. A total of 234 patients were included in the final analysis, representing 55 cases and 179 controls. Multivariable analysis was conducted using logistic regression to control for confounding variables. ^ Results. Three variables were found to be significant risk factors for SSI in the study population: presence of comorbidities (odds ratio 3.15, 95% confidence interval 1.20 to 8.26), cut time above the population median of 100 minutes (odds ratio 2.98, 95% confidence interval 1.12 to 5.49), and use of iodine only for preoperative skin antisepsis (odds ratio 0.16, 95% confidence interval 0.06 to 0.45). Several risk factors of specific concern to the study hospital, such as operating room, hospital staff involved in the procedures and workers' compensation status, were not shown to be statistically significant. In addition, multiple factors that have been identified in prior studies, such as method of hair removal, smoking status, or incontinence, were not shown to be statistically significant in this population. ^ Conclusions. This study confirms that increased cut time is a risk for post-operative infection. Use of iodine only was found to decrease risk of infection; further study is recommended in a population with higher usage of chlorhexadine gluconate. Presence of comorbidities at the time of surgery was also found to be a risk factor for infection; however, specific comorbidities were not studied. ^

The burden of parainfluenza virus infection in patients with hematological malignancy and hematopoietic stem cell transplant (HSCT) recipients in the absence of active immunization and approved therapy: The role of infection control

Background. Community respiratory viruses, mainly RSV and influenza, are significant causes of morbidity and mortality in patients with leukemia and HSCT recipients. The data on impact of PIV infections in these patients is lacking. Methods. We reviewed the records of patients with leukemia and HSCT recipients who developed PIV infection from Oct'02–Nov'07 to determine the outcome of such infections. Results. We identified 200 patients with PIV infections including 80(40%) patients with leukemia and 120 (60%) recipients of HSCT. Median age was 55 y (17-84 y). As compared to HSCT recipients, patients with leukemia had higher APACHE II score (14 vs. 10, p<0.0001); were more likely to have ANC<500 (48% vs. 10%, p<0.0001) and ALC<200 (45% vs. 23.5%, p=0.02). PIV type III was the commonest isolate (172/200, 86%). Most patients 141/200 (70%) had upper respiratory infection (URI), and 59/200 (30%) had pneumonia at presentation. Patients in leukemia group were more likely to require hospitalization due to PIV infection (77% vs. 36% p=0.0001) and were more likely to progress to pneumonia (61% vs. 39%, p=0.002). Fifty five patients received aerosolized ribavirin and/or IVIG. There were no significant differences in the duration of symptoms, length of hospitalization, progression to pneumonia or mortality between the treated verses untreated group. The clinical outcome was unknown in 13 (6%) patients. Complete resolution of symptoms was noted in 91% (171/187) patients and 9% (16/187) patients died. Mortality rate was 17% (16/95) among patients who had PIV pneumonia, with no significant difference between leukemia and HSCT group (16% vs. 17%). The cause of death was acute respiratory failure and/or multi-organ failure in (13, 81%) patients. Conclusions. Patients with leukemia and HSCT could be at high risk for serious PIV infections including PIV pneumonia. Treatment with aerosolized ribavirin and/or IVIG may not have significant effect on the outcome of PIV infection.^

Effects of breastfeeding and naturally acquired immunity on infection with {\it Giardia lamblia}: A study in a cohort of Mexican infants

Giardia lamblia is one of the most common causes of gastrointestinal tract infection among young children worldwide. Yet host protection against this parasite and the effect of infection with Giardia on infant growth are poorly understood. It was hypothesized that among young children, protection against infection with Giardia is afforded by breastfeeding and previous infection with the parasite and further, that infection with Giardia decreases growth velocity. From 4/88 to 4/90, 197 infants in a poor area of Mexico City were followed from 0 to 18 months of age, with stool specimens, symptoms and feeding status data collected weekly. A total of 6,031 stool specimens were tested for Giardia antigen by enzyme-linked immunosorbent assay. There were 1.0 Giardia infections per child-year; 25% were symptomatic and 54% lasted more than 1 month; 94 infants had 1, and 33 had 2 or more infections. Breastfeeding status was coded and analyzed for each child-week of follow up. 91% of study infants were breastfed from birth, 57% at 6 months and 38% at 12 months of age. Rate ratios for non-breastfeeding adjusted for confounding factors were calculated from stratified analyses and the Cox proportional hazards model. Not breastfeeding was a significant risk factor for first infection with Giardia vs. any breastfeeding (adjusted RR = 1.8; 1.1, 2.8) at all ages; a dose response was demonstrated by degree of breastfeeding. The adjusted rate ratio for non-breastfeeding vs. partial breastfeeding was 1.6 (1.03, 2.6) and for non-breastfeeding vs. complete breastfeeding was 4.7 (1.4, 15.9). Among Giardia infected infants, breastfeeding did not protect against diarrheal symptoms or shorten the duration of carriage. First and repeat infections with Giardia did not differ in duration or the percent symptomatic. The analysis of growth and Giardia infection was inconclusive but suggested that a history of Giardia infection might be associated with decreased weight velocity, while an immediate chronic infection might be associated with increased weight velocity. In summary, these data indicate that breastfeeding protects infants against infection with Giardia; provide no evidence of protection against repeat infections resulting from a prior infection and suggest but do not establish that a history of Giardia infection might be associated with decreased growth in young children. ^

Role of {\it Mycobacterium avium-intracellulare\/} complex infection in AIDS mortality

Disseminated MAC (dMAC) is the third most prevalent opportunistic infection in AIDS patients. In order to understand the role MAC infection plays in affecting survival of AIDS patients, a cohort of 203 suspected dMAC veterans seen at the Houston Veterans Affairs Medical Center between August 14, 1987 and December 31, 1991 were analyzed. The criteria for suspected dMAC infection was HIV+ men having a CD4+ level $\le$200 cells/mm$\sp3,$ on zidovudine treatment $\ge$1 month and who had any of the following: (a) a confirmed respiratory MAC infection, (b) fever $\ge$101$\sp\circ\rm F$ for $\ge$48 hours, (c) unexplained weight loss of 10 lbs or $\ge$10% BW over 3 months or (d) Hgb $\le$7.5 g/dl or decrease in Hgb $\ge$3.0 g/dl, while on 500-600 mg/day AZT. The study was conducted before the commencement of an effective MAC anti-mycobacterial therapy, so the true course of MAC infection was seen without the confounder of a therapeutic regimen. Kaplan-Meier and Cox regression survival analysis was used to compare 45 MAC culture positive and 118 MAC culture negative veterans. The 1 year survival rate of veterans with documented dMAC infection was 0.37 compared to 0.50 for veterans not acquiring dMAC infection. Significant differences between subgroups were also seen with the variables: PCP prophylaxis, the AIDS indicator disease Candida esophagitis, CD4+ lymphocyte level, CD4 percent lymphocyte level, WBC level, Hgb and Hct levels. Using multivariate modeling, it was determined that PCP prophylaxis (RR = 6.12, CI 2.24-16.68) was a predictor of survival and both CD4% lymphocytes $\le$6.0% (RR = 0.33, CI 0.17-0.68) and WBC level $\le$3000 cells/mm$\sp3$ (RR = 0.60, CI 0.39-0.93) were predictors of mortality. CD4+ level $\le$50 cells/mm$\sp3$ was not a significant predictor of mortality. Although MAC culture status was a significant predictor of mortality in the univariate model, a positive dMAC culture was not a significant predictor of AIDS mortality in the multivariate model. A positive dMAC culture, however, did affect mortality in a stratified analysis when baseline laboratory values were: CD8+ lymphocytes $>$600 cells/mm$\sp3,$ Hgb $>$11.0 g/dl, Hct $>$31.0% and WBC level $>$3000 cells/mm$\sp3.$ ^

A systematic review of clostridium difficile infection in patients with iatrogenic immunesuppression

Background: Incidence of C. difficile infection (CDI) has increased dramatically in the past decade and is the most frequent cause of nosocomial infectious diarrhea. The outcome of infection may range from mild diarrhea to life-threatening pseudomembranous colitis depending on the immunological response of the host, which is highly compromised in this special population that includes bone marrow transplant (BMT), solid organ transplant (SOT) and cancer patients on cytotoxic chemotherapy. ^ Objectives: We conducted a meta-analysis to assess the incidence rates of CDI and the time to onset of infection in patients with iatrogenic immune suppression. ^ Methods: Original studies were identified through an extensive search of electronic databases including PubMed, Ovid Medline (R), RefWorks and Biological Abstracts and their references. The overall incidence rate of CDI in the immune suppressed population was calculated using random effects model and their 95% confidence interval was derived. Differences in the incidence of CDI and time to onset of infection were calculated between the groups and within the groups. Publication bias was assessed using a funnel plot. Results: Twenty nine published articles involving 7,424 patients met the eligibility requirements. The overall incidence of CDI in the immune suppressed population is 11.1% (95% Confidence Interval (CI): 9.2–13.4%). The incidence of CDI was higher in SOT patients (14.2%, 95% CI: 6.8–21.5%); (p-value-0.022) and in cancer patients on cytotoxic chemotherapy (11.4%, 95% CI: 8.4–15.4%); (p = 0.042) than in BMT patients (10.5%, 95% CI: 7.9–13.1%). In a subgroup analysis of BMT population, the incidence of CDI is significantly higher in patients who received allogeneic BMT (15.1%, 95% CI: 11.2–20.0%; p value <0.0001). Similarly, in the SOT population, the incidence of CDI was higher in patients who underwent liver transplantation (11.0%, 95% CI: 5.6–20.3%); (p= 0.0672). The median time to onset of infection was shorter in BMT patients (p=0.0025). ^ Conclusions: It is evident from the combined analysis of these 29 published studies that the incidence of CDI in the immune suppressed population is higher. However, early diagnosis and treatment of CDI will help reduce the morbidity and mortality due to CDI in this special population.^

A descriptive study of syphilis infection in Houston, Texas, 1999--2008

The rate of syphilis nationally has been on the rise since 2001. Syphilis, if left untreated can facilitate the transmission of HIV infection. An epidemiologic study describing the trends of syphilis is important to the public health community to lay the foundation for the development and implementation of programs to prevent and eliminate syphilis in the United States. ^ The objective of this study was to describe the trends of syphilis among the population in Houston/Harris County, Texas. ^ We reviewed surveillance data that included 11,605 unique cases from the Houston Department of Human and Health Service from 1999 through 2008. The rates were calculated per 100,000 population. ^ We show the prevalence of syphilis at testing (excluding congenital) increased 40% in Houston/Harris County, Texas from 2001 through 2008, and the ratio of syphilis comparing men to women was 2:1. The 18–29 years age group had the highest percentage of cases of syphilis among all age groups in Houston/Harris County. Primary and Secondary (P&S) syphilis, the most infectious stage, had an 85% increase in rate among males from 1999 through 2008. ^ Between 1999 and 2000, 71% of cases were identified through public facilities compared to private facilities. However, after 2001 rates shifted over more to the private facilities. By 2008, private facilities identified 54.7% of cases, compared to 45.3% identified through public facilities. This may be due to an increase among individuals who have a higher socio-economic status with access to health care insurance. ^ In conclusion, syphilis rates from 1999 through 2008 increased among all race ethnicities, age groups, and genders in Houston/Harris County. Blacks still are disproportionally affected by syphilis infections, and for the first time, White males displayed a significant increase in cases among males. It is vital to Houston public health professionals to have improved surveillance techniques to track syphilis trends and engage high risk groups to better understand their risks in hope of treating and preventing syphilis.^

Implementation of active surveillance cultures and associated infection control practices for the reduction of methicillin resistant Staphylococcus aureus in the healthcare setting: An interrupted time series analysis

OBJECTIVE. To determine the effectiveness of active surveillance cultures and associated infection control practices on the incidence of methicillin resistant Staphylococcus aureus (MRSA) in the acute care setting. DESIGN. A historical analysis of existing clinical data utilizing an interrupted time series design. ^ SETTING AND PARTICIPANTS. Patients admitted to a 260-bed tertiary care facility in Houston, TX between January 2005 through December 2010. ^ INTERVENTION. Infection control practices, including enhanced barrier precautions, compulsive hand hygiene, disinfection and environmental cleaning, and executive ownership and education, were simultaneously introduced during a 5-month intervention implementation period culminating with the implementation of active surveillance screening. Beginning June 2007, all high risk patients were cultured for MRSA nasal carriage within 48 hours of admission. Segmented Poisson regression was used to test the significance of the difference in incidence of healthcare-associated MRSA during the 29-month pre-intervention period compared to the 43-month post-intervention period. ^ RESULTS. A total of 9,957 of 11,095 high-risk patients (89.7%) were screened for MRSA carriage during the intervention period. Active surveillance cultures identified 1,330 MRSA-positive patients (13.4%) contributing to an admission prevalence of 17.5% in high-risk patients. The mean rate of healthcare-associated MRSA infection and colonization decreased from 1.1 per 1,000 patient-days in the pre-intervention period to 0.36 per 1,000 patient-days in the post-intervention period (P<0.001). The effect of the intervention in association with the percentage of S. aureus isolates susceptible to oxicillin were shown to be statistically significantly associated with the incidence of MRSA infection and colonization (IRR = 0.50, 95% CI = 0.31-0.80 and IRR = 0.004, 95% CI = 0.00003-0.40, respectively). ^ CONCLUSIONS. It can be concluded that aggressively targeting patients at high risk for colonization of MRSA with active surveillance cultures and associated infection control practices as part of a multifaceted, hospital-wide intervention is effective in reducing the incidence of healthcare-associated MRSA.^

Is H. pylori infection associated with diarrhea in a cohort of 3- to 8-year-old Colombian children?

The Estudio Comunitario sobre la Salud del Niño cohort study followed 326 3- to 8-year-old Colombian children for 4 years to observe the natural history of Helicobacter pylori infection and identify risk factors for acquisition, recurrence and persistence. Acute H. pylori infection during childhood may predispose to other enteric infections and therefore increase the risk of diarrheal disease. This dissertation aimed to estimate the effect of H. pylori infection on the occurrence of diarrhea and parasitic co-infections. The analysis used Generalized Estimating Equations to obtain odds ratios to estimate relative risks for diarrhea and the Zhang-Yu algorithm to estimate relative risks for on parasitic infections. Andersen-Gill models were used to estimate rate ratios for the effect of H. pylori status on the recurrence of parasitic infections. H. pylori status was classified for the entire follow-up duration in 1 of 3 categories: persistently positive, intermittently positive, and persistently negative. Multivariable models included child’s sex, age, symptoms, medication use, and socio-environmental factors. H. pylori infection was weakly and imprecisely associated with diarrheal disease, which occurred at an unexpectedly low frequency in this study. Persistently H. pylori-positive children had a somewhat higher incidence of reported diarrhea than intermittently positive or persistently negative children. Stratified analysis revealed that the presence of specific helminthes modified the effect of persistent H. pylori infection on diarrhea. The incidence of any parasitic infections was higher in children with persistent H. pylori infection relative to those with intermittent or persistently negative status, but this association did not hold when adjusted for the full set of selected covariates. The effects of H. pylori persistent status were similar for the occurrence or recurrence of Giardia duodenalis, Entamoeba histolytica, and Ascaris lumbricoides. These results show that H. pylori frequently co-exists with other parasites in Andean children and suggest that intermittently H. pylori–positive children might be at a lower risk of parasitic infections than persistently positive children. The relationship of H. pylori infection, helminthic infection and diarrheal disease should be further explored in studies that devote more intensive resources to accurate ascertainment of diarrhea.^