International Journal of Infectious Diseases

Editorial Board

2012-06-01

Highly effective and inexpensive parasitological technique for diagnosis of intestinal parasites in developing countries: spontaneous sedimentation technique in tube

2012-04-12

Summary: Millions of low-income people in the world are affected by intestinal parasites. Inexpensive, simple, and effective techniques for diagnosis are necessary. The spontaneous sedimentation technique in tube (SSTT), for application in poor healthcare settings and under field-work conditions, was described 25 years ago in Peru by Tello. The advantages of the SSTT are its ability to detect the majority of intestinal parasites, including eggs, larvae, cysts, and trophozoites, and its low cost.

Comparison of attitudes about polio, polio immunization, and barriers to polio eradication between primary health center physicians and private pediatricians in India

2012-04-05

Summary: Objectives: The objectives of this study were to compare attitudes and perceptions of primary health center (PHC) physicians and pediatricians in Uttar Pradesh and Bihar toward polio disease, immunization, and eradication, and to identify barriers to polio eradication.Methods: PHC physicians from blocks with at least one confirmed polio case during January 2006 to June 2009 were selected for an in-person survey. Pediatricians were members of the Indian Academy of Pediatrics and were selected from a national directory of members for telephone or mail survey.Results: A higher percentage of PHC physicians than pediatricians reported that an unvaccinated child was susceptible to polio (82.1% vs. 63.0%, p<0.0001) and that polio disease was severe in a child aged 1–5 years (77.7% vs. 62.2%, p<0.0001). PHC physicians and pediatricians expressed confidence in the protectiveness and safety of oral polio vaccine and cited parents’ lack of awareness of the importance of polio eradication as an important barrier to eradication. Strengthening routine immunization efforts was reported as the leading intervention required to eradicate polio.Conclusions: PHC physicians and pediatricians support and have confidence in the success of polio eradication efforts. These findings will be useful for policy-makers involved in the planning of eradication strategies. Providers and parents need to maintain confidence in polio vaccination if polio is to be eradicated.

Healthcare-associated infection in hematopoietic stem cell transplantation patients: risk factors and impact on outcome

2012-03-30

Summary: Objective: The objective of this study was to analyze the incidence of and risk factors for healthcare-associated infections (HAI) among hematopoietic stem cell transplantation (HSCT) patients, and the impact of such infections on mortality during hospitalization.Methods: We conducted a 9-year (2001–2009) retrospective cohort study including patients submitted to HSCT at a reference center in São Paulo, Brazil. The incidence of HAI was calculated using days of neutropenia as the denominator. Data were analyzed using EpiInfo 3.5.1.Results: Over the 9-year period there were 429 neutropenic HSCT patients, with a total of 6816 days of neutropenia. Bloodstream infections (BSI) were the most frequent infection, presenting in 80 (18.6%) patients, with an incidence of 11.7 per 1000 days of neutropenia. Most bacteremia was due to Gram-negative bacteria: 43 (53.8%) cases were caused by Gram-negative species, while 33 (41.2%) were caused by Gram-positive species, and four (5%) by fungal species. Independent risk factors associated with HAI were prolonged neutropenia (odds ratio (OR) 1.07, 95% confidence interval (CI) 1.04–1.10) and duration of fever (OR 1.20, 95% CI 1.12–1.30). Risk factors associated with death in multivariate analyses were age (OR 1.02, 95% CI 1.01–1.43), being submitted to an allogeneic transplant (OR 3.08, 95% CI 1.68–5.56), a microbiologically documented infection (OR 2.96, 95% CI 1.87–4.6), invasive aspergillosis disease (OR 2.21, 95% CI 1.1–4.3), and acute leukemias (OR 2.24, 95% CI 1.3–3.6).Conclusions: BSI was the most frequent HAI, and there was a predominance of Gram-negative microorganisms. Independent risk factors associated with HAI were duration of neutropenia and fever, and the risk factors for a poor outcome were older age, type of transplant (allogeneic), the presence of a microbiologically documented infection, invasive aspergillosis, and acute leukemia. Further prospective studies with larger numbers of patients may confirm the role of these risk factors for a poor clinical outcome and death in this transplant population.

Extrapolating respiratory tract infection incidences to a rural area of Ghana using a probability model for hospital attendance

R. Krumkamp, N.G. Schwarz, N. Sarpong, W. Loag, H. Zeeb, Y. Adu-Sarkodie, J. May — 2012-04-09

Summary: Objective: The aim of the current study was to extrapolate incidences for respiratory tract infections (RTI) using referral data from a local hospital in Ghana weighted by the individual likelihood of a hospital visit.Methods: Diagnoses from children visiting a rural hospital in Ghana during August 2007 to September 2008 were recorded. A logistic regression model, based on a population study conducted within the hospital catchment area, was used to calculate the individual probability of clinic attendance and to extrapolate the number of recorded cases. Cumulative incidences for children living in the hospital catchment area were estimated.Results: Upper RTI was the most common respiratory diagnosis, with an extrapolated incidence of 17481 cases per 100000 per year, followed by pneumonia with an incidence of 2496 per 100 000 per year. All diseases analyzed were most common in the first year of life.Conclusions: In general the study results are in line with comparable studies. Several methodological issues biasing the results in different directions were identified. For example, opportunistic infections that are more often observed in hospital attendees are likely to be overestimated. However, the applied approach presents a tool for areas where disease monitoring systems are not established.

The effect of metformin on the efficacy of antiviral therapy in patients with genotype 1 chronic hepatitis C and insulin resistance

Jian-Wu Yu, Li-Jie Sun, Yong-Hua Zhao, Peng Kang, Bing-Zhu Yan — 2012-04-09

Summary: Objectives: Insulin resistance (IR) affects sustained virological response (SVR) in chronic hepatitis C (CHC). The aim of this study was to investigate the effect of adding metformin to peginterferon alfa-2a and ribavirin on the efficacy in patients with genotype 1 CHC and IR.Methods: Ninety-eight patients with genotype 1 CHC and IR were randomized into the treatment group (n=49) and the control group (n=49). Patients in the control group received peginterferon alfa-2a and ribavirin, and patients in the treatment group received metformin in addition to peginterferon alfa-2a and ribavirin. The rate of virological response, changes in the homeostasis model assessment of insulin resistance (HOMA-IR) index, and the incidence of side effects were compared between the two groups. Factors influencing the SVR were studied by multivariate analysis.Results: The SVR rate of the treatment group was significantly higher than that of the control group (59.2%, 29/49 vs. 38.8%, 19/49; Chi-square=4.083, p=0.043). The HOMA-IR index of patients in the treatment group was lower than that of patients in the control group at weeks 12, 24, and 48 of the treatment period, and at week 24 of follow-up (3.00±0.65 vs. 3.50±0.72, 1.90±0.45 vs. 2.90±0.64, 1.75±0.40 vs. 2.74±0.48, and 1.60±0.35 vs. 2.60±0.55, respectively; t=3.610, 8.947, 11.091, and 10.738, respectively; p<0.01). Diarrhea was more often seen in the treatment group (28.6%, 14/49 vs. 10.2%, 5/49; Chi-square=5.288, p=0.021). In the multivariate logistic regression analysis, the independent factors associated with SVR were treatment method (p=0.009) and HOMA-IR <2 at week 24 (p=0.011).Conclusions: A combination of metformin, peginterferon alfa-2a, and ribavirin improved insulin sensitivity and increased the SVR rate of patients with hepatitis C genotype 1 and IR, with a good safety profile.

Epidemiology and predictors of a poor outcome in elderly patients with candidemia

2012-04-09

Summary: Background: Candidemia affects patient populations from neonates to the elderly. Despite this, little information is available about the epidemiology of candidemia in elderly patients.Methods: We performed a retrospective analysis of 987 episodes of candidemia in adults (>14 years of age) from the databases of three laboratory-based surveys of candidemia performed at 14 tertiary care hospitals. Patients aged ≥60 years were considered elderly (group 1, n=455, 46%) and were compared to younger patients (group 2, n=532, 54%) regarding demographics, underlying diseases, comorbidities, exposure to medical procedures, species, treatment, and outcome.Results: The median APACHE II score was significantly higher in the elderly patients (19 vs. 15, p=0.03). Variables that were observed significantly more frequently in elderly patients included admission to an intensive care unit, diabetes mellitus, renal failure, cardiac disease, lung disease, receipt of antibiotics or H2 blockers, insertion of a central venous catheter, mechanical ventilation, and candidemia due to Candida tropicalis. The 30-day mortality of elderly patients was significantly higher than that of younger patients (70% vs. 45%, p<0.001). Factors associated with higher mortality by multivariate analysis included APACHE II score and being in group 1 (elderly). Factors associated with mortality in elderly patients were lung disease and the receipt of mechanical ventilation.Conclusions: Elderly patients account for a substantial proportion of patients with candidemia and have a higher mortality compared to younger patients.

Epidemiology of Japanese encephalitis in South Korea, 2007–2010

2012-04-12

Summary: Background: Japanese encephalitis (JE) was the leading cause of viral encephalitis among children in South Korea in the 20th century. This study summarizes recent changes in the epidemiology of JE following the implementation of a vigorous immunization program in the country.Methods: Epidemiological investigations were performed for all reported laboratory-confirmed JE cases, and the cumulative incidence was calculated for the surveillance years 2007–2010.Results: During the surveillance period, 45 cases of JE were confirmed in the country, resulting in a cumulative incidence of 0.013–0.055 cases per 100 000 population. The median age of cases was 49.4 years, and by age group, 44.4% were aged 40–49 years. Just under a quarter (22.2%) of the cases were found to live close to a pigsty, while 42.2% of the cases were found to reside in the metropolitan areas of Seoul, Incheon, and Gyeonggi-do. None of the cases had a history of vaccination.Conclusions: Although JE has traditionally been regarded as a children's disease, the majority of cases now occur in adults in countries where strong immunization programs exist, such as in South Korea. Consideration should be given to an adult vaccination policy in the near future.

Predictors of septic shock in patients with methicillin-resistant Staphylococcus aureus bacteremia

Simon W. Lam, Seth R. Bauer, Elizabeth A. Neuner — 2012-04-13

Summary: Objectives: Risk factors for septic shock associated with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia are not well described. We designed this study to assess the independent predictors of septic shock in patients with MRSA bacteremia.Methods: This retrospective chart review included 234 patients with MRSA bacteremia admitted to a tertiary care academic medical center. Cases of septic shock and non-septic shock MRSA bacteremia were compared in terms of patient baseline characteristics and co-morbidities, modes of acquisition, and MRSA genotyping. Independent risk factors were determined by multivariable analysis.Results: On univariate analysis the presence of chronic kidney disease, respiratory failure, acute renal failure, staphylococcal cassette chromosome (SCCmec) type II, and higher APACHE II scores were significantly correlated with the presence of septic shock. On multivariate analysis, baseline APACHE II score (adjusted odds ratio (AOR) for 1-point increase 1.13, 95% confidence interval (CI) 1.04–1.22, p=0.005), acute renal failure (AOR 2.57, 95% CI 1.02–6.48, p=0.045), and SCCmec type II (AOR 2.60, 95% CI 1.01–6.75, p=0.049) were independently associated with MRSA bacteremic septic shock.Conclusions: The development of septic shock associated with MRSA bacteremia was independently correlated with baseline severity of illness, presence of acute renal failure, and an MRSA genotyping consistent with nosocomially acquired MRSA infection.

Healthcare-associated vs. hospital-acquired Staphylococcus aureus bacteremia

2012-04-13

Summary: Objective: To analyze clinical features and outcomes of patients with hospital-acquired (HA) and healthcare-associated (HCA) Staphylococcus aureus bacteremia.Methods: A retrospective cohort study was conducted from 1988 to 2007. We compared patients with clinically significant HA with those with HCA S. aureus bacteremia. Risk factors for 30-day all-cause mortality were assessed using multivariable logistic regression analysis. Cox regression analysis was used to estimate the hazard ratio (HR) for 5-year mortality with 95% confidence intervals (CI).Results: Of 1261 episodes, 735 (58.3%) were HA and 526 (41.7%) were HCA. The percentage of MRSA was 48.2% (354/735) in HA vs. 42.2% (222/526) in HCA bacteremia; p=0.04. The percentages of HCA S. aureus bacteremia and MRSA bacteremia did not vary throughout the study period. Mortality at 30 days was 40.2% (507/1261) and at 1 year was 63.4% (800/1261); this was comparable for HA and HCA bacteremia. Five-year survival curves in both settings followed very similar patterns (HR 1.01, 95% CI 0.89–1.15). Risk factors for 30-day mortality were similar, except for primary bacteremia and pre-existing heart valve disease in the HA group.Conclusions: HCA S. aureus bacteremia shares many similarities with HA bacteremia with respect to the prevalence of MRSA strains, mortality rates, and risk factors for death, and should be managed similarly.

Characterization of Staphylococcus lugdunensis endocarditis in patients with cardiac implantable electronic devices

2012-04-12

Summary: Objectives: Although the application of cardiac implantable electronic devices (CIED) has greatly increased over the past few decades, CIED endocarditis is becoming a challenging scenario in clinical practice. Recently, Staphylococcus lugdunensis has emerged as a pathogen in CIED endocarditis. However, a detailed phenotypic characterization has not been addressed.Methods: We conducted a systematic literature review covering the period between 1989 and 2011 using the PubMed, Medline, Cochrane, and Embase databases. All cases included had a CIED in use and met the modified Duke criteria for infective endocarditis, and all had isolates of S. lugdunensis. The clinical features, predisposing conditions, echocardiographic findings, and therapeutic strategies/outcomes were evaluated. Polymorphonuclear neutrophil functions were examined to test whether the defect of innate immunity may play a permissive role in host susceptibility to tissue destruction in S. lugdunensis endocarditis.Results: Eleven patients with CIED endocarditis caused by S. lugdunensis were identified. Their mean age was 61.7±11.2 years, and there was a male preponderance (72.7%). Six patients (54.5%) had undergone re-manipulation of the pacing system within a few months to years before the occurrence of clinical symptoms. The median time of symptoms before the diagnosis of CIED endocarditis was 60 days. On echocardiography, vegetations in the CIED were detected in nine cases (81.8%). Nine patients (81.8%) underwent surgical removal of the entire device, and one patient received medical treatment alone. The overall mortality rate was 18.2%. One patient had a septic perforation of the ventricular septum, with a high serum level of N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP) in the absence of pump failure. The assessment of polymorphonuclear neutrophil (PMN) functions revealed normal PMN responses to the various stimuli and normal oxidative burst responses.Conclusions: Identification and differentiation of staphylococcal species in a timely manner would allow us to intervene more aggressively at an earlier stage to prevent unfavorable outcomes. Clinicians should never consider the isolation of S. lugdunensis as contamination. In selected individuals, therapeutic abstention may be preferable to exposing patients to a high risk of S. lugdunensis CIED endocarditis due to re-manipulation of the pacing system. The prognostic value of NT-pro-BNP warrants further investigations.

Inequality and infection in China

Nicholas X. Tan, Joseph D. Tucker — 2012-04-09

In their Letter to the Editor, Zhang et al. suggest that increasing income inequalities may be associated with increases in notifiable infectious diseases in China, highlighting the need for epidemiological investigation. We would like to enrich this discussion with two important points about income inequalities and health.