Understanding the local factors influencing the transmission of communicable diseases is important to minimize social damage. The aim of this study was to investigate local factors influencing seasonal influenza epidemics in Aomori prefecture consisting of 6 regions, i.e., Seihoku, Chunan, and Tosei on the west side, and Sanpachi, Kamikita, and Shimokita on the east side. Four indices (epidemic onset, duration, scale, and steepness of epidemic curves) were defined, and their correlations with regional characteristics and meteorological factors were investigated. Data for influenza seasons from 2006–2007 to 2014–2015 were collected. The 2009–2010 season was excluded because of the pandemic of A (H1N1)pdm09. Average income was strongly correlated with epidemic onset, duration, and scale. The ratio of children aged ≤5 years to the total population was strongly correlated with epidemic duration and scale. Low temperature in January showed moderate correlation with epidemic duration and scale. Cluster analysis showed that 2 isolated regions, Seihoku and Chunan, belonged to the same cluster in the 4 indices of epidemic curves, and other 2 relatively urbanized regions formed another cluster in 3 of the 4 indices. This study highlights important local factors that influence seasonal influenza epidemics and may help in implementation of preventive measures.
In developed countries, the infection related-mortality rates in children hospitalized in tertiary medical facilities, where many patients with underlying disease are also hospitalized, are uncertain. We investigated the characteristics of infectious diseases-related fatal cases in the pediatric ward of a Japanese tertiary medical facility. A total of 188 patients who died in the pediatric ward or intensive care unit at Kyushu University Hospital from 2002 to 2011 were enrolled. The patient characteristics were investigated based on their medical records. A total of 35 patients died of infections, 31 of whom had underlying diseases. Most patients died of sepsis or pneumonia (n = 27). All 9 patients who died within 7 days of birth were premature. Nine of the 13 patients with malignancy or hematological disorders died of hematopoietic stem cell transplantation (HSCT)-associated infections. The ratio of infectious disease-related fatal cases to the total cases decreased in the latter half of the study period. In particular, the proportion of preterm infants who died of infections was significantly lower in the latter 5 years (p = 0.02). Many of the infectious disease-related fatal cases were in premature infants and HSCT or post-HSCT patients. However, the mortality due to infectious diseases decreased in these patient groups.
A rapid, simple method for detecting foodborne pathogenic bacteria in human feces is greatly needed. Here, we examined the efficacy of a method that employs a combination of a commercial PCR master mix, which is insensitive to PCR inhibitors, and a DNA extraction method which used sodium dodecyl benzene sulfonate (SDBS), and Tween 20 to counteract the inhibitory effects of SDBS on the PCR assay. This method could detect the target genes (stx1 and stx2 of enterohemorrhagic Escherichia coli, invA of Salmonella Enteritidis, tdh of Vibrio parahaemolyticus, gyrA of Campylobacter jejuni, ceuE of Campylobacter coli, SEA of Staphylococcus aureus, ces of Bacillus cereus, and cpe of Clostridium perfringens) in a fecal suspension containing 1.0 × 101 to 1.0 × 103 CFU/ml. Furthermore, the assay was neither inhibited nor influenced by individual differences among the fecal samples of 10 subjects or fecal concentration (40–160 mg/ml in the fecal suspension). When we attempted to detect the genes of pathogenic bacteria in 4 actual clinical cases, we found that this method was more sensitive than standard culture method. These results showed that this assay is a rapid, simple detection method for foodborne pathogenic bacteria in human feces.
The aim of this study was to determine the prevalence and virulence factors of Shigella species isolated from patients with diarrhea. Shigella species were isolated from 1,022 stool samples collected from different hospitals in Rosario, Argentina. The isolates were characterized using phenotypic tests, serotyping, and detection of virulence genes by PCR. One hundred strains (9.8% of samples collected) of Shigella were isolated. Shigella flexneri was the most frequently identified species (74%), followed by S. sonnei (26%). S. flexneri was also the predominant species isolated from children aged 6–14 years. These clinical strains of Shigella were then tested for the presence of ipaH, virA, ial, sen, and set using specific primers. virA was present in all strains, whereas ipaH was detected in 98% of strains and ial in 83%. sen was found in 71.6% of S. flexneri and 42.3% of S. sonnei isolates, and 41.9% of S. flexneri isolates were positive for set. Furthermore, 32.4% of S. flexneri isolates were positive for both set and sen. This study provides data on the prevalence and distribution of diverse Shigella strains.
Vitamin D is known to be closely associated with periodontitis; however, its exact mechanisms remain to be clarified. The present study aimed to investigate the influence of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on Porphyromonas gingivalis (Pg)-stimulated cytokine production and the involved signaling pathways in macrophages. The main observation was that 1,25(OH)2D3 inhibited Pg-induced interleukin (IL)-6 cytokine expression but up-regulated the expression of anti-inflammatory cytokine IL-10. Further analyses showed that 1,25(OH)2D3 decreased p38 mitogen-activated protein kinase (MAPK) and extracellular signal regulated kinase (ERK)1/2 phosphorylation. Inhibited phosphorylation of p38 MAPK and ERK1/2 was associated with decreased level of IL-6 expression, but was not related to increased level of IL-10 expression in macrophages stimulated with Pg. These results suggest that 1,25(OH)2D3 might exert its anti-inflammatory effects on Pg-stimulated macrophages partly through its inhibitory effect on the p38 MAPK and ERK1/2 signaling pathway.
The procedure of ultra-rapid extraction (PURE) and loop-mediated isothermal amplification for tuberculosis (LAMP-TB) is a simple and rapid manual tuberculosis diagnostic with medium-throughput capability. Because of its simplicity, this method could be useful in resource-limited conditions such as microscopy centers in developing countries. This study was conducted to evaluate the clinical performance of this method in a point-of-care setting. The performance was compared to that of smear microscopy and liquid culture in a hospital laboratory in Haiti, which is considered a representative facility for the implementation of this method. The sensitivity, based on culture-positivity, was 86% (95% confidence interval: 81.3–90.3%) and that based on the smear-negative and culture-positive results was 51% (38.7–63.5%). The specificity based on sample negativity for both smear and culture was 98.4% (96.8–99.2). These results are nearly equivalent to those of a clinical study performed in Japan and are comparable with those of other nucleic acid amplification methods. Thus, approximately 18% more tuberculosis patients could be identified by adding the LAMP-TB method to routine smear microscopy in field settings in Haiti. In addition, it is suggested that local technicians could perform LAMP-TB after only short-term training.
Transgender people are at a high risk for sexually transmitted viruses such as hepatitis B virus (HBV) and human immunodeficiency virus (HIV). Moreover, Indonesia has a moderate-to-high rate of HBV infection and rapid epidemic growth of HIV infection; hepatitis C virus (HCV) infection can co-occur with HBV and HIV infections. In this study, 10 of 107 individuals (9.3%) were positive for HBV surface antigen (HBsAg) and/or HBV DNA, whereas 19 of 101 individuals (18.8%) with negative results for HBsAg were positive for HBV core antibody (anti-HBc). Seven of the 107 individuals (6.5%) were anti-HCV positive, and 16 of the 100 tested samples (16.0%) were HIV positive. Genotype and subtype analyses of all 10 HBV DNA (6 HBsAg positive and 4 anti-HBc positive) strains showed that 3 were of the HBV genotype/HBsAg subtype C/adrq+, one was of C/adw2, and 5 were of B/adw2. The HCV subtype distribution showed that 33.3% were of HCV-1b, and 66.7% were of HCV-3k (n = 6). These distributions differed from those found in the general population of Surabaya, Indonesia. Interestingly, HIV subtype analysis showed a high prevalence of HIV, with possible recombinants of CRF01_AE and subtype B.
Adenoviruses are responsible for approximately 5–10% of acute respiratory infections globally. However, there are a limited number of reports on the types of circulating respiratory human adenoviruses (HAdV) in India. We detected HAdV in the post-mortem specimens of a young child who died as a result of an acute febrile illness. To retrospectively investigate the circulating adenovirus types in the Alappuzha region, samples (n = 235) collected from patients with influenza-like illnesses who participated in the influenza surveillance program were screened for HAdV. Fourteen samples were identified as positive for adenovirus by PCR analysis. Adenovirus was isolated from 3 of the 14 PCR-positive samples cultured using HEK-293 cell lines. The viral strains isolated in the study were from children between 6 and 10 years of age. The isolates were identified as adenovirus species C and E. Sequencing analysis of the fiber gene and a BLAST search revealed that 2 of the isolates were type HAdV-C2, and the third isolate was a HAdV-E4. A fiber gene sequence-based phylogenetic tree showed that the HAdV-E4 isolate was similar to the Japanese HAdV-E4 strain, whereas the HAdV-C2 isolates formed a distinct cluster. Respiratory infections due to HAdV-E4 are generally observed in adults; this study is the first to demonstrate the involvement of the HAdV-E4 strain in respiratory illnesses in children.
Levels of presepsin (a soluble cluster of differentiation subtype 14 [CD14]) are thought to increase in cases of bacterial infection. CD14 has also been found to play a role in the pathogenesis of various viral diseases. Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic arboviral infection. Our study focuses on presepsin levels as a biomarker for CCHF. Serum presepsin levels in a CCHF group (n = 59) and control group (n = 28) were compared. Patients with CCHF were classified according to severity grading score as having mild, moderate, or severe infection and were allocated to corresponding subgroups (groups 1, 2, and 3, respectively). Presepsin levels were measured in serum samples by using a commercial enzyme-linked immunosorbent assay kit. The mean presepsin levels in the CCHF group as a whole and the healthy group were found to be significantly different (1,499.46 ± 411.96 pg/ml and 430.68 ± 61.21 pg/ml, respectively). The mean presepsin levels of the CCHF subgroups (1, 2 and 3) and the healthy group were also found to be significantly different (1,204.53 ± 371.18, 1,464.21 ± 338.37, 2,007.36 ± 82.18, and 430.68 ± 61.21 pg/ml, respectively) (p < 0.05). We also found that as the severity of the disease increased, the presepsin level also increased. We postulate that the presepsin levels could be used as a supportive biomarker for diagnosis and follow-up of the disease.
The present study examined the susceptibility of rats to the Middle East respiratory syndrome coronavirus (MERS-CoV) and determined whether this animal is a suitable model for MERS-CoV infection. Immunohistochemical analysis identified dipeptidyl peptidase 4 (DPP4), a known receptor for MERS-CoV on type I pneumocytes from infected rats. Whereas adult rats developed antibodies against MERS-CoV spike protein after intranasal inoculation, there was no evidence of viral replication in the lungs of adult, young, or neonatal rats after intranasal inoculation with MERS-CoV. In addition, human DPP4-expressing rat kidney fibroblasts, but not rat DPP4-expressing cells, were susceptible to MERS-CoV. Taken together, these results suggest that the rat is not a useful animal model for studying MERS-CoV infection.
We report the first case of spondylitis with bacteremia caused by Campylobacter fetus subsp. testudinum identified by 16S ribosomal ribonucleic acid (rRNA) gene sequencing. An 81-year-old man presented with fever and general weakness. His medical history included end-stage renal disease, hypertension, and type 2 diabetes. Despite empirical antibiotic treatment, his fever and back pain persisted. Magnetic resonance imaging with gadolinium enhancement showed a low-signal-intensity lesion in T1-weighted imaging and a high-signal-intensity lesion in T2-weighted imaging at the L3 vertebral body. C. fetus grew on 1 pair of blood cultures. C. fetus subsp. testudinum was identified via 16S rRNA sequencing of the cultivated organisms. The patient recovered uneventfully after 6 weeks of optimal antibiotic treatment, selected using susceptibility tests. C. fetus spondylitis is a very rare disease. In this unique case involving end-stage renal disease, the underlying pathogen was identified by 16S rRNA sequencing.
Lodderomyces elongisporus infrequently causes bloodstream infections and has been isolated from Asia and Mexico. We encountered a catheter-related bloodstream infection, which involved some risk factors, due to L. elongisporus masquerading as Candida parapsilosis. A 39-year-old man who received a total arch and thoracoabdominal aortic replacement was admitted with a diagnosis of aorto-esophageal fistula. After thoracic drainage for the aorto-esophageal fistula, a catheter-related bloodstream infection was diagnosed. Micafungin (100 mg/day) was successfully administered to treat the catheter-related bloodstream infection for 42 days in total. The bloodstream and catheter tip yeast was grown on Candida agar medium and produced dark green colonies indicating Candida albicans. We performed sequencing analysis using a GenBank BLAST search. The sequence of the internal transcribed spacer region was 99.9% identical with that of the type strain L. elongisporus. This yeast organism has frequently been technically mistaken for non-albicans Candida spp. Furthermore, the prognosis and risk factors of L. elongisporus infection remain unclear owing to the scarcity of reported cases. Catheter-related bloodstream infection caused by this organism has not been described to date.
Pulsed-field gel electrophoresis (PFGE) is a reliable method for analyzing outbreaks of methicillin-resistant Staphylococcus aureus (MRSA); however, it is time-consuming and technically demanding. A new strain-differentiation method for MRSA, namely phage open reading frame (ORF) typing (POT), is a rapid PCR-based technique, in which the ORFs of lysogenized phage genomes in MRSA are amplified. The aim of this study was to evaluate the utility of the POT method for epidemiological analysis of nosocomial MRSA outbreaks. Forty-four strains from 12 episodes of 3 or more nosocomial MRSA infections in 1 ward within a 4-week period were characterized using PFGE and POT methods. The strains were classified into 16 distinct types using POT and 19 subtypes using PFGE. We defined an outbreak as 3 or more new MRSA infections caused by strains with indistinguishable genetic patterns. The identification of 11 (91.7%) episodes by PFGE, including 4 outbreaks and 7 sporadic events, was consistent with the results of POT analysis. These results suggest that POT is a useful epidemiological tool for evaluating nosocomial MRSA outbreaks.
Severe fever with thrombocytopenia syndrome (SFTS) is a novel bunyavirus infection caused by the SFTS virus (SFTSV, family Bunyaviridae, genus Phlebovirus) with a high case fatality rate. A previously healthy 72-year-old man showed symptoms of fever, general fatigue, and altered consciousness. He was hospitalized for treatment. On day 3, considering the day on which fever appeared first during the disease course as day 0, he had bloody emesis. An emergency upper gastrointestinal endoscopic examination revealed multiple ulcerative lesions with continuously oozing hemorrhage in the stomach. He died on day 7. He was retrospectively diagnosed as having SFTS, Although it was less likely that the gastric ulcerative lesions were directly induced by SFTSV replication, it was evident that hemorrhagic emesis might occur in the patient in association with the pathophysiology of SFTS. The real-time imaging of gastric ulcerative lesions in a patient with SFTS is reported.
Among 144 carbapenem-resistant Enterobacteriaceae strains isolated from 4 hospitals in Yunnan province, 113 were identified as carbapenemase-producing Enterobacteriaceae (CPE). BlaKPC-2 (99/113, 87.6%) was the most common carbapenemase gene and Klebsiella pneumoniae (100/113, 88.5%) was the most common species. BlaNDM-1 (11/113, 9.7%), blaIMP-4 (10/113, 8.8%), and blaIMP-1 (1/113, 0.9%) genes were also detected. Extended-spectrum β-lactamase genes were common in CPE, and the SHV- and CTX-M-types were predominant.
The risk factors are unclear for peripheral venous catheter-associated bloodstream infections (PVCBSIs) caused by Bacillus cereus. We aimed to examine for these risk factors in patients with B. cereus PVCBSI by conducting a 2-year case-control study in a large teaching hospital. We analyzed all adult cases of B. cereus PVCBSI (37 patients) and 180 controls who were randomly selected from among patients who had a PVC in place for at least 2 days. Multivariate analysis using a conditional logistic regression model indicated that independent risk factors were use of a peripheral parenteral nutrition (PPN) solution with an adjusted odds ratio (OR) of 88.7 (95% confidence interval [CI], 17.4–451.9), and steroid therapy (adjusted OR, 5.7 [95% CI, 1.3–24.4]). In conclusion, use of PPN solutions or steroids was an independent risk factor for B. cereus PVCBSI. Appropriate use of PPN solutions may help prevent B. cereus PVCBSI. Prospective studies are needed to confirm these results.
Cytomegalovirus (CMV) retinitis is typically diagnosed in patient with AIDS and those who underwent allogeneic hematopoietic cell transplant. However, it may develop in patients with acute lymphoblastic leukemia (ALL) who have not undergone hematopoietic cell transplantation. To increase awareness of CMV retinitis in this group, we describe 3 patients ages 3, 9, and 12, with ALL who developed CMV retinitis. The diagnosis of CMV retinitis was made on the basis of ophthalmological findings suggesting typical retinal lesions. In 2 cases, CMV DNAemia was present, while in 1 patient CMV DNA was detected only in vitreous fluid using the PCR technique. All cases were treated with intravenous ganciclovir for 2 or 3 weeks as induction therapy, followed by oral valganciclovir prophylaxis. Initially, active retinitis lesions resolved in all cases; however, in 1 patient CMV retinitis relapsed 3 times during follow-up. In this case, by using foscarnet therapy, satisfactory responses were achieved and the progression of CMV retinitis lesions stopped and eventually regressed.