Clinical Features, Antimicrobial Resistance, and Serogroups of Nontyphoidal Salmonella Isolated From Infants Less Than 3 Months Old in the Recent Decade.

BACKGROUND: Antibiotic treatment is indicated for infants with nontyphoidal Salmonella (NTS) enterocolitis. However, whether antimicrobial resistance (AMR) is a problem among young infants is unknown. This study investigated the characteristics of NTS infections in young infants. METHODS: Infants less than 3 months old with NTS infections were enrolled and grouped into 2 cohorts (diagnosed 2010-2015 or 2016-2021). Salmonella isolated from blood or cerebrospinal fluid was defined as invasive NTS (iNTS). The clinical features, AMR and serogroups were compared between cohorts. RESULTS: In total, 102 young infants had NTS infections, 6.9% of which were iNTS. Infants with iNTS infections were younger, hospitalized longer, and received longer antibiotic courses. More than half of cases of iNTS were resistant to ciprofloxacin, ceftriaxone and greater than or equal to 3 antibiotics. iNTS was mainly observed in Salmonella groups C2 and E. Over the past decade, group B (44%), group E (26%) and group C2 (16%) have been the most common serogroups. NTS significantly increased AMR to ciprofloxacin, ceftriaxone and trimethoprim-sulfamethoxazole, and greater than or equal to 3 antibiotics. Both multidrug resistance and extensive drug resistance in NTS also significantly increased. CONCLUSIONS: The serogroups varied with time, and the main causes of iNTS, groups C2 and E, increased over the past decade. The prevalence of AMR also increased, especially for iNTS. Given the low iNTS rate and high AMR, routine antibiotic use among infants with NTS infections between 1 and 3 months old should be reconsidered. Further large-scale research is required to formulate therapeutic strategies.

Macrolide Resistance, Clinical Features, and Cytokine Profiles in Taiwanese Children With Mycoplasma pneumoniae Infection.

BACKGROUND: The factors that predict the progression of Mycoplasma pneumoniae infection remain inconclusive. Therefore, we investigated macrolide resistance prevalence, M pneumoniae genotype, and clinical characteristics of childhood M pneumoniae respiratory tract infections in Taiwan. METHODS: A total of 295 children hospitalized with respiratory tract infections with positive serological M pneumoniae immunoglobulin M test results were enrolled in this 3-year prospective study. Oropharyngeal swabs were obtained for M pneumoniae cultures and polymerase chain reaction tests. All M pneumoniae specimens were further characterized by P1 typing, multilocus variable-number tandem-repeat analysis (MLVA), and macrolide resistance genotyping. The clinical characteristics and blood cytokine profiles were analyzed accordingly. RESULTS: Of 138 M pneumoniae specimens, type I P1 was the predominant (136 of 138, 98.6%). The MLVA type P (4-4-5-7-2) was the leading strain (42 of 138, 30.4%), followed by type J, U, A, and X. The overall macrolide-resistant rate was 38.4% (53 of 138); the resistance rate increased dramatically yearly: 10.6% in 2017, 47.5% in 2018, and 62.5% in 2019 (P < .001). All macrolide-resistant M pneumoniae (MRMP) harbored the A2063G mutation and were MLVA type 4-5-7-2 (49 of 53, 92.5%), especially type U and X. No significant differences in clinical symptoms, duration of hospital stay, and radiographic findings were identified among patients between MRMP and macrolide-sensitive M pneumoniae (MSMP) groups. Patients with MRMP infection had more febrile days before and during hospitalization and higher interleukin (IL)-13 and IL-33 levels than patients with MSMP infection (P < .05). CONCLUSIONS: Macrolide-resistant M pneumoniae surged in Taiwan throughout the study period, but macrolide resistance was not a determinant factor of clinical severity.

Model-Based Individualized Treatment of Chronic Granulomatous Disease.

The cost of collecting the data and assessing the benefits derived from better information about chronic granulomatous disease (CGD) are rarely examined. Bayesian decision analyses to incorporate individual risk and clinical data to identify patients for when to take the treatment. This study developed a sensitivity analysis to calculate individualized information as a function of individual outcome risk. In addition, we used simulation to explore how the ranges of numerical values for which each option will be most efficient with respect to the input parameters and decision-making thresholds. Experimental results show that, this proposed model can not only for taking action in the light of all available relevant information, but also for minimizing expected loss by considering the optimal prior / posterior decision making.

Nosocomial neonatal legionellosis associated with water in infant formula, Taiwan.

We report 2 cases of neonatal Legionella infection associated with aspiration of contaminated water used in hospitals to make infant formula. The molecular profiles of Legionella strains isolated from samples from the infants and from water dispensers were indistinguishable. Our report highlights the need to consider nosocomial legionellosis among neonates who have respiratory symptoms.

Clinical and laboratory analysis of influenza B infection in children in Taichung, Taiwan during the 2006-2007 flu season.

BACKGROUND: An epidemic of influenza B/Malaysia/2506/2004 was reported in Taiwan during the 2006-2007 flu season. We investigated the flu vaccination history and clinical and Laboratory characteristics of children with influenza B infection. METHODS: We enrolled children younger than 18 years old who visited one of two hospitals between November 2006 and February 2007 with influenza-like illnesses. Throat swabs were taken on their first visit and cultured for viruses. Complete and differential blood counts and blood biochemical parameters were analyzed in some children. RESULTS: Influenza virus was cultured from 51.0% of patients (101/198), 87 (86.1%) of who were infected with influenza virus type B. The remaining 14 (13.9%) were infected with influenza virus type AH3. The 87 children (median age 7.8 years) with culture-proven influenza B virus infection were enrolled. Nine parents reported that enrolled children had been vaccinated against influenza. Leukopenia was found in 56.1% (32/57) of patients, leukocytosis in 3.5% (2/57), and thrombocytopenia in 1.8% (1/57). Thirteen of 23 patients (56%) tested for creatine kinase (CK) had elevated levels ( >160 U/L), and 11 of 23 (47.8%) had myalgia associated with raised CK (p < 0.05). Twenty-six children developed complications, including one case of pneumonia with acute respiratory distress syndrome and one case of flu-associated encephalitis. CONCLUSION: Most children who contracted influenza B infection had not been vaccinated. Almost half the children had leukopenia, and some had leukocytosis, but thrombocytopenia was rare. There was a significant association between raised CK levels and myalgia in influenza B infection.

Mycoplasma pneumoniae-associated cerebral infarction in a child.

The central nervous system's involvement is the most common reported extra-pulmonary manifestations of Mycoplasma pneumoniae infection, and stroke was one of the most special situations. We presented a 4-year-old child who presented with acute stroke on the third day of the onset of Mycoplasma respiratory tract infection. Brain magnetic resonance angiography demonstrated that occlusion of bilateral internal carotid arteries and vertebral arteries above the level of the first cervical vertebrate which is not been reported previously.

Do serological tests provide adequate rapid diagnosis of Mycoplasma pneumoniae infection?

This study was designed to evaluate the serologic response to Mycoplasma pneumoniae infection. A total of 589 children < or =18 years (190 in the year 2004; 399 in 2005) and 2,073 adults > or = 18 years of age (980 in the year 2004; 1,093 in 2005) with respiratory symptoms underwent serological testing for M. pneumoniae infection. The tests included passive particle agglutination (PA) and enzyme-linked immunosorbent assay (ELISA). The seroprevalence rates of M. pneumoniae infection in the years 2004 and 2005 were 6.9 and 10.1%, respectively. The seropositivity rate was significantly higher in children (29.6% in 2005; 23.7% in 2004) than in adults (2.9% in 2005; 3.7% in 2004) (odds ratio, 8.138 in 2004; 13.923 in 2005; 95% confidence interval, 5.077-13.045 in 2004; 9.220-21.026 in 2005). Paired sera for the PA test were obtained from 32 of 399 children, and 22 of them demonstrated at least fourfold rises in antibody titer. ELISA had a sensitivity of 77.3% and a specificity of 40.0%; PA had a sensitivity of 9.5% and a specificity of 80%. The ELISA test was superior to the PA test in diagnosing acute M. pneumoniae infection in children. Both tests were significantly more sensitive when they were performed 1 week after the onset of infection.

Rapid diagnosis of Mycoplasma pneumoniae infection in children by polymerase chain reaction.

BACKGROUND AND PURPOSE: Endemic atypical pneumonia was noted in central Taiwan during 2005. The serological response to Mycoplasma pneumoniae infection was usually poor in its early course; convalescent serum was needed in most cases, which was sometimes difficult to obtain in children. Empiric antimicrobial therapy was usually initiated before serological testing. A rapid test would be useful to define the etiology and initiate appropriate management. We studied the usefulness of polymerase chain reaction (PCR) analysis for diagnosis in this setting. METHODS: This 1-year prospective study conducted during 2005 in central Taiwan enrolled 307 hospitalized children (aged 3 months to 16 years) with respiratory tract infections, some complicated with systemic manifestations, such as encephalitis and skin rash. Fifty one patients were excluded due to unavailability of data or lack of consent. PCR analysis of samples using a primer set for the P1 gene of M. pneumoniae was compared to serological testing, including particle agglutinin test and enzyme-linked immunosorbent assay. RESULTS: 263 throat swabs from 256 patients were available for PCR tests, and serological tests were performed in 140 children (55%) with clinical suspicion of atypical pneumonia. Eighty two children (32%) were positive by the PCR method and 76 (30%) were serologically positive. Seventy one patients (87%) with duration of disease onset of 2 to 7 days had positive PCR results. The mean age of patients with M. pneumoniae infection was 5.2 years, with 27% of patients <2 years old and 73% of patients >2 years of age. The diagnoses were as follows: pneumonia (n = 44); pneumonia complicated with pleural effusion (n = 12); bronchitis and bronchopneumonia (n = 18); asthmatic bronchitis (n = 2); croup syndrome (n = 1); pharyngitis (n = 3); and herpangina (n = 2). Coinfection with bacteria or virus was found in 21% of patients with M. pneumoniae infection. CONCLUSIONS: The PCR method could provide earlier diagnosis of M. pneumoniae infection and was useful to identify variable clinical features of infection, especially in younger children.