Epidemiological evolution of early-onset neonatal sepsis over 12 years: A single center, population-based study in central Taiwan.

BACKGROUND: We aimed to explore the epidemiology and evolution of pathogens, antibiotic susceptibility, and mortality rate in cases of neonatal early-onset sepsis (EOS) reported over a period of 12 years in a level III neonatal center in Central Taiwan. METHODS: Patients' medical records in a neonatal center from 2007 to 2018 were reviewed to obtain information on infants with culture-proven EOS, which included pathogens found in the blood or cerebrospinal fluid cultures. RESULTS: The incidence of neonatal EOS during this period was 2.11 cases/1,000 admissions. Group B streptococcal (GBS) and Escherichia coli were the most common pathogens. The overall rates of GBS and E. coli infections were 0.68/1,000 and 0.77/1,000 live births, respectively. The incidence of EOS in infants with a birth weight ≥1,500 g decreased significantly with decreasing incidence of GBS-related sepsis. The incidence of EOS remained high in very-low-birth-weight (VLBW) infants and increased over time. There was an increasing trend in of E. coli infection and emergence of drug-resistant strains. In addition, E. coli sepsis had high mortality in VLBW infants. CONCLUSION: Novel screening and prevention strategies against E. coli and reserving broad-spectrum antibiotics for the most critically ill or VLBW patients with maternal chorioamnionitis might help in early diagnosis and further improve the outcomes of EOS.

Biological treatment of volatile organic compounds (VOCs)-containing wastewaters from wet scrubbers in semiconductor industry.

This study investigated biological treatment for two kinds of volatile organic compounds (VOCs)-containing wastewaters collected from wet scrubbers in a semiconductor industry. Batch test results indicated that one wastewater containing highly volatile organic compounds was not suitable for aerated treatment conditions while the other containing much lower volatile organic compounds was suitable for aerobic treatment. Accordingly, two moving bed bioreactors, by adding commercial biocarrier BioNET, were operated under aerobic and anoxic conditions for treating low volatility wastewater (LVW) and high volatility wastewater (HVW), respectively. During 280 days of operation, the aerobic LVW bioreactor attained the highest chemical oxygen demand (COD) removal rate of 98.9 mg-COD/L/h with 81% of COD removal efficiency at hydraulic retention time (HRT) of 1 day. The anoxic HVW bioreactor performed above 80% of COD removal efficiency with the highest COD removal rate of 16.5 mg-COD/L/h at HRT of 2 days after 380 days of operation. The specific COD removal rates at different initial substrate-to-biomass (S0/X0) ratios, using either suspended sludge or microorganisms attached onto BioNET from both bioreactors, followed the Monod-type kinetics, while the half-saturation coefficients were generally higher for the microorganisms onto BioNET due presumably to relatively poor mass transfer efficiency. Based on the results of microbial community analysis using the next generation sequencing technique, the dominant communities of suspended sludge and BioNET, including nitrifiers, denitrifiers, and degraders for polycyclic aromatic hydrocarbons, were similar in the corresponded bioreactors, but microbial community shifts were observed with increased organic loadings.

Effects of copper on biological treatment of NMF- and MDG-containing wastewater from TFT-LCD industry.

This study aimed to evaluate the effects of copper on N-methylformamide (NMF)- and methyl diglycol (MDG)-containing wastewater treatment using batch experiments and a lab-scale anoxic-oxic (A/O) sequencing batch reactor (SBR). Batch experimental results indicated that aerobic degradation of NMF followed Monod-type kinetics. Copper inhibition on nitrification also followed Monod-type inhibition kinetics with copper-to-biomass ratio instead of copper concentration. Specific degradation rates of NMF and MDG under both aerobic and anoxic conditions decreased in the matrix of full-scale wastewater, and high copper dosage would further reduce the degradation rates. In the long-term presence of 0.5 mg/L copper, the A/O SBR could maintain stable and complete degradations of NMF and MDG, 95% of COD removal, and more than 50% of total nitrogen (TN) removal. High concentrations of copper spikes, including 40 mg/L and 110 mg/L, slowed down degradation rates for both NMF and MDG, but did not affect COD and TN removal efficiencies in the full 24 h-cycle operation. The long-term A/O SBR operation revealed that daily dosage of 0.5 mg/L copper was not detrimental to NMF/MDG degradations due to regularly wasting sludge, but 110 mg/L of copper spike obviously reduced NMF/MDG degradation rate although it could be recovered later by regularly wasting sludge and maintaining SRT at 20 days.

Therapeutic strategy of patent ductus arteriosus in extremely preterm infants.

The ductus arteriosus is likely to close without treatment in most infants born at gestational age (GA) > 28 weeks (73%), and those with birth weight > 1000 g (94%). However, the rates of spontaneous ductal closure among less mature or smaller infants with respiratory distress syndrome are not known. Extremely preterm infants born at GA < 28 weeks are associated with a high risk of severe intraventricular hemorrhage (IVH) or pulmonary hemorrhage, which usually occur within 72 h after birth and affect mortality and long-term neurological development. These serious hemorrhagic complications may be closely related to hemodynamic changes caused by a hemodynamically significant patent ductus arteriosus (hs-PDA). While prophylactic indomethacin has been shown to reduce the rates of PDA, PDA ligation, severe IVH and early pulmonary hemorrhage, the available evidence does not support its prophylactic use in preterm infants. Symptomatic or late treatment is associated with lower success rate, and increased complications of a hs-PDA. The issue of "to treat or not to treat a PDA" is controversial. Considering the relationship between the effectiveness and timing of pharmacological treatment, early targeted treatment may be an alternative approach for the early identification of a hs-PDA in specific high-risk patient population, especially infants <26 weeks GA who are at the highest risk of severe IVH or pulmonary hemorrhage. Serial echocardiographic studies can be used to select patients who are candidates for early targeted medical treatment of hs-PDA. Surgical ligation of PDA, and transcatheter closure if proven to be safe, can be used as back-up therapy for patients who fail medical treatment and continue to have cardiopulmonary compromise.

Monitoring of arsenic exposure with speciated urinary inorganic arsenic metabolites for ion implanter maintenance engineers.

For wafer fabrication in the semiconductor industry, maintenance engineers are potentially exposed to hazards during their work of disassembling machine components for cleanup. One special concern is the presence of arsenic or arsenic compounds in the working environment. This study analyzed speciated urinary inorganic arsenic metabolites of the maintenance engineers using high-performance liquid chromatography-hydride generation atomic absorption spectrometry to study the potential arsenic exposure during their maintenance work. In total, from six wafer fabrication facilities, 30 maintenance engineers were recruited as the exposed group and another 12 office-based engineers served as the control group. First morning-voided urine samples of each study subject were collected for 7 consecutive days. The levels of total urinary inorganic arsenic metabolites for the exposed group were 1.7+/-1.4, 1.4+/-1.1, 6.2+/-6.7, 20.2+/-14.1, and 29.5+/-17.2 micro g/L for As3+, As5+, monomethylarsonic acid, dimethylarsinic acid, and total inorganic arsenic, respectively. Both the concentration of monomethylarsonic acid and its percentage in total urinary inorganic arsenic metabolites showed significantly ascending trends for the control group, for the engineers without preventative maintenance work prior to their urine sampling, and for the engineers with such work prior to their urine sampling (P<0.05 and P<0.0005, respectively). The data also suggested that, at low-level occupational arsenic exposure, the concentration of total urinary inorganic arsenic metabolites might be misleading due to the confounding effect resulting from intake of seafood, such as arsenosuger. Nevertheless, monitoring of urinary arsenic species by using the percentage change of monomethylarsonic acid in total urinary inorganic arsenic metabolites as an indicator for the verification of arsenic exposure is helpful and appropriate in such cases.