Pertussis Infants Needing Mechanical Ventilation and Extracorporeal Membrane Oxygenation: Single-Center Retrospective Series in Vietnam.

OBJECTIVES: Pertussis is an infectious disease that causes epidemics and outbreaks and is associated with a high mortality rate, especially in infants, in both developed and developing countries. We aimed to characterize infants with pertussis with respiratory failure and shock and investigated the factors related to mortality. DESIGN: A retrospective, observational study conducted between January 2015 and October 2020. SETTING: This study was conducted at the Vietnam National Children's Hospital, which is a government hospital that serves as a tertiary care center in Hanoi, Vietnam. PATIENTS: Children who fulfilled the following inclusion criteria were included: 1) admitted to the PICU, 2) less than 16 years old, 3) pertussis confirmed by real-time polymerase chain reaction, and 4) treated with mechanical ventilation due to respiratory failure and shock. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Seventy-three mechanically ventilated children (40 boys; median age, 56 d), whereas 19 patients received extracorporeal membrane oxygenation support. Twenty-six patients (36%) died including 12 who received extracorporeal membrane oxygenation. Those who received extracorporeal membrane oxygenation support had higher leukocyte counts upon admission and were more frequently diagnosed with pulmonary hypertension and stage 3 acute kidney injury. Compared with survivors, nonsurvivors showed increased heart rates, leukocyte and neutrophil counts, and lower systolic and diastolic blood pressure at admission. Increased Vasoactive-Inotropic Score, stage 3 acute kidney injury, fluid overload, the use of renal replacement therapy, and extracorporeal membrane oxygenation use were prevalent among nonsurvivors. CONCLUSIONS: In this study, around one third of mechanically ventilated patients with pertussis died. Those who received extracorporeal membrane oxygenation had higher leukocyte counts, a higher prevalence of pulmonary hypertension, and advanced stages of acute kidney injury. Higher Vasoactive-Inotropic Score and advanced stages of acute kidney injury were associated with a greater risk of mortality.

Diagnostic Performance of Dengue Virus Envelope Domain III in Acute Dengue Infection.

Dengue, one of the most prevalent illnesses caused by dengue viruses that are members of the genus Flavivirus, is a significant global health problem. However, similar clinical symptoms and high antigenic homologies with other Flaviviruses in the endemic area pose difficulties for differential diagnosis of dengue from other arbovirus infections. Here, we investigated four types of recombinant envelope protein domain III (DV-rED III) derived from four dengue virus (DENV) serotypes for diagnostic potential in detecting IgM in acute phase (mainly 2-3 days after onset of fever). Each independent DV-1, -3, and -4-rED III-ELISA showed less than 60% sensitivity, but the combined results of DV-1, -3, and -4-rED III-ELISA led to sensitivity of 81.82% (18/22) (95% CI, 59.72 to 94.81) and 100% specificity (46/46) (95% CI, 92.29 to 100.00) as each antigen compensated the other antigen-derived negative result. In conclusion, the independent combination of data derived from each recombinant antigen (DV1-, DV3-, and DV4-rED III) showed comparable efficacy for the detection of IgM in patients with acute-phase dengue infection.

Genotyping and macrolide-resistant mutation of Bordetella pertussis in East and South-East Asia.

OBJECTIVES: Macrolide-resistant Bordetella pertussis (MRBP) has been emerging and prevailing in mainland China since 2011. In this study, we aimed to investigate the genotype and macrolide resistance of circulating B. pertussis in East and Southeast Asia using genetic analyses. METHODS: A total of 302 DNA extracts from clinical specimens and isolates from 2010 to 2020 were analyzed: 145 from Vietnam, 76 from Cambodia, 48 from Taiwan, and 33 from Japan. Genotypes were determined by multilocus variable-number tandem-repeat analysis (MLVA). Macrolide-resistant A2047G mutation in B. pertussis 23S rRNA was investigated using the duplex Cycleave real-time polymerase chain reaction (PCR) assay. Whole-genome sequencing was performed on two MRBP isolates that were identified for the first time in Taiwan. RESULTS: Overall, 286 DNA extracts (95%) generated a complete MLVA genotype and 283 DNA extracts (94%) yielded a complete result for the A2047G mutation analysis. The A2047G mutation was detected in 18 DNA extracts: fourteen from Vietnam, one from Cambodia, two from Taiwan, and one from Japan. Most of them (78%) showed the genotypes MT104 and MT195, which have previously been reported in Chinese MRBP isolates. Further, the Taiwanese MRBP isolates were classified into the MT104 clade of Chinese MRBP isolates. CONCLUSION: After MRBP emerged and spread in mainland China, it may have spread to East and Southeast Asia in the 2010s. Continued surveillance targeting the A2047G mutation of MRBP is needed to prevent further spread of this emerging pathogen.

Cerebral spinal fluid positive pertussis encephalopathy in infants: Case reports.

Pertussis has re-emerged in both developed and developing countries and is an ongoing public health problem, even in countries with high rates of vaccination. Pertussis encephalopathy is a known complication of the disease, but the pathophysiology of this complication and the role of the pertussis bacteria have not been elucidated. We report three confirmed cases of pertussis infant younger than 3 months of age with neurological complications including lethargy, encephalopathy, and seizures. In each case, the cerebrospinal fluid was positive for Bordetella pertussis as determined by polymerase chain reaction. One patient did not survive and two were discharged with a normal neurological exam on follow-up. The cases emphasize the importance of analyzing cerebrospinal fluid in cases of pertussis-associated encephalopathy including polymerase chain reaction.