Chin-Jung Chang

Community-acquired bacterial meningitis in adults: the epidemiology, timing of appropriate antimicrobial therapy, and prognostic factors

Between January 1986 and December 1999, 109 adult patients with culture-proven community-acquired bacterial meningitis were identified at Kaohsiung Chang Gung Memorial Hospital. To compare changes over time, the appearance of disease among our patients was divided into two equal time periods: an earlier time period (1986-1992) and a later time period (1993-1999). In this study, there was a decreasing proportion of community-acquired bacterial meningitis compared with nosocomial bacterial meningitis in adult patients in recent years. Its proportion declined dramatically from 81% in the earlier 7 years to 37% in the later 7 years. Of the pathogens, Klebsiella (K.) pneumoniae was the most frequently implicated pathogen, followed by Viridans (V.) streptococci, Streptococcus pneumoniae, and Staphylococcus aureus. Other rare organisms including Acinetobacter baumannii, Salmonella Group B and D, Proteus mirabilis, Group B, D, and non-A, non-B and non-D streptococci, and coagulase-negative staphylococci emerged during the second period. There was a decrease in the mortality rate from 44% in the first to 34% in the second time period, but the overall mortality rate remained high. Of the implicated pathogens, patients infected with V. streptococci had a consistently favorable prognosis, while a dramatic decrease in the mortality rate of those infected with K. pneumoniae was seen in recent years. In the multiple logistic regression analysis, only the presence of septic shock and seizures was independently associated with mortality. The timing of appropriate antimicrobial therapy, as defined by consciousness level, was a major determinant of survival and neurological outcomes for patients with community-acquired bacterial meningitis, and the first dose of an appropriate antibiotic should be administrated before a patients consciousness deteriorates to a Glasgow coma scale score lower than 10.

Bacterial meningitis in infants: the epidemiology, clinical features, and prognostic factors.

This 16-year (1986-2001) retrospective study enrolled 80 infantile patients (aged, 30-365 days old) with culture-proven bacterial meningitis. The most prevalent pathogens were Salmonellaspecies, Streptococcus (S.) agalactiae, Escherichia (E.) coli, and Haemophilus (H.) influenzae, accounting for about 59% of the episodes. Meningitis caused by Salmonella species, E. coli and H. influenzae occurs more often in the older infants, while that caused by S. agalactiae occurs more often in young infants. Our study revealed a decrease in the proportion of Salmonella meningitis from 27% in the first 8 years to 9% in the second 8 years with E. coli replacing Salmonella species as the leading pathogen of this disease during the second period. Overall mortality rate for both periods of time was 11%. However, if we take those with undesirable poor outcomes into account, 43% of patients could be considered treatment failures. The study also reveals a high prevalence of neurological complications when this disease is caused by H. influenzae, S. pneumoniae, and Salmonella species. Stepwise logistic regression analysis revealed that only initial changing levels of consciousness (P = 0.006) were independently associated with treatment failure. The most frequent neurological complications associated with this disease included subdural empyema, hydrocephalus, cerebral infarctions, and seizures. Because therapeutic regimens may require attention to the eradication of bacterial pathogen but also the neurological complications, early diagnosis and choice of appropriate antibiotics are essential to increasing the possibility of survival.

A clinical and electrophysiologic survey of childhood Guillain-Barré syndrome

In this 16-year (1986-2001) retrospective study, 23 childhood patients were identified with Guillain-Barré syndrome. According to clinical and electrophysiologic findings, 18 patients manifested acute inflammatory demyelinating polyradiculoneuropathy, 2 had Miller Fisher syndrome, 1 had axonal forms, and 2 were unclassified. Seasonal preponderance was evident in 39% of patients with Guillain-Barré syndrome, developing the disease in the winter (November to January) with upper respiratory infection the most frequent preceding event. The most common manifestation was limb weakness, with various degrees of motor weakness in 22 patients. Bulbar involvement was the most common cranial palsy, and it was evident in 30% of the episodes. Only one of these progressed to mechanical ventilation during hospitalization. Altogether, approximately 61% of the episodes exhibited sensory symptoms. At a follow-up of 1 year or more, 20 patients recovered and 3 had residua. Furthermore, no fatality occurred in our study. Our study also demonstrates that the clinical course of childhood Guillain-Barré syndrome has a shorter recovery time as compared with an adult patient group. Therapeutic outcome is favorable for patients who receive prompt treatment.

Brain abscess caused by aerobic Gram-negative bacilli: clinical features and therapeutic outcomes

Thirty-three patients (24 males and nine females) with brain abscesses resulting from infection by aerobic Gram-negative bacilli were identified at Kaohsiung Chang Gung Memorial Hospital over a period of 14 years. Of these, 23 cases developed spontaneously, with the remaining ten postneurosurgery. The organisms most frequently involved were Klebsiella (K.) pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Proteus species and included some rare pathogens, such as Salmonella and Enterobacter species, K. oxytoca, Vibrio and Morganella morganii. Apart from one exception, the locations of the abscess were supratentorial. Twenty-four patients presented with a single abscess, while nine revealed multiple abscesses, with 26 treated surgically and seven with antibiotics exclusively. In total, seven patients died, representing an overall mortality rate of 21%. This study demonstrates that brain abscesses associated with neurosurgical procedures are not rare, accounting for 30% of cases in this study, with K. pneumoniae, Proteus and Enterobacter species the most prevalent of the revealed pathogens. Further, Proteus species were the most prevalent pathogens demonstrated for cases of both otogenic and polymicrobial infections. If brain abscesses are diagnosed for diabetic patients or have a gas-forming appearance, a diagnosis of K. pneumoniae infection should be considered, with particular attention paid to detection of other metastatic septic abscesses. In light of the high mortality rate, early treatment is essential to maximize the chances of survival.

Predictive Factors and Long-Term Outcome of Respiratory Failure after Guillain-Barré Syndrome

Objective:To analyze predictive factors and long-term recovery in patients with Guillain-Barré syndrome (GBS) who are in need of mechanical ventilation. Methods:In this 15-year retrospective study, 77 adult patients were identified with GBS. A comparison was made between the clinical data from patients who required mechanical ventilation and those who did not. Furthermore, the therapeutic outcomes of those 25 patients in need of mechanical ventilation during hospitalization at 1 year were determined using a modified Barthel index. A score below 12 was defined as a poor outcome, whereas a score of 12 or more was good. Results:The study revealed 32% of patients (25/77) in need of respiratory support during hospitalization. At a follow-up of 1 year among the 25 ventilated patients, 7 patients (28%) had normal or minor signs and symptoms, 6 had unassisted gait, 3 had assisted gait, 6 were wheelchair- or bed-bound, and 3 died. The cause of death was septicemia with septic shock in all 3 cases. Factors that predict respiratory failure in the study GBS patients were disability grade on admission and areflexia. Those ventilated patients who had low maximal inspiratory pressure (PImax) (<14.5 cmH2O) and maximal expiratory pressure (PEmax) (<13.5 cmH2O) values at the time of intubation and the presence of complications after mechanical ventilation inevitably had worse outcomes than those who had not. Conclusion:If low values of PImax and PEmax at intubation were detected, aggressive respiratory management, which might include tracheostomy to allow more efficient bronchial clearing, and prevention of complications caused by prolonged course of mechanical ventilation are essential to maximize the potential for survival.

Neonatal bacterial meningitis in southern Taiwan.

To determine the epidemiologic trends, prognostic factors, and therapeutic results of neonatal bacterial meningitis, 60 neonatal patients with culture-proven neonatal bacterial meningitis were enrolled in this study. To compare changes over time, the appearance of disease among the patients was divided into two equal periods (1986-1993 and 1994-2001). Group B streptococci were the most common causative pathogens, accounting for approximately 32% of the episodes. Escherichia coli, the next most common pathogen, was more frequently observed in the second period. Seventy-seven percent of gram-negative bacilli isolates were resistant to ampicillin. Moreover, oxacillin-resistant Staphylococcus and ampicillin-resistant group B streptococci strains occurred in the second periods as late-onset neonatal bacterial meningitis. The overall mortality rates for the first and second study period were 17% and 8%, respectively. However, if individuals with poor outcomes were taken into account, 38% of patients were considered treatment failures. Significant prognostic factors included the presence of seizures, thrombocytopenia, and high cerebrospinal fluid protein and low cerebrospinal fluid glucose concentration. Although the mortality rate was significantly reduced in the second period, there has been increasing incidence of the emergence of resistant strains presenting a therapeutic challenge. The presentation in neonatal bacterial meningitis might be nonspecific, and blood culture results were negative in 45% of the episodes. Early diagnosis, choice of appropriate antibiotics, and correction of metabolic derangement are essential to improving outcomes.

Adult Streptococcus pneumoniae meningitis in Southern Taiwan: epidemiologic trends and prognostic factors

The clinical features of 22 adult patients with Streptococcus pneumoniae meningitis, retrospectively collected over a 16-year period, were reviewed. Otopharyngeal infection, haematogenous spread and cranial neurosurgery continue to be the predominant routes of infection. Most patients acquired the infection in the community, and predisposing underlying conditions are common. The proportion of S. pneumoniae meningitis compared to all microorganisms causing meningitis in adults declined dramatically from 17% in the first 8 study years to 4% in the last 8 study years. However, all penicillin-resistant S. pneumoniae strains were found in the second half of the study period, accounting for 25% of these episodes. The overall mortality rates for the first and second halves of the study period were 43% and 63%, respectively. Third-generation cephalosporins were the antibiotics of choice for the treatment of S. pneumoniae meningitis in this study, however, the emergence of resistant strains may create a therapeutic challenge in the future. To avoid treatment failure, early diagnosis, careful monitoring of the clinical course and the choice of appropriate antibiotics according to the in vitro antimicrobial susceptibilities, are necessary.