Histologically confirmed necrotizing fasciitis: risk factors, microbiology, and mortality in Hawaii

Abstract

Tsai et al.1 recently reported a retrospective study of 143 patients with surgically confirmed necrotizing fasciitis (NF) in southwest Taiwan. Although the authors concluded that hypotensive shock, hypoalbuminemia, and increased banded leukocytes were predictors of mortality, these risk factors necessitate immediate surgical intervention. These indicators may reflect the high severity of disease in these NF patients. Once NF is suspected, prompt surgical intervention should be performed. We conducted a retrospective study at a major tertiary care hospital in Hawaii between 1998 and 2005 to specifically examine the risk factors and microbiology associated with mortality in histologi-cally confirmed NF. One hundred and twenty NF cases were identified by ICD-9 code (rate of 75 cases/100 000 hospital admissions). Among 58 cases confirmed by histopathology, the median age was 58 years; 69% were male and 36% Hawaiian/Pacific Islanders. Demographic information, bacteriology, co-morbidities, ethnicity, intensive care unit (ICU) admission, and APACHE II scores were determined, along with the time from admission to surgery and the length of hospital stay. These factors were compared between those who survived and those who died (Table 1). An APACHE II score >17 was a significant independent predictor of mortality. The majority of NF wound infections in our study were polymicrobial (58.6%), which is different to the study of Tsai et al. and others.1–3 Table 1 Comparison of characteristics and mortality of necrotizing fasciitis survivors versus non-survivors Group A Streptococcus (GAS) was also found to be associated with higher mortality.4 Erdem et al.5 reported molecular epidemi-ologic components of GAS in six NF patients (from two clusters of fatal GAS skin infection in 1997 and 2002) and 116 community-associated GAS infections in Hawaii in 2005. The results showed no predominant emm types from NF patients (emm types 1, 12, 74, 99, and 103), but emm type 64 was the most common type in GAS isolated in Hawaii and this may account for the increased mortality in Hawaii. Although Hawaii has a high prevalence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) infections,6 our study did not show a high prevalence of MRSA infection in NF compared to a study from California.7 The mortality rate of 22% in our cohort was significantly associated with GAS, age over 60 years, ICU admission, and APACHE II score >17. Overall, the mortality of patients with NF was related to patients with severe clinical diseases. Rapid detection and regional differences in pathogens can provide additional insight into severity and mortality risks. The prompt institution of broad-spectrum antibiotics, surgical intervention, and intensive support are essential for the effective management of NF patients.