This was a 7-year retrospective study of candidaemia in a regional tertiary teaching hospital in Southwest China. We not only analysed the epidemiological characteristics, including the basic information of patients, underlying comorbidities, risk factors, distribution of Candida species, antifungal agent use, antifungal agent susceptibility results and patient outcomes, but also made epidemiologically compared paediatric patients and adult patients.
Our data showed that there was no significant difference in the sex ratio, length of hospital stay or mortality between adult and paediatric patients (P>0.05). However, the proportions of underlying comorbidities in paediatric patients, including pulmonary infection, neurological diseases, congenital malformations/syndromes and haematologic (nonmalignant) disease, were higher than those in adult patients (P<0.05), and the other proportions in adult patients were similar or higher than those in paediatric patients (Table 2). There were differences in the type and number of underlying comorbidities between paediatric patients and adult patients, and the low proportion of underlying comorbidities in paediatric patients is similar to the results of other studies on paediatric candidaemia. Among the risk factors, only CVC, other invasive catheters and abdominal surgery in adult patients had higher risks than those in paediatric patients (P<0.05), and other risk factors in children had higher or similar risks as those in adult patients (Table 2). The univariate predictors of poor outcomes in paediatric patients with candidaemia were only four predictors, which was significantly less than that in adults patients (11 predictors) (Table 4). This situation has not been clearly shown in other studies, and more epidemiological investigations are needed to confirm it. The incidence of candidaemia in pediatric patients was significantly higher than that in adults(P<0.05) (Table 2), however, there was no significant difference in mortality between pediatric patients and adult patients(P>0.05)(Table 2), it is different from other studies[16, 17].
Our data showed that the median age of patients with candidaemia and the proportion of males were similar to those in other studies[8, 18-23]. Moreover, our study showed that the patients with candidaemia were hospitalized mostly in internal medicine wards, which was different from other studies that reported hospitalisation in mainly ICU wards[8, 22, 24-27], and similar to other studies[28-31]. This phenomenon may be related to the demographic characteristics of the inpatients in our hospital, most of whom had more than two underlying diseases and were hospitalized in internal medicine wards. However, the incidence of candidaemia was still the highest in the ICU, similar to other studies[8, 30-34]. In accordance with other studies[17-19, 24, 25, 30, 32, 35, 36], C. albicans was the most common cause of candidaemia in the whole hospital, but the proportion of non-C. albicans infections was higher than that of C. albicans infections. Moreover, the proportions of C. glabrata in surgical, internal medicine and paediatric wards were the highest, which was different from other studies in China[18, 19, 35-37] and similar to other studies in other countries[4, 22, 27, 29, 32]. This may be due to the large number of elderly patients and the increasing use of azole antifungal agents.
Our data showed that the incidence of candidaemia increased from 0.20 episodes/1,000 admissions in 2013 to 0.37 episodes in 2016 and then dropped to 0.26 between 2017 and 2019. The change in the annual incidence rate was mainly due to the change in the incidence rate in paediatric patients. The reasons may be due to the gradual easing of restrictions of China's two-child policy since 2013. The number of geriatric pregnant women has increased annually, resulting in an increase in the incidence of neonatal diseases. The change trend was similar to that reported by Oeser et al[38]. The overall morbidity and 30-day mortality in ICUs and hospitals in this study were similar to those in another hospital in this region of China[18], but lower than those in hospitals in other regions of China[35, 37] and other countries[5, 8, 16, 20, 21, 23, 25, 30]. It has been reported that the overall mortality rate of candidaemia is 20%-49% globally[39], and the mortality rate was 20.4% in our hospital, which is low compared to global rate. This may be because the demographic characteristics and underlying diseases of patients in this region are different from those in other regions or countries, and few severe patients were admitted to our hospital.
With regard to resistance, resistance to FCA, ITR and VRC were common in C. albicans and non-C. albicans species (Table 3). In our study, AMB and 5-FC were highly active against all Candida species. In paediatric patients, the resistance rate of ITR was higher than that in adult patients, but the resistance rates of FCA and VRC were lower than those in adult patients; however, and the resistance rate of Candida species was no significant difference in satisfaction between paediatric and adult patients(P>0.05). Moreover, FCA was highly active against all Candida species in paediatric patients and could be used in paediatric patients with candidaemia as a first-line agent. In the whole hospital, the resistance rate to azole was higher than those reported in other regions[18, 19, 36] and countries[17, 19, 25, 29, 30, 34]. This may be related to the long-term use of empirical prophylactic drugs by clinicians. Therefore, it was necessary to conduct an epidemiological analysis of antifungal agent susceptibility and guide clinicians to choose the rational antifungal agents to avoid the continuous increase in resistance rates.
In this study, we analysed the prognostic factors in all patients and adult patients with candidaemia. Age, length of hospital stay, respiratory dysfunction, pulmonary infection, cardiovascular disease, chronic/acute renal failure, other invasive catheters, mechanical ventilation and septic shock were the common predictors of mortality in the univariate analysis (P<0.05) in both adult patients and all patients, and the univariate predictors of poor outcomes in paediatric patients were less than that in adults patients (4 vs 11 predictors), as shown in Table 4. Because the total number of paediatric patients (35 patients) and deaths (3 patients) were very small, multivariable logistic regression analysis was not performed in paediatric patients. However, our study showed that respiratory dysfunction and septic shock were common independent predictors of 30-day mortality in both adult patients and all patients, and length of hospital stay and other invasive catheters were protective factors for 30-day mortality in all patients. The prognostic factors of 30-day mortality in all patients and adult patients were almost the same, and the independent predictors were the same; there were no significant differences. Septic shock was an independent predictor of 30-day mortality; this has been reported in many other studies[18, 35]. However, the other factors reported here have rarely been reported in other studies[35, 40-43], possibly because the demographic characteristics, underlying diseases and risk factors of the patients in our study were different from those in other studies; this may be the reason that the independent predictors and protective factors in this study were different from those in other studies[5, 35, 40-43]. The independent predictors and protective factors in different regions and countries are shown in Table 6.
This study has several potential limitations. First, due to the technical limitations of the clinical microbiology laboratory and the impact of hospital policies, there are were data on echinocandins in our hospital. Second, this was a single-centre retrospective study. Our data might be influenced by the distribution of the regional population, the level of medical intervention, and the distribution of patient types. Therefore, the results may not be generalizable to all patients with candidaemia in China. The epidemiological findings will pave the way for more in-depth studies and help us establish better antifungal stewardship in our hospital.