Blood stream infections are regarded as the most devastating human diseases that lead to complex treatment procedure (15, 21). The current study mainly illustrated the magnitude of BSIs along with the main risk factors. To our knowledge, this study was the first in addressing Burkholderia cepacia as a cause of BSIs in Ethiopia’s hospital setting particularly from NICU wards. Furthermore, this study differs from previous research conducted in the same laboratory in BSIs with identification and susceptibility testing for antifungal agents that was not considered a routine testing procedure in many laboratories.
In our study higher prevalence of blood culture confirmed cases [175 (50.58%)] were observed compared to studies conducted in Port blair india 14.24% (22) and Kanpur 22.3% (23). The differences may be due to blood specimen volume, time of blood culture taken and epidemiological variation of etiologic agents (2, 4). Our finding might be higher due to the emerging of new nosocomial pathogen Burkholderia cepacia.
The percentage of bacterial isolation in this study was 159 (45.95%), which was approximately similar to the previous study conducted in Ethiopia [164 (32.8%)] (11). In contrast to the above finding, different studies conducted in European, African countries, and Ethiopia reported a lower isolation rate of bacterial infections (12, 24–30). The possible reason for this variation may be the predominance of Burkholderia cepacia detection that may increase the positivity rate in the present study.
The prevalence of bacterial blood stream infections in relation to age groups illustrated that blood culture positivity was higher among infants (77.36%) than other age groups. This finding was in line with the study performed in rural tertiary care hospital in India (21), Gonder university hospital (30) and Nigeria (12). The predominance of bacterial BSIs among infants may be due to immaturity of the immune system which contributes to ease of susceptibility to infections (31).
The predominant pathogens causing BSIs in our study were found to be Gram-Negative bacteria, which is similar to other studies in Rim Hospital (32), Nigeria (12), Jimma (33), Addis Ababa (34) and Tikur Anbesa (27). The higher percentage of Gram-negative bacteria in this study most likely due to a higher number of Burkholderia cepacia which is emerging as outbreak NICU wards.
Bacterial isolation varies among country to country. Burkholderia cepacia, Coagulase-negative staphylococcus, Klebsiella pneumoneia, Escherchia coli, Acinetobacter spp and pseudomonas spp were the most commonly isolated bacteria that caused bloodstream infections in this study, which is more or less similar to previous studies (12, 24, 35–37). Among the Gram-negative bacteria Burkholderia cepacia was found as the highest percentage. The predominancy of this bacteria may be due to about 77.36% of patients in the current study was infants from NICU and all of these isolates were identified from these patients. Burkholderia cepacia is an important nosocomial pathogen that causes outbreak in hospital settings especially in neonatal units. It is also capable of adhering to various medical instruments and colonizing solutions taken as an injection for medication that may be capable of transmitting to neonates (38).
Like many other studies (15, 26, 31, 39–43), Coagulase-negative staphylococcus was the predominant Gram-positive organism in our study as a causative agent of BSIs. The high prevalence of Coagulase-negative staphylococcus could be the higher number of blood samples in our study were from neonatal intensive care unit which was frequently associated with the utilazation of intravascular devices that serve as portals of entry to the bloodstream. (44).
Fungemia has been confirmed in 9 (9.14%) cases. The result was consistent with a study conducted in New York City 9.8% (45), Saudi Arabia 9.5% (15) and India 9.2% (46). All fungemia infections in this study were due to non-candida albicans species which is in agreement with other studies (23, 40, 47). But our finding was different from studies conducted in Turkey (48) and India (13) which found Candida albicans as a cause of BSIs. The major risk factors leading to fungal infection in our study were prolonged hospital stay and previous broadspectrum antimicrobial treatment (13).
Klebsiella spp showed high resistance to folate pathway inhibitors, floroqunioles, aminoglycoside, and βeta lactamases inhibitors. Third-generation and fourth-generation cephalosporins also exhibited very weak activity against this organism. A similar finding was noted among studies carried out in Nepal (31), Gonder university hospital (30) and India (49).
Among non-fermenter, Acinetobacter spp showed extremely resistance to flouroquniole and carbnem drugs. They were also moderately resistance to other antibiotics such as aminoglycoside, third and fourth generation cephalosporin, and aminoglycoside and βeta lactam inhibitors. This finding was consistent with the study done in Iran which showed that Acinetobacter spp was the most resistant bacteria against most antibiotics tested (50). The main reason for this problem may be inappropriate use of antibiotics and lack of standard antibiotic policy in the hospital. Amikiacin was the most effective antibiotic against Gram-negative agents that is comparable in studies performed in Asian and Arab countries (47, 50–52).
In our study, a higher degree of resistance was observed in pencillin among Gram- positive organisms which showed conformity with studies done in Jimma (29) and Afghanistan (41). All Gram-positive bacteria were sensitive to vancomycin that is similar to other studies (40, 43, 49, 51, 53). However, different from the study in India, vancomycin resistance and intermediate Staphylococcus aureus were observed (46). The difference may be the number of isolates that were identified. MRSA was observed in the predominant organism Coagulase- negative staphylococcus which similar to study in tertiary care hospital in India (49) and Nepal (31).
In our study, the highest resistance rate of azole drugs observed in fluconazole in Candida krusei showed similarity in studies conducted in India (35) and Turkey (48). However, Study in Qatar showed most candida spp were sensitive to fluconazole, which is different from our study (47). There is no resistance against voriconazole in all candida isolates which was in line with study done in Turkey (48).
Many factors contribute to the prevalence of BSIs. In the current study Sex, Age, and utilization of complicated devices were independent risk factors for BSIs caused by bacterial infection. This finding agrees with a study conducted in Gonder university hospital that has a significant association between age and BSIs (30).