A blood culture comprises a blood sample of a patient probably suffering from a bloodstream infection, protected inside a specific blood culture flask comprising a broth, i.e., the fluid medium that facilitates the optimal evolution of microbes. The concentration of microbes found inside the blood of patients with bloodstream infections is very low. Thus, direct culture on an agar plate could not carry out the detection of microbes in the blood of patients. After the injection of the blood is done inside the blood culture bottle. The bacteria can be further amplificated. Medical professionals need to obtain blood cultures whenever they clinically suspect bloodstream infections.
Contamination Of Blood In Low- And Middle-Income Countries:
Blood culture contamination is a crucial problem with blood contamination rates like ten per cent even in high-income countries. It is suspected that blood contamination is more frequent in low and middle-income countries as some countries such as Malawi, Gambia, Ghana, and South Africa have reported very high infection rates. The range of contaminants in low income and middle-income countries slightly differs from high-income countries. For instance, scientists can witness more bacillus species in low and middle-income countries. This finding tells us that the source of blood cultures’ contamination is the environment in low and middle-income countries. This is because bacillus is found in dust.
Blood Culture Practices:
Blood Culture Collection Packs:
One of the best practices in blood culture is the employment of blood culture collection packs. Blood culture collection packs are prepacked kits that medical professionals use to assemble all substances required for blood culture. Many researchers have reported lower contamination percentages following the launch of blood collection culture packs. A meta-analysis done in 2012 found no decisive evidence for this blood collection practice. Several publications reporting a decrease in blood contamination rates combined the launch of blood culture collection packs with awareness campaigns and hospital staff training, which comprises the validity of this research. Given the extra cost of blood culture collection packs, researchers need to find more evidence before recommending its use in low income and middle-income countries.
Diversion Of Blood’s First Portion:
Blood samples’ contamination could occur during venepuncture due to dislodging of skin pieces invaded by bacteria. Discarding or diverting the first few drops of blood can probably cut down blood contamination because of this cause. The first research conducted to assess this practice was a trial that exhibited a decline in contamination after the first drop of blood is diverted into a sterile blood collection tube that hospitals or medical professionals can buy from a disposable blood collection tube exporter. Blood contamination decreased from 2.8 per cent to 1.4 per cent. When researchers repeated this practice, they found actual results with reduced contamination rates from 3.4 to 2.4 per cent and 1.78 per cent to 0.22 per cent, respectively. In all three pieces of research, pre-intervention blood contamination rates were already low. Inside low and middle-income countries with higher blood contamination rates, a relative or same decline can significantly reduce infected samples.
Usually, it is recommended to first sample blood cultures and then sample the blood collection tubes to analyse other blood samples. Researchers give this advice based on the opinion that reflux from ethylenediaminetetraacetic acid tubes or contaminated citrate in the syringe might occur with possible blood culture sample contamination. Nevertheless, these pseudo bacteraemia reports causing by infected blood collection tubes all date from the nineteen eighteen and nineteen seventies and the present risk for this is not known. Given the efficiency of diverting the first drop of blood, contamination can be declined by first sampling the rest of the blood collection tubes. Provided that a butterfly needle is employed with the help of a vacutainer system. If medical professionals sterilize their blood tubes, they can further decrease cross-contamination.
Researchers have found good evidence for the employment of devoted phlebotomy groups for blood culture. As divergent to blood samples being sampled by every intern or ward nurse to reduce blood contamination further. This practice has helped attain decent results in a low-income country; after the launch of a nurse’s team specializing in phlebotomy inside Malawi, the rates of blood contamination declined from 19.6% to five per cent.
Sterilizing The Blood Culture Bottle Septum:
Another practice that medical professionals can employ to reduce contamination is carrying the bottle septum’s disinfection. With seventy per cent ethanol or isopropyl before carrying out the blood sample injection in several institutions. Nevertheless, researchers have not done this on a routine basis. Researchers could not find evidence for the efficiency of this practice in decreasing contamination; nevertheless, they have being seeing that their research was not supporting for detecting such an impact because they had quite low contamination rates overall. As far as the greater environmental blood contamination in low- and middle-income countries is concerned, the blood culture bottle septum disinfection is a low cost and easy strategy for avoiding contamination.