A study on the causes of bacterial and parasitic bloody diarrhea and its effect on some haematological and biochemical parameters

Bacteria are responsible for about 80% of cases. Among them, the most isolated causal agent has been enterotoxigenic Escherichia coli (ETEC). This strain is responsible for 25%-50% of cases, followed in frequency by species of Shigella, Salmonella and Campylobacter. Viruses (adenoviruses, astroviruses, rotaviruses, and caliciviruses) can be a significant cause of diarrhea in travelers, and outbreaks on ships caused by norovirus (one of the caliciviruses) are relatively common. Intestinal parasites (Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum and Cyclospora cayetanensis) are generally responsible for the most prolonged diarrhea, lasting longer than 14 days. Acute diarrhea lasts less than two weeks and is a very frequent condition and is more easily treated. Chronic diarrhea occurs over a period of more than four weeks and can have a variety of causes. Other serious causes of bloody diarrhea include bowel obstruction, poisoning or severe abdominal trauma, and requiring urgent medical attention as it is very intense and life-threatening. Radiotherapy can also cause bloody diarrhea, being a side effect when performed in the abdominal region. In this case, the doctor must be warned that he is presenting this symptom to indicate a way to relieve it, and the use of supplements is usually indicated, to restore the normal bacterial flora, and medicines to stop the diarrhea. The etiological diagnosis of the infection is made with the parasitological examination of feces, using the Baermann method, which is more sensitive than direct microscopy. The rhabditoid larva is the most commonly identified form, but filarioid larvae, adult female parasites and eggs can be found. Indirect immunofluorescence detects serum IgG antibodies to surface antigens of filarial larvae, but ELISA has higher sensitivity (about 90%).