Infectious Diarrhoea
Firza Alexander Gronthoud in Practical Clinical Microbiology and Infectious Diseases, 2020
Medically important Salmonella spp. causing diarrhoea are S. choleraesuis, S. typhimurium and S. enteritidis. Most infections are acquired by eating poultry, eggs or dairy products and are transmitted through the fecal-oral route. Shigella spp. cause dysentery, which is a clinical syndrome consisting of fever, bloody diarrhoea and abdominal pain. Shigellosis is primarily caused by S. dysenteriae, S. flexneri, S. boydii and S. sonnei. Shigella spp. are genetically very similar to E. coli and are now biogroups within the species E. coli. Humans are the only reservoir for Shigella spp., with more than half of all infections occurring in children younger than 10 years. Shigellosis is transmitted person-to-person by the fecal-oral route through contaminated hands and, less commonly, contaminated water or food. Yersinia enterocolitica can grow in cold temperature and can grow to high numbers in refrigerated food or blood products and is associated with transfusion-related sepsis. Enteric disease in children may manifest as enlarge mesenteric lymph nodes and mimic acute appendicitis. Yersinosis is a zoonotic infection, with humans as accidental hosts.
Gastrointestinal Infections
Miriam Orcutt, Clare Shortall, Sarah Walpole, Aula Abbara, Sylvia Garry, Rita Issa, Alimuddin Zumla, Ibrahim Abubakar in Handbook of Refugee Health, 2021
Dysentery may be caused by Escherichia coli, Shigella, Campylobacter, Salmonella and Entamoeba hystolytica. If there is profuse, watery ‘rice water’, suspect Vibrio cholerae. Salmonella typhi and S. paratyphi may cause constipation in immunocompetent adults; however, they can be associated with diarrhoea (see below). Consider non-gastrointestinal infections that can cause diarrhoea, for example, toxic shock, severe malaria and pneumonia. Patients positive for human immunodeficiency virus (HIV; more common among refugees from sub-Saharan Africa) are susceptible to similar pathogens, as well as non-typhoidal salmonellosis, mycobacteria, cytomegalovirus (CMV), cryptosporidiosis and microsporidiosis; the latter is associated with malaise, nausea, crampy abdominal pain and low-grade fever. If diarrhoea is green and offensive with recent antibiotic use, consider Clostridium difficile. Consider enterotoxigenic E. coli in patients with suspected haemolytic uraemic syndrome (HUS). E. histolytica can cause extra-intestinal disease, including amoebic liver, lung or brain abscesses.
Waterborne and water-washed disease *
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
Examples of highly infectious faecal–oral pathogens that have a high probability of causing infection and possibly illness from a very low dose (as few as one ingested microorganism) are the human noroviruses and rotaviruses. For these viruses the 50 per cent infectious doses (doses for which the probability of infection are about 50:50 or 50 per cent based on human volunteer studies) are perhaps one or a few virus particles (Ward et al., 1986; Teunis et al., 2008). Other faecal–oral microorganisms with relatively high infectivity (high probability of infection at relatively low doses) are some strains of the protozoan parasite Cryptosporidium parvum and some enteric bacteria that cause dysentery, such as Shigella species and enterohemorrhagic strains of Escherichia coli, for which 50 per cent infectious doses are in the range of 10–100 microorganisms. In contrast, some other faecal–oral pathogens are relatively low in infectivity, such as certain species of Salmonella bacteria, for which the 50 per cent infectious doses for different species are >1000 microorganisms based on human volunteer studies (Teunis et al., 1996; Haas et al., 1999). However, compilation of data from careful and timely epidemiological investigations of foodborne and waterborne outbreaks suggest that some species and strains of Salmonella are infectious and have the potential to cause disease at relatively low doses of between 10 and 100 microorganisms (Food and Drug Administration, 2012).
Mechanisms of bacillary dysentery: lessons learnt from infant rabbits
Published in Gut Microbes, 2020
The presence of blood in stool is a hallmark of bacillary dysentery. Our comparative analysis with bacterial mutants in the infant rabbit model provided critical insight into the mechanisms supporting bloody diarrhea. In animals infected with wild type bacteria, we observed vascular lesions as indicated by massive presence of red blood cells in the intestinal mucosa (Figure 2(a), top, RBC and Figure 2(b), middle). Importantly, we also observed vascular lesions in animals infected with the spreading-defective mutant ΔicsA (Figure 2(a), bottom and Figure 2(c), middle). Since we did not observe signs of vascular lesions in animals challenged with the invasion-defective T3SS mutant, these results indicate that vascular lesions occur in response to intracellular infection of epithelial cells, regardless of the ability of the bacteria to spread from cell to cell. We speculate that in response to the presence of bacteria in the cytosol, epithelial cells produce cytokines that may remotely affect endothelial cell junctions, leading to massive leakage of blood vessels. It is also possible that the production of chemokines leads to infiltration of immune cells, which may also affect the integrity of endothelial cell junctions. The mechanisms supporting S. flexneri cytosolic detection in vivo and leading to cytokine and chemokine expression are poorly understood. In addition to the mechanisms supporting epithelial fenestration, the infant rabbit model offers a new platform to dissect the mechanisms mediating vascular lesions.
The impact of water crises and climate changes on the transmission of protozoan parasites in Africa
Published in Pathogens and Global Health, 2018
Shahira A. Ahmed, Milena Guerrero Flórez, Panagiotis Karanis
Entamoeba spp., were presented in ten African countries (Zimbabwe, Tunisia, Sudan, Nigeria, Morocco, Ethiopia, Egypt, Cote d´Ivoire, Cameroon, Burkina Fasso). Diarrhea and dysentery are the most common symptoms after infection with this parasite. Extra-intestinal complications are less frequent to occur; however, high mortality can be associated. In recent cross sectional study in South Africa, E. histolytica was highly loaded in the diarrhea samples [40]. In Ethiopian patients, Entamoeba spp. were the highest predominant protozoa in the diarrhea samples from adults [41] and one of the most identified parasites in children under five years [42]. In Cameroon, Egypt and Sudan, Entamoeba spp., were detected in drinking water [42–44]. Direct wet mount/iodine is a simple, cost effective popular method used in African reports to identify cysts of Entamoeba spp. in water samples which probably raises its reporting numbers.
Empirical antibiotic treatment for children suffering from dysentery, cholera, pneumonia, sepsis or severe acute malnutrition
Published in Paediatrics and International Child Health, 2018
In the first paper, Williams and Berkley review data on the treatment of dysentery, i.e. bloody diarrhoea assumed to be caused by Shigella species. At the beginning of this millennium, more than 100 million episodes of dysentery were estimated to occur annually in children under 5 years of age [10], and there is no evidence to show that the incidence would have fallen much since then. The review focuses on papers published after 2005 when the most recent technical WHO guideline was published [11]. The authors conclude that there are few new data to warrant a change in the WHO recommendation to treat children with dysentery primarily with ciprofloxacin and secondarily with pivmecillinam or ceftiaxone. As an alternative, the authors suggest azithromycin and cefixime as orally administered second-line drugs, although with certain caveats.
Related Knowledge Centers
- Dehydration
- Entamoeba Histolytica
- Fever
- Rectal Tenesmus
- Shigella
- Gastroenteritis
- Diarrhea
- Blood
- Shigellosis
- Amoebiasis