Combined acute intestinal infections in children: clinical features, treatment approaches
Acute intestinal infections (acute intestinal infections) remain an important public health problem due to their mass, severe course and the associated economic damage. OCI occupy the 2nd place in the structure of infectious diseases in children after acute respiratory infections, and such a structure has remained practically unchanged over the past decade. According to the state report on the state of sanitary and epidemic well-being of the population of the Russian Federation among children under 14 years old, 526,613 cases of acute intestinal infections, including shigellosis and salmonella, were recorded in 2017. In 2018, this indicator changed slightly and amounted to 518,959 cases. The high incidence rate is largely due to a wide range of pathogens, a variety of transmission routes, high susceptibility of the contingent, as well as the limited arsenal of specific prophylaxis.
Etiology of OKI
Currently, the causative agents of acute respiratory infections in children in the Russian Federation in the vast majority of cases are viruses – about 70% of diarrhea in the warm season and up to 90% of diarrhea in the autumn-winter period are caused by diarrheagenic viruses. Most often, rotaviruses cause diarrhea, but other viruses can also be causative agents of acute intestinal infections: Caliciviridae (genera Norovirus, Sapovirus), Adenoviridae (genus Mastadenovirus), Astroviridae (genus Astrovirus), Picornaviridae (genera Enterovirus, Parechovirus), Coronaviridae, Toronaviridae , Parvoviridae (genus Bocavirus), Picornaviridae (genus Picornavirus). The spectrum of bacterial pathogens of OCI includes both unconditionally pathogenic microorganisms (Salmonella, Shigella, pathogenic strains of Escherichia coli, Campylobacter), as well as opportunistic bacteria (Staphylococcus, Klebsiella, Clostridium, etc.).
Thanks to the development of molecular genetic diagnostic methods, it has become apparent that in some cases several microorganisms can act as a cause of acute intestinal infections. The share of acute intestinal infections of combined etiology in our country, according to various sources, ranges from 26 to 32%. In other countries, such as Rwanda and Tanzania, concomitant intestinal infections were detected even more often – in 65% of children under 5 years of age.
According to the literature, the most common causative agents of intestinal mixed infections, as well as monoinfections, are viruses, and in various studies a diverse combination of viruses is detected. So, in Spanish children, the combination of rotavirus infection (RVI) with astrovirus infection and RVI with adenovirus infection was most often recorded. In Korean children with acute gastroenteritis, a combination of RVI and norovirus infection (NVI) and RVI and astrovirus infection was more common – a total of mixed infections were detected in 2.7% of all acute intestinal infections. According to N. Koh et al., The most common was the combination of RVI and NVI in 12.9% of children, while mixed infections were recorded in 18.1% of cases of acute intestinal infections. P.E. Imade et al. recorded a combination of RVI and adenovirus infection in 5.4% of cases, and S. Ozdemir et al. – in 7.2% of cases, while mixed infections were detected in 10.2% of children
with OKI. Domestic authors more often determined the combination of RVI and NVI in 4.9% and 6.4% of the examined children with acute gastroenteritis.
AEI of viral and bacterial etiology is most often represented by a combination of salmonellosis and RVI. According to W.T. Lan et al. , the detection rate of a combination of salmonellosis and RVI is 3.7%. In the study A.A. Ploskoreva this indicator was slightly higher – 9.2%, which exceeded the number of mixed infections of RVI and NVI (4.9%). It should be noted that since 2007, an annual increase in the incidence of salmonella rotavirus mixed infection has been noted in the Russian Federation: in a third of children with bacteriologically confirmed salmonellosis screened for rotaviruses, these etiological agents are determined. The combination of salmonellosis and other viruses does not lose its relevance. In the Russian Federation, when examining children with salmonellosis, 21.2% also have NII, and 30.2% have an adenovirus infection.
Along with salmonellosis, in the structure of acute intestinal infections of bacterial etiology, infections caused by pathogenic E. coli strains did not lose their relevance. The proportion of Escherichiosis when combined with other etiological agents of acute intestinal infections in children is 4.9% of cases of all acute intestinal infections. According to other data, the proportion of acute intestinal infections caused by a combination of RVI and Escherichiosis reaches 10.3%.
An analysis of the studies allows us to conclude that the most common etiological agent for acute enteric infections of combined etiology is rotavirus, and some differences in the indicators in the data presented are apparently due to national characteristics, age groups and the number of children examined, time of year during the study, laboratory diagnostic methods.
Clinical picture of OKI
The clinical picture of mixed infections is characterized by a significant variety. Unlike mono-infections, in which it is more likely by clinical symptoms that an etiology of acute intestinal infections is possible (bacterial is characterized by the presence of pathological impurities of mucus and blood in the stool.