Although intestinal parasites are mild and in many cases asymptomatic, if left untreated for a long time, they can lead to serious complications
This is what Dr. Kalina Stoyanova, MD, said in an interview for the "Doctor" magazine. - chief assistant at the department of "Infectious diseases, parasitology and dermatovenerology" of the Medical University "Prof. Dr. Paraskev Stoyanov" - city of Varna. Dr. Stoyanova is a member of the expert council on "Medical Parasitology" at the Ministry of He alth.
Dr. Stoyanova, what are the most common parasitic diseases in childhood and how do you get infected with them?
- Intestinal parasitoses affect all ages, but some of their features favor their wider distribution in childhood. The most common helminthiasis in children is enterobiasis, the causative agents of which are known in our country under the name "stings".
Enterobiosis is widespread in all corners of the world, including among children in well-developed countries. In some parts of Bulgaria there is a risk of infection with the so-called geohelminthosis - ascariasis and trichocephalosis. In them, the eggs develop in the soil under the specified environmental conditions.
Although these two parasitoses have been significantly limited in recent years, they still represent a serious problem in endemic regions and especially among children housed in various social institutions - homes for children deprived of parental care; for children with mental problems and others.
This risk group also includes the most common taenidiosis in childhood - hymenolepidosis, which is caused by the so-called dwarf tapeworm. High morbidity in childhood is also characteristic of intestinal protozoan invasions - giardiasis, blastocystosis and cryptosporidiosis.
And what are the reasons for this wider distribution and correspondingly higher morbidity in children?
- The reason for the wider spread of intestinal parasitosis in children is the general and multicomponent fecal-oral route of transmission. This method of transmission can occur through direct contact with a sick or infected person, which most often happens within the family and the children's closest environment - the various children's collectives (nurseries, kindergartens, schools)
. Contagion also occurs through contact with various contaminated objects. At this age, these are most often toys, cutlery, general toiletries and more.
The contact-bite route of transmission is particularly characteristic in childhood due to insufficiently developed personal hygiene habits. They often put their hands and various objects in their mouths, crawl, walk and grope in all kinds of places.
Therefore, one of the mechanisms for protection is the parents' concern for the good hygiene of the little ones. Often in childhood, infection with both intestinal parasitoses and other more serious parasitic diseases such as canine tapeworm or toxocarosis can occur during outdoor play and unavoidable contact with contaminated soil or sand.
The other way of infection is related to the poor washing of fruits and vegetables, especially those that are grown close to the ground - leafy vegetables (various salads, green onions, fresh spices) and small, hard-to-clean fruits (strawberries, blackberries, raspberries). And last but not least, infection, especially in protozoan invasions, occurs through a waterborne route of transmission
That is why it is good to drink only water intended for drinking purposes (tap, bottled). It is very important to be careful when traveling, hiking, and bathing and swimming in various natural and artificial water bodies.
Dr. Stoyanova, what is the clinical picture of the most common intestinal parasitosis in children?
- The clinical picture of intestinal parasitosis even in childhood is relatively mild, but it can include a wide range of different symptoms, which is why the diseases remain unrecognized for a long time. They usually start after a relatively short incubation period - from 2-3 days to 1-2 weeks.
In some cases, especially in infants and the youngest children, the invasion can proceed acutely, with nausea, vomiting, several days of diarrhea and signs of intoxication. These symptoms are more characteristic of intestinal protozoan invasions - giardiasis and cryptosporidiosis.
But although the symptoms are generally milder compared to viral and bacterial acute diarrhoea, a longer course is characteristic here. At this early age, diarrheal episodes lasting more than a week pose a serious risk for dehydration, and in some cases hospital treatment may be required.
Other complaints in intestinal parasitosis may include abdominal pain of varying intensity, change in appetite, increased salivation, grinding of teeth, alternating periods with diarrhea and constipation, and others. In most cases, the symptoms are uncharacteristic and may remain unnoticed by parents for a long time.
Perhaps the most recognizable symptom is itching in the anus area, but it is mainly characteristic of enterobiosis and is caused by a specific part of the parasite's life cycle. Female pinworms, usually nocturnal, exit through the anus and lay thousands of microscopic eggs in the perianal folds.
This leads to itching and scratching, where the eggs fall on the hands and under the nails of the infested child. From there, the surrounding objects - clothes, toys and others - are easily contaminated.
This favors the possibility of repeated or so-called self-parasitism by pawing and sucking fingers, biting nails, etc.
You said that intestinal parasites are generally mild, but can they still cause serious complications?
- Although, in general, intestinal parasitoses are mild, and in many cases even asymptomatic, yes, untreated for a long time, especially in childhood, they can lead to serious complications.
Such as chronic diarrhea with symptoms of malabsorption of various nutrients (sugars, fats, fat-soluble vitamins). This leads to weight loss, delay in physical, and hence mental development in childhood.
Chronic pain and lack of sleep caused by perianal itching can, for example, lead to a change in the child's behavior - he becomes more irritable, which sometimes manifests as aggression; or else distracted and inattentive, and this, in turn, can lead to failure to cope with the learning material in preschool and school age.
In some cases, some more serious conditions such as bedwetting and night terrors can also be provoked.
Dr. Stoyanova, the seasonal prophylactic tests for intestinal parasites, which are required when children are admitted to kindergartens and nurseries, have already begun. Or if they have been absent from these collectives for a longer time. How do you rate the effectiveness of this system?
- I want to emphasize that the system of preventive examinations for intestinal parasites in childhood, which exists in our country, is extremely effective. It makes it possible to detect a large percentage of children with intestinal parasites, which, as I mentioned above, are generally mild or asymptomatic.
In this way, the sick are treated before entering or returning to the children's facilities, and in this way the extremely easy spread of intestinal parasites in the organized collectives is limited. As proof of my statement, I can compare the extent of spread of the most common parasitosis - enterobiosis in our country and in the rest of Europe.
Studies from many European countries (Great Britain, Germany, Norway, Italy, the Czech Republic and others) indicate data affecting 10%, and in some cases more than 20% of the examined children of preschool and early school age. In Bulgaria, this indicator is much lower - the total relative share of enterobiosis for the country is close to 1% precisely thanks to the prevention system.
Of course, we find a higher frequency among children in children's groups, where enterobiosis in 2018 covered 2.1% of those examined. Despite this positive comparison, I must point out that in recent years there has been an alarming and stable trend of increasing the frequency of enterobiosis in our country.
The relative share of the disease has increased twice - from 0.75% in 2013 to 1.45% in 2018. This necessitates strengthening prevention and control measures both in nurseries and kindergartens, and and among the most frequently affected - children between 7 and 11-12 years of age, where the infection rate exceeds 5%
The reasons for this extremely high result are easily explained - in early school age, the disease spreads through contact just as easily as in younger children. However, there is a lack of regular preventive examinations for schoolchildren, and the affected children may remain undiagnosed and, accordingly, untreated for a long time.
What would you say as a summary of this topic and in conclusion?
- Intestinal parasitosis in children, despite being mild in course, is a common phenomenon. For this reason, it is good to pay serious attention to the correct construction of hygiene habits in childhood and school age.
For this purpose, it is necessary to organize more he alth and educational events both among children and their parents, and among the staff working at all levels in the system of organized upbringing and education.
Broader awareness of the symptoms and course of intestinal parasitosis will make them easily recognizable, and knowledge and application of prevention and prophylaxis methods will increase their effectiveness.
