Update: October 2018
Trichinosis in humans is considered to be one of the most dangerous
helminth infections, because getting rid of parasites completely,
penetrated into the body is impossible, they remain in the muscles and retain
its activity up to 40 years. This helminthiasis often leads to
disability, and death when infected with trichinosis
reaches 30%. Postponed disease forms a lifelong
immunity (antibodies circulating in the blood protect against repeated
infection), but immunity remains non-sterile (in the body
encapsulated larvae are present).
Causative agent of trichinosis
The causative agent of this helminthiasis are trichinae, in the genus
which includes more than 10 species (class of nematodes) But only one of them
causes the disease – the parasite Trichinella spiralis.
Mature individuals enter the digestive tract, where (thin
intestines) begin to multiply actively. Trichinella refer to
to viviparous parasites, one female for the entire period of existence
capable of producing up to 2000 larvae. The length of the females do not exceed 1.8
mm, and after fertilization reach 4.4 mm. In males, body length
slightly less – 1.2 – 2 mm. It is characteristic that after fertilization
male parasites die, and females begin to secrete larvae.
The man for trichinae is also the final
(adults parasitize in the intestine) and intermediate (larvae
are located in the muscles) host.
How can you get infected
The mechanism of infection with trichinosis is alimentary, and the transmission path is
oral, through meat infected with trichinosis. Disease
belongs to the natural focal, although the foci of infection may not be
only natural, but also synanthropic.
In natural foci, helminthiasis is common among wild animals.
(source of trichinosis):
- bears (both brown and white);
Synanthropic foci are formed in human habitats, after
feeding of game waste to pets. Distributed
helminthiasis among pigs, dogs and cats. In this case, the infection
human trichinosis occurs when eating infected
pigs (in some areas of dogs).
Susceptibility to this disease in humans is sufficient
high. By eating 10 to 15 grams of contaminated meat
parasite invasion occurs in 100% of cases. Characteristic development
helminthiasis in whole groups of people or families after sharing
feast and eating game.
After 1 – 1.5 hours after eating infected
the larvae of the parasite meat they are in the digestive tract with the help
enzymes and gastric juice are released from the capsule and penetrate into
small intestine. In 1.5 days the larvae reach the stage of mature
individuals and on days 3–4 female parasites begin to produce new ones.
the larvae. The female can survive in the small intestine 42 – 56
days. New maggots perforate the intestinal mucosa,
penetrate the lymphatic system, and from it into the bloodstream. With current
the blood of newly formed larvae spread throughout the body and
settle in striated muscle (5 – 8 days after
infection). As a rule, the musculature of all organs is affected,
exclusion of the heart (muscles of the tongue and forearm, diaphragm and
intercostal, gastrocnemius and deltoid). On the 17th – 18th day after
penetration of the muscles of the larvae mature and become infectious. In
the time spent by the larvae in the muscles they actively begin to produce
hyaluronidase, through which penetrate the muscle fiber where and
are covered with a capsule (3-4 weeks). Capsule covering larva,
provides her with nutrition and protection. Six months later – a year capsule
calcified (deposited calcium salts), which indicate
about the end of the parasite. In this encapsulated form
larvae retain their vitality for 25 – 40
Natural helminthiasis foci are recorded from North America,
Germany and Poland, Ukraine and Belarus, as well as in the Baltic States.
In the Russian Federation, trichinosis is most common in
Khabarovsk and Krasnoyarsk Krai, in the Magadan Region and in
Krasnodar region. In total, the disease is fixed
everywhere, except for the Australian continent.
Promote the spread of helminthiasis:
- the ability of the pathogen to tolerate high and low
temperature, which ensures its survival in any
- high human susceptibility to trichinosis;
- group outbreaks – collective consumption of infected
- unstable immunity that provokes repeated cases
infection after primary infection.
Phases of helminthiasis
The development of helminthiasis occurs in several stages:
- Enzymatic toxic
The initial phase of the disease – takes 7 – 14 days after
infection. Invasive larvae enter the intestinal mucosa, where
develop to adult trichinas that are in the process
life forms of enzymes and metabolites that serves
cause of inflammation intestine.
Allergic фаза развивается на 3 – 4 неделю после infection.
Inзникновение аллергических реакций, во-первых, связано с действием
toxins and dead parasites on blood vessels and blood clotting, a,
secondly, with the introduction of newly formed larvae in
striated muscle. Inкруг личинок в мышцах формируется
protective granulation roller, and appear in the blood and grow
protective antibodies. As a result, there is a massive death of the larvae,
which leads to the development of allergic myositis and the formation of
internal organs nodular infiltrates, which include
eosinophils, plasma cells and lymphoid elements.
Develops by 5-6 weeks after invasion. Inзникает системный
vasculitis and associated severe organ damage. Appear
such complications of trichinosis, as meningoencephalitis, myocarditis,
focal pneumonia and others.
Depending on the severity of the disease occurs in mild,
moderate and severe form. Also distinguish typical forms.
helminthiasis and atypical. The atypical ones are erased and
asymptomatic trichinosis. They are acute and chronic.
Visible physical harm when infected with this helminthiasis is not
is observed. Changes in the muscles are absent. Negative influence
have parasite proteins that are very strong
allergens, which provokes the development of the strongest allergic
reactions leading to damage to blood vessels and joints. Symptoms
trichinosis depends on the degree of invasion of parasites. Incubation
the period is 10-25 days, but it can be lengthened to 45
days It is characteristic that the harder the helminthiasis, the
longer hidden period.
Manifestations of light and moderate form
Disease включает 2 периода:
- acute (allergic reactions and damage to internal
- recovery period.
A tetrad of trichinosis symptoms in humans includes:
- edema syndrome;
- pain syndrome (in muscles);
- high content of eosinophils in the blood.
The temperature rises to 40 degrees in a few days,
затем резкое ее снижение до 37, которая держится 7 – 10 days AT
in some cases, low-grade fever persists somewhat
months. Mild disease may not be accompanied.
hyperthermia. On the background of high temperature signs of general
intoxication: weakness, chills, sweating and nausea, headache
- Facial swelling
A characteristic feature of helminthiasis is the appearance of edema of the eyelids and
the person as a whole, which is often combined with conjunctivitis. ATследствие
this trichinosis is also called “puffy-wool”. Edema occurs at 1
0 5 days of illness and lasts up to two weeks. AT случае
severe disease swelling appear slower but keep
longer. The sequence of the appearance of edema: eyelids, eyebrows,
the whole face. AT тяжелом случае отек доходит до шеи, туловища,
seize the hands and feet, which is considered unfavorable
From the third day of the illness, sometimes later,
muscle pain in different muscle groups. AT первую очередь миалгии
appear in the leg muscles (calf), then spread to
gluteus muscles, muscles of the back and abdomen, capture the arms and shoulder
belt, rise to the cervical and pharyngeal muscles, the muscles of the tongue,
chewing and oculomotor. Such pains are very pronounced,
усиливаются при движении, а пальпация мышц доставляет pain. With
severe develop myalgia with contractures, which leads to
immobilize the patient. Both myalgia and edema persist until 1 – 3
weeks and periodically recur, which is accompanied by an increase
The acute phase of the disease is accompanied by abdominal syndrome.
(pain, nausea, vomiting, diarrhea) and allergic manifestations – rash
(roseolite – pink blisters, which turn pale when pressed,
urticaria – spots merging with each other, urtikarnaya blisters,
raised above the skin).
The level of eosinophils increases to 80%, which appears with the first
symptoms of helminthiasis. Maximum increase in eosinophils
noted at 2-4 weeks of illness (mild for up to 30%,
moderate to 60%). Unfavorable prognostic sign –
increase in eosinophils to 95%.
A severe form of the disease is accompanied by the development of organ organs.
lesions that appear 3 to 4 weeks after
infection. It is organ lesions that often become
cause of death of the patient.
Inзникают следующие осложнения:
- allergic myocarditis – the leading cause of patient death
(increased heartbeat, lower blood pressure, signs
acute vascular insufficiency, ecg diffuse symptoms
- damage to the lungs – the development of pneumonia in combination with pleurisy,
due to systemic vasculitis;
- brain damage (encephalomyelitis, encephalitis,
- liver damage – hepatitis;
- thrombohemorrhagic syndrome (coagulation disorder
- kidney damage – nephritis.
The duration of the disease in the case easy flow
ranges from 7–14 days to 35–42. If treatment is started on time,
длительность каждого периода уменьшается на 3 – 5 days. Period
recovery in case of severe helminthiasis is delayed to
half naked and more. Prolonged muscle pains occur in patients
receiving immunosuppressive agents (glucocorticoids).
Symptomatology depending on the stage of the disease
Stage of invasion
Lasts a week from the time of consumption of contaminated
meat. Parasite larvae enter the stomach, from there into thin
the intestines, where they are fixed in its mucous membrane and cause inflammation.
At this stage, the disease is accompanied by diarrhea, alternating
constipation, epigastric pain, nausea and vomiting, lack of
Stage of dissemination
Развивается через 14 – 28 дней после infection. ATновь
educated larvae produced by sexually mature parasites
penetrate with blood and lymph into the muscles. There they are fixed, grow and
begin to secrete allergens in the blood. Intoxication develops
organism and allergic reactions. At this stage appear
The following are signs of the disease:
- periorbital edema – ocular muscles affected by larvae
inflamed, interstitial fluid accumulates in them – eyelids,
nose bridge swell, and eye movement is painful;
- retinal hemorrhage, conjunctiva – an allergic vasculitis,
accompanied by itching and tearing;
- hyperthermia – due to the action of parasite toxins;
- puffiness of face – penetration of larvae into lingual and
chewing muscles – rash on the skin of the face;
- headache – a consequence of toxic damage to the head
- failure of the central nervous system – damage to brain cells with toxins
parasites leads to insomnia and depression;
- dysphagia – difficulty swallowing due to penetration
larvae in swallowing and chewing muscles;
- cough, breathing problems – as a result of allergic
reaction in a large number of sputum;
- rash – an allergic response to toxins
Lasts 6 weeks – 6 months after the invasion. At this stage
tissue regeneration begins. Larvae grow to 0.8 mm and
twisted into a spiral. Each spiral larva
delimited in the muscles of the capsule and freezes in development. Toxins
parasites can not enter the body, and gradually all
manifestations of the disease taper off. The deposition of calcium salts in the capsule
may destroy the larva, but in general they retain their
жизнеспособность до 25 – 40 years old. On the health of the patient
encapsulated larvae do not affect.
At this stage восстанавливаются функции пораженных органов (15
– 20 days), muscle pain persists up to 2 months, and eosinophilia
Diagnostics трихинеллеза затруднительна, так как на ранних
stages of the disease are often confused with flu, colds
infections and allergies of unknown origin. ATажную роль в диагностике
playing a thorough history, the doctor should be alerted
use by the patient game. With этом в обязательном порядке
all participants of a feast are surveyed.
Also suspicion of trichinosis should cause a characteristic
set of symptoms: periorbital edema, high fever and
Laboratory research methods:
AT периферической крови обнаруживается высокое содержание
eosinophils (50 – 80% of the total number of leukocytes), which
indicates an allergic reaction of the body to food
vital activity of parasites. Also the level of leukocytes increases,
signaling the inflammatory process.
It consists in the identification of antibodies that are produced
the body of the patient after the introduction of parasites. Analysis on
trichinosis includes blood reaction with injected antigens that
isolated from Trichinella larvae. AT качестве серологической
Diagnostics are carried out the following tests:
- RIF and others.
The essence of the method is to provoke an allergic reaction.
as a response to the administration of the trichinosis antigen. To this end
subcutaneously injected solution of antigens. AT случае появлении гиперемии и
blistering at the injection site is a positive test,
which confirms the presence of parasites in the body. Sample becomes
positive from the 2nd week of the disease and lasts for 10
For trichinoscopy – to identify the larvae in the muscles
investigate deltoid and gastrocnemius muscles. Material is obtained from
using puncture muscles, and then study it under a microscope.
AT обязательную диагностику предполагаемого гельминтоза входит
a study of meat that was consumed by the patient and his family.
A study on trichinosis should be made in preventive
for all killed game and meat (pork), coming on sale. AT
Infected meat can contain up to 200 larvae per gram. ATнешне
such meat is no different from normal, color and smell
identical to the meat of healthy animals. ATыявить личинки паразита можно
only under a microscope in the laboratory. On proven and
safe against trichinosis meat is put corresponding to
Checks for this helminthiasis are engaged in the veterinary laboratory,
available in the markets and laboratories sanitary epidemiological station. Sample selection
made with all carcasses. Intake of small pieces of meat (about 5
gram) is carried out with intercostal muscles, diaphragm, tongue and
masticatory muscles. In case of detection of at least one larva meat
considered infected and destroyed. For the destruction of digging a hole
at least one meter deep, the meat is poured with kerosene and
bury. Or clean meat is poured with quicklime and
Treatment трихинеллеза у человека в обязательном порядке
It is carried out permanently, with the exception of erased forms of the disease.
Disease therapy includes 2 areas: etiotropic and
pathogenetic. The etiotropic treatment of trichinosis includes
prescription drugs that are detrimental to the parasites,
localized in the intestine, inhibit their ability to produce
new larvae disrupt the encapsulation process and increase death
helminths located in the muscles. For this purpose, apply:
- Mebendazole (Vermox)
Interferes with the absorption of glucose by parasites, which violates
ATP production in their organisms leads to metabolic derangement
substances and the further death of Trichinella. Drug is not prescribed
pregnant and lactating women. Dosage: 1 to 2 tablets
three times a day for 10 to 14 days.
The effect of the drug is similar to mebendazole, high activity
noted for parasite larvae. Dosage: 10 mg per kg weight
patient duration of 10-14 days.
The effectiveness of the drug is lower due to pronounced adverse reactions.
Dosage: 25 mg per kg patient weight. Course duration 3 – 5
days, the medication is taken twice a day. If necessary
Repeated treatment is carried out (after 7 days).
Pathogenetic treatment includes the appointment of nonsteroidal
anti-inflammatory drugs that help reduce pain in
muscles, fight inflammation and reduce fever (nurofen,
paracetamol, diclofenac and others). Also, be sure
antihistamines are prescribed, especially during treatment
antiparasitic agents. Antihistamines
reduce allergic manifestations and prevent severity
allergic reactions in response to etiotropic treatment.
In severe cases, with the development of organ pathology in the scheme
treatments include glucocorticoids. Glucocorticoids suppress
immunity, thereby reducing allergic manifestations.
The effectiveness of treatment is estimated in six months – a year.
In case of immobilization of the patient and the development of his muscular
Massage, physiotherapy and special treatments are offered.
In parallel with the main treatment, the patient is prescribed
hepatoprotectors and multivitamins, as well as drugs to improve
Inпрос: Можно ли вылечить трихинеллез народными
It is impossible to get rid of trichinosis even when using
medicines as the larvae encapsulated in
muscles do not disappear. Traditional methods of treatment are applied as
addition to the main therapy and only at the stage of invasion and
reproduction of parasites in the intestine. They help expel intestinal
Trichinella, are powerless in the fight against the penetration of larvae into the blood,
and then into the muscles. Popular folk remedies are a decoction of tansy and
Inпрос: Как нужно готовить подозрительное на
Suspicious meat should be subjected to prolonged heat
processing. When cooking meat cut into pieces no more than 8 cm and
boil for at least 3 hours. Frying suspicious meat should
produced in small pieces (up to 2.5 cm), and after frying the meat
extinguish at least 1.5 hours. It is forbidden to use fat
for salting / smoking, and use it only after heating.
Inпрос: Можно ли с помощью заморозки обеззаразить
Yes, this method is quite effective, but subject to
certain conditions. Meat should be kept for 20 days at
temperature -15 degrees or three days at -20
Inпрос: Можно ли заразиться трихинеллезом при
eating salted or smoked bacon?
Since the larvae of the parasite prefer to be located in the muscles,
the risk of infection remains high when eating fat, which
has streaks of meat.