Clonorchosis: Causes, Symptoms, Diagnosis, Treatment

Clonorchiasis is a biogelmintosis, which at an early stage manifests itself as allergic symptoms, and in the chronic stage proceeds with a predominant lesion of the liver and pancreas.

[1], [2], [3], [4], [5],

Epidemiology of clonorchosis

The source of infestation is infected people, as well as dogs, cats and wild carnivores. A person becomes infected with this disease by eating raw and insufficiently decontaminated fish, as well as shrimp.

The development cycle, like that of opisthorchiasis, occurs with the change of three hosts. The final hosts are people, cats, dogs, pigs, otters, martens, badgers, rats and some other animals eating fish. Eggs of the helminth, excreted with feces, when ingested into water are swallowed by intermediate hosts - mollusks. Genera Codiella, etc., in the body of which larval development passes to the stage of cercariae. Cercariae leave mollusks and penetrate into additional hosts, which are used by many species of carp fish (crucian carp, ide, bream, carp, etc.), less often - bull and herring; in China, the number of additional hosts also includes shrimp. Cercariae settle in muscles, subcutaneous tissue and other tissues, where for about 35 days they are encysted and transformed into metacercariae. When the metacercariae enter the gastrointestinal tract of a person or other final hosts, the cyst shell dissolves, and the released larva passes through the bile duct or portal veins into the liver, where it becomes a sexually mature fluke, which begins laying eggs a month after infection of the host. The development of the larva before the mature stage can also occur in the ducts of the pancreas. The life span of the Chinese fluke in the host can reach 40 years.

[6], [7], [8], [9]

What causes a clonorchosis?

Clonorchiasis is caused by the Chinese duodenum Clonorchis sinensis, which has a flat body, 10-20 mm long, 2-4 mm wide. At the anterior end of the body there is an oral sucker, at the border of the first and second quarters of the body - a smaller abdominal sucker.

According to the structure of the body, the clonorchids are similar to opisthorhs. Their distinctive features are the larger size and the narrower front end of the body. Testes of clonorchids, in contrast to otpidistors, are deeply dissected, their branches go beyond intestinal canals. Hence the name Clonorchis (Greek klonos - branchy, Latin orchis - testis).

Eggs of the causative agent are yellowish brown, 26-35 x 17-20 microns in size, with a lid on one pole and a tubercle on the other. The anterior end of the egg is markedly narrowed, the protrusions along the edges of the lid are well defined, which is a distinctive feature from the eggs of the opisthorchus.

The clonorhoz is widely distributed in China, Japan, Korea and in a number of countries in South-East Asia. In some endemic areas, up to 80% of the population is affected, and a total of millions of people are invaded by the clonorchosis. In Russia, clonorhoz occurs in the Amur basin and in Primorye, the incidence rate is relatively low. However, in the lower Amur Region (from Khabarovsk to Komsomolsk-on-Amur) among the indigenous population (Nanais), the incidence is 25%.

Clonorchosis Symptoms

Symptoms of the clonorchosis are basically the same as in opisthorchiasis. More often than with opisthorchiasis, there is a sudden onset with severe allergic symptoms. Suddenly, a high fever of a constant or relapsing type occurs with chills. There is a polymorphous skin rash, eosinophilic infiltrates in the lungs, bronchitis, reactive pleurisy, diffuse changes in the myocardium, myalgia, arthralgia, lymphadenopathy. Approximately 30% of patients have an enlarged spleen.

[10], [11], [12], [13], [14]

Clonorchosis Diagnosis

In the blood, as a rule, leukocytosis is detected up to 20-30 x 10 ⁹ / l, eosinophilia (up to 70%), an increase in ESR to 30-40 mm / h. The final diagnosis of "clonorchosis" is established when helminth eggs are found in duodenal contents or feces.

The carcinogenicity of the clonorchs is not definitely established.

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Treatment of clonorchosis

Treatment clonorchosis is basically the same as in  opisthorchiasis.