Diphyllobothrium latum - Complication, Prognosis, Laboratory Diagnosis, Epidemiology, Reservoir, Transmission, Treatment

Complications of Diphyllobothrium latum

The most serious complication of diphyllobothriasis, caused by Diphyllobothrium latum, is pernicious anemia - resulting from vitamin B12 deficiency.

Pernicious anemia

• pernicious anemia is hyperchromic, macrocytic megaloblastic anemia with thrombocytopaenia and mild leucopenia

• occurs approximately in 2% of cases

• more common in patients of ages 20 years to 40 years and less vitamin B12 dietary intake

• also, people with defective intrinsic factor secretion and reduced vitamin B12 absorption capacity are more prone to this complication

• clinical manifestations usually involve neurological issues such as weakness, numbness, disturbances of coordination and movements, paraesthesia, impairment of deep sensibilities

• in severe cases, symptoms include fever, dyspnoea, hemorrhage, and tachycardia

• cholecystitis or cholangitis is the result of the migration of proglottids

Prognosis of Diphyllobothrium latum

The prognosis of diphyllobothriasis, caused by Diphyllobothrium latum, is excellent with treatment.

Epidemiology of Diphyllobothrium latum

Diphyllobothrium latum is common in areas of poor sanitation and in places with the practice of using night soil as fertilizers is prevalent.

Geographically, the tapeworm is endemic in Baltic countries, Scandinavia, South America, Africa, Ireland, Israel, parts of Canada, the USA, Japan, and Central Europe.

Reservoir, Source of Diphyllobothrium latum

Man is the opportunistic host and the reservoir of infection. On the Pacific coast of South America’s Seville, a popular raw fish dish is a common source of Diphyllobothrium latum infection for men.

Transmission of Diphyllobothrium latum

Diphyllobothrium latum is transmitted by consuming:

• raw fish liver

• undercooked fish

• raw, smoked, lightly salted fish

Laboratory diagnosis of Diphyllobothrium latum

The lab diagnosis of Diphyllobothrium latum is done by demonstration of eggs in the feces.

Sample

• stool

Microscopy

In direct wet mount microscopy, the wet mount is prepared by mixing saline, iodine, or lactophenol cotton blue (LPCB).

As eggs are always passed in large numbers in the stool, they can be easily detected in the stool sample. Also, sometimes chains of proglottids are passed alongside feces. These proglottids are found shrunken, and empty and are identified by the presence of rosette-shaped uteri.

Antigen Detection in stool

Coproantigen detection test

Diphyllobothrium latum infection can also be detected by a coproantigen detection test. They use an antigen-capture EIA using antibodies targeting somatic or excretory-secretory antigens present in Diphyllobothrium latum. The specificity and sensitivity depend on the platform and quality of reagents but can be used for the identification of genus.

Since the Diphyllobothrium latum parasite antigen disappears from a stool after treatment, it can be used to monitor treatment success.

However, coproantigen detection tests are usually only available in large reference laboratories or laboratories in endemic areas.

Treatment of Diphyllobothrium latum

Treatment of Diphyllobothrium latum is done by:

• use of drugs such as praziquantel and niclosamide

• Vitamin B12 must be administered orally as a suppurative treatment

Prevention, Control of Diphyllobothrium latum

• preventing contamination of freshwater sources from human feces

• avoid eating raw or undercooked fish

• freezing the fish at -10°C for 24 to 48 hours which will kill plerocercoid larvae of Diphyllobothrium latum