Can direct contact with dogs lead to canine tapeworm infection in Vietnam in humans? What symptoms will the patient show when infected?
Can direct contact with dogs lead to canine tapeworm infection in Vietnam in humans?
Pursuant to Section 1 of the Guidelines issued together with Decision 1658/QD-BYT in 2022, there are guidelines on the source of canine tapeworm infection in humans as follows:
"first. OUTLINE
Canine tapeworm disease is a disease caused by flukes of the genus Echinococcus. Canine tapeworm disease in humans has 2 main lesions:
- Cystic echinococcosis-CE: caused by human infection with the larvae of the dog tapeworm E. granulosus, the disease is found in most continents, especially in areas where many sheep and cows are raised. In Asia, the disease is distributed in Japan, Korea, China, Thailand, Mongolia, Indonesia, Bangladesh, Nepal, and India. In Vietnam, patients with pulmonary cysts due to E. ortleppi species have been recorded.
- Alveolar echinococcosis (AE): caused by human infection with the larvae of the dog tapeworm E. multilocularis, the disease is endemic in the northern hemisphere such as China, Russia, Northern Europe, and North America.
1.1. Agent
The genus Echinococcus has about 10 species recorded, of which the two main species causing disease in humans are: E. granulosus and E. multilocularis.
1.2. Inoculum
- E. granulosus has the main host: domestic dogs, wild dogs...; The intermediate host is herbivores, especially sheep.
- E. multilocularis whose main host is wild animals: fox, weasel...; The intermediate host is rodents such as hamsters, house mice.
1.3. Infectiousness and immunity
All people, of both sexes, can be infected with tapeworm larvae and can be reinfected if they ingest tapeworm eggs.
1.4. Mode of transmission
People get the disease by swallowing dog tapeworm eggs when eating foods contaminated with dog tapeworm eggs or people after having direct contact with infected dogs, foxes and ferrets.
Accordingly, direct contact with infected dogs, foxes or ferrets or ingesting tapeworm eggs given on foods contaminated with tapeworm eggs are thought to be the causes leading to canine tapeworm disease in humans.
Can direct contact with dogs lead to canine tapeworm infection in Vietnam in humans? What symptoms will the patient show when infected? (Image from the internet)
What are the symptoms of a dog tapeworm infection?
Pursuant to Section 2 of the Guidelines issued together with Decision 1658/QD-BYT in 2022, there are guidelines related to the symptoms of canine tapeworm disease in humans as follows:
"2. CLINICAL
Echinococcus larval disease can clinically depend on the species of tapeworm infected. The disease is characterized by slow development, for a long time may be completely without clinical manifestations. The cysts are most common in the liver, then the lungs and other organs such as kidneys, spleen, heart, nerves or bones.
2.1. Cystic echinococcosis (CE)
- Symptoms usually appear in the late stage, when the cyst has grown, causing compression, the size of the cyst ranges from 1-15 cm. Symptoms vary with the location, size, and number of cysts.
- Common locations of E. granulosus cysts are liver and lungs, clinical symptoms are often non-specific:
+ In the liver: indigestion, cholecystitis, jaundice, mild fever.
+ In the lungs: persistent cough, low-grade fever, sometimes coughing up blood, rash.
2.2. Alveolar echinococcosis (AE)
Symptoms also depend on the location and size of the cyst, but are often misdiagnosed with cirrhosis or secondary liver cancer.
- The disease is common in the elderly.
- The liver is enlarged, hard, painless, no primary tumor was found.
- Initially, cystic cysts usually appear in the liver, then spread to nearby organs or through the bloodstream to the lungs and brain.
- The disease progresses to a state of exhaustion and death after several years.
Accordingly, when people have canine tapeworm disease, they may not have any symptoms for a long time with canine tapeworm disease. However, in the cystic form, in the last stage, symptoms of indigestion, jaundice, persistent cough, low-grade fever, bloody cough and itching will appear. For honeycomb cysts, the disease will progress to a state of exhaustion and lead to death after a few years of infection.
What is the life cycle of canine tapeworm infection in humans?
Pursuant to Section 1 of the Guidelines issued together with Decision 1658/QD-BYT in 2022, analysis of the infection cycle of canine tapeworm infection in humans is as follows:
(first). The adult dog tapeworm E. granulosus is 2-7 mm long, living in the small intestine of the main host.
(2). Tapeworm eggs contain infectious embryos (larvae) that are released into the environment in feces and can cause immediate infection.
(3). In the intermediate host, the larvae escape the shell, penetrate the intestinal wall, enter the circulatory system to travel to the internal organs.
(4). Tapeworm larvae develop into thick-walled water cysts, which gradually enlarge, mainly found in the liver and lungs. The cyst fluid is clear, salty, and hypertonic, containing flukes and may form cysts. In humans, the cysts can rupture, creating secondary cysts.
(5)_(6). The main host after eating the viscera with cysts, the tapeworms will escape, attach to the intestinal wall, develop into an adult dog tapeworm after about 32-80 days.
Thus, the human canine tapeworm infection cycle will include 6 stages as shown in the content of the guidelines mentioned above.
LawNet
