Prevalence and Incidence of Trichinosis

Trichinosis: Rare Disease

Trichinosis is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Trichinosis, or a subtype of Trichinosis, affects less than 200,000 people in the US population.

Ophanet, who are a consortium of European partners, currently defines a condition rare when if affects 1 person per 2,000. They list Trichinosis as a "rare disease". More information about Trichinosis is available from Orphanet

Incidence (annual) of Trichinosis:

12 annual cases notified in USA 1999 (MMWR 1999) ... see also overview of Trichinosis.

Incidence Rate:

approx 1 in 22,666,667 or 0.00% or 11 people in USA [Source statistic for calcuation: "12 annual cases notified in USA 1999 (MMWR 1999)" -- see also general information about data sources]

Incidence extrapolations for USA for Trichinosis:

11 per year, 0 per month, 0 per week, 0 per day, 0 per hour, 0 per minute, 0 per second. [Source statistic for calculation: "12 annual cases notified in USA 1999 (MMWR 1999)" -- see also general information about data sources]

Prevalance of Trichinosis:

Infection was once very common; however, infection is now relatively rare. From 1991-1996, an annual average of 38 cases per year were reported. (Source: excerpt from Trichinosis: DPD)

Prevalence/Incidence of Trichinosis: Online Medical Books

16 MEDICAL BOOKS ONLINE! Review excerpts from medical books online, free, without registration, for more information about the prevalence and/or incidence of Trichinosis.

Hookworm disease: Causes and incidence
(Professional Guide to Diseases (Eighth Edition))

Both forms of hookworm disease are transmitted to humans through direct skin penetration (usually in the foot) by hookworm larvae in soil contaminated with feces containing hookworm ova. These ova develop into infectious larvae in 1 to 3 days. Larvae travel through the lymphatics to the pulmonary capillaries, where they penetrate alveoli and move up the bronchial tree to the trachea and epiglottis, where they're swallowed and enter the GI tract. When they reach the small intestine, they mature, attach to the jejunal mucosa, and suck blood, oxygen, and glucose from the intestinal wall. These mature worms then deposit ova, which are excreted in the stool, starting the cycle anew. Hookworm larvae mature in approximately 5 to 6 weeks.

Hookworm disease, affecting billions of people worldwide, is most common in moist tropical and subtropical regions. There's little risk of aquiring hookworm disease in the United States because of advances in sanitization and waste control.

» READ BOOK EXCERPT ONLINE »

Source: Professional Guide to Diseases (Eighth Edition), 2005

Trichinosis: Causes and incidence
(Professional Guide to Diseases (Eighth Edition))

Transmission is through ingestion of uncooked or undercooked meat that contains T. spiralis cysts. Such cysts are found primarily in swine, less commonly in dogs, cats, bears, foxes, wolves, and marine animals. These cysts result from the animals' ingestion of similarly contaminated flesh. In swine, such infection results from eating table scraps or raw garbage.

After gastric juices free the worm from the cyst capsule, it reaches sexual maturity in a few days. The female roundworm burrows into the intestinal mucosa and reproduces. Larvae are then transported through the lymphatic system and the bloodstream. They become embedded as cysts in striated muscle, especially in the diaphragm, chest, arms, and legs. Human-to-human transmission doesn't take place.

Trichinosis, though common worldwide, is seldom seen in the United States because of regulations regarding animal feed and meat processing.

» READ BOOK EXCERPT ONLINE »

Source: Professional Guide to Diseases (Eighth Edition), 2005

Trichinosis: Trichinosis - epidemiology
(The 5-Minute Pediatric Consult)

• Worldwide distribution, disease concentrated in Europe and North America: 8 Trichinella species (T. spiralis, T. brivoti, T. pseudosprilais, T. papuae, T. nativa, T. nelsoni, T. murrelli, and T. zimbawensis)
• Historically, majority of US infections are due to T. spiralis in commercial pork.
• In 1997–2001, majority of US infections were associated with wild game.
• Infections sporadic and in epidemics (e.g., families and communities with common exposure)
• Consider in patients who have had recent foreign travel, consumed foreign meat or wild game (e.g., bear, cougar, hyena, lion, panther, fox), horse, dog (China), seal, or walrus meat
• Carried by rodents, domesticated animals (e.g., dogs, cats), raccoons, opossums, and skunks
• Disease not transmissible person to person

Trichinosis - incidence

Between 1997 and 2001 in the US, median of 12 cases annually, 9 outbreaks involving 33 cases, and no deaths:

• Decreasing number of cases attributed to decline in prevalence of Trichinella in commercial swine (1.41% in 1900, 0.125% in 1966, and 0.013% in 1995), federal regulation preventing uncooked meat consumption by commercial swine, increased public awareness regarding properly frozen and cooked meat

Trichinosis - prevalence

~4% of cadavers in 1970 study with evidence of previous infection (additional estimates range from 10–20% prevalence)

» READ BOOK EXCERPT ONLINE »

Source: The 5-Minute Pediatric Consult, 2008

About prevalence and incidence statistics:

The term 'prevalence' of Trichinosis usually refers to the estimated population of people who are managing Trichinosis at any given time. The term 'incidence' of Trichinosis refers to the annual diagnosis rate, or the number of new cases of Trichinosis diagnosed each year. Hence, these two statistics types can differ: a short-lived disease like flu can have high annual incidence but low prevalence, but a life-long disease like diabetes has a low annual incidence but high prevalence. For more information see about prevalence and incidence statistics.