Slideshow: Cases Involving Animal Exposure, Part 1

Welcome to our latest slideshow! Click through the slides to view cases involving exposure to various animals. Each slide links to the full case report for more details. This is part 1 of a 2-part series.

On average, 150 to 250 cases of leprosy, also known as Hansen disease, are reported annually in the United States, with the predominant incidence (85%-95%) in immigrants from endemic regions such as Asia, Africa, and South America.

The disease is caused by infection with M leprae, an aerobic, acid-fast, rod-shaped bacterium. Humans serve as the primary reservoir for M leprae, but the nine-banded armadillo, found in the southern United States and Mexico, also can serve as a natural host. Although the precise mode of transmission remains unclear, M leprae is thought to be transmitted through aerosol spread of nasal secretions. The organism’s incubation period can range from several months to 20 to 50 years.

Read the full case report here.

The puss caterpillar is the larval form of the southern flannel moth (Megalopyge opercularis) and is native to the southeastern and southern United States. Its hair-like spines grow long during the summer months, resembling a fluffy cat. When touched, the caterpillar stings the skin with its venomous hairs as opposed to biting with its mouth, causing an extremely painful vesicular rash. The treatment is usually observation and palliative measures, and the lesions eventually resolve.

Read the full case report here.

While playing on a brick walkway in her backyard, a 4-year-old girl stepped on a puss caterpillar and was stung. The ecchymosis exactly outlined the caterpillar's spines and remained visible for at least 3 months. The initial sting caused intense pain that lasted for more than an hour.

Read the full case report here.

While scuba diving in the Philippines, a healthy 36-year-old man noticed a red rash on his wrists and dorsa of both hands after he surfaced from a dive. Within a couple of hours, the rash had become painful, swollen, itchy, and papular. The man reported that he had brushed against multiple small white jellyfish, which suggested that he most likely had been stung.

Jellyfish tentacles contain nematocysts that fire on tactile stimulation. The sting causes immediate burning, numbness, inflammation, and paresthesia. Linear papules or wheals develop where the tentacles come in contact with the skin. Systemic toxic reactions can occur in persons with severe or widespread stings or in those with a history of severe allergic reactions. Movement of the envenomed part, such as a limb, leads to mobilization of the venom from the inoculation site. Fatalities from jellyfish stings, while rare, can occur; box jellyfish, prominent in the Indo-Pacific region, are considered the most lethal.

Read the full case report here.

Four hours after a 12-year-old boy was stung by a honeybee on his right middle finger, he noticed localized hand swelling, erythema, and tenderness. The following morning, his entire hand was swollen and erythematous, with contiguous erythema on the medial aspect of his forearm and arm.

Insects in the order Hymenoptera include yellow jackets, hornets, wasps, honeybees, sweat bees, and imported fire ants. Reactions to stings by these insects fall into 1 of 3 categories: local reactions (also called normal reactions), large local reactions, and anaphylaxis. Local reactions involve swelling, erythema, or pain near the sting site; symptoms usually resolve within a few hours. Large local reactions (as seen in this boy) involve swelling over a large area (greater than 10 cm) and can extend past more than 1 joint.

Read the full case report here.

Leishmaniasis is a vector-borne parasitic disease endemic to 98 countries worldwide. It is primarily found in the tropical regions of Southern Europe, Northern Africa, the Middle East, Central and South America, and the Indian subcontinent.

The causative organism is the protozoan Leishmania. At least 20 species of Leishmania have been identified, causing a range of clinical manifestations in different geographical areas.1 The parasite is transmitted by the bite of infected Phlebotomus sand flies, with more than 98 species of this vector having been identified. Rodents, canines, and humans serve as the primary reservoirs of Leishmania, and thus this disease undergoes both zoonotic (animal-to-human) and anthroponotic (human-to-animal) transmission when female sand flies take blood meals from their mammalian hosts.

Three clinical syndromes are possible, depending on the Leishmania species. Once inside the host, the promastigote develops into an amastigote within macrophages of the skin, causing the cutaneous form of this disease. Mucosal leishmaniasis can evolve from dissemination of the parasite from the skin to the laryngeal or naso-oropharyngeal mucosa, which can erode the nasal cartilage and produce a disfiguring scar.2 When development occurs within the reticuloendothelial system of the spleen, liver, and bone marrow, the visceral form of leishmaniasis (kala-azar) occurs.

Read the full case report here.

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