The Centers for Disease Control and Prevention (CDC) has warned that cases of leishmaniasis are growing in the United States, even affecting people who have not traveled to Africa, Asia, Latin America and the Middle East, where this parasitic disease is endemic and more prevalent.
Infected dogs imported from the aforementioned tropical regions are believed to be the carriers of the disease, which can then be transmitted to humans. Many of the 86 identified cases of the milder form of leishmaniasis were found in Texas, while others were detected in Arizona, Florida and Oklahoma.
Leishmaniasis is a disease caused by a single-celled protozoan (parasite) from the genus Leishmania. Dogs and humans can get this disease if they are bitten by a blood-sucking sandfly carrying the Leishmania infantum parasite.
When a female phlebotomine sandfly bites an infected reservoir host, it also sucks in the parasite, which continues to multiply inside the insect. It can then transmit the parasite to another reservoir (animal or human) during its next blood meal.
Canine leishmaniasis is widespread in more than 70 countries but is most common in Mediterranean areas as the Leishmania parasite thrives in warm climates. The period in which leishmaniasis risk is the highest is from the months of April to October.
Sandflies hide during daytime and come out late in the afternoon, becoming very active from dusk until dawn.
Many dogs manage to lead almost normal lives even if the Leishmania parasite stays with them for many years.
Types of leishmaniasis
Experts believe there are about 20 different Leishmania species that can spread the infection to humans in three forms: cutaneous, mucocutaneous and visceral leishmaniasis.