Babesiosis is a zoonotic parasitic disease that can be transmitted from animals to humans causing fever, headache, chills, fatigue, and several harmful effects on man's health.
Dr.provet has addressed babesiosis in cattle through a previous article and decided to show the transmission of this serious disease to man through this article.
This article includes:
Causes of babesiosis in man
Babesiosis, piroplasmosis are 2 names that indicate malaria-like parasitic disease
It is caused by Babesia specieCausess within the family Babesiadae, 40 species that parasitize different domestic and wild vertebrates
The species of animal babesiosis of special interest as of human infection are Babesia microti, agents B.bovis (B.argentina), B.divergens, and possibly some of the equine
How can babesiosis be transmitted to man?
The infected tick is the source of infection
The infection is transmitted by a tick from one animal to another and accidentally to man
Trans-ovarial and trans-stadial transmission have been confirmed in many tick species.
The reservoirs are domestic and wild animals. B.microti occurs in rodents, B.bovis and B.divergens in cattle
Inter-human transmission does not occur naturally but can take place via blood transfusion between human
Life cycle and pathogenesis of babesiosis
The life cycle of the protozoan consists of two phases, including:
The first one in the animals by binary fission in erythrocytes of animals.
The second phase occurs in ticks by sporogony forming the infective forms (Sporozoites) which reach the salivary glands of ticks.
The sporozoites pass from salivary glands of ticks to the host.
sporozoites in blood change to merozoites which invade the RBCs and change to trophozoites which multiply by binary fission and differentiate into macro and microgametes.
The parasites inside RBCs release proteolytic enzymes that lead to rupture of RBCs causing hemoglobinemia, hemoglobinuria, and jaundice.
The metabolic product of the parasite act as a non-specific toxin leading to disturbance of the thermoregulatory center resulting in rising in body temperature
Death occurs as a result of anoxic anoxia (anoxia means failure of the tissues to receive an adequate supply of oxygen).
Incubation period: 1-3 weeks in cattle and 7 - 28 days in humans.
Clinical signs of babesiosis in man
Clinical disease is infrequent as ½ of all children and ¼ of previously healthy adults with babesiosis are asymptomatic
The spleen plays a very important role in the host's resistance against the parasite. Splenectomy is undoubtedly a predisposing factor in contracting the disease.
In splenectomized patients, illness is severe often with pyrexia, anemia, prostration, Hemoglobinuria, and jaundice. The majority of patients died of kidney failure.
In non-splenectomized patients, the onset of the disease is gradual with anorexia, fatigue, fever, sweating, and generalized muscle pain.
Some patients may develop slight splenomegaly and hepatomegaly.
Mild to severe hemolytic anemia is common.
. Recovery is slow, malaise and fatigue persist for several months.
Diagnosis of babesiosis in man
This disease is one of the highly under-reported diseases, as it can be diagnosed through:
Case history
Babesiosis develops in patients who travel to or live in an endemic area or have blood transfusions within 7 weeks before the onset of symptoms.
Laboratory diagnosis
Different laboratory tests can be used to diagnose babesiosis in man, including:
blood smears stained with Giemsa stain during febrile periods.
The indirect immunofluorescence test
Serologically, testing for antibodies that formed against Babesiosis.
PCR testing in conjunction with the blood film examination.
Complete blood count which shows decreasing the number of platelets and red blood cells.
Prevention and control of babesiosis
The control of this serious zoonotic disease includes control of the disease in animals, including:
Tick control where economically feasible, eradication is the most important preventive measure against babesiosis in cattle and other domestic animals.
Some protection against human infection can be obtained by the use of tick repellents.
Control of ticks through several means such as:
The use of acaricides as organophosphorus compounds by spraying, dipping, dusting, or washing e.g Pyrethroid 1/1000.
Application of such drugs should be repeated according to the type of ticks, 20 days for one host ticks, 10 days for two host ticks, and 3-4 days for three-host ticks.
Precautions should be taken during spraying, such as:
Avoid extreme hot and cold weather. Water the animals before treatment.
Sufficient rest should be given before and after treatment.
Before treatment of animals with acaricides, it must follow the indications given by the producing factory.
The use of Ivermectin against ticks in one or two doses.
Vaccination of cattle against tick using extracts of tick brain.
Treatment of infected animals and avoiding the transmission through needles and surgical
instruments.
Treatment of the diseased man and avoiding blood transfusion from a previously infected man.
Blood donors especially those from endemic areas should be examined for the presence of the parasite.
Immunization by Using whole blood from carriers or vaccines of irradiated babesia.
Chemo Immunization
This occurs in enzootic areas using therapy that does not sterilize the infection completely.
Premunition is a condition of mild, harmless infection in which the parasite is in a state of suppressed activity and its presence in the
animal body stimulates protections against virulent infection with the same species of the parasite that cause babesiosis.
Premunity may break down when the animal is subjected to stress factors, which depress the animal, such as overwork or intercurrent of viral infections and vaccination.
Finally, applying the perfect control measures is the key to the protection of both animals and humans from Babesiosis.
Written by: Dr. Mai Foda
Resources
.
.