Introduction
Epidemiology
Infectivity-Low
|
Pathogenicity-Low
|
Virulence-Low |
Toxoplasma gondii a parasite that can cause the disease Toxoplasmosis. It can be spread to humans through 4 different types of transmission:
1. Zoonotic transmission, primarily by oocysts found in cat feces.
2. Congenital transmission.
3. Foodborne transmission.
4. Through blood transfusion or organ donation, although these instances are the most rare. [1]
Due to these modes of transmission, the individuals most susceptible to contracting Toxoplasmosis are those with compromised immune systems, women trying to become or are already pregnant, fetuses, and others with high exposure to the parasite [1] [3].
The infectivity, pathogenicity, and virulence of this disease are all quite low. The only exception is that the level of virulence can be increased for fetuses and those with weakened immune systems.
Most people who have become infected with Toxoplasma gondii are asymptomatic. Adults who are symptomatic tend to have flu-like symptoms consisting of fever, headache, and nausea [1] [3]. For fetuses who contract the disease, symptoms and complications are much more severe with increased risk of neurological defects. In humans, the incubation period of this disease is between 5 and 23 days, for cats it is only about 5 to 6 days [8].
Currently, 11% of individuals in the U.S. ages six and up are infected with Toxoplasma gondii, while some populations of the world may have up to 95% of individuals infected [1]. From this it has been gathered that populations inhabiting climates with higher humidity, heat, and lower altitude are also more susceptible to becoming diseased with Toxoplasmosis [1].
Toxoplasmosis is one of the main sub-clinical or 'hidden' diseases, making it easier for people to have the infection or disease without knowing it. Luckily, the case fatality rate is very low with few individuals dying from complications.
1. Zoonotic transmission, primarily by oocysts found in cat feces.
2. Congenital transmission.
3. Foodborne transmission.
4. Through blood transfusion or organ donation, although these instances are the most rare. [1]
Due to these modes of transmission, the individuals most susceptible to contracting Toxoplasmosis are those with compromised immune systems, women trying to become or are already pregnant, fetuses, and others with high exposure to the parasite [1] [3].
The infectivity, pathogenicity, and virulence of this disease are all quite low. The only exception is that the level of virulence can be increased for fetuses and those with weakened immune systems.
Most people who have become infected with Toxoplasma gondii are asymptomatic. Adults who are symptomatic tend to have flu-like symptoms consisting of fever, headache, and nausea [1] [3]. For fetuses who contract the disease, symptoms and complications are much more severe with increased risk of neurological defects. In humans, the incubation period of this disease is between 5 and 23 days, for cats it is only about 5 to 6 days [8].
Currently, 11% of individuals in the U.S. ages six and up are infected with Toxoplasma gondii, while some populations of the world may have up to 95% of individuals infected [1]. From this it has been gathered that populations inhabiting climates with higher humidity, heat, and lower altitude are also more susceptible to becoming diseased with Toxoplasmosis [1].
Toxoplasmosis is one of the main sub-clinical or 'hidden' diseases, making it easier for people to have the infection or disease without knowing it. Luckily, the case fatality rate is very low with few individuals dying from complications.
Figure 1 Map of toxoplasmosis prevalence across the globe (estimates). Higher prevalence is seen in area of high humidity and larger domesticated cat populations (such as Brazil / South America). In the U.S., it is estimated that ~11% of the population is infected with the T. gondii parasite [1] .