## **Core Concept**
Toxoplasmosis is an infectious disease caused by *Toxoplasma gondii*, a protozoan parasite. It can affect various hosts, including humans and cats, and can be transmitted through different routes, including oocysts in cat feces, contaminated food and water, organ transplantation, and from mother to fetus.

## **Why the Correct Answer is Right**
The correct statement regarding toxoplasmosis that stands out as not true relates to the risk of transmission to the fetus based on the timing of maternal infection. Generally, the risk of transmission increases with gestational age, but the severity of the disease in the fetus is inversely related to the gestational age at the time of infection. The statement about maternal infection acquired after 6 months having a high risk of transmission needs scrutiny because the highest risk of transmission occurs later in pregnancy, but the risk of severe disease in the fetus is higher if infection occurs early in pregnancy.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Oocysts in freshly passed cat's feces are not immediately infective. They require 1-5 days to sporulate and become infective. Therefore, this statement is incorrect, making it a potential correct answer to the question.
- **Option B:** Toxoplasmosis can indeed spread by organ transplantation, particularly from a seropositive donor to a seronegative recipient. This statement is true.
- **Option C:** The statement that maternal infection acquired after 6 months has a high risk of transmission is misleading. The risk of transmission to the fetus is higher in the third trimester (after 6 months), but the disease is often less severe. This statement might seem true but can be misleading without context; however, the critical point of contention is the severity and risk correlation with gestational age.
- **Option D:** Arthralgia, sore throat, and abdominal pain are among the common manifestations of toxoplasmosis, particularly in immunocompetent individuals. This statement is true.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that while the risk of transmitting *T. gondii* to the fetus increases with gestational age, the severity of congenital toxoplasmosis is greater when the infection is acquired early in pregnancy. This makes prenatal screening crucial for identifying at-risk pregnancies.

## **Correct Answer: C.** Maternal infection acquired after 6 months has high risk of transmission.