**Core Concept**
The Integrated Disease Surveillance Programme (IDSP) is a national programme in India aimed at strengthening the disease surveillance system to detect and respond to public health events. IDSP focuses on surveillance of diseases that are of significant public health importance.

**Why the Correct Answer is Right**
IDSP primarily monitors diseases that are of high public health importance, such as malaria, dengue, chikungunya, and other vector-borne diseases. These diseases are typically under regular surveillance due to their potential to cause outbreaks and severe morbidity. However, some diseases are not prioritized for regular surveillance under IDSP, as they are either notifiable but not of significant public health concern or are notifiable but can be managed by other surveillance systems.

**Why Each Wrong Option is Incorrect**
**Option A:** Malaria - This disease is under regular surveillance under IDSP due to its significant public health importance and potential for outbreaks.
**Option B:** Tuberculosis - This disease is also under regular surveillance, although the primary focus is on contact tracing and treatment under the Revised National Tuberculosis Control Programme (RNTCP).
**Option C:** Rabies - This disease is under regular surveillance, particularly for animal bite cases, as it is a significant public health concern in India.

**Clinical Pearl / High-Yield Fact**
IDSP primarily focuses on diseases that can be prevented or controlled through public health measures, such as vaccination, vector control, and sanitation. Regular surveillance of these diseases helps in early detection of outbreaks and timely implementation of control measures.

**Correct Answer: D.**