What are the Clinical Manifestations of Kala-azar?

Kala-azar is primarily a disease that affects middle-aged and elderly individuals. It is curable in the early stages of onset, but in the later stages, patients may develop malnutrition and anemia, leading to symptoms such as mental lethargy, palpitations, and pale complexion. In the early stages, kala-azar patients typically manifest with fever, decreased appetite, swollen lymph nodes, and nosebleeds. Therefore, it is crucial to seek immediate medical attention upon noticing these clinical symptoms.

1. Fever: Typical cases present with a biphasic fever pattern, often characterized by long-term irregular fever accompanied by symptoms such as chills, night sweats, decreased appetite, fatigue, and dizziness. Although the fever may persist for a prolonged period, the systemic toxic symptoms are generally not pronounced, and some patients may still be able to maintain their work and daily activities.

2. Splenic, hepatic, and lymphadenopathy: The spleen gradually enlarges, becoming palpable within two to three weeks and reaching its maximum size within half a year. If there is splenic embolism or bleeding, it may cause splenic pain and tenderness. The liver may also enlarge mildly to moderately, and occasionally, jaundice and ascites may occur. Lymph nodes may also become slightly to moderately enlarged.

3. Anemia and malnutrition: These symptoms may appear in the later stages of the disease, manifesting as mental lethargy, palpitations, shortness of breath, pale complexion, edema, and rough skin. The skin color may darken, leading to the name "kala-azar".

4. Thrombocytopenia: This condition can lead to symptoms such as nosebleeds, gum bleeds, and skin petechiae. Relief and exacerbation of symptoms may alternate during the course of the disease. Typically, after one month of onset, patients enter a remission phase with a decrease in body temperature, alleviation of symptoms, and a reduction in spleen size. However, the symptoms may recur after several weeks, and the longer the disease duration, the shorter the remission period, ultimately leading to persistent symptoms without relief.