[Visceral leishmaniasis (kala-azar) as an opportunistic infection in immunosuppressed patients]

Immunodeficiency disorders are conditions in which the immune system's ability to fight infectious disease and cancer is compromised or entirely absent. The immune system comprises a complex network of cells, tissues, and organs that work together to protect the body from potentially harmful invaders. When this system is deficient or not functioning properly, it leaves the body susceptible to infections, diseases, or other complications.
There are three main causes of immunodeficiency disorders...

Tuberculosis, often called TB, is a contagious illness primarily caused by Mycobacterium tuberculosis. It mainly affects the lung parenchyma but can also impact other body parts.
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...

Leishmaniasis is a protozoal disease caused by species of the genus Leishmania and transmitted through the bite of infected female sandflies. The parasite exists in two principal morphological forms during its life cycle. A sandfly acquires intracellular amastigotes from an infected reservoir host, such as a dog. Within the sandfly, these forms differentiate into motile, flagellated promastigotes. During a subsequent blood meal, promastigotes are injected into the human host, where they...

Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,...

Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective...

Leishmaniasis is a widespread parasitic disease caused by several Leishmania species. It affects millions of people each year and remains a major public health problem in endemic regions. First-line treatment relies on pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate. Even so, how these drugs work has not been fully clear, especially their interaction with parasite-specific biochemical pathways. One key target is trypanothione reductase (TR), an enzyme that...