Global emergence of the chikungunya epidemic: A narrative review of the virus-kidney relationship in Pakistan and beyond.

Chikungunya, a vector-borne viral disease, has become a critical global health issue due to its capacity for widespread outbreaks, especially in tropical and subtropical regions, and its recent global expansion. The resurgence of Chikungunya virus (CHIKV) in Karachi, Pakistan, has amplified public health challenges, driven by factors such as urbanization, climate change, and socioeconomic vulnerabilities, including limited healthcare infrastructure. Clinically, the disease primarily manifests with fever, rash, and debilitating joint pain, which often leads to prolonged discomfort and decreased quality of life. However, emerging evidence points to atypical and severe complications affecting the neurological, cardiac, and kidney systems, increasing the risk of morbidity and mortality. Kidney involvement in Chikungunya is of particular concern, with acute kidney injury being identified as a critical complication. Timely diagnosis of the infection and early identification of individuals at heightened risk of progressing to severe kidney dysfunction is crucial to improving patient outcomes. Such individuals often include those with pre-existing kidney conditions or other underlying comorbidities, making them more susceptible to complications. This narrative review aims to synthesize and expand upon the current understanding of the mechanisms underlying CHIKV-induced kidney injury. These mechanisms encompass direct viral invasion of kidney tissue, immune-mediated inflammatory responses that inadvertently damage the kidneys, and the aggravation of pre-existing kidney pathologies. Furthermore, the complex interplay between the virus and the host's immune system may exacerbate kidney complications, highlighting the multifaceted nature of CHIKV pathophysiology.