Volume-11, Issue-10, October 2025

Abstract

This report describes the case of a 64-year-old female with morbid obesity (BMI 70) diagnosed with a partially obstructing adenocarcinoma of the transverse colon in August 2023 following episode of PR (per rectal) bleeding. The patient's high BMI makes her a significant anaesthetic risk, requiring preoperative weight loss through a low-carbohydrate, highprotein (LCHP) diet. She achieved a remarkable weight loss before undergoing a successful robotic-assisted right hemicolectomy in February 2024. A repeat CT scan performed prior to surgery showed no evidence of metastatic disease despite the delayed treatment. This case emphasises the importance of tailored, multidisciplinary care in managing colorectal cancer in obese patients with comorbidities and highlights the role of dietary interventions in weight management and cancer care.

Keywords: Colorectal cancer, Low-Carbohydrate High-Protein (LCHP) Diet, Peri-operative Weight Loss, Obesity.

References

References not available

Abstract

Naegleria fowleri, the so-called "brain-eating amoeba," is a thermophilic free-living amoeboflagellate protozoan that causes Primary Amoebic Meningoencephalitis (PAM) — one of the deadliest human infectious diseases ever documented, with a case fatality rate exceeding 97%. Despite six decades of scientific investigation since its first characterisation in 1965, PAM remains therapeutically refractory, with fewer than ten globally documented survivors. This comprehensive review synthesises current knowledge across all dimensions of N. fowleri biology and clinical science: its taxonomy within the phylum Percolozoa; the morphology and functional roles of its trophozoite, flagellate, and cyst forms; its thermophilic ecology and widening environmental distribution; global and Indian epidemiology, including the unprecedented 2024–2025 Kerala outbreak; the molecular mechanisms of olfactory nerve invasion and central nervous system destruction; an expanded catalogue of virulence factors (naegleriapores, Nfa1, cysteine proteases, matrix metalloproteinases); the host innate and adaptive immune response; clinical staging from prodrome to coma; and diagnostic strategies encompassing cerebrospinal fluid (CSF) microscopy, culture, polymerase chain reaction (PCR), and neuroimaging. Therapeutic coverage includes the pharmacological profiles of amphotericin B and miltefosine, CDC-recommended combination regimens, the fundamental challenge of blood–brain barrier penetration, and an appraisal of emerging drug candidates (auranofin, nitroxoline, berberine, and nanotechnology-based delivery systems). The review also evaluates prevention strategies at individual, institutional, and governmental levels, including guidelines from the CDC, WHO, and ICMR. The article concludes with a critical assessment of future research priorities: point-of-care diagnostics, climate-integrated surveillance, paediatric pharmacokinetics, and vaccine development. Given the organism's escalating global epidemiological footprint against a backdrop of climate-driven freshwater warming, a deepened scientific and public health engagement with N. fowleri is both timely and imperative.

Keywords: Naegleria fowleri, Primary Amoebic Meningoencephalitis (PAM), brain-eating amoeba, miltefosine, amphotericin B, thermophilic protozoa, Kerala outbreak, blood–brain barrier, free-living amoeba

References

Naegleria fowleri exemplifies a biological paradox that challenges modern medicine: a microscopically small, environmentally ubiquitous organism capable of defeating the immunological and pharmacological arsenal of the 21st century with near-perfect consistency. Six decades of sustained scientific investigation have illuminated its biology, ecology, pathogenesis, and therapeutic vulnerabilities in remarkable detail, yet the case fatality rate remains obstinately above 97%, and the global case burden is growing rather than declining.

This review has synthesised current knowledge across all dimensions of N. fowleri science: its phylogenetically ancient taxonomy within Percolozoa; the morphological elegance of its three developmental forms; the thermophilic ecology that makes rising global temperatures an increasingly powerful epidemiological driver; its expanding geographic distribution documented by cases in previously non-endemic northern US states and by the unprecedented 2024–2025 Kerala outbreak; the molecular choreography of its nasal-to-brain invasion pathway; and its sophisticated virulence arsenal — naegleriapores, Nfa1-mediated trogocytosis, cathepsin B-driven immune evasion, and GPCR-mediated neurotropic chemotaxis.

On the diagnostic and therapeutic fronts, real-time PCR has transformed detection speed and sensitivity, miltefosine has introduced the first genuinely new pharmacological class into PAM management in decades, and combination regimen optimisation has produced a small but statistically significant cohort of survivors. Yet fundamental barriers remain: a diagnostic window compressed to hours by explosive disease progression; BBB pharmacokinetics that prevent reliable CNS drug delivery; an absence of validated treatment response biomarkers; and global inequity in access to miltefosine and molecular diagnostics.

Two overarching messages emerge from this review. First, PAM is a preventable disease — the singular, well-defined transmission route means that informed public behaviour, rigorous water quality management, and accessible safe-water technologies can prevent virtually all cases. The gap between this preventability and the ongoing case toll is a remediable failure of public awareness, clinical education, and institutional infrastructure. Second, N. fowleri is an organism whose epidemiological trajectory is unfavourable in a warming world. The investment required to close the diagnostic, therapeutic, and preventive gaps — in research funding, regulatory facilitation, international data sharing, and health system capacity building — is modest relative to the human tragedy of every preventable PAM death. The scientific and public health communities must act with the urgency that a 97% fatality rate demands.