Incidence, Clinical Features, and Outcomes of Acute Kidney Injury in Adults and Children Admitted with Dengue Infection in Jamaica

This single-center retrospective study in Jamaica found that acute kidney injury affects 25.8% of adults and children hospitalized with dengue infection, with higher incidence in adults and associations linked to older age, male sex, elevated bilirubin, and neutrophil-to-lymphocyte ratio, highlighting the need for improved early recognition and vector control.

The Gist

Imagine the human body as a bustling city. The kidneys are the city's water treatment plants, constantly filtering out waste and keeping the water (blood) clean. Dengue fever is like a sudden, chaotic storm that hits this city. While most people recover from the storm with just a few days of rain and wind, for some, the storm is so severe that it damages the water treatment plants, causing them to shut down. This shutdown is called Acute Kidney Injury (AKI).

This research paper is like a detective report from Jamaica, where scientists investigated exactly how often this "water treatment plant failure" happens when people get hit by the Dengue storm. They looked at both adults and children who were admitted to a major teaching hospital between 2023 and 2024.

Here is the story of their findings, broken down into simple concepts:

1. The Storm Was Stronger Than Expected

The researchers expected that maybe 1 in 12 people (about 8%) with Dengue would get kidney trouble, based on what other countries have seen. However, in Jamaica, the storm was much rougher.

• The Finding: Nearly 1 in 4 people (25.8%) admitted with Dengue developed kidney injury.
• The Analogy: Imagine a traffic jam. If you expect 8 cars to get stuck, but instead 25 cars are gridlocked, you know something is very different about this particular intersection. The kidney injury rate in Jamaica was significantly higher than the global average.

2. Who Got Hit Hardest? (The Victims)

The study looked at who was most likely to have their "water treatment plant" fail.

• Age: Older adults were more likely to get kidney injury than children. Think of it like an older house; the plumbing might be a bit more fragile and less able to handle a sudden flood compared to a newer house.
• Gender: Surprisingly, men were more likely to get kidney injury than women.
  • The Science Metaphor: Scientists think this might be because male hormones (like testosterone) can sometimes make the body's inflammatory response to the virus more aggressive, like turning up the volume on a fire alarm until it causes more damage. Female hormones might act like a fire extinguisher, offering a bit of protection.
• The "Warning Signs": People who had the virus for a longer time before coming to the hospital were at higher risk. It's like waiting too long to call a plumber when a pipe is leaking; by the time help arrives, the damage is already done.

3. The Clues in the Blood (The Detectives)

The doctors looked at blood tests to find clues that predicted who would get kidney trouble. They found two main "smoke signals":

• The NLR (Neutrophil-Lymphocyte Ratio): This is a ratio of two types of white blood cells. Imagine your immune system is an army. When the Dengue virus attacks, the "soldiers" (neutrophils) rush out, but the "strategists" (lymphocytes) might get tired or outnumbered. A high NLR means the army is in a chaotic, high-stress battle. The study found that a high NLR was a strong predictor of kidney damage.
• Bilirubin: This is a yellow substance in the blood that usually indicates the liver is struggling. High bilirubin meant the liver was also under attack, which often went hand-in-hand with the kidneys failing. It's like a building fire where the smoke (liver damage) and the heat (kidney damage) are hitting the same structure at the same time.

4. The Difference Between Adults and Kids

The study noticed that the "rules of the game" were slightly different for adults and children:

• In Adults: Higher potassium levels in the blood were actually linked to a lower risk of kidney injury. This was a bit of a mystery, but the researchers guessed that adults with diabetes might have been admitted to the hospital earlier and treated more carefully (like getting a head start on the repairs), which accidentally protected their kidneys.
• In Children: Higher potassium levels were linked to a higher risk. For kids, high potassium might be a sign that their kidneys were already struggling to filter waste, much like a clogged drain causing water to back up.

5. The Aftermath (Outcomes)

• Time in Hospital: People with kidney injury stayed in the hospital longer (about 6 days vs. 4 days). It takes longer to fix a broken water treatment plant than to just treat a fever.
• Deaths: Fortunately, very few people died (only 3 out of 167), and no one needed a dialysis machine (an artificial kidney). This is likely because the patients were generally young and healthy, and the kidney damage wasn't usually severe enough to be fatal.

The Big Takeaway

This paper tells us that in Jamaica, Dengue is a bigger threat to the kidneys than we previously thought. It's not just a fever; it's a systemic storm that can shut down vital organs.

The Lesson:
The researchers suggest that we need better public health policies.

1. Vector Control: We need to stop the mosquitoes (the storm clouds) from breeding in the first place.
2. Early Recognition: People need to know the signs of Dengue early. If you feel sick, don't wait. The longer you wait to get help, the more likely your "water treatment plant" is to get damaged.

In short: Dengue is a serious storm. In Jamaica, it's knocking over the kidneys more often than expected. By spotting the storm early and treating it quickly, we can save the water treatment plants and keep the city running smoothly.

Technical Summary

1. Problem Statement

Dengue fever is a rising global health burden, particularly in the Americas and the Caribbean, with 2024 recorded as the worst year for incidence and mortality. While dengue is known to cause multi-organ failure, including Acute Kidney Injury (AKI), there is a significant paucity of data regarding the epidemiology, risk factors, and outcomes of dengue-associated AKI in the Caribbean region. Existing global meta-analyses suggest a pooled AKI prevalence of 8%, but these studies are heavily skewed toward East Asia and West Africa. Furthermore, data distinguishing between adult and pediatric populations in low-to-middle-income countries (LMICs) is limited. This study addresses the gap in understanding the specific burden and predictors of AKI in a Jamaican tertiary care setting.

2. Methodology

• Study Design: A single-center, retrospective cohort study conducted at the University Hospital of the West Indies (UHWI), Mona, Jamaica.
• Study Period: January 2023 to November 2024.
• Population:
  • Inclusion Criteria: Patients aged ≥1 year admitted for ≥8 hours with laboratory-confirmed dengue (positive NS1 antigen or IgM/IgG serology) and at least two creatinine measurements (one during admission).
  • Exclusion Criteria: Age <1 year, pre-existing End-Stage Renal Disease (ESRD), or suspected dengue without confirmatory testing.
  • Final Cohort: 167 patients (103 adults, 64 children).
• Definitions:
  • AKI: Defined using Kidney Disease Improving Global Outcomes (KDIGO) criteria (increase in serum creatinine ≥0.3 mg/dL within 48h, or ≥1.5x baseline within 7 days, or urine volume <0.5 mL/kg/h for 6h).
  • Stratification: Analysis was stratified by age group: Adults (≥16 years) and Pediatrics (<16 years).
• Data Collection: Retrospective chart review of demographic, clinical, and laboratory data (including Neutrophil-Lymphocyte Ratio [NLR], bilirubin, electrolytes).
• Statistical Analysis: Descriptive statistics, t-tests/Mann-Whitney U tests for comparisons, and multivariable logistic regression to identify independent associations with AKI, adjusting for age and sex.

3. Key Contributions

• Regional Epidemiology: This is the first study to estimate AKI incidence specifically in both adults and children admitted with dengue in the Anglophone Caribbean.
• Pediatric-Adult Stratification: It provides a rare comparative analysis of AKI risk factors between pediatric and adult populations within the same dengue outbreak context.
• Biomarker Identification: It highlights the utility of admission Neutrophil-Lymphocyte Ratio (NLR) and bilirubin as early predictors of renal injury in dengue.
• Policy Implications: The findings suggest a need for targeted public health interventions focusing on early symptom recognition to mitigate renal complications.

4. Key Results

• Incidence:
  • Overall AKI incidence was 25.8% (43/167 patients), significantly higher than the global pooled estimate of 8%.
  • Adults: 30.2% incidence.
  • Children: 18.0% incidence.
  • Severity: The majority (65.1%) were KDIGO Stage 1; 18.6% Stage 2; 16.3% Stage 3.
• Outcomes:
  • Mortality: 3 in-hospital deaths (1.8%); no patients required renal replacement therapy (dialysis).
  • Length of Stay (LOS): Patients with AKI had a significantly longer median LOS (6 days) compared to those without AKI (4 days; p < 0.001).
• Risk Factors (Multivariable Analysis):
  • Overall Cohort: Independent predictors of AKI included older age (OR 1.02 per year), higher admission bilirubin (OR 1.02), and higher admission NLR (OR 1.09). Male sex showed a trend toward significance (p=0.064).
  • Adults: Male sex (aOR 2.68), higher bilirubin, and longer symptom duration were associated with AKI. Interestingly, admission potassium and diabetes showed an inverse association (protective effect), though the latter may be due to selection bias (earlier admission for diabetics).
  • Children: Higher admission NLR (aOR 1.40) and admission potassium (aOR 3.00) were associated with AKI.
• Demographics: The mean age was 26.1 years; 61.7% were male. No significant sex difference was found in overall AKI rates (30.1% males vs. 18.8% females, p=0.108).

5. Significance and Conclusion

The study reveals that AKI is a frequent and under-recognized complication of dengue in Jamaica, occurring in over a quarter of hospitalized patients. The incidence is notably higher than global averages, potentially reflecting delays in healthcare access, specific viral virulence, or the use of KDIGO criteria which captures milder cases.

• Clinical Implications: The strong association between NLR (a cheap, readily available marker of inflammation) and AKI suggests it could serve as an early prognostic tool in resource-limited settings to identify patients at risk for renal deterioration.
• Public Health: The correlation between longer symptom duration and AKI underscores the critical need for public health policies that improve early symptom recognition and reduce delays in seeking care.
• Limitations: The study is limited by its retrospective nature, single-center design, lack of urine output data (potentially underestimating AKI in children), and the inability to capture disease severity scores.

Conclusion: Dengue-associated AKI in the Caribbean is a significant clinical burden leading to prolonged hospitalization. Early identification of high-risk patients using inflammatory markers like NLR and bilirubin, alongside aggressive public health education on early presentation, is essential to improve renal outcomes in this region.