Eighty per cent of the general population is infected by at least one adenovirus serotype by the age of 6.¹⁴ This is understandable, as adenovirus infection is common, especially among children due to their lack of humoral immunity.¹ 

However, the virus can also affect adults who live in close quarters, such as barracks and college dorms, and the immunocompromised. Those who are immunocompromised are at risk of rare adenovirus complications such as hemorrhagic cystitis, hepatitis, hemorrhagic colitis, pancreatitis, nephritis, and encephalitis.¹ 

Adenoviruses are among many pathogens and opportunistic infections that can cause serious diseases. The virus can easily spread or localise in those with weak immune systems.¹³ One interesting complication that adenovirus may cause is tubulointerstitial nephritis, which is relatively common among renal and kidney transplant recipients.¹² 

What are adenovirus and kidney complications?

Viruses are organisms the naked eye cannot see; potentially they can be harmful when introduced into the body. There are two types of viruses: DNA (Deoxyribonucleic acid) and RNA( Ribonucleic acid) viruses. Adenovirus is a DNA virus responsible for mild infections involving the upper or lower respiratory tract, gastrointestinal (GI) tract, or conjunctiva.¹ Only 49 of the 100 types of adenovirus affect the human population.² However, the virus is more common among young children and those who lack humoral immunity. 

Kidney complications cover a range of kidney problems arising from various underlying factors, such as pre-existing medical conditions, specific diseases, or even certain medications. 

Kidney diseases, on the other hand, refer to conditions that impact both the structure and functionality of the kidneys.⁴ The kidney is a vital organ, helping to maintain overall health and balance within the body. Therefore, any damage or impairment can result in severe and life-threatening complications. Some common kidney diseases include:

• Chronic Kidney Disease (CKD)
• Acute Kidney Infection (AKI)
• Pyelonephritis 
• Glomerulonephritis 
• Renal Calculi 
• Nephrotic syndrome
• Kidney cancer
• Nephritis

Chronic kidney disease stands out as one of the leading causes of death worldwide. Over the past two decades, there has been a notable increase in deaths caused by chronic kidney disease as a complication of other conditions.⁵ Kidney complications are often seen in patients with cardiovascular diseases such as stroke, diabetes, and hypertension (high blood pressure). 

Understanding adenovirus infection 

Adenovirus infection is a worldwide endemic disease isolated in 1953⁷ from samples of military recruits.⁸ The virus causes fevers that often resolve without treatment in young children, and it is so common that multiple individuals have tested positive for multiple strains by age 10.⁷ It has an incubation period of 2–14 days. Although infections can persist for years, producing low levels of virions.⁸ 

The infection is transmittable and sometimes highly contagious.⁸ Ways it can be transmitted include:⁷

• Droplets: breathing in droplets when an infected person sneezes, coughs, or talks, or when they land on the skin 
• Fomites: transmission as a result of contact with contaminated surfaces and objects 
• Faecal-oral route: occurs due to unhygienic practices when handling food after using the restroom 

Adenovirus infections can either be asymptomatic (having no symptoms) or present with symptoms.⁹ Some common symptoms of an adenovirus infection include: ⁷ 

• Upper or lower respiratory tract infections
• Gastroenteritis, which is common in infants and children 
• Viral conjunctivitis, which is common in both adults and children

Adenovirus and kidney complications

In battle, the president gives instructions to the military head, who deploys soldiers to fight for their citizens, protecting them against the frontlines of war. Similarly, the body works when a threat or foreign material is present; it could be viruses, bacteria, or tumours. 

The brain sends signals to the immune system with directions to protect the body against these threats or materials. In return, the immune system deploys its soldiers—macrophages, dendritic cells, natural killer cells, and a range of B and T cells—to eliminate the threat. 

This line of defence is the same when it comes to adenovirus, and the immunity obtained will suppress recurring infections from happening.⁸ Therefore, if an individual's immunity is compromised due to conditions like HIV/AIDS, autoimmune conditions, organ transplants, cancer, or prolonged steroid use, adenovirus can lead to fatal infections.¹⁰ This is because the virus often either restricts itself to a particular organ or spreads.⁹ 

Hence, immunocompromised individuals are at risk of complications, especially adenovirus types 11, 34, and 35.¹¹ These strains have been closely associated with and have been shown to cause both hemorrhagic cystitis, especially in boys,⁷ and tubulointerstitial nephritis.¹¹ Tubulointerstitial nephritis has arisen in multiple cases over the past 30 years.¹¹ Nephritis usually occurs in children under five years of age; they present with fever, acute kidney failure, gross hematuria and diarrhoea.³ Nephritis and kidney failure are also reported in adults.

Diagnosis and treatment of adenovirus kidney complications 

The following are methods to diagnose kidney complications associated with adenovirus:

• Renal biopsy: To diagnose a kidney complication of adenovirus, a renal biopsy is done to reveal viral infections of smudge cells.¹¹ It is also used to rule out acute rejection of transplanted organs and other pathologies and confirm the diagnosis of adenoviral nephritis¹¹ 
• Urine/Blood/Stool Culture: urine and stool cultures test positive over time for adenovirus cells,¹² however, blood samples are taken weekly¹⁴ 
• Polymerase chain reaction: blood specimens obtained from the patient can be tested through this diagnostic technique. It is effective as it detects adenovirus DNA from the blood, which is predictive of how the virus spreads. It is also promising because the virus can be detected in the blood 2 to 3 weeks before symptoms develop, providing time for prompt intervention

Although it can be diagnosed, no treatment for adenovirus has been approved by the Food and Drug Administration.¹⁴ However, several studies have highlighted the use of cidofovir, immunotherapy, ribavirin, and brincidofovir. 

It is important to note that cidofovir can cause nephrotoxicity⁶ and regular renal checkups are required, but brincidofovir is not nephrotoxic and has a higher antiviral drug potency. This treatment is continued until two rounds of PCR tests produce negative results for adenovirus.¹⁴ 

Once this is established, immunosuppression is initiated.¹⁴ A study suggests the prognosis to be good; out of eleven patients who participated, all had allograft failure, while the seven that were available made full recovery.¹⁵

Preventive strategies for adenovirus kidney complications

The following are preventive strategies to take concerning adenovirus kidney complications: 

• Personal hygiene: adenovirus is globally distributed and is more prevalent in regions with limited sanitation.⁴ Therefore, regular cleaning of households and surfaces with hypochlorite or bleach can help prevent the spread of adenovirus infection. It is important not to use lipid disinfectants, as they are ineffective against adenovirus. This is due to its resistance to the lipid disinfectant.⁷ In addition, it is recommended to use alcohol-based sanitisers when out of reach⁷ of children, and take up the practice of routine handwashing
• Vaccination: There is a vaccine for adenovirus; it is an oral, live, non-attenuated vaccine. The vaccine protects individuals from adenovirus strains 4 and 7. This is because these strains can cause severe respiratory complications. Although it is readily available, it is currently limited to military personnel, who may have this administered from the ages of 17 to 50¹⁵

In addition to these measures, immunocompromised individuals can take further precautions by 

• Isolating themselves from infected individuals  
• Avoiding crowded places, and using personal protective equipment such as facial masks when necessary
• Adequate nutrition
• Using vitamin supplements as prescribed by their healthcare provider 

Summary

Adenovirus infection is highly contagious, typically causing mild infections; however, in individuals with compromised immunity, it can be fatal, causing complications that affect the respiratory, urinary, digestive, and ocular systems. 

Furthermore, case studies have shown that adenovirus can cause adenoviral nephritis. Individuals usually present with fever, hematuria, acute kidney failure and diarrhoea. Although it can be diagnosed, treatment is still being researched for drug potency. 

It is important to take preventive measures such as personal hygiene, nutrition, use of personal protective equipment and isolation for the immunocompromised.