Pyelonephritis is a kidney infection and one of the potential serious complications of cystitis

Pyelonephritis is a kidney infection and one of the potential serious complications of cystitis, although its symptoms and care differ. Dr Camara-Sampil talks to us about acute simple pyelonephritis in women.

Urinary tract infection and pyelonephritis

Urinary tract infections, including cystitis, are very common and are the most frequent bacterial community infection in women. They affect the urinary tract which is divided into two areas:

• the lower urinary tract (bladder and urethra in women, causing cystitis)
• the upper urinary tract (kidney, causing pyelonephritis)

Pyelonephritis is a bacterial urinary tract infection that affects the kidney and, like cystitis, is usually caused by E. coli bacteria. Equally, the same factors that are propitious for urinary tract infections, such as cystitis, also favor pyelonephritis.

What are the symptoms suggestive of pyelonephritis and cystitis?

Focus on the symptoms of pyelonephritis

Pyelonephritis is an infection of the upper urinary tract.

The infection is preceded by symptoms similar to those of cystitis in almost all cases. Pyelonephritis is sometimes caused by poorly treated or untreated cystitis (especially in the case of asymptomatic cystitis). Such clinical scenarios involve asymptomatic cystitis or poorly treated cystitis for different reasons (i.e. going to the doctor too late, cystitis treated with an antibiotic resistant to the bacteria responsible for the infection, etc.).

The patient will generally feel unwell and experience pain in one side of her back (either left or right), have a temperature above 38°C, and chills, which are indicative of pyelonephritis, a type of urinary tract infection. Symptoms can include nausea, vomiting, and abdominal distension, which are also common in pyelonephritis cases. However, it should be noted that pyelonephritis, a more severe form of urinary tract infection, may not be accompanied by all of these symptoms and, equally, all of the above symptoms do not always indicate pyelonephritis.

The traditional symptoms of cystitis, a lower urinary tract infection, can sometimes be observed in pyelonephritis as well, as both conditions are caused by bacterial infections.

The different types of pyelonephritis include:

• simple acute pyelonephritis without signs of severity
• acute pyelonephritis with a risk of complications without signs of severity
• severe acute pyelonephritis

The symptoms described above are the same for the three types of pyelonephritis, a severe form of urinary tract infection. However, the treatment differs for each type of pyelonephritis. The doctor will determine the specific type of pyelonephritis and provide the appropriate care accordingly. In some cases, the doctor may call upon a specialist, depending on the severity of the situation and the medical history of the patient. Note: Each type of pyelonephritis is unique to the individual patient, and not all aspects of the condition will be discussed in this section

Depending on the medical history of the patient, special management may be required for pyelonephritis. For example, if the patient has a malformation of the urinary tract, has a urological history, is pregnant, or has specific risk factors, the treatment approach may need to be tailored accordingly.

Focus on the diagnosis of simple acute pyelonephritis

When a patient presents with symptoms of pyelonephritis (chills, temperature over 38°C, back pain, possible nausea, and vomiting), the doctor first carries out a medical examination (history) and a clinical examination to diagnose the condition accurately. This will help the doctor determine the type of pyelonephritis, a severe form of urinary tract infection, and provide the appropriate care. If simple acute pyelonephritis is suspected, the doctor will perform other tests, including a urine test strip followed by a cytology and urinary examination. The test is very similar to that for cystitis, a lower urinary tract infection, but in cases of suspected pyelonephritis, the urine sample is sent to the medical laboratory to identify the bacteria causing the infection.

The laboratory will then conduct further tests to determine the susceptibility of the isolated bacteria to different antibiotics, assessing any potential antibiotic resistance. This information is crucial in guiding the choice of antibiotics for effective treatment.

Although not performed in every case, additional tests such as blood tests or ultrasound of the urinary tract may be required, especially in situations where the pyelonephritis is very painful, there are recurrences, or the progress following treatment is unsatisfactory.

Initial treatment of simple acute pyelonephritis without signs of severity

Pyelonephritis is treated with antibiotics for 7-14 days (depending on the class of antibiotics recommended by the doctor).

The antibiotics used for cystitis (single dose fosfomycin and nitrofurantoin) cannot be used to treat pyelonephritis. These antibiotics only exert a very weak action on the kidneys meaning that the response will be very limited.

As a general rule, it is better to use antibiotics from the fluoroquinolone class (ciprofloxacin, levofloxacin, ofloxacin) or cephalosporins (ceftriaxone).

Medical follow-up of simple acute pyelonephritis without signs of severity after the initial treatment

Within 48-72 hours after taking the initial antibiotic for cystitis, a lower urinary tract infection, the doctor reassesses the clinical status of the patient, then readjusts the antibiotic, if necessary, based on the response to the treatment. Antimicrobial susceptibility testing may then be carried out if necessary, to determine the most effective antibiotic for treating the specific bacteria causing the cystitis infection.

If the patient progresses favorably with a reduction or absence of the initial cystitis symptoms, another urine test (called a control test) is required to ensure that the infection is effectively under control. When symptoms persist or worsen, the doctor will perform additional tests, including a urine test, cytology examination, and scan of the urinary tract. The purpose of additional testing is to provide the doctor with more information, allowing them to adjust the initial care for cystitis.

Conclusion

Pyelonephritis is a urinary tract infection that can be extremely serious. It requires extensive medical monitoring to avoid irreversible complications. It is one of the complications of cystitis. Symptoms include (but are not limited to): chills, temperature over 38°C, right or left back pain, nausea, vomiting.

#Story time

Adele, aged 27, is a waitress in a bar. She never really has the time to take a break at lunchtime and to hydrate herself enough. She is well aware about urinary tract infections as she has previously suffered from them. She knows that if she doesn’t drink enough water or if she drinks alcohol, she faces a risk of infection.

One Wednesday evening, during after-work drinks organised by an insurance company she is well aware that she is putting herself at risk. These employees are regulars and she is used to sharing a shot or two with them. So, as a preventive measure, when she gets home, she takes her probiotics, and then the next day she takes a dose of cranberry juice. However, she experiences discomfort in the genital area when going to the toilet. She ups her hydration and this seems to be working.

But on Friday, she wakes up and doesn’t feel at all well. The burning sensation when she goes to the toilet is even greater, and she feels nauseous. She decides to take her emergency bag of antibiotics, which she keeps in case of cystitis, because tonight there's no way she’s going to miss work, the bar will be full and they're already short-staffed.

When she wakes up on Saturday, unfortunately, things have got worse. Her back hurts, she is tired, going to the toilet is even more painful and she has to go increasingly frequently, and Adele has noticed blood in her urine. She is very hot and realises that she has a temperature. She then decides to go to the on-call service at the medical clinic.

After examining her, the doctor diagnosed pyelonephritis, a kidney infection. He explained that this sometimes happens after a poorly treated cystitis, as the bacteria can travel from the bladder to the kidneys. A urine test performed in the surgery confirmed the diagnosis. Also, when he touched her lower back, on the left-hand side, the pain was intense. He explained that the combination of urinary symptoms and temperature indicates that the entire organ is affected. The bladder is actually considered as a hollow organ which, when infected, does not cause you to have a high temperature. The tests performed on site were sent to the laboratory for urinalysis and antimicrobial susceptibility testing. While waiting for the results, the doctor prescribed an antibiotic treatment which she started to take. After resting for three days, Adèle returned to work in better shape. She told her friend and colleague Justine about what had happened to her. Justine also suffered from pyelonephritis one year ago but she wasn’t as lucky and had to spend three days in hospital.

ADÈLE REALISES THAT SHE HAS BEEN LUCKY.

What an adventure!