Title of Case(s)

A case of severe invasive bacterial infection in a six-month-old infant

Background

The prevalence of community-acquired methicillin-resistant Staphylococcus Aureus (CA-MRSA) infections among children in Italy has scarcely been reported. We describe the case of an infant with sepsis and osteomyelitis by Panton-Valentine leukocidin (PVL⁺), CA-MRSA ST-121.

Case Presentation Summary

A six-months-old infant was admitted to our hospital for fever, rash and wheezing. Inhaled bronchodilator and steroid were started with improving of symptoms. One week after hospitalization, the patient’s clinical conditions worsened presenting clinical signs suggestive for sepsis. Laboratory tests showed an elevation of white blood cell count 3830/mmc and C-reactive protein (CRP) 65 mg/dl (normal value < 0.5 mg/dl). The blood culture resulted positive for PVL⁺ MRSA. A bronchoalveolar lavage was also performed and its culture resulted positive for PVL⁺ MRSA ST-121, Streptococcus Pneumonia and Hemophilus Influenzae. He was admitted to the paediatric intensive care unit where intravenous antibiotic treatment with Cefotaxime was introduced. A total body computed tomography scan showed osteomyelitis of left humerus, right femur and of the left shoulder with multiple abscesses, and pulmonary septic embolisms. These findings were also confirmed by a total body magnetic resonance (MRI). The antibiotic therapy was replaced with Ceftaroline, Daptomycin and Clindamycin for 3 weeks and then with Ceftaroline for a total of 6 weeks. A surgical drainage of the extended abscess of the left shoulder was performed and also the culture of the purulent exudate resulted positive for PVL⁺ MRSA. There was a normalization of the CRP values and an improvement of clinical conditions. He was discharged with oral Linezolid for one month. The total body MRI performed after 6 month showed radiological resolution.

Key Learning Points

Infections by PVL+ MRSA are rare but, if not recognized, can progress to severe and potentially fatal outcomes. Further epidemiological studies are needed to know the incidence and spread of PVL+ MRSA.

Title of Case(s)

A rare complication of inappropriate timing of culture

Background

Renal abscesses are an unlikely but potentially severe form of kidney infection in children. Symptoms can be non-specific and the identification by abdominal ultrasound (AUS) may be difficult at an initial phase, often resulting in a delayed diagnosis.

Case Presentation Summary

A 3-year-old girl was admitted for fever of unknown origin since 10 days. Ceftazidime was started based on neutrophilic leukocytosis, raised CRP(9.66 mg/dl) and a suspected pneumonia on the chest X-ray. Urine dipstick was positive, but urine culture, collected after antibiotic administration, resulted negative. AUS showed no urinary tract abnormalities. Fever disappeared on day 3 and the patient was discharged.

A week later she had recrudescence of fever. Urine dipstick was positive and AUS was negative.

A therapy with cefixime was started. Urine culture, collected before treatment, documented a MDR E. Coli. Therapy was not changed because of clinical improvement with defervescence.

Other two unexplained febrile episodes occurred in the following two months, with spontaneous defervescence. Two weeks after the last febrile event, the child was admitted for a planned MR-cholangiography. During the exam a 20-mm focal lesion in the upper third of the left kidney was accidentally discovered, compatible with a renal abscess, subsequently confirmed by AUS.

Meropenem was started and a second urine culture, collected at the admission, confirmed a MDR infection. Treatment was continued for 3 weeks, until both clinical and echographic resolution. At nephrologic follow-up, voiding cystourethrography showed grade II left vescico-ureteral reflux. DMSA-scintigraphy was negative. Antimicrobial prophylaxis was not indicated.

Key Learning Points

Considering the increasing prevalence of MDR pathogens, this case remarks the importance to collect urine culture before starting the antimicrobial therapy.

In our case the use of empirical therapy with broad spectrum beta lactamase, highly concentrated in urine, may have led to a transient resolution of symptoms without eradication of MDR strain with following evolution to abscess.

Title of Case(s)

What could have been done better

Background

In a setting where a broad-spectrum antimicrobial therapy is needed, what can be done with the emerging multidrug-resistant pathogens?

Case Presentation Summary

9-month-old girl after 3 days of feverish state was admitted to the Department of Infectious Diseases due to dehydration and suspected viral infection. Examination showed mild tonsil exudate. Laboratory showed CRP 100 mg/L, 80% of lymphocytes in the differential, with no other abnormalities. Due to persisting fever 24h after control laboratory was performed: CRP >300, anaemia, thrombocytopenia, neutropenia, lymphocytosis and atypical Ly. She became tachycardic, tachypnoeic, with distended abdomen. Cefotaxime was initiated and she was transferred to haemato-oncology department where AML was confirmed. Due to worsening state antibiotic was switched to piperacillin/tazobactam. Cultures were negative and her state improved. She received 1st block of chemotherapy and was, as expected, severely neutropenic. Teicoplanin and micafungin were added. Due to another episode of FN she received meropenem. 10 days after, despite antimicrobial therapy and prophylaxis she became septic, blood cultures were positive for Pseudomonas aeruginosa CRPs and Cyberlindnera fabianii. Antimicrobial therapy was adjusted according to the antibiogram (cefepime, gentamicin, metronidazole, amphotericin B). Due to the emerging septic shock she was transferred to the ICU. The blood cultures were permanently positive for both Pseudomonas and Cyberlindnera. Due to the evolving resistance to antibiotic therapy, multiple-antibiotic (ciprofloxacin, amikacin, ceftolozane/tazobactam) and antifungal therapy (amphotericin B, voriconazole) were readily adapted according to the antibiograms and consultations with infectious disease specialists and haemato-oncologists. She was also started on CytoSorb therapy. Despite intensive dialysis, vasoactive treatment and antimicrobial therapy the shock was refractory with severe lactic acidosis and multiorgan system failure that ended with girl’s death one month after the diagnosis was made.

Key Learning Points

Initial treatment of febrile neutropenia with broad-spectrum antimicrobials in severely neutropenic patient is necessary but could lead to the emergence of MDR pathogens with a fatal outcome.

Title of Case(s)

Empirical antimicrobial management of returning travellers from Pakistan

Background

Typhoid fever continues to inflict a great health burden worldwide and disproportionately affects the low-to-middle income nations with poor sanitation and healthcare infrastructure. Many nations empirically treat typhoid with third-generation cephalosporins such as ceftriaxone however, there is a large outbreak of extensively drug-resistant (XDR) typhoid emerging from Pakistan that is resistant to ceftriaxone. We diagnosed the first case of outbreak-related XDR typhoid in Canada, which serves as an important lesson on how we should adapt our empirical guidelines for those with suspected typhoid returning from Pakistan.

Case Presentation Summary

We report on a three year-old male who became unwell during a visit to South Pakistan. Before his return to Canada, he developed fever, abdominal pain, diarrhoea and vomiting. He consumed mostly home-cooked meals and bottled water, he had multiple mosquito bites and the family did not seek pretravel precautions such as typhoid vaccination or malaria prophylaxis.

The child presented to the Emergency Room shortly after returning to Canada. Inflammatory markers and transaminases were mildly elevated and multiple malaria screens were negative. He was started on empirical ceftriaxone for presumed typhoid fever. Stool and blood cultures isolated Salmonella enterica serovar Typhi which harboured extensive drug-resistance to all first-line antibiotics including ceftriaxone. Empirical ceftriaxone was switched to meropenem and he was successfully treated with a two-week course. Whole genome sequencing (WGS) confirmed that the child was infected with an XDR outbreak-strain emerging from Pakistan.

Key Learning Points

A large outbreak of XDR typhoid is currently emerging from Pakistan and several outbreak-related cases have been identified around the world in returning travellers. All XDR strains are so far sensitive to azithromycin and carbapenems. Current empirical strategies using ceftriaxone will be ineffective and clinicians should adapt their empirical guidelines for febrile travellers returning from Pakistan. Using WGS, we identified the first Canadian case of XDR typhoid originating from the Pakistan outbreak.

Title of Case(s)

Problems grow in a liver transplant: a history of multirresistant bacteria

Background

The development of resistance to carbapenems is one of the most worrisome scenarios within antimicrobial resistance.

Case Presentation Summary

We present the case of a 5-year-old boy in his fourth liver transplantation performed because of biliary atresia. Currently, he presents hepatic artery stenosis that requires angioplasty with arterial stent placement.

In the 24 hours after this intervention begins with persistent fever. Blood test and blood central and peripheral cultures were performed (CRP of 30 mg/dl, PCT 15 ng/ml). We started empirical treatment with Piperacillin-Tazobactam and Teicoplanin. The patient presents progressive clinical worsening and increase in cytolysis and cholestasis enzymes. In peripheral blood culture was isolate Enterobacter cloacae resistant to carbapenemes (CMI meropenem 32), likely MBL-producing strain (susceptible to aztreonam and gentamicin). In addition, in central blood culture was isolate Enterococcus faecium susceptible to glycopeptides. Central catheter were removed and abdominal doppler ultrasound was performed (no flow at hepatic artery). Echocardiogram did not show endocarditis data.

We adjusted treatment with Aztreonam, Gentamicin and Vancomycin. In control blood cultures, Enterobacter cloacae was not isolated again, however, it presents persistent bacteraemia due to E. faecium for 10 days, requiring the addition of Dalvabancin (compassionate use) as a treatment of persistent endovascular focus bacteremia. Finally, he presented progressive clinical improvement, with disappearance of fever and decrease in CRP and PCT, as well as absence of bacterial growth in blood cultures. Aztreonam was suspended after 10 days of treatment and vancomycin and gentamicin were maintained 6 weeks after the last sterile blood culture.

Key Learning Points

Despite the low circulation of these strains in children, a predominance of MBL type VIM has been documented. In the case of isolates with MIC of meropenem> 8 mg/L, the alternative is the use of a β-lactam and another active antibiotic based on the results of the antibiogram, in our patient Aztreonam and Gentamicin.

Title of Case(s)

Is intrathecal antibiotic an option?

Background

There are few cases described in the literature of successfully treated multiresistant Acinetobacter Baumannii ventriculitis.This case inspires us not to give up in the face of an infection caused by antibiotic resistant bacteria

Case Presentation Summary

An eleven-year old boy,previously healthy,presented severe headache,treated with symptomatic medication.Five days later,he was hospitalized with sinusitis,and treated with ceftriaxone.He evolved with presumed bacterial meningitis(liquor culture negative),brain abscess and intracranial hypertension.He was transferred to our hospital for a neurosurgery assessment.

In our service,the brain death protocol was initially opened,but after undergoing an external ventricular drainage and antibiotic exchange for meropenem and vancomycin,the patient evolved with clinical improvement.He was treated with these antibiotics for28days.He was also intubated and needed tracheostomy due to vocal cord paralysis.He received nasoenteral tube feeding during the entire hospitalization.

After this initial treatment,he started multidisciplinary rehabilitation follow-up,with great improvement.Near discharge he presented fever and seizures,and he was diagnosed with Staphylococcus aureus oxacillin resistance ventriculitis.The ventricular drainage was changed to an external shunt,the brain MRI showed maintenance of abscess,and he was treated with meropenem and vancomycin for 8weeks.Near the end of the treatment,he presented again with fever and seizures and he was diagnosed with Acinetobacter baumanni multidrug resistance ventriculitis.We decided to treat him with intrathecal polymyxin B for 4 consecutive days and after that every other day for 14 days.The patient evolved with significant improvement and CSF clearance.At the end of treatment,a new ventricular-peritoneal shunt was placed,and the patient was discharged to continue outpatient rehabilitation.

Three months later he came to visit us at the hospital:he was walking alone,without tracheostomy,without nasoenteral tube,feeding orally,and mentioning that his greatest wish was to be football player.

Key Learning Points

Faced an infection by antibiotic resistant bacteria, we have to think of alternative ways to administer antibiotics.Intrathecal administration of antibiotics appears to be an effective and safe treatment for infections of the CNS.