Nocardiosis is an opportunistic infection[11]. The clinical presentation and outcome of nocardiosis depend on the patient's initial immune status [12]. Among those diagnosed with AIDS, the incidence of Nocardiosis ranges from 0.2–1.8%[13], while the incidence of pericarditis is even lower. To our understanding, a total of 11 cases of AIDS patients complicated with Nocardia pericarditis have been reported since 1985 (Table 1). The patients' ages ranged from 24 to 52 years, with males accounting for 81.8% (9/11). Cardiac tamponade was a life-threatening complication that ultimately arose in 54.5% (6/11) of the cases. Nocardia species were isolated from the pericardial effusion cultures in all cases. Tragically, 28.3% (3/11) of the cases resulted in fatalities. A case of pericarditis co-infected with both Nocardia and MTB underscores the critical importance of differential diagnosis for these diseases.
Table 1
Summary of all published cases of nocardial pericarditis in AIDS.
Age
|
Sex
|
cardiac tamponade
|
CD4 cell count(cells/mm3)
|
Misdiagnose tuberculous pericarditis
|
Drainage /surgery/ drainage flow
|
Drug Treatment
|
Antiretroviral therapy
|
Outcome
|
References
|
32
|
Male
|
No
|
48
|
No
|
Subxiphoid pericardiostomy (1100 mL fluid)
|
SMX/TMP, IV
|
Not reported
|
Recovered
|
Holtzet al.[39]
|
34
|
Male
|
No
|
66
|
No
|
Pericardiostomy (400 mL fluid)
|
SMX/TMP, IV, 3 weeks
|
Not reported
|
Died
|
Holtzet al. [39]
|
34
|
Male
|
Yes
|
239
|
No
|
Pericardiostomy (400 mL fluid)
|
SMX/TMP, IV, 5 days →Sulfadiazine, PO, 3 months
|
Yes
|
Recovered
|
Rivero et al. [13]
|
42
|
Male
|
No
|
91
|
Yes
|
Pericardial window
|
SMX/TMP but allergy →Ceftriaxone+
Minocycline, 6 weeks
|
Not reported
|
Recovered
|
Ramanathan and Rahimi[40]
|
24
|
Female
|
Yes
|
Not reported
|
No
|
Pericardial aspirations with indwelling catheter (900 mL fluid)
|
SMX/TMP, PO
|
Not reported
|
Recovered
|
Leang et al. [41]
|
44
|
Male
|
No
|
42
|
Yes
|
Pericardiocentesis followed by surgical drainage with pericardial window
|
SMX/TMP, IV
→PO
|
No
|
Recovered
|
Jinno et al. [42]
|
35
|
Female
|
Yes
|
32
|
Yes
|
Pericardiocentesis (500 mL fluid)
|
SMX/TMP + ceftriaxone + doxycycline, IV →
SMX/TMP + doxycycline, PO
|
Yes
|
Recovered
|
Chandrashekar et al. [43]
|
37
|
Male
|
Yes
|
50
|
No
|
Subxiphoid pericardial drain (800 mL fluid)
|
Imipenem/ cilastatin +
SMX/ TMP, IV
→SMX/TMP, PO
|
No
|
Recovered
|
Aisenberg and Martin[44]
|
32
|
Male
|
Yes
|
17
|
Yes
|
Emergency pericardiocentesis
|
Imipenem/ cilastatin + SMX/TMP, IV
|
Yes
|
Died
|
Laksananun et al. [45]
|
32
|
Male
|
Yes
|
4
|
No
|
Pericardiocentesis
|
→SMX/ TMP + Imipenem/ cilastatin, IV, Continue anti-TB therapy(HREZ)
|
Not reported
|
Died
|
Griessel et al. [46]
|
52
|
Male
|
No
|
Not reported
|
No
|
pericardiocentesis with indwelling catheter (4280mL of pus)
|
SMZ/TMP, PO + ceftriaxone + Amikacin, IV
→SMZ/TMP and amoxicillin/
clavulanic acid, PO
|
No
|
Recovered
|
Xinxin Z et al.
(current study)
|
AIDS: Acquired Immune Deficiency Syndrome; SMX/TMP: sulfamethoxazole/trimethoprim; IV: intravenous; PO: per oral; TB: tuberculosis; H: isoniazid; R: rifampin, Z: pyrazinamide; E: ethambutol. |
The clinical presentation of pericarditis caused by Nocardia lacks specificity. Apart from non-specific constitutional symptoms, reported cases reveal that patients commonly present with fever, night sweats, dyspnea, loss of appetite and weight, chest pain, chills, cough, and fatigue. Before obtaining the results of etiology detection, clinical diagnosis of pericarditis caused by Nocardia remains a challenge and should be differentiated from other types of purulent pericarditis as follows.
In developing countries, tuberculous pericarditis remains the predominant cause of purulent pericarditis[14].The MTB can disseminate via retrograde lymphatic spread, hematogenous dissemination, or by infiltrating the pericardium through neighboring lung, pleura, and spine[15]. In patients coinfected with HIV, only 35% of individuals with TBP exhibit positive findings in pericardial effusions cultures[16]. Xpert MTB/RIF and Xpert MTB/RIF Ultra are cartridge-based nucleic acid amplification tests that can detect MTB and simultaneously assess rifampicin resistance in less than 2 hours. In a study evaluating the accuracy of Xpert MTB/RIF in TBP and other forms of extrapulmonary tuberculosis, the sensitivity was 63.8%, while demonstrating high specificity (100%)[17]. Besides, in high tuberculosis prevalence areas, the utility of interferon-gamma release assays (IGRAs) is limited, as positive results simply indicate exposure to MTB antigens and do not reliably identify active tuberculosis disease[18]. In our study, the patient was initially misdiagnosed with TBP before obtaining etiological evidence. When patients experience ineffective anti-tuberculosis treatment, they should be alert to the possibility of Nocardia infection and obtain pathogen and drug sensitivity test results as soon as possible. In the case, patient’s pericardial effusions tested negative for Xpert MTB/RIF, cultures, and IGRA, and the ineffectiveness of anti-tuberculosis treatment, a definitive exclusion of the diagnosis of TBP was made.
Methicillin-resistant Staphylococcus aureus (MRSA) pericarditis and pericardial abscesses are rare and typically associated with chronic medical conditions that require prolonged stays in healthcare settings [19, 20]. 94.9% of cases show pericardial effusion, and 83.8% exhibit tamponade[21]. In reported cases of MRSA pericarditis, MRSA has been isolated from pericardial effusions without exception, and 64.1% of MRSA blood cultures test positive [21]. The adult mortality rate is 20.5%, with an average survival of 21.8 days, primarily attributed to multi-organ dysfunction associated with septic shock[21]. In this study, the patient did not have prolonged exposure to healthcare settings, and neither the blood cultures nor the pericardial fluid cultures showed the presence of MRSA. Consequently, the etiology of purulent pericarditis attributed to MRSA can be definitively excluded.
In most reported cases of severe pericarditis or cardiac tamponade secondary to influenza, Influenza A is the implicated virus[22–24]. Isolated pericarditis is more often associated with pericardial effusions [25]. Male and older patients are more likely to have isolated pericarditis, while female and younger patients are more likely to have myopericarditis[25]. Patients of any age presenting with chest pain, tachycardia, and hemodynamic instability within 2–4 weeks of symptom onset should be considered to have cardiac involvement [25]. In our study, the patient presents with pericardial effusion without other typical clinical symptoms such as influenza-like respiratory symptoms or chest pain, exhibiting a low clinical index of suspicion.
Pericarditis caused by fungal infections is rare. β-D-glucan (BDG), found in various fungal cell walls, serves as a surrogate marker for diagnosing invasive fungal infections (IFIs)[26–28]. BDG has been utilized for diagnosing IFIs, including Pneumocystis jirovecii pneumonia (PJP), cryptococcosis, and others in people living with HIV (PLHIV). Several studies of serum BDG, utilizing the Fungitell assay with varying cutoff values for diagnosing PJP, demonstrated a sensitivity ranging from 90–100% and specificity ranging from 61.3–96.4%[29–31]. However, in the diagnosis of cryptococcosis, the sensitivity of BDG in cerebrospinal effusions is 89%, with a specificity of 85%, while in serum, the sensitivity is 79%, with a specificity of 61%[32]. Currently, there is a lack of reports on the sensitivity and specificity of serum BDG in diagnosing pericarditis caused by fungal infections. In our study, the patient’s serum BDG was negative, although fungal etiology causing pericarditis was not promptly ruled out at that time. Subsequent culture of the pericardial effusions, however, revealed the presence of Nocardia species, with negative fungal cultures. Effective antibiotic therapy subsequently excluded fungal etiology as the cause of pericarditis.
Microbiological examination is the gold standard for diagnosing pericarditis caused by Nocardia. However, in AIDS patients with negative pericardial effusion cultures and ineffective antibiotic treatment, extending the culture period to at least 10 days becomes necessary to overcome false-negative results[33]. As we have previously summarized, the presence of fever, dyspnea, chest pain, and pericardial effusion, along with the isolation of slow-growing Gram-positive bacteria in pericardial fluid cultures, should raise suspicion of Nocardia infection.
The clinical features of Nocardia infection include rapid disease progression and a propensity for infection recurrence or exacerbation [33]. In this case, despite the presence of massive purulent pericardial effusions and rapid disease progression, accurate etiological identification, sensitive antibiotics, and timely pericardiocentesis drainage were key factors for successful treatment.
When considering Nocardia infection, empirical antibiotic therapy should be promptly initiated. Early diagnosis, early treatment, adequate dosage, and prolonged treatment duration are recommended. he selection of antimicrobial therapy should take into account factors such as epidemiology, clinical presentation (e.g., severity, organs involved), patient-specific factors, antibiotic minimal inhibitory concentration (MIC), and side effects [2, 34–36]. SMZ/TMP is regarded as the preferred antimicrobial agent for the treatment of nocardiosis [37]. For patients resistant to sulfonamide drugs, high-dose sulfonamide therapy or combination therapy can still be used, among which carbapenems and linezolid exhibit higher sensitivity [12, 38]. Immunocompromised patients typically require prolonged antimicrobial therapy for a duration of at least 6–12 months. [37]. In this case, the pericardial effusion culture of the patient indicated positivity for Nocardia. Following treatment with a combination of ceftriaxone and amikacin, along with SMZ/TMP, a significant reduction in pericardial effusion was observed on chest CT and echocardiography, suggesting favorable therapeutic efficacy of SMZ/TMP combination therapy. This case highlights the necessity to include Nocardia pericarditis in the differential diagnosis of immunosuppressed patients presenting with purulent pericarditis. Early identification, accurate diagnosis, prompt initiation of treatment, and efficacious management can significantly influence patient outcomes. It is crucial to maintain vigilance for timely pericardial puncture, ensure extended antimicrobial therapy, and closely monitor potential side effects associated with antimicrobial drugs.
Pericarditis caused by Nocardia is a rare but potentially fatal opportunistic infection that should be considered in the differential diagnosis of other purulent pericarditis. Bacterial culture is the gold standard for diagnosis. Optimal outcomes can be achieved through timely diagnosis, drainage treatment, and prolonged antimicrobial therapy.