II. Epidemiology
III. Risk Factors
- HIV with CD4 Count related risk of Pneumocystis
-
Immunosuppression in non-HIV conditions
- Solid organ or Hematopoietic Stem Cell Transplant recipients
- High dose Corticosteroids (Prednisone 20 mg or higher)
- Cancer Chemotherapy patients
- Rheumatologic Disease
- References
IV. Pathophysiology
- Pneumocystis defies classification
- Both Protozoan and Fungal Characteristics
- Recently renamed as Pneumocystis jiroveci
- Ubiquitous organism
- Most humans and mammals exposed early in life
- Clinically Significant infection occurs in AIDS with CD4 Count <250 cell/ul
- Clinical infection may represent reactivation
V. Symptoms
- Symptoms usually develop over 1-2 weeks
- Typical Bacterial Pneumonia develops over 3-5 days
- Initial Symptoms (occur in 66%, often subtle)
- Pronounced Symptoms
- Sputum production
- Chest Pain
- Chills
- Exertional Dyspnea
- Profound Hypoxia occurs with even just a few steps taken
VI. Labs
-
White Blood Cell Count Normal
- Elevated WBC Count in typical Bacterial Pneumonia
-
Lactate Dehydrogenase (LDH) > 350 units/L associated with PCP
- Test Sensitivity: 78 to 100%
- Normal LDH may decrease the likelihood of PCP
- Test Specificity: 35 to 78%
- Elevated LDL also seen with Bacterial Pneumonia and Tuberculosis
- Test Sensitivity: 78 to 100%
-
Sputum induction
- Methods
- Efficacy
- Test Sensitivity 80-90% for Pneumocystis (induced Sputum with PCR)
- However expectorated Sputum has low Test Sensitivity
- Negative Predictive Value only 50-60%
- Test Sensitivity 80-90% for Pneumocystis (induced Sputum with PCR)
- Examination stains
- Methenamine silver
- Giemsa stains
- Serum Beta D-Glucan
- High False Positive Rate
- Negative Predictive Value >95%
- Efficacy in AIDS for Beta D-Glucan >80 pg/ml
- Test Sensitivity: 92%
- Test Specificity: 65% (75% if respiratory symptoms)
- References
VII. Imaging: Chest XRay
- Diffuse bilateral Interstitial Infiltrates (80-95%)
- Seen in Tuberculosis
- Seen in Bacterial Pneumonia
- Bat winging appearance
- Focal infiltrates rarely seen with Pneumocystis
- Images
VIII. Diagnosis
- Clinical diagnosis
- Definitive diagnosis is typically by bronchoalveolar lavage
- Factors suggestive of PCP
- Interstitial Infiltrates AND Thrush (Odds Ratio 11.8)
- Exertional Dyspnea
- Inspiratory crackles
- Subacute disease course
IX. Management: General
- Treatment Duration for 21 days (followed by PCP Prophylaxis)
- Treatment protocols are based on level of illness (esp if PaO2 <70 mmHg)
- Initiate Antiretroviral therapy within 2 weeks of PCP diagnosis (HIV patients)
X. Management: First-line agents
- Duration: 21 days of treatment and then prophylaxis
- Not critically ill (PaO2 >70 mmHg) and able to take oral medications
- No Corticosteroids indicated
- Trimethoprim-Sulfamethoxazole (Bactrim, Septra) DS 2 tabs orally every 8 hours (15 mg/kg of trimethoprim/day)
- Adverse reactions occur in 40-60% within 3 weeks
- Alternative (Fewer dose limiting adverse reactions, but risk of Methemoglobinemia)
- Dapsone 100 mg orally every 24 hours AND Trimethoprim 5 mg/kg orally every 8 hours
- Critically ill with Hypoxia (PaO2 <70 mmHg or A-a Gradient >35) or unable to take oral medications
- Start Corticosteroids 15-30 min before Antibiotics (see dosing below)
- Trimethoprim-Sulfamethoxazole (Bactrim, Septra) 15-20 mg/kg of trimethoprim/day IV divided every 6-8 hours
XI. Management: Alternative Regimen
- Duration: 21 days of treatment and then prophylaxis
- Not critically ill (PaO2 >70 mmHg) and able to take oral medications
- No Corticosteroids indicated
- Clindamycin 600 mg IV or 300-400 mg PO every 6 hours AND
- Primquine 15-30 mg of based every 24 hours or Atovaquone 750 mg po bid
- Critically ill (PaO2 <70 mmHg or A-a Gradient >35) or unable to take oral medications
- Start Corticosteroids 15-30 min before Antibiotics (see dosing below)
- Clindamycin 600 mg IV every 8 hours AND Primquine 15-30 mg of based every 24 hours OR
- Pentamidine 4 mg/kg/day IV (or IM)
XII. Management: Corticosteroids
- Efficacy
- Prevents alveolar inflammation and exudation
- Results from the killing of Pneumocystis organisms
- Reduces the risk of intubation and death by 50%
- Indications (based on Arterial Blood Gas)
- Arterial pO2 < 70 mmHg
- A-a Gradient > 35 mmHg on room air
- Dosing: Prednisone
- Start: 40 mg twice daily for 5 days
- Next: 40 mg every 24 hours for 5 days
- Taper: 20 mg every 24 hours for 11 days
XIII. Prevention: Pneumocystis Prophylaxis
- Indications
- CD4 Count <200 cells
- HIV patients with respiratory symptoms
- Duration
- Continue prophylaxis until CD4 Count >200 for at least 3 months
- First-Line Protocol
- Alternative Protocols
- Pentamidine 300 mg in 6 ml sterile water aerosolized every 4 weeks OR
- Atovaquone 1500 mg orally every 24 hours with food OR
- Dapsone 200 mg and Pyrimethamine 75 mg AND Folinic Acid 25 mg once each week
XIV. Prognosis
- Treated appropriately: 10 to 20% mortality
- Higher mortality with severe infections
- Untreated: Uniformly fatal
XV. References
- Parker and Bond (2023) Crit Dec Emerg Med 37(10): 4-9
- Gilbert (2017) Sanford Guide (accessed IOS version 8/3/2017)
- Weller (2001) BMJ 322:1350-4 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
Definition (SNOMEDCT_US) | The rat specific species of Pneumocystis. |
Definition (SCTSPA) | Especie de Pneumocystis específica de la rata. |
Definition (MSH) | The prototype species of PNEUMOCYSTIS infecting the laboratory rat, Rattus norvegicus (RATS). It was formerly called Pneumocystis carinii f. sp. carinii. Other species of Pneumocystis can also infect rats. |
Definition (CSP) | opportunistic pathogen which can cause a fatal pneumonitis in an immunocompromised host; occurs in 75% of AIDS patients. |
Concepts | Fungus (T004) |
MSH | D045363 |
SnomedCT | 639000, 699877004, 79909001 |
English | Pneumocystis carinii, Finding of Pneumocystis carinii present, Pneumocystis carinii f. sp. ratti, carinii, Pneumocystis, Pneumocystis carinius, carinius, Pneumocystis, Pneumocystis carinus, carinus, Pneumocystis, carini, Pneumocystis, pneumocystis carini, pneumocystis carinii, carinii pneumocystis, Pneumocystis carinii (organism), Pneumocystis carinii f. sp. carinii, Pneumocystis carini |
Swedish | Pneumocystis carinii |
Czech | Pneumocystis carinii |
Finnish | Pneumocystis carinii |
Japanese | カリニ肺炎菌, ニューモシスチス・カリニ, ニューモシスチスカリニ |
Croatian | PNEUMOCYSTIS CARINII |
Polish | Pneumocystis carini |
Norwegian | Pneumocystis carini, Pneumocystis carinii |
Spanish | Pneumocystis carinii (organismo), Pneumocystis carinii |
French | Pneumocystis carini, Pneumocystis carinii |
German | Pneumocystis carinii |
Italian | Pneumocystis carinii |
Russian | PNEUMOCYSTIS CARINII |
Dutch | Pneumocystis carinii |
Portuguese | Pneumocystis carinii |
Ontology: Pneumocystis jiroveci (C0320385)
Definition (SNOMEDCT_US) | The human specific species of Pneumocystis. |
Definition (SCTSPA) | Especie de Pneumocystis específica del ser humano. |
Definition (MSH) | A species of PNEUMOCYSTIS infecting humans and causing PNEUMOCYSTIS PNEUMONIA. It also occasionally causes extrapulmonary disease in immunocompromised patients. Its former name was Pneumocystis carinii f. sp. hominis. |
Concepts | Fungus (T004) |
MSH | D045382 |
SnomedCT | 79909001 |
LNC | LP17137-8, MTHU025383 |
Swedish | Pneumocystis jiroveci |
English | Pneumocystis jirovecii, jiroveci, Pneumocystis, jirovecus, Pneumocystis, jirovecii, Pneumocystis, Pneumocystis jirovecus, jirovecius, Pneumocystis, Pneumocystis jirovecius, Pneumocystis jiroveci (organism), Pneumocystis jirovecii (organism), Pneumocystis carinii f. sp. hominis, Pneumocystis jiroveci |
Portuguese | Pneumocystis jirovecii |
Finnish | Pneumocystis jirovecii |
French | Pneumocystis jiroveci, Pneumocystis jirovecii |
German | Pneumocystis jirovecii, Pneumocystis jiroveci |
Italian | Pneumocystis jirovecii, Pneumocystis jiroveci |
Russian | PNEUMOCYSTIS JIROVECII, PNEUMOCYSTIS JIROVECI |
Czech | Pneumocystis jiroveci, Pneumocystis jirovecii |
Polish | Pneumocystis jiroveci, Pneumocystis jirovecii |
Japanese | ニューモシスチス・イロベジイ |
Norwegian | Pneumocystis jiroveci, Pneumocystis jirovecii |
Spanish | Pneumocystis jirovecii (organismo), Pneumocystis jirovecii, Pneumocystis jiroveci (organismo), Pneumocystis jiroveci |
Dutch | Pneumocystis jiroveci |
Ontology: Pneumocystis Infections (C0851886)
Definition (MEDLINEPLUS) |
Pneumocystis jirovec is a tiny fungus that lives in the lungs of many people. Most people's immune systems keep the fungus under control. But if your immune system is weak, the fungus can make you very sick. The most common problem of infection is pneumocystis pneumonia (PCP). PCP once was the major cause of death for people with HIV/AIDS. But now, it is possible to prevent or treat most cases. The key to surviving PCP is early treatment. The first signs of PCP are difficulty breathing, fever and a dry cough. If you have these symptoms, see your doctor right away. |
Definition (MSH) | Infections with species in the genus PNEUMOCYSTIS, a fungus causing interstitial plasma cell pneumonia (PNEUMONIA, PNEUMOCYSTIS) and other infections in humans and other MAMMALS. Immunocompromised patients, especially those with AIDS, are particularly susceptible to these infections. Extrapulmonary sites are rare but seen occasionally. |
Concepts | Disease or Syndrome (T047) |
MSH | D016720 |
SnomedCT | 111918002 |
English | PNEUMOCYSTIS CARINII INFECTION, Pneumocystis carinii Infection, PNEUMOCYSTIS CARINII INFECT, PNEUMOCYSTIS INFECT, Pneumocystis infections, Pneumocystis Infections, Pneumocystis Infections [Disease/Finding], Infection by Pneumocystis carinii, Infection by Pneumocystis carinii (disorder), Pneumocystis carinii infection, Pneumocystis carinii Infections, Infection, Pneumocystis, Infections, Pneumocystis, Pneumocystis Infection, Pneumocystis carinii; infection, infection; Pneumocystis carinii |
Italian | Infezioni da Pneumocystis, Infezione da Pneumocystis carinii, Infezioni da Pneumocystis carinii |
Japanese | ニューモシスティス感染, ニューモシスティスカンセン, ニューモシスチス感染症, ニューモシスティスカリニカンセン, ニューモシスティスカリニ感染 |
Swedish | Pneumocystis infektioner |
Finnish | Pneumocystis-infektiot |
Russian | PNEUMOCYSTIS INFEKTSII, PNEUMOCYSTIS CARINII INFEKTSII, PNEUMOCYSTIS CARINII ИНФЕКЦИИ, PNEUMOCYSTIS ИНФЕКЦИИ |
Portuguese | INFECCAO A PNEUMOCISTIS CARINI, Infecção a Pneumocystis carinii, Infecções a Pneumocystis, Infecções por Pneumocystis |
Spanish | INFECCION PNEUMOCISTYS CARINII, infección por Pneumocystis carinii, infección por Pneumocystis carinii (trastorno), Infección por Pneumocystis carinii, Infecciones por pneumocystis, Infecciones por Pneumocystis |
French | INFECTION A PNEUMOCYSTIS CARINII, Infection à Pneumocystis carinii, Infections à Pneumocystis carinii, Infections à Pneumocystis |
German | PNEUMOCYSTIS CARINII INFEKTION, Pneumocystis carinii Infektion, Pneumocystis-Infektionen, Pneumocystis-carinii-Infektionen |
Czech | Pneumocystové infekce, Infekce vyvolaná Pneumocystis carinii, infekce Pneumocystis carinii, Pneumocystis - infekce |
Croatian | PNEUMOCYSTIS CARINII, INFEKCIJE, PNEUMOCISTOZA |
Hungarian | Pneumocystis fertőzések, Pneumocystis carinii fertőzés |
Polish | Infekcje Pneumocystis, Infekcja Pneumocystis, Zakażenia Pneumocystis |
Dutch | Pneumocystis carinii-infectie, Pneumocystis carinii; infectie, infectie; Pneumocystis carinii, Infecties, pneumocystis-carinii-, Pneumocystis-carinii-infectie, Pneumocystis-carinii-infecties, Pneumocystis-infecties |
Norwegian | Pneumocystis carinii-infeksjoner, Pneumocystisinfeksjoner |
Ontology: Pneumocystis jiroveci pneumonia (C1535939)
Definition (NCI) | Pneumonia resulting from infection with Pneumocystis carinii, frequently seen in the immunologically compromised, such as persons with AIDS, or steroid-treated individuals, the elderly, or premature or debilitated babies during their first three months. Patients may be only slightly febrile (or even afebrile), but are likely to be extremely weak, dyspneic, and cyanotic. This is a major cause of morbidity among patients with AIDS. |
Definition (CSP) | pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by dyspnea, tachypnea, and hypoxemia; Pneumocystis pneumonia is a frequent opportunistic infection in AIDS; also found in other mammals where it is caused by related species of Pneumocystis. |
Definition (MSH) | A pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by DYSPNEA, tachypnea, and HYPOXEMIA. Pneumocystis pneumonia is a frequently seen opportunistic infection in AIDS. It is caused by the fungus PNEUMOCYSTIS JIROVECII. The disease is also found in other MAMMALS where it is caused by related species of Pneumocystis. |
Concepts | Disease or Syndrome (T047) |
MSH | D011020 |
ICD9 | 136.3 |
ICD10 | B59 |
SnomedCT | 88860002, 57541005, 155557008, 415125002 |
English | Pneumocystoses, Pneumonia, Interstitial Plasma Cell, Pneumonias, Pneumocystis carinii, interstitial plasma cell pneumonia, PCP - Pneumocyst carinii pneum, PCP - Pneumocystis carinii pneumonia, PNEUMOCYSTIS PNEUMONIA, Pneumocytosis, Pneumocystis carinii pneumonia (diagnosis), plasma cell interstitial pneumonia (diagnosis), Pneumocystis jiroveci pneumonia (diagnosis), plasma cell interstitial pneumonia, lymphoplasmacytic interstitial pneumonia, Pneumocystis Jiroveci Pneumonia, Pneumocystis, PCP, PJP, Pneumocystis Carinii Pneumonia, Pneumocystis jiroveci pneumonia, Pneumonia due to Pneumocystis carinii, Pneumonia, Pneumocystis [Disease/Finding], pneumocystis pneumonia, pneumocystis carinii pneumonia (PCP), pneumocystis carinii pneumonia, Pneumocystis carinii pneumonia (disorder), Pulmonary pneumocystosis (disorder), Pneumocystis carinii pneumonia, Interstitial plasma cell pneumonia, Pneumocystis jirovecii pneumonia, Pneumocystis pneumonia, Pneumocystosis jiroveci pneumonia, Pneumocystosis jirovecii pneumonia, Pneumocystosis jiroveci pneumonia (disorder), Pneumocystosis jirovecii pneumonia (disorder), Pneumocystis carinii Pneumonia, Pneumocystosis, Pneumonia, Pneumocystis carinii, Pneumonia, Pneumocystis, Pneumocystis Pneumonias, Pneumocystis Pneumonia, Pneumonias, Pneumocystis, Pneumocystosis (disorder), pneumocystosis, Pulmonary pneumocystosis, PCP - Pneumocystis pneumonia, Pneumocystosis pneumonia |
Czech | pneumocystóza, pneumocystová pneumonie, pneumonie pneumocystová, Zánět plic vlivem pneumocystis jiroveci, Pneumocystová pneumonie, Pneumonie způsobená Pneumocystis jirovecii, Pneumonie vyvolaná Pneumocystis carinii, PCP, Pneumocystóza, Intersticiální pneumonie s plasmocytickou infiltrací |
Finnish | Pneumocystis-keuhkokuume |
German | Pneumonie, Pneumocystis-carinii-, Pneumonie, Pneumocystis-, Pneumocystis-Pneumonie, Pneumocystosis, Pneumozystose, Pneumocystose, Pneumonie durch Pneumocystis jiroveci, Pneumocystis jirovecii-Pneumonie, PCP, interstitielle Plasmazellenpneumonie, Pneumonie durch Pneumocystis carinii, Pneumonie durch Pneumocystis, Pneumocystis-carinii-Pneumonie, Pneumonie, interstitielle plasmazelluläre |
Russian | PNEVMONIIA, PNEUMOCYSTIS, PNEVMONIIA INTERSTITSIAL'NAIA PLAZMOKLETOCHNAIA, PNEVMOTSISTOZ, PNEVMONIIA, PNEUMOCYSTIS CARINII, PNEVMOTSISTNAIA PNEVMONIIA, ПНЕВМОНИЯ, PNEUMOCYSTIS CARINII, ПНЕВМОНИЯ, PNEUMOCYSTIS, ПНЕВМОНИЯ ИНТЕРСТИЦИАЛЬНАЯ ПЛАЗМОКЛЕТОЧНАЯ, ПНЕВМОЦИСТНАЯ ПНЕВМОНИЯ, ПНЕВМОЦИСТОЗ |
Japanese | 肺炎-カリニ, ニューモシスチス肺炎, ニューモシスチス・カリニ肺炎, Pneumocystis肺炎, Carinii肺炎, 肺炎-ニューモシスチス, ニューモシスティスカリニ肺炎, ニューモシスティスショウ, ニューモシスティス肺炎, ニューモシスチス・イロベチイ肺炎, カンシツケイシツサイボウセイハイエン, ニューモシスティスハイエン, ニューモシスティスカリニハイエン, ニューモシスティス症, ニューモシスチスイロベチイハイエン, Pneumocystis carinii肺炎, カリニ肺炎, ニューモシスチスカリニ肺炎, 肺炎-間質形質細胞性, 間質形質細胞性肺炎, ニューモシスチス-カリニ肺炎, 肺炎-Pneumocystis carinii, 肺炎-ニューモシスチスカリニ |
Swedish | Lunginflammation, Pneumocystis |
Italian | Pneumocistosi, Polmonite interstiziale plasmacellulare, PCP, Polmonite da Pneumocystis jiroveci, Polmonite da Pneumocystis, Polmonite da Pneumocystis jirovecii, Polmonite interstiziale plasmocitaria, Polmonite da Pneumocystis carinii |
Korean | 폐포자충증 |
Polish | Zapalenie płuc wywołane Pneumocystis carinii, Zapalenie płuc pneumocystozowe, Zapalenie płuc plazmatycznokomórkowe |
Spanish | neumocistosis pulmonar, neumocistosis pulmonar (trastorno), neumonía por Pneumocystis carinii, Neumonía plasmocitioide intestinal, Neumonía por P carinii, Neumonía por Pneumocystis jiroveci, Neumocistiasis, Neumonía por pneumocystis, Neumonía por Pneumocystis jirovecii, Neumonía por Pneumocystis carinii, neumocistosis (trastorno), neumocistosis, neumonía por Pneumocystis jiroveci (trastorno), neumonía por Pneumocystis jiroveci, Neumocistosis, Neumonía Intersticial de Células Plasmáticas, Neumonía por Pneumocystis |
Dutch | pneumocystose, Pneumocystis jiroveci-pneumonie, interstitiële plasmacelpneumonie, PCP, Pneumocystis carinii-pneumonie, Pneumocystose, Pneumocystis-pneumonie, Pneumonie, interstitiële plasmacel-, Pneumonie, Pneumocystis- |
French | PCP, Pneumonie à Pneumocystis jirovecii, Pneumonie à Pneumocystis Carinii, Pneumonie interstitielle à cellules plasmatiques, Pneumonie à pneumocytose, Pneumonie à Pneumocystis jiroveci, Pneumonie interstitielle à Pneumocystis carinii, Pneumocystose, Pneumonie à Pneumocystis carinii, Pneumonie à Pneumocystis, Pneumopathie à Pneumocystis |
Hungarian | Pneumocystis jirovecii pneumonia, pneumocystosis, Pneumocystis jiroveci pneumonia, Pneumocystis carinii pneumonia, PCP, Interstitialis plazmasejtes pneumonia, Pneumocystis pneumonia |
Portuguese | Pneumonia intersticial de plasmocitos, Pneumonia a Pneumocystis, Pneumonia por Pneumocystis jirovecii, Pneumonia a Pneumocystis carinii, Pneumonia a Pneumocystis jiroveci, Pneumocistose, Pneumonia Intersticial de Células Plasmáticas, Pneumonia por Pneumocystis |
Norwegian | Pneumocystis carinii pneumoni, Pneumocystose, Pneumocystis-lungebetennelse |