Middle East Respiratory Syndrome

Infectious Disease MONDO:0100116 Pathograph 2 Show in embeddings browser Viral Respiratory Infection

Middle East respiratory syndrome (MERS) is a severe viral respiratory infection caused by the Middle East respiratory syndrome coronavirus (MERS-CoV), a zoonotic betacoronavirus first isolated in 2012 from a patient in Saudi Arabia who died of pneumonia and renal failure. Dromedary camels are the reservoir for human spillover, and limited human-to-human transmission occurs, particularly in health-care settings. MERS-CoV enters host cells using dipeptidyl peptidase 4 (DPP4/CD26) as its receptor and causes a spectrum from asymptomatic infection to severe pneumonia, acute respiratory distress syndrome, and multiorgan failure, with a high case-fatality rate concentrated in older adults with comorbidities.

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2
Pathophys.
10
Phenotypes
2
Pathograph
1
Medical Actions
⚙

Pathophysiology

2
MERS-CoV Spike-Mediated Entry via DPP4
MERS-CoV enters host cells through its spike (S) glycoprotein, whose receptor-binding S1 domain engages the host cell-surface enzyme dipeptidyl peptidase 4 (DPP4, also known as CD26); host serine proteases then prime the spike for membrane fusion. DPP4 is expressed on respiratory epithelium and pneumocytes, defining the tropism for the lower respiratory tract, and is also expressed on renal and intestinal epithelium and liver — a tissue distribution consistent with the extrapulmonary (notably renal and gastrointestinal) manifestations of severe MERS. Receptor engagement is independent of DPP4 enzymatic activity: clinically used gliptin DPP4 inhibitors do not block infection, so DPP4 serves as an attachment protein rather than through its peptidase catalysis. Because the receptor is a host protein, antibodies against DPP4 block infection — the host-directed-target logic shared with SARS-CoV-2/ACE2.
bronchial epithelial cell CL:0002328 pulmonary alveolar type 2 cell CL:0002063
DPP4 hgnc:3009
virion attachment to host cell GO:0019062 symbiont entry into host cell GO:0046718
Downstream
Severe Lower Respiratory Infection and Systemic Spread Productive infection of the lower respiratory epithelium drives severe pneumonia that can progress to ARDS and multiorgan involvement.
Show evidence (4 references)
PMID:23486063 SUPPORT In Vitro
"Here we identify dipeptidyl peptidase 4 (DPP4; also known as CD26) as a functional receptor for hCoV-EMC."
Identifies DPP4 (CD26) as the functional host receptor for MERS-CoV (hCoV-EMC), the druggable host-factor entry step. Evidence source is IN_VITRO as this is a cell-based receptor-identification study.
PMID:23486063 SUPPORT In Vitro
"Antibodies directed against DPP4 inhibited hCoV-EMC infection of primary human bronchial epithelial cells and Huh-7 cells."
Shows that blocking the host DPP4 receptor inhibits MERS-CoV infection of human bronchial epithelial cells, the host-directed antiviral proof of principle. Evidence source is IN_VITRO as this is a cell-culture experiment.
PMID:23486063 SUPPORT In Vitro
"In humans it is primarily expressed on the epithelial cells in kidney, small intestine, liver and prostate, and on activated leukocytes"
DPP4 tissue distribution — including renal, intestinal, and hepatic epithelium — is consistent with the extrapulmonary (renal and gastrointestinal) tropism of MERS beyond the respiratory tract. Evidence source is IN_VITRO as this receptor-characterization study reports the distribution of the host entry protein.
+ 1 more reference
Severe Lower Respiratory Infection and Systemic Spread
MERS-CoV replication in the lower respiratory tract produces severe pneumonia that frequently progresses to acute respiratory distress syndrome and respiratory failure. Systemic and extrapulmonary involvement — notably acute kidney injury and gastrointestinal symptoms — is common, and the disease carries a high case-fatality rate concentrated in older adults with comorbidities.
viral genome replication GO:0019079 inflammatory response GO:0006954 ↑ INCREASED
lung UBERON:0002048
Show evidence (3 references)
PMID:23075143 SUPPORT Human Clinical
"A previously unknown coronavirus was isolated from the sputum of a 60-year-old man who presented with acute pneumonia and subsequent renal failure with a fatal outcome in Saudi Arabia."
The index MERS case establishes the core severe phenotype — acute pneumonia with renal failure and a fatal outcome. Evidence source is HUMAN_CLINICAL as this is a clinical case report.
PMID:23891402 SUPPORT Human Clinical
"Disease caused by MERS-CoV presents with a wide range of clinical manifestations and is associated with substantial mortality in admitted patients who have medical comorbidities."
Descriptive cohort of 47 cases establishing the wide clinical spectrum and substantial mortality in comorbid patients. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
PMID:23891402 SUPPORT Human Clinical
"28 patients died, a 60% case-fatality rate. The case-fatality rate rose with increasing age."
Quantifies the high case-fatality of hospitalized MERS in the primary Saudi cohort and its rise with age, supporting the severe outcome and age-dependent mortality. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Middle East Respiratory Syndrome Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

10
Blood 2
Lymphopenia FREQUENT Decreased total lymphocyte count HP:0001888
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"lymphopenia (16 [34%])"
Lymphopenia was present in 16 of 47 patients (34%) in the primary Saudi cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Thrombocytopenia FREQUENT Thrombocytopenia HP:0001873
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"thrombocytopenia (17 [36%])"
Thrombocytopenia was present in 17 of 47 patients (36%) in the primary Saudi cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Digestive 2
Diarrhea OCCASIONAL Diarrhea HP:0002014
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"diarrhoea (12 [26%])"
Diarrhoea was reported in 12 of 47 patients (26%) in the primary Saudi cohort, supporting an OCCASIONAL band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Vomiting OCCASIONAL Vomiting HP:0002013
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"vomiting (ten [21%])"
Vomiting was reported in 10 of 47 patients (21%) in the primary Saudi cohort, supporting an OCCASIONAL band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Genitourinary 1
Acute Kidney Injury Acute kidney injury HP:0001919
Show evidence (1 reference)
PMID:23075143 SUPPORT Human Clinical
"A previously unknown coronavirus was isolated from the sputum of a 60-year-old man who presented with acute pneumonia and subsequent renal failure with a fatal outcome in Saudi Arabia."
The index case developed renal failure, the characteristic extrapulmonary manifestation. Evidence source is HUMAN_CLINICAL as this is a clinical case report.
Immune 1
Pneumonia Pneumonia HP:0002090
Show evidence (2 references)
PMID:23075143 SUPPORT Human Clinical
"A previously unknown coronavirus was isolated from the sputum of a 60-year-old man who presented with acute pneumonia and subsequent renal failure with a fatal outcome in Saudi Arabia."
The index case presented with acute pneumonia. Evidence source is HUMAN_CLINICAL as this is a clinical case report.
PMID:23891402 SUPPORT Human Clinical
"All patients had abnormal findings on chest radiography, ranging from subtle to extensive unilateral and bilateral abnormalities."
Every patient in the 47-case cohort had abnormal chest radiography, reflecting the near-universal pulmonary involvement of symptomatic MERS. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Metabolism 1
Fever VERY_FREQUENT Fever HP:0001945
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"Common symptoms at presentation were fever (46 [98%])"
Fever was the most common presenting symptom in the 47-case series, present in 46 of 47 (98%), supporting a VERY_FREQUENT band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Respiratory 2
Cough VERY_FREQUENT Cough HP:0012735
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"cough (39 [83%])"
Cough was present in 39 of 47 patients (83%) in the primary Saudi cohort, supporting a VERY_FREQUENT band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Dyspnea FREQUENT Dyspnea HP:0002094
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"shortness of breath (34 [72%])"
Shortness of breath (dyspnea) was present in 34 of 47 patients (72%) in the primary Saudi cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
Constitutional 1
Myalgia FREQUENT Myalgia HP:0003326
Show evidence (1 reference)
PMID:23891402 SUPPORT Human Clinical
"myalgia (15 [32%])"
Myalgia was reported in 15 of 47 patients (32%) in the primary Saudi cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as this is a clinical case series.
💊

Medical Actions

1
Supportive Care
Action: Supportive Care NCIT:C15747
Management of MERS is primarily supportive, including supplemental oxygen and respiratory support (up to mechanical ventilation/ECMO for ARDS); no antiviral therapy is approved as standard of care, and management of severe disease is organ-supportive.
{ }

Source YAML

click to show 
name: Middle East Respiratory Syndrome
creation_date: "2026-06-28T00:00:00Z"
description: >
  Middle East respiratory syndrome (MERS) is a severe viral respiratory infection
  caused by the Middle East respiratory syndrome coronavirus (MERS-CoV), a
  zoonotic betacoronavirus first isolated in 2012 from a patient in Saudi Arabia
  who died of pneumonia and renal failure. Dromedary camels are the reservoir for
  human spillover, and limited human-to-human transmission occurs, particularly in
  health-care settings. MERS-CoV enters host cells using dipeptidyl peptidase 4
  (DPP4/CD26) as its receptor and causes a spectrum from asymptomatic infection to
  severe pneumonia, acute respiratory distress syndrome, and multiorgan failure,
  with a high case-fatality rate concentrated in older adults with comorbidities.
category: Infectious Disease
parents:
- Viral Respiratory Infection
synonyms:
- MERS
- MERS-CoV infection
- Middle East respiratory syndrome coronavirus infection
disease_term:
  preferred_term: Middle East respiratory syndrome
  term:
    id: MONDO:0100116
    label: Middle East respiratory syndrome
pathophysiology:
- name: MERS-CoV Spike-Mediated Entry via DPP4
  conforms_to: "host_directed_antiviral_dependency#Host Receptor and Protease Engagement"
  description: >
    MERS-CoV enters host cells through its spike (S) glycoprotein, whose
    receptor-binding S1 domain engages the host cell-surface enzyme dipeptidyl
    peptidase 4 (DPP4, also known as CD26); host serine proteases then prime the
    spike for membrane fusion. DPP4 is expressed on respiratory epithelium and
    pneumocytes, defining the tropism for the lower respiratory tract, and is
    also expressed on renal and intestinal epithelium and liver — a tissue
    distribution consistent with the extrapulmonary (notably renal and
    gastrointestinal) manifestations of severe MERS. Receptor engagement is
    independent of DPP4 enzymatic activity: clinically used gliptin DPP4
    inhibitors do not block infection, so DPP4 serves as an attachment protein
    rather than through its peptidase catalysis. Because the receptor is a host
    protein, antibodies against DPP4 block infection — the host-directed-target
    logic shared with SARS-CoV-2/ACE2.
  genes:
  - preferred_term: DPP4
    term:
      id: hgnc:3009
      label: DPP4
  cell_types:
  - preferred_term: bronchial epithelial cell
    term:
      id: CL:0002328
      label: bronchial epithelial cell
  - preferred_term: pulmonary alveolar type 2 cell
    term:
      id: CL:0002063
      label: pulmonary alveolar type 2 cell
  biological_processes:
  - preferred_term: virion attachment to host cell
    term:
      id: GO:0019062
      label: virion attachment to host cell
  - preferred_term: symbiont entry into host cell
    term:
      id: GO:0046718
      label: symbiont entry into host cell
  evidence:
  - reference: PMID:23486063
    reference_title: Dipeptidyl peptidase 4 is a functional receptor for the emerging human coronavirus-EMC.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Here we identify dipeptidyl peptidase 4 (DPP4; also known as CD26) as a
      functional receptor for hCoV-EMC.
    explanation: >-
      Identifies DPP4 (CD26) as the functional host receptor for MERS-CoV
      (hCoV-EMC), the druggable host-factor entry step. Evidence source is IN_VITRO
      as this is a cell-based receptor-identification study.
  - reference: PMID:23486063
    reference_title: Dipeptidyl peptidase 4 is a functional receptor for the emerging human coronavirus-EMC.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Antibodies directed against DPP4 inhibited hCoV-EMC infection of primary
      human bronchial epithelial cells and Huh-7 cells.
    explanation: >-
      Shows that blocking the host DPP4 receptor inhibits MERS-CoV infection of
      human bronchial epithelial cells, the host-directed antiviral proof of
      principle. Evidence source is IN_VITRO as this is a cell-culture experiment.
  - reference: PMID:23486063
    reference_title: Dipeptidyl peptidase 4 is a functional receptor for the emerging human coronavirus-EMC.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      In humans it is primarily expressed on the epithelial cells in kidney,
      small intestine, liver and prostate, and on activated leukocytes
    explanation: >-
      DPP4 tissue distribution — including renal, intestinal, and hepatic
      epithelium — is consistent with the extrapulmonary (renal and
      gastrointestinal) tropism of MERS beyond the respiratory tract. Evidence
      source is IN_VITRO as this receptor-characterization study reports the
      distribution of the host entry protein.
  - reference: PMID:23486063
    reference_title: Dipeptidyl peptidase 4 is a functional receptor for the emerging human coronavirus-EMC.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      hCoV-EMC infection could not be blocked by the DPP4 inhibitors sitagliptin,
      vildagliptin, saxagliptin or P32/98
    explanation: >-
      MERS-CoV entry depends on DPP4 as an attachment receptor rather than on its
      peptidase catalytic activity: clinically used gliptin DPP4 inhibitors did
      not block infection. Evidence source is IN_VITRO as this is a cell-culture
      inhibitor experiment.
  downstream:
  - target: Severe Lower Respiratory Infection and Systemic Spread
    description: >-
      Productive infection of the lower respiratory epithelium drives severe
      pneumonia that can progress to ARDS and multiorgan involvement.

- name: Severe Lower Respiratory Infection and Systemic Spread
  description: >
    MERS-CoV replication in the lower respiratory tract produces severe pneumonia
    that frequently progresses to acute respiratory distress syndrome and
    respiratory failure. Systemic and extrapulmonary involvement — notably acute
    kidney injury and gastrointestinal symptoms — is common, and the disease
    carries a high case-fatality rate concentrated in older adults with
    comorbidities.
  biological_processes:
  - preferred_term: viral genome replication
    term:
      id: GO:0019079
      label: viral genome replication
  - preferred_term: inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: INCREASED
  locations:
  - preferred_term: lung
    term:
      id: UBERON:0002048
      label: lung
  evidence:
  - reference: PMID:23075143
    reference_title: Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A previously unknown coronavirus was isolated from the sputum of a
      60-year-old man who presented with acute pneumonia and subsequent renal
      failure with a fatal outcome in Saudi Arabia.
    explanation: >-
      The index MERS case establishes the core severe phenotype — acute pneumonia
      with renal failure and a fatal outcome. Evidence source is HUMAN_CLINICAL as
      this is a clinical case report.
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Disease caused by MERS-CoV presents with a wide range of clinical
      manifestations and is associated with substantial mortality in admitted
      patients who have medical comorbidities.
    explanation: >-
      Descriptive cohort of 47 cases establishing the wide clinical spectrum and
      substantial mortality in comorbid patients. Evidence source is HUMAN_CLINICAL
      as this is a clinical case series.
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      28 patients died, a 60% case-fatality rate. The case-fatality rate rose
      with increasing age.
    explanation: >-
      Quantifies the high case-fatality of hospitalized MERS in the primary Saudi
      cohort and its rise with age, supporting the severe outcome and
      age-dependent mortality. Evidence source is HUMAN_CLINICAL as this is a
      clinical case series.
  downstream: []
phenotypes:
- category: Respiratory
  name: Pneumonia
  description: >
    Severe viral pneumonia is the defining manifestation of symptomatic MERS.
  phenotype_term:
    preferred_term: Pneumonia
    term:
      id: HP:0002090
      label: Pneumonia
  evidence:
  - reference: PMID:23075143
    reference_title: Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A previously unknown coronavirus was isolated from the sputum of a
      60-year-old man who presented with acute pneumonia and subsequent renal
      failure with a fatal outcome in Saudi Arabia.
    explanation: >-
      The index case presented with acute pneumonia. Evidence source is
      HUMAN_CLINICAL as this is a clinical case report.
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All patients had abnormal findings on chest radiography, ranging from
      subtle to extensive unilateral and bilateral abnormalities.
    explanation: >-
      Every patient in the 47-case cohort had abnormal chest radiography,
      reflecting the near-universal pulmonary involvement of symptomatic MERS.
      Evidence source is HUMAN_CLINICAL as this is a clinical case series.
- category: Constitutional
  name: Fever
  description: >
    Fever is the most common presenting symptom of MERS.
  phenotype_term:
    preferred_term: Fever
    term:
      id: HP:0001945
      label: Fever
  frequency: VERY_FREQUENT
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common symptoms at presentation were fever (46 [98%])
    explanation: >-
      Fever was the most common presenting symptom in the 47-case series, present
      in 46 of 47 (98%), supporting a VERY_FREQUENT band. Evidence source is
      HUMAN_CLINICAL as this is a clinical case series.
- category: Respiratory
  name: Cough
  description: >
    Cough is a common presenting symptom of MERS, reported in the majority of the
    47-case Saudi series.
  phenotype_term:
    preferred_term: Cough
    term:
      id: HP:0012735
      label: Cough
  frequency: VERY_FREQUENT
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      cough (39 [83%])
    explanation: >-
      Cough was present in 39 of 47 patients (83%) in the primary Saudi cohort,
      supporting a VERY_FREQUENT band. Evidence source is HUMAN_CLINICAL as this
      is a clinical case series.
- category: Respiratory
  name: Dyspnea
  description: >
    Shortness of breath is a frequent presenting symptom and reflects progression
    to severe lower respiratory disease.
  phenotype_term:
    preferred_term: Dyspnea
    term:
      id: HP:0002094
      label: Dyspnea
  frequency: FREQUENT
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      shortness of breath (34 [72%])
    explanation: >-
      Shortness of breath (dyspnea) was present in 34 of 47 patients (72%) in the
      primary Saudi cohort, supporting a FREQUENT band. Evidence source is
      HUMAN_CLINICAL as this is a clinical case series.
- category: Renal
  name: Acute Kidney Injury
  description: >
    Renal failure is a characteristic extrapulmonary complication of severe MERS.
  phenotype_term:
    preferred_term: Acute kidney injury
    term:
      id: HP:0001919
      label: Acute kidney injury
  evidence:
  - reference: PMID:23075143
    reference_title: Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A previously unknown coronavirus was isolated from the sputum of a
      60-year-old man who presented with acute pneumonia and subsequent renal
      failure with a fatal outcome in Saudi Arabia.
    explanation: >-
      The index case developed renal failure, the characteristic extrapulmonary
      manifestation. Evidence source is HUMAN_CLINICAL as this is a clinical case
      report.
- category: Gastrointestinal
  name: Diarrhea
  description: >
    Gastrointestinal symptoms including diarrhea occur in a substantial minority of
    MERS cases.
  phenotype_term:
    preferred_term: Diarrhea
    term:
      id: HP:0002014
      label: Diarrhea
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      diarrhoea (12 [26%])
    explanation: >-
      Diarrhoea was reported in 12 of 47 patients (26%) in the primary Saudi
      cohort, supporting an OCCASIONAL band. Evidence source is HUMAN_CLINICAL as
      this is a clinical case series.
- category: Gastrointestinal
  name: Vomiting
  description: >
    Vomiting occurs as part of the gastrointestinal symptom complex in a minority
    of MERS cases.
  phenotype_term:
    preferred_term: Vomiting
    term:
      id: HP:0002013
      label: Vomiting
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      vomiting (ten [21%])
    explanation: >-
      Vomiting was reported in 10 of 47 patients (21%) in the primary Saudi
      cohort, supporting an OCCASIONAL band. Evidence source is HUMAN_CLINICAL as
      this is a clinical case series.
- category: Musculoskeletal
  name: Myalgia
  description: >
    Myalgia is a common systemic symptom at presentation in MERS.
  phenotype_term:
    preferred_term: Myalgia
    term:
      id: HP:0003326
      label: Myalgia
  frequency: FREQUENT
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      myalgia (15 [32%])
    explanation: >-
      Myalgia was reported in 15 of 47 patients (32%) in the primary Saudi
      cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as
      this is a clinical case series.
- category: Hematologic
  name: Lymphopenia
  description: >
    Lymphopenia is a characteristic laboratory feature of MERS, reflecting the
    lymphotropic and immunopathologic component of severe infection.
  phenotype_term:
    preferred_term: Lymphopenia
    term:
      id: HP:0001888
      label: Decreased total lymphocyte count
  frequency: FREQUENT
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      lymphopenia (16 [34%])
    explanation: >-
      Lymphopenia was present in 16 of 47 patients (34%) in the primary Saudi
      cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as
      this is a clinical case series.
- category: Hematologic
  name: Thrombocytopenia
  description: >
    Thrombocytopenia is a laboratory abnormality seen in a substantial minority of
    MERS cases.
  phenotype_term:
    preferred_term: Thrombocytopenia
    term:
      id: HP:0001873
      label: Thrombocytopenia
  frequency: FREQUENT
  evidence:
  - reference: PMID:23891402
    reference_title: "Epidemiological, demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus disease from Saudi Arabia: a descriptive study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      thrombocytopenia (17 [36%])
    explanation: >-
      Thrombocytopenia was present in 17 of 47 patients (36%) in the primary Saudi
      cohort, supporting a FREQUENT band. Evidence source is HUMAN_CLINICAL as
      this is a clinical case series.
treatments:
- name: Supportive Care
  description: >
    Management of MERS is primarily supportive, including supplemental oxygen and
    respiratory support (up to mechanical ventilation/ECMO for ARDS); no antiviral
    therapy is approved as standard of care, and management of severe disease is
    organ-supportive.
  treatment_term:
    preferred_term: Supportive Care
    term:
      id: NCIT:C15747
      label: Supportive Care
notes: >-
  Created as part of the Respiratory Infections project (Intercept-aligned,
  pandemic-potential coronavirus backlog item). Conforms to the
  host_directed_antiviral_dependency module via the DPP4 receptor entry node,
  paralleling SARS-CoV-2/ACE2. The infectious_agent (NCBITaxon) block for
  MERS-CoV was omitted at creation and is described in the text; it can be added
  later.