Volume 26, Number 9—September 2020
Research
Risk-Based Estimate of Human Fungal Disease Burden, China
Table 2
Assumptions and calculations for the estimations of fungal disease burden, China*
Fungal diseases† | Assumptions | Calculations |
---|---|---|
Candidemia | 1. Candidemia episodes in ICU = (ICU beds × 365/median length of ICU stay) × (rate of candidemia in ICU/1,000 admissions) | Candidemia = Candidemia episodes in ICU/0.20 |
2. 20% of candidemia episodes in Asia occur in ICU |
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Candida peritonitis |
Rate of Candida peritonitis is 50% of cases of candidemia in ICU |
Candida peritonitis = candidemia in ICU × 50% |
Candida peritonitis CAPD | 1. 3.7% were Candida peritonitis in all episodes of infection | Candida peritonitis CAPD = peritoneal dialysis × 0.27 × 3.7% |
2. Overall infection incidence was 0.27 episodes/patient/ year |
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Oral candidiasis |
Assumed to occur in 45% of AIDS cases annually |
Oral candidiasis = AIDS × 45% |
Esophageal candidiasis |
Assumed to occur in 20% of HIV patients not on ART and 5% of patients taking ART annually |
Esophageal candidiasis = (0.2 × HIV patients not on ART) + (0.05 × HIV patients on ART) |
RVVC |
Assumed to occur in 7.2% of the female population 15–49 years of age |
RVVC = (female population 15–49) × 7.2% |
IA | 1. In hematologic malignancy, annual incidence of all leukemias and multiple myeloma × 40% × 13% | IA = IA in hematologic malignancy + IA in solid and HSCT recipients + IA in lung cancer patients + IA in COPD patients + IA in HIV/AIDS patients |
a. Acute myeloid leukemia estimated at 40% of annual incidence of leukemias and multiple myeloma | ||
b. 13% of patients with acute myeloid leukemia developed IA |
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2. IA in solid and HSCT recipients: assumed 10% in a-HSCT recipients, 2% of renal transplants, 6% of heart transplants, 4% of liver transplants, 20% of lung transplants | ||
3. IA in 2.6% of patients with lung cancer | ||
4. IA in COPD: COPD patients × 20.9% × 3.9% | ||
a. Annual hospitalization rate for COPD = 20.9% | ||
b. 3.9% of hospitalized COPD patients developed IA | ||
5. IA in 4% of HIV/AIDS patients |
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CPA | 1. TB-related CPA: assuming rate of 22% among patients with lung cavities, 2% of patients without cavities | Total CPA = TB-related CPA × 3 |
2. 22% of patients with pulmonary TB have residual lung cavities | ||
3. One third of underlying diseases of CPA are TB |
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ABPA | 1. 4.2% of adults in China have asthma | ABPA = adults with asthma × 2.5% |
2. 2.5% of adults with asthma have ABPA |
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SAFS | 1. Assume a conservative 33% rate of fungal sensitization in patients with severe asthma | SAFS = adult population × 33% × 10% |
2. 10% of adults with asthma have severe asthma |
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CM | 1. 7.1% of patients with HIV/AIDS | CM = (7.1% × HIV/AIDS patients / 21%) + 0.43/100,000 × child population |
2. HIV-related CM is 21% of total CM | ||
3. Annual incidence of 0.43/100,000 in children |
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PCP | 1. 22.4% of HIV-positive patients during a 2y period | PCP = 22.4% × HIV/AIDS patients / 2 / 70.22% |
2. HIV-related PCP is 70.22% of total PCP |
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Talaromycosis |
Assume 20% of AIDS patients geographically exposed, attack rate 15% |
Talaromycosis = HIV/AIDS patients × 20% × 15% |
Histoplasmosis |
Assume 67% of AIDS patients geographically exposed, attack rate 5% |
Histoplasmosis = HIV/AIDS patients × 5% × 67% |
Mucormycosis |
Assume prevalence is 0.2/100,000 in total population |
Mucormycosis = total population × 0.2/100,000 |
Fungal keratitis |
0.007% of total population |
Fungal keratitis = total population × 0.007% |
Onychomycosis | 2.6% of total population | Onychomycosis = total population × 2.6% |
*ABPA, allergic bronchopulmonary aspergillosis; ART, antiretroviral therapy; CAPD, continuous ambulatory peritoneal dialysis; CM, cryptococcal meningitis; CPA, chronic pulmonary aspergillosis; HSCT, hematopoietic stem cell transplant: IA, invasive aspergillosis; ICU, intensive care unit; PCP, pneumocystis pneumonia; RVVC, recurrent Candida vaginitis; SAFS, severe asthma with fungal sensitization.
†Example for reading the table: burden of candidemia = candidemia episodes in ICU / 0.20 = (ICU beds × 365 / median length stay in ICU) × (rate of candidemia in ICU/1000 admissions) /0.20 = (86,027 × 365 / 6.126) × (3.2 / 1000) / 0.20 = 82,011.
1These authors contributed equally to this article.
2These authors contributed equally to this article.