For the purposes of the calculations in this report, the committee estimated that 40% of all C. immitis infections were asymptomatic. Symptomatic infections manifested as mild respiratory illness with and without complications of erethyma nodosum, pneumonia, and as a persistent, disseminated infection. The health utility indices associated with C. immitis infection vary from .65 for hospitalization with disseminated infection to .90 for the prolonged outpatient phase of a persistent, disseminated infection. Table A3–2 illustrates the estimated number of cases in each health state, the duration of time that state is experienced, and the health utility index (HUI) associated with each state.
Table A3–3 summarizes the health care costs incurred by C. immitis infections. For the purposes of the calculations used in this report, it was assumed that the mild respiratory illness associated with C. immitis infection leads to the costs of a limited physician visit and that only half of those with this illness would seek medical attention. It is assumed that 100% of people with more severe complications seek medical attention. Those people with complications of erythema incur costs associated with the respiratory illness (limited physician visit, diagnostic, medication) and several specialist visits for assessment and treatment of the complications.
Outpatient pneumonia is assumed to be associated with physician visits, diagnostics, and medications. Inpatient hospital costs were included for the few patients who were assumed to require it. Persistent/disseminated infection was associated with several hospitalizations as well as numerous outpatient visits, diagnostics, and medications over a 3-year period.
Although the health care scenarios are the same for those who would be immunized in infancy and as migrants (at older ages), the costs are calculated separately to allow for the effects of discounting, which will be different in infants (who might have a lag of many years until disease manifestations) and in migrants (some of whom will have much less of a lag between immunization and prevention of disease and the associated health care costs).
The committee estimated that development is feasible but is not imminent. The estimates are that it will take 15 years until licensing and that $360 million needs to be invested.