TABLE 4.
Classification of different clinical forms of trichinellosis, in dependence of the severity of signs and larval densitya
| Clinical form/outcome of infectionb | Serology | Presence of eosinophils (>500 eosinophils per mm3) | Presence of main clinical signs (fever, edema, myalgia) | Recovery after infection | Hypoalbuminemia | Complications | Estimated no. of larvae/g muscle | Hospitalization | Putative fatality |
|---|---|---|---|---|---|---|---|---|---|
| Asymptomatic | + | Transient | − | − | − | − | <10 | − | − |
| Abortive | + | + | Transient (1-2 days) | − | − | − | > | − | − |
| Mild | + | + | + | 3 wk | − | − | > | − | − |
| Pronounced | + | + | ++ | 6 wk | +/− | Rare | > | +/− | − |
| Severe | + | Sometimes absent | +++ | >6 mo | + | Frequent | >100 | + | +/− |
Modified from reference 73 with permission of the publisher, with additional data from reference 153.
The asymptomatic form of trichinellosis relates to a history of exposure, but signs and/or symptoms are lacking. The diagnosis of asymptomatic cases is usually based upon serological findings. In the abortive form, the clinical signs and symptoms are weakly expressed and last up to a few days; diagnosis should also be confirmed by serological testing. The mild form exhibits a low intensity of signs and/or symptoms. No complications are encountered, and serological testing is indispensable in establishing a diagnosis. The pronounced form is characterized by the appearance of the complete syndrome of significant intensity, but complications are rare, and if present, they are benign and vanish soon. The severe form is characterized by the development of the full syndrome of highly pronounced signs and symptoms with metabolic disturbances accompanied by circulatory and/or neurological complications.