Table 2. Parasitic causes of eosinophilia and diagnostic tests of choice.
| Parasite | Diagnostic test |
|---|---|
| Angiostrongylus | Larvae in CSF, PCR of CSF (CDC). |
| Anisakis spp | <12 hrs from raw fish/squid ingestion: EGD for visualization of larvae >12hrs from ingestion: Anti-Anisakis IgG and IgA [86] |
| Ascaris lumbricoides | Eggs in stool, serology |
| B aylisascaris procyonis | Larva or larval tracks seen on ocular exam. Serology (EIA, reference lab) |
| Basidiobolus ranarum | Fungal elements on histopathologic exam, fungal culture of surgical specimen. |
| Brachylaima spp. | Eggs in stool |
| Capillaria hepatica | Eggs/worms on liver biopsy Serology—high titer (Low titer indicates spurious infection from ingesting infected liver) |
| Coccidioides spp. | Fungal elements on histopathologic exam, fungal culture of surgical specimen, serology (complement fixation). |
| Clonorchis spp. | Eggs in stool, Serology (not available in US) |
| Cystoisospora belli (formerly Isospera belli) | Oocysts in stool |
| Dicrocoelium dendritium | Ova in stool (after abstaining from ingestion of liver) |
| Dirofilaria immitis | Worm in surgical specimen, appearance on radiograph. |
| Echinococcus granulosus | Combination of imaging (appearance on ultrasound or CT) and serology (50-75% sensitive)[126] |
| Fasciola spp. | Serology Eggs in stool (late in disease) |
| Gnathostoma spp. | Larvae in biopsy, serology (reference lab) |
| Hookworm (A. duodenale and N. americanus) | Eggs in stool |
| Loa loa | MF in mid-day blood (concentrate with filtration) Serology (Nonspecific filarial antibody, reference lab). Presence of eyeworm |
| Lymphatic filariasis (W. bancrofti, B. malayi) | MF in nighttime blood (concentrate with filtration) Serology (Nonspecific filarial antibody, reference lab) Circulating filarial antigen card test (not available in US) |
| Mansonella perstans, M. ozzardi | MF in blood (concentrate with filtration) |
| Mansonella streptocerca | Skin snips |
| Onchocerca volvulus | Skin snips, Serology (Nonspecific filarial antibody, reference lab) |
| Opisthorchis spp. | Eggs in stool |
| Paragonimus spp. | Serology (ELISA or Immunoblot)[48, 193]. Eggs in sputum (sensitivity 60%, 2 samples) [194] Eggs in stool (insensitive) [166]. |
| Sarcocystis spp. | Muscle biopsy |
| Schistosoma haematobium | Eggs in urine, Serology |
| Schistosoma intercalatum | Eggs in stool, Serology |
| Schistosoma japonicum | Eggs in stool, Serology |
| Schistosoma mansoni | Eggs in stool/rectal biopsy, Serology |
| Schistosoma mekongi | Eggs in stool |
| Strongyloides stercoralis | Serology (SSIR and NIE IgG LIPS sensitivity 100%, spec 100%) [195], Larvae in stool (insensitive except in hyperinfection) |
| Sparganosis (Spirometra spp., Sparganum proliferum) | Sparganum in infected tissue. For CNS disease, positive CSF ELISA, typical CT findings, and history of eating frogs or snakes from endemic area strongly supports diagnosis [205] |
| Toxocara canis (Visceral larva migrans) | Serology. Larvae in liver biopsy (rarely seen). |
| Trichinella spp. | Serology, muscle biopsy |
| Trichostrongyloides spp. | Eggs in stool |