Volume 31, Number 12—December 2025
Research
Guinea Pig Model for Lassa Virus Infection of Reproductive Tract and Considerations for Sexual and Vertical Transmission
Table
Pathologic findings and virus localization by immunohistochemistry or in situ hybridization in reproductive and mammary tissues of LASV-Josiah or LASV-NJ2015 strain–infected guinea pigs at different timepoints in study of guinea pig model for LASV infection of reproductive tract and considerations for sexual and vertical transmission*
| Sex | Tissue | Group† | Hematoxylin and eosin |
Immunohistochemistry or in situ hybridization |
|||
|---|---|---|---|---|---|---|---|
| n/N (%)‡ | Lesion/change | n/N (%)‡ | Cellular location | ||||
| F |
Ovary | Early | 1/15 (7) | PILPI, PE | 7/15 (47) | TIC, GC | |
| Lethal | 5/6 (83) | PILPI, PE | 5/6 (83) | TIC, GC, IMC, VSMC, ENDC | |||
| Survivor | 2/10 (20) | PILPI | 0/10 (0) | ND | |||
| Oviduct | Early | 1/15 (7) | PILPI | 3/15 (20) | IMC | ||
| Lethal | 5/6 (83) | PILPI, PE, congestion | 5/6 (83) | PV/IMC, VSMC, OSMC, intravascular inflammatory cells | |||
| Survivor | 3/10 (30) | PILPI | 0/10 (0) | ND | |||
| Uterus | Early | 6/15 (40) | PILPI, PIE, congestion | 10/15 (67) | Endometrial stromal, epithelial cells, IFMC, ENDC | ||
| Lethal | 6/6 (100) | PILPI, PIE, congestion, vasculitis | 6/6 (100) | PV/IMC, IFMC, ENDC, VSMC, OSMC, endometrial stromal | |||
| Survivor | 4/10 (40) | PILPI, PIE, congestion | 0/10 (0) | ND | |||
| Cervix/ vagina |
Early | 2/12 (17) | PILPI, PIE | 8/12 (67) | IMC, VSMC, epithelial cells, intraluminal debris, FMC | ||
| Lethal | 3/6 (50) | PILPI, PIE | 3/6 (50) | IMC, VSMC, epithelial cells, ENDC, intraluminal debris, IFMC | |||
| Survivor |
4/10 (4) |
PILPI, PIE |
0/10 (0) |
ND |
|||
| M |
Testis | Early | 0/10 (0) | None | 2/10 (20) | IMC, ENDC, intravascular | |
| Lethal | 0/5 (0) | None | 2/5 (40) | IMC, seminiferous tubule | |||
| Survivor | 0/11 (0) | None | 0/11 (0) | ND | |||
| Epididymis | Early | 1/10 (10) | PILPI, epithelial necrosis, intratubular debris | 3/10 (30) | IMC, peritubular, tubular epithelium, intraluminal cells (including spermatozoa) | ||
| Lethal | 3/5 (60) | PILPI, epithelial necrosis, intratubular heterophils | 4/5 (80) | IMC, VSMC, ENDC, tubular epithelium, intraluminal cells/debris (including spermatozoa) | |||
| Survivor | 3/11 (27) | PILPI, PIE, intratubular heterophils, MXI, loss of tubules | 0/11 (0) | ND | |||
| Seminal vesicle/prostate | Early | 0/10 (0) | None | 3/10 (30) | PV/IMC | ||
| Lethal | 1/5 (20) | PILPI, PE | 3/5 (60) | IMC, intraluminal debris, VSMC | |||
| Survivor | 0/11 (0) | None | 0/11 (0) | ND | |||
| Penis/prepuce |
Early | NS | NS | NS | NS | ||
| Lethal | 1/3 (33) | MXI (preputial gland duct) | 0/3 (0) | ND | |||
| Survivor |
2/7 (29) |
PLPI |
0/7 (0) |
ND |
|||
| Both | Mammary tissue | Early | 8/20 (40) | PILPI (glands and skin), histiocytic infiltrates, PIE (glands), epidermal necrosis | 11/20 (55) | IMC, dermis, follicular wall, epidermis, IFMC | |
| Lethal | 3/4 (75) | PILPI, PIE (glands and skin) | 2/4 (50) | IMC, ENDC, glandular epithelial cells, IFMC, intraluminal debris, epidermis, follicular wall | |||
| Survivor | 4/13 (31) | PILPI (glands and skin), PIE, congestion, MXI (glands) | 0/13 (0) | ND | |||
*dpi, days postinfection; ENDC, endothelial cells; GC, granulosa cells; IFMC, inflammatory cells; IMC, interstitial mesenchymal cells; LASV, Lassa virus; MXI, mixed inflammatory infiltrate; ND, not detected; NS, not sampled; PE, perivascular edema; PIE, perivascular and interstitial edema; PILPI, perivascular and interstitial lymphoplasmacytic inflammation; PLPI, perivascular lymphoplasmacytic inflammation; PV, perivascular; OSMC, other (nonvascular) smooth muscle cells; TIC, Theca-interstitial cells; VSMC, vascular smooth muscle cells. †Early refers to animals serially euthanized 2–16 dpi after infection with LASV-Josiah-strain. Lethal refers to animals lethally infected with LASV-Josiah-strain and euthanized because of severity of clinical disease 14–28 dpi. Survivor refers to animals that survived LASV-Josiah-strain or LASV-NJ2015 strain infection and were euthanized 41–42 dpi. ‡n indicates number of animals with pathologic changes or staining in the tissue; N represents total number of animals evaluated in the group; percentage indicates percentage of animals evaluated that had the histopathologic finding present or with positive staining by immunohistochemistry or in situ hybridization in that tissue; not all tissues were evaluated or tested by immunohistochemistry or in situ hybridization for all animals (Appendix Tables 1–3, https://wwwnc.cdc.gov/EID/article/31/12/25-0396-App1.pdf).
1Current affiliation: StageBio, Frederick, Maryland, USA.