Table 9. Schistosomes and Interactions with HPV, HTLV-1, and Measles.
| Study | Subject Type | Sample Size | Sex (% Female) | Age in Years (Weighted Mean) | Country | Species† | Differences in Schistosome Infected Compared to Uninfected | Overall Effects of Schisto-some Infection |
|---|---|---|---|---|---|---|---|---|
| HPV Prevalence | ||||||||
| Kjetland 2010 [119] | Human | 37 | 100% F | Range, 20–55 | Zimbab-we | Sh |
7 women developed HGSIL and 6 had Sh* No effect on HPV persistence (29% versus 19%) |
Possible increases in HPV prevalence and sequelae; larger studies needed |
| Petry 2003 [120] | Human | 218 | 100% F | Median,28.4 | Tanzaniaand Germany | Sh | Borderline ↑ HPV prevalence (83% in confirmed Sh vs 39% in uninfected) | |
| HPV Vaccine | ||||||||
| Gent 2019 [121] | Baboon | 10 | Not reported | Sub-adult | NA | Sm |
↓ HPV-specific IgG after vaccination in Sh IgG restored in baboons given PZQ before vaccine |
Discrepant data; large human study suggests no effect |
| Brown 2014 [122] | Human | 298 | 100% F | Range, 10–25 | Tanzania | Sh, Sm | No difference in HPV IgG antibody titers | |
| HTLV-1 | ||||||||
| Lima 2013 [125] | Human | 26 | 42% F | 48 | Brazil | Sm | ↓ IFN-ɣ and ↑ IL-10 after schistosome antigen stimulation | Decreased Th1 cytokines and HTLV-1 viral load in vitro, which may contribute to observed lower rates of tropical spastic paralysis |
| Lima 2017 [126] | Human | 38 | 76% F | 47.2 | Brazil | Sm | ↓ CXCL9 after schistosome antigen stimulation | |
| Santos 2004 [127] | Human | 120 | Not reported | Not reported | Brazil | Sm | ↓ IFN-ɣ and ↑ IL-10 in unstimulated cultures | |
| Porto 2005 [124] | Human | 70 | Approx-imately 15% F | Approx-imately 46 | Brazil | Sm |
↓ IFN-ɣ and ↑ IL-10 ↓ frequency of CD4+ and CD8* IFN-ɣ secreting cells ↓ HTLV-1 proviral DNA load in PBMCs |
|
| Response to Rubeola (Measles) Vaccine | ||||||||
| Tweyon-gyere 2019 [128] | Human | 239 | 53% F | 3.9 years | Uganda | Sm |
↓ anti-measles IgG in Sm at one week; lower IgG trend at 6 months ↓ % with protective antibody levels in Sm ↓ anti-measles IgG after PZQ |
Active schisto-some infection during measles vaccine may impair anti-measles antibody response. Maternal Sm infection did not consistently impact children’s measles vaccine response. Adults with Sm did not have decreased measles IgG. |
| Nono 2018 [129] | Human | 85 | Not reported for sub-study | Range, 5–18 | Came-roon | Sh, Sm | ↓ anti-measles IgG in Sm but not in Sh (children had been previously vaccinated) | |
| Jiz 2013 [130] | Human | 104 | Not reported | Range, 7–16 | Phili-ppines | Not listed | No difference in post-vaccine anti-MMR cytokine responses in schistosome infected | |
| Ondigo 2018 [131] | Human | 99 | Not reported | 2 years | Kenya | Sm | ↓ anti-measles IgG in 2-year-olds whose mothers had Sm during pregnancy | |
| Kizito 2013 [132] | Human | 711 | Not reported | 1 year | Uganda | Sm | No difference in post-vaccine anti-measles IgG in 1-year-olds whose mothers had Sm during pregnancy | |
| Storey 2017 [133] | Human | 100 | 82% F | 41 | Kenya | Sm | No difference in anti-measles IgG in HIV-infected adults with Sm | |
*HGSIL = High grade squamous intraepithelial lesion
†Sm = S. mansoni; Sh = S. haematobium