None listed
Conditions
Brief summary
Schistosomiasis japonica, a zoonotic parasitic disease, is a major public health problem in the Philippines with approximately 6.7 million people at risk of infection. Passive surveillance and mass human praziquantel (PZQ) chemotherapy has formed the cornerstone of control and recent prevalence estimates have shown that this approach has failed. Our central thesis is that: Human mass PZQ chemotherapy alone is unable to successfully control schistosomiasis in the Philippines. Transmission reduction is a key step towards elimination and interventions should target definitive (human and animal) and intermediate (invertebrate) host transmission pathways. Such an integrated approach is highly appropriate in the Philippines with carabao now identified as playing a major role in schistosomiasis transmission. A five year phase III cluster randomised control trial was conducted among 18 schistosomiasis- endemic barangay comprising 18,221 residents in Northern Samar, The Philippines. We examined the impact of a combination of human mass chemotherapy, snail control through mollusciciding and SjCTPI bovine vaccination on the human incidence of infection.
Interventions
A five year phase III cluster randomised control trial was conducted among 18 schistosomiasis- endemic barangay comprising 18,221 residents in Northern Samar, The Philippines. We examined the impact of a combination of human mass chemotherapy, snail control through mollusciciding and SjCTPI bovine vaccination on the human incidence of infection. Following the baseline survey, the interventions were implemented in 18 intervention groups from 2013 to 2017. The investigators, including the research
A five year phase III cluster randomised control trial was conducted among 18 schistosomiasis- endemic barangay comprising 18,221 residents in Northern Samar, The Philippines. We examined the impact of a combination of human mass chemotherapy, snail control through mollusciciding and SjCTPI bovine vaccination on the human incidence of infection. Following the baseline survey, the interventions were implemented in 18 intervention groups from 2013 to 2017. The investigators, including the research team, and study participants were blind to the vaccine allocation. At baseline all residents (60 mg/kg directly observed split oral dose) and bovines (30 mg/kg directly feed oral dose) were treated with a directly observed oral dose of PZQ. Villages were then pair-matched for the RCT based on historical prevalence, baseline outcomes, and transmission ecology. One of three intervention ARMs (no specific intervention (control), human mass praziquantel (PZQ) treatment, mollusciciding) were randomly assigned to each pair to achieve three pairs per intervention type. Within each pair, one village was randomly assigned the active vaccine for vaccinating bovines and the other village received a placebo vaccine. The intervention matrix is shown below: Intervention---------Vaccinated Bovines-------Unvaccinated bovines Mollusciciding----------3 Villages (A)----------------3 Villages (B) Human treatment-----3 Villages (C)----------------3 Villages (C) Neither------------------3 Villages (D)----------------3 Villages (e) Controls Bovines received the priming SjCTPI DNA vaccine and then the protein boost or placebo control in VacSIM® six months later, in 2013 with subsequent booster vaccinations or placebo controls in VacSIM® given in 2014, 2015 and 2016. Full details of the production and formulation of the SjCTPI vaccines (plasmids encoding SjCTPI-HSP70 and UMVC3-mIL12 and recombinant SjCTPI), placebo control vaccine, the vaccination regimen, and the procedures for injecting bovines with the vaccine/placebo formulations have been provided (Da'Dara AA et al., Front Immunol. 2019 Feb 20;10:284. doi: 10.3389/fimmu.2019.00284. eCollection 2019) . VacSIM® was previously described (Grenfell RF et al., Clin. Vaccine Immunol. 2015 Mar 22(3):336-43). Human mass treatment with PZQ was carried out annually in the three randomly selected village pairs. Mollusciciding (following the annual snail surveys) was conducted in the three other randomly chosen pairs. Targeted snail ‘hotspots’ (areas close to human habitation with maximum or daily access to both human and bovines in an environment favored by snails), were sprayed with niclosamide (2 g/m2) annually.
Sponsors
Griffith University
Study design
Allocation
Randomised controlled trial
Intervention model
Other
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
5 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
Individuals residing in endemic schistosomiasis villages in Norther Samar, the Philippines and expect to be living there for the next five years.
Exclusion criteria
Outside the designated age range (5-65 years) and/or do not plan to resident in the study area on the next five years.
Outcome results
None listed