ABSTRACT
Novel methods are required to aid the monitoring of schistosomiasis control and elimination initiatives through mass drug administration. Portable digital and mobile phone microscopy is a promising tool for this purpose. This cross-sectional study evaluated the diagnostic operating characteristics of a converted mobile phone microscope (the SchistoScope) for the detection of Schistosoma haematobium eggs, as determined by community-based field workers and expert microscopists, compared with a field gold standard of light microscopy. Three hundred sixty-five urine samples were evaluated by conventional light microscopy, with 49 (13.4%) positive for S. haematobium. Compared with light microscopy, the sensitivity and specificity of S. haematobium detection by field microscopists trained to use the SchistoScope were 26.5% (95% CI: 14.9-41.1%) and 98.4% (95% CI: 96.3-99.5%), respectively. The sensitivity and specificity of S. haematobium detection by expert microscopists using the SchistoScope was 74% (95% CI: 59.7-85.4%) and 98.1% (95% CI: 95.9-99.3%), respectively, compared with light microscopy. The sensitivity rose to 96.1% and 100% when evaluating for egg counts greater than five and 10 eggs per 10 mL, respectively. A point-of-care circulating cathodic anion (POC CCA) test was used to evaluate Schistosoma mansoni; however, there were too few positive samples to reliably comment on diagnostic characteristics. This study demonstrated that a "urine-only" approach to rapidly screen for schistosomiasis at the point of sample collection can be conducted with mobile phone microscopy (S. haematobium) coupled with POC CCA (S. mansoni). Such an approach may aid in streamlined schistosomiasis control and elimination initiatives.
ABSTRACT
PEP-In-Pocket (Post-Exposure Prophylaxis-In-Pocket, or "PIP") is a biobehavioural HIV prevention strategy wherein patients are proactively identified and given a prescription for HIV post-exposure prophylaxis (PEP) medications to self-initiate in case of high-risk exposures. We evaluated this strategy in a prospective observational study at two hospital-based clinics in Toronto, Canada. HIV-negative adults using PIP underwent chart review and completed quarterly electronic questionnaires over 12 months. The primary objective was to quantify appropriate PIP initiation, defined as starting PIP within 72 h of a high-risk exposure. Secondary objectives were to quantify HIV seroconversions, changes in sexual risk behaviour, sexual satisfaction, and satisfaction with the PIP strategy. From 11/2017 to 02/2020, 43 participants enrolled and completed ≥1 questionnaire. PIP was self-initiated on 27 occasions by 15 participants, of which 24 uses (89%) were appropriate, 2 were unnecessary, and 1 was for an unknown exposure. Chart review identified no inappropriate non-use. Over 32 person-years of testing follow-up, we observed zero HIV seroconversions. Sexual risk declined modestly over follow-up, with a HIRI-MSM (HIV Incidence Risk Index for MSM) change of -0.39 (95% CI = -0.58, -0.21 per 3 months, p < .001). Sexual satisfaction was stable over time. At 12 months, 31 (72%) remained on PIP, 8 (19%) had transitioned to pre-exposure prophylaxis and 4 (9%) were lost-to-follow-up. Among participants who remained on PIP and completed questionnaires at 12 months, 24/25 (96%) strongly/somewhat agreed that PIP decreased their anxiety about contracting HIV and 25/25 (100%) strongly/somewhat agreed that they would recommend PIP to a friend. PIP is a feasible HIV prevention strategy in carefully selected individuals at modest HIV risk.
ABSTRACT
BACKGROUND: HIV postexposure prophylaxis-in-pocket ("PIP") is a self-initiated, event-driven HIV prevention modality for individuals with a low frequency of HIV exposures. METHODS: A cohort of 111 patients using PIP as their primary HIV prevention modality was longitudinally evaluated for PIP self-initiation, HIV and sexual transmitted infections, and switching to other HIV prevention modalities between February 2016 and December 2022. RESULTS: A total of 111 patients had 178.7 cumulative patient-years of PIP use. PIP was self-initiated 69 times by 35 (31.5%) individuals, with 0 HIV seroconversions identified. Thirty four individuals (30.6%) transitioned from PIP to pre-exposure prophylaxis and 33 individuals (29.7%) switched from pre-exposure prophylaxis to PIP. CONCLUSIONS: PIP is a useful addition to other pharmacologic HIV prevention tools, and may help prevent infection in those with a lower frequency of unanticipated HIV exposures.
Subject(s)
Acquired Immunodeficiency Syndrome , Anti-HIV Agents , HIV Infections , Pre-Exposure Prophylaxis , Humans , HIV Infections/prevention & control , HIV Infections/drug therapy , Anti-HIV Agents/therapeutic use , Acquired Immunodeficiency Syndrome/drug therapy , Sexual Behavior , Canada/epidemiology , Post-Exposure ProphylaxisABSTRACT
Schistosomiasis infections continue to impact African settings disproportionately, and there is an urgent need for novel tools to evaluate infection control and elimination strategies at the community level. Mobile phone microscopes are portable and semiautomated devices with multiple applications for screening neglected tropical diseases. In a community-based schistosomiasis screening program in Azaguié, Côte d'Ivoire, mobile phone microscopy demonstrated a sensitivity of 85.7% (95% CI: 69.7-95.2%) and specificity of 93.3% (95% CI: 87.7-96.9%) for Schistosoma haematobium identification compared with conventional light microscopy, and 95% sensitivity (95% CI: 74.1-99.8%) with egg concentrations of five or more per 10 mL of urine. Mobile phone microscopy is a promising tool for schistosomiasis control and elimination efforts.
