RESUMEN
Introduction: Due to lower intensity of infection and greater intervals from last exposure, parasitologic detection methods for schistosomiasis are poorly sensitive in non-endemic areas, challenging accurate diagnosis. Methods: We evaluated parasitologic versus indirect detection methods for schistosomiasis. We included specimens submitted for Schistosoma serology, and stool for ova and parasite microscopy. Three real-time PCR assays targeting Schistosoma mansoni and S. haematobium were performed. Primary outcome measures were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), where both microscopy and serology were the composite reference standard against serum PCR. Results: Of 8168 serum specimens submitted for Schistosoma serology, 638 (7.8%) were reactive and 6705 (82.1%) were non-reactive. Of 156,771 stool specimens submitted for ova and parasite testing, 46 (0.03%) were positive for eggs of S. mansoni. Four (0.5%) urine specimens were positive for eggs of S. haematobium. Combined serum PCRs targeting S. mansoni had a sensitivity and specificity of 27.8% (95% CI = 18.3-39.1%) and 100% (95% CI = 83.9-100%), respectively, with PPV of 100% (95% CI = 100%) and NPV of 26.9% (95% CI = 24.3-29.7%). The one serum sample positive for S. haematobium was also detectable by our S. haematobium PCR. No cross-reactivity was observed for all three PCR assays. Conclusions: Although serology is highly sensitive, parasitologic tests signify active infection, but are limited by low population-level sensitivity, particularly in non-endemic settings. Although serum PCR offered no performance advantage over stool microscopy, its role in diagnostic parasitology should be pursued due to its high-throughput and operator-independent nature.
RESUMEN
BACKGROUND: Gestational helminth infections are correlated to adverse outcomes including maternal anaemia; as such, treatment is recommended. However, little published high-quality data exist around the efficacy, safety and tolerability of anti-helminthics in pregnancy. We therefore conducted a systematic review and synthesized the available data on maternal outcomes following gestational treatment of intestinal nematodes to help guide clinical decision-making. METHODS: Five electronic databases were searched for studies reporting the efficacy, safety or tolerability of anti-helminthic drugs for gestational treatment of intestinal nematodes. Studies were systematically screened followed by data extraction. Trial quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. We conducted a narrative synthesis followed by meta-analyses using random effects models as appropriate. Data were summarized using qualitative and quantitative measures for specific parasitic infections as well as efficacy and safety of anti-parasitic agents. Outcomes of interest included maternal anaemia, minor adverse outcomes, pregnancy loss, pre-mature delivery, prevalence of infection and cure rate. RESULTS: Twenty-three studies were included. Gestational treatment with albendazole had cure rates up to 90% for hookworm and Ascaris, but only 50% for Trichuris. Mebendazole had an overall cure rate of ≤ 70% for Ascaris, hookworm and Trichuris. Pooled relative risk reduction of hookworm prevalence at delivery with albendazole compared to placebo was 90% (95% confidence interval, 0.09-0.15; n = 2; I2 = 0%). Rate of pregnancy loss and haemoglobin concentration did not differ between albendazole or mebendazole vs placebo, and rates of pre-term delivery were similar in albendazole-treated pregnant women vs controls. Ivermectin demonstrated a cure rate of 29% for hookworm and 56% for Trichuris in pregnant women. No serious adverse events were attributable to any drug studied. CONCLUSIONS: With increased international travel and migration of vulnerable populations, practitioners will encounter nematode infections in pregnant patients. Our analysis supports that albendazole in pregnancy has high cure rates for soil-transmitted helminths and is safe for the mother.
