Primaquine 30 mg/day versus 15 mg/day during 14 days for the prevention of Plasmodium vivax relapses in adults in French Guiana: a historical comparison.

BACKGROUND: The preventive treatment of Plasmodium vivax relapse recommended by the World Health Organization is primaquine at a dose of 15 mg/day for 14 days, except for malaria cases from Asia and Oceania. Since 2006, CDC recommends the use of primaquine at 30 mg/day for 14 days. In France, all cases of malaria due to P. vivax are treated with 30 mg of primaquine. This systematically increased dosage needs to be evaluated according to epidemiological context. The aim of the study was to compare relapses after 14 days of primaquine at 15 or 30 mg/day. METHODS: All patients treated with primaquine after a vivax malaria episode in French Guiana, between 1 January, 2007 and 1 August, 2016, were studied. Based on the compulsory hospital pharmacy forms for primaquine delivery, adult patients who received 15 or 30 mg of primaquine during 14 days for hypnozoite eradication were included. The recommended dose was initially 15 mg and was changed to 30 mg in 2011. Vivax malaria recurrences within 2 months after primaquine treatment, and vivax malaria recurrences 2-6 months after primaquine in each treatment group were analysed using survival analysis at 2, 3 and 6 months. RESULTS: Out of 544 patients included, 283 received 15 mg/day and 261 received 30 mg/day of primaquine. At 2 and 3 months after primaquine treatment, the number of recurrences was 7 (2.5%) and 19 (7.3%), and 9 (3.4%) and 15 (5.3%), in the 15 and 30 mg groups (p = 0.51 respectively 0.35), respectively. Within 3 months, the median time to recurrence was 2.05 months in the 15 and 30 mg groups. At 6 months after primaquine treatment, the number of recurrences was 25 (8.8%) and 31 (11.9%) at 15 and 30 mg, respectively (p = 0.24). The median time to recurrence was 2.38 months at 15 mg/day and of 2.64 months at 30 mg/day. CONCLUSIONS: There were no significant differences between primaquine at 15 or 30 mg/day for 14 days in the prevention of P. vivax relapses at 2, 3 and 6 months after primaquine treatment in French Guiana.

Levers and Barriers to Vaccinate against COVID-19 in the Multicultural Context of French Guiana: A Qualitative Cross-Sectional Survey among Health Care Workers.

In French Guiana, a French overseas territory in South America facing a fourth wave of COVID-19, vaccination coverage is very low, both in the population and among health care workers (HCWs). Vaccine hesitancy concerned 35.7% of the latter in early 2021. The objective of this complementary study is to understand barriers and levers and to adapt messages to increase vaccination coverage among HCWs. We conducted a regional cross-sectional survey of HCWs with a questionnaire containing open-ended questions exploring factors associated with vaccine hesitancy and the needs to adapt the vaccination campaign in French Guiana. The discourses were analyzed using a qualitative approach based on grounded theory, with open coding of data by themes and construction of abstract categories. The analysis of the 357 responses collected from January to March 2021 reveals several trends. The ethical aspect of the HCWs' role emphasizes the importance of getting vaccinated themselves (to protect patients, to set an example...) and of vaccinating as many people as possible, including the most geographically or socially distant, such as undocumented migrants. However, some HCWs remain suspicious of the vaccine with concerns over the efficacy and side effects, of health institutions, and of the pharmaceutical industry. The role of fake news circulating on social networks has been widely discussed. Efforts to explain and convince HCWs must be continued in French Guiana using the identified levers to improve the acceptability of vaccination.