Self-diagnosis and self-treatment of Plasmodium spp. infection by travellers (1989-2019): A systematic review and meta-analysis.

BACKGROUND

Standby emergency self-treatment (SBET) is often recommended as an anti-malaria strategy for travellers to low-risk endemic areas. This self-treatment enables competent malaria therapy, if medical assistance is unavailable. The World Health Organization (WHO) recommends performing reliable diagnostic tests before starting antimalarial treatment. For the self-diagnosis of malaria in travellers, rapid diagnostic tests (RDT) can be used to confirm the infection before SBET is used. The aim of this research is to assess the use of RDT and/or SBET in travellers.

METHODS

We searched the databases (PubMed, Scopus, Embase, CINAHL) using terms and synonyms for 'self-diagnosis' and 'self-treatment' combined with 'malaria' and 'travel'. Articles in English, French and German were included. Potential articles were screened and extracted by two authors (KU and PS). Only original articles and case reports documenting the self-use of RDT and/or SBET in travellers were included. Data were extracted using a standardised approach. We defined 'correct use' of RDT and SBET. Data on number and performance of RDT and SBET use, as well as malaria verification were collected in an Excel table. Five meta-analyses were performed using a random effects model and calculating pooled proportions. This systematic review was conducted according to the PRISMA guidelines and registered in PROSPERO (CRD42018108874).

RESULTS

The research resulted in 867 articles of possible relevance on RDT and 955 articles on SBET. After screening, a total of 4 articles on RDT use and 17 articles for SBET use in travellers were included in the systematic review. Most of the RDT were performed and interpreted properly by the travellers (pooled proportion 88%, 95% confidence interval (CI) from 64% to 97%), whereby the proportion of correct performance was increased after a pre-travel test run (97%). Major problems in the implementation such as pricking finger, placing blood drop, identifying lines and interpreting results could be discovered. We found data on 1025 SBET uses in studies of travellers to high-risk African countries. In these studies, the pooled proportion of SBET uses was 6% (95% CI from 2% to 13%). We found 545 SBET uses in studies of travellers to countries of mixed malaria risk. In these studies, the pooled proportion of SBET uses was 2% (95% CI from 1% to 7%). Furthermore, the evaluation showed a high proportion of correct SBET use (pooled proportion 69%, 95% CI from 35% to 90%). As a cause for incorrect use, errors in dosage (under- or overdose), disregard of minimal incubation period (< 7 days since first possible malaria exposure) and absence of fever were identified. Four cases of post-SBET severe adverse events were documented. In a third of travellers who used SBET, a Plasmodium spp. infection could be detected (pooled proportion 31%, 95% CI from 16% to 51%).

CONCLUSIONS

This systematic review and meta-analysis showed that the majority of travellers were able to use RDT and SBET correctly. Standardised pre-travel instructions and specific training are indicated to increase the proportions of correct RDT and SBET use. With improved and user-friendly technology, RDT may become an integral part of SBET malaria recommendations for travellers. Combined use of RDT and SBET could be an appropriate strategy for selected subgroups of travellers to low-risk, remote malaria areas. Future research should focus on combined RDT and SBET strategies.