Ethics statement

The FISH CRT is registered in the ISRCTN registry, number ISRCTN14354324 accessible at https://www.isrctn.com/ISRCTN14354324 and was approved by COMREC institutional review board in Malawi and the Liverpool School of Tropical Medicine Ethics Committee. The survey participants voluntarily participated and gave written or thumbprint with a witness consent

Study design

This was a cross-sectional baseline survey conducted between November 2019 and February 2020 prior to the implementation of a community cluster-randomized trial (CRT) [11]. The trial’s main aim is to investigate the effect of using peer-educators, with or without HIV self-test kits, on increasing the uptake of services for schistosomiasis and HIV by adult fishermen.

Setting

Preceding the baseline survey we undertook a formative social and physical mapping exercise on the shores of Mangochi, a district in the southeastern region of Malawi which borders Lake Malawi and Mozambique. On the southern lakeshore of Malawi, fishing is predominantly undertaken by men through small boats of up to 10 fishermen. We defined clusters to be landing sites, i.e. fishing communities on the lakeshore. Fishing communities were located using Google Earth maps together with local residents, and circumferential walks with global positioning satellite (GPS) devices were done to demarcate trial cluster boundaries. Community and peer leaders (fishermen representatives) were engaged to agree on the cluster boundaries, and to introduce the baseline survey and the subsequent CRT.

Participants and procedures

The baseline survey set out to investigate knowledge, attitudes and previous testing and treatment behaviour of fishermen in southern Malawi fishing communities. Within each cluster peer leaders provided a list of fishing boats operating in the cluster as well as a list of fishermen operating in the listed boats. To be eligible for the survey, fishermen needed to: be 18 years old or over; have a fixed residence in a trial cluster; and consent to participate. We excluded fishermen who were not permanent residents of the fishing community or were underage (<18y).

Fishermen completed a face-to-face interview on tablets running open data kit (ODK) questionnaires. A total of seven interviewers were involved in the data collection. The interviewers were selected on the basis of being from within the Mangochi district to ensure quality of responses due to familiarity with the local dialect spoken in this part of the district. Interviews were conducted on the lakeshore at a private space chosen by the fishermen. All outcomes were measured via self-reports by the fishermen.

Outcomes

Three main fisherman-level outcomes were examined in this analysis: proportion reported to have ever tested for HIV; proportion reported having tested for HIV in the last 12 months; and proportion who reported having taken praziquantel in the preceding 12 months. Explanatory variables included: age, literacy; educational attainment; male circumcision status; self-rated general health status; and knowing someone who died of HIV. Knowledge of HIV status was examined as an explanatory variable for the taking praziquantel outcome and vice versa, being indicative of health-seeking behaviour by the participant. We additionally investigated fishermens’ willingness to attend a beach clinic offering free integrated HIV and schistosomiasis services, measured by asking “Would you be wiling to attend a beach clinic offering both HIV and schistosomiaisis services?”

Statistical methods

The sample size for the survey was determined by the total number of fishermen in the clusters of the CRT. Assuming conservatively that 44% of fishermen had never tested for HIV[12] then for the sample proportion to be estimated to within +/-0.02 (2%) using the 95% confidence level, a sample of 2,367 fishermen would be required. This sample size would also be adequate to address the outcome of taking praziquantel in the last 12 months with precision of +/- 1.5%[13].

Analysis used R version 4.1.3 (R Core Data Team[14]) with p<0.05 indicating statistical significance. Frequencies were computed for categorical variables while mean and standard deviation (SD) or median and inter quartile range were computed for continuous variables that were normally distributed or skewed on visual inspection, respectively. To estimate knowledge of HIV status and exposure to praziquantel use we constructed random-effects binomial regression models, with standard errors adjusted to account for clustering. In multivariable analysis, we calculated adjusted odds ratios and 95% confidence intervals to compare between levels of explanatory variables. Covariates with evidence of association with the outcomes of interest were included in the multivariate models through forward selection method beginning with the null model. The alpha significance level of the explanatory variables provided the critical threshold for subsequent stages of the analysis.

Key results

The main findings from this study included low utilization of free HIV services and schistosomiasis treatment (Praziquantel) among a high risk population of fishermen on the shores of Lake Malawi, (indicating that service integration is likely to increase uptake of both services), and extremely high willingness to attend beach clinics. The literature identifies mobility among fishermen, inconvenient offer of health services where there is mistiming, long distances to health facilities and stigma as key factors that contribute to low utilization[15–17]. Furthermore, limited information to the fisherfolks on the significance of early testing and subsequent interventions using the approved medications is also a key contributor to low utilization of health services in this population[18]. Consequently, individual, peer and societal attitudes towards drugs used to treat schistosomiasis and ART also lead to increased misinformation and heighten refusal of free drugs[19,20].

The recent data from the Malawi population-based HIV impact assessment (MPHIA) indicate that 12% of people living with HIV in Malawi are not aware of their HIV status [21]. Our survey results suggest that up to 21% of the fishermen did not know their HIV status which may be in keeping with the MPHIA data yet indicative of the problems in achievement of universal health coverage which states that all people should have access to the health services they need. Furthermore, only 17% of the fishermen had been circumcised which suggests low utilization of free health services. Again only 34% of fishermen had taken praziquantel in the last 12 months which is way below the target of 100% considering their ongoing risk of infection due to ongoing freshwater contact.

Malawi implements twice a year mass drug administration of praziquantel among the fishing communities[22]. Our data showed that surveyed fisherfolk who had received praziqualntel were more likely to have tested for HIV, and vice-versa. This is an indicator of high willingness to receive either intervention and potentially indicates acceptability of integrated HIV and schistosomiasis services. A call for such integration supports the United Nations AIDS (UNAIDS) report of 2019 which advocates for similar approaches among women [23]. It is therefore plausible to develop specific interventions for HIV and schistosomiasis aimed for programmatic integration, using existing opportunities to reach fishermen and other populations at risk throughout their life course[8]. The benefits of such an integrated approach should be straightforward to document the increasing uptake of HIV testing and distribution of the drug praziquantel. Elsewhere, integrated approaches have been successful in the management of female genital schistosomiasis, HIV and cervical cancer as well as successfully strengthening existing health programmes[8].

Contrary to the strongly held opinion that fishermen are unwilling to utilize health services, we found extremely high willingness to attend a mobile beach clinic when offered hypothetically among the surveyed fishermen. The key difference was that we made it clear that such a beach clinic would firstly be made available right on the lakeshore to provide convenience and secondly that fishermen would be able to access it during a wide range of hours. Such a flexible approach in service delivery has been shown in various studies and programmes to increase the uptake of services dramatically, especially for men[24].

The main strength of this study is that we showed promising results on potential significant uptake of integrated HIV and schistosomiasis services among the fishing population in Mangochi, Malawi as this will inform demand creation efforts.

The main limitation of this study was that it gives a snapshot of the baseline prevalence of the two hazards, but does not measure the impact of the services being rendered in the beach clinics. Self-reporting of HIV testing and uptake of the schistosomiasis drug praziquantel might have contributed to information bias. Given that all outcomes were self-reported there is likelihood of information bias. HIV and schistosomiasis services are free of charge and fishermen know that they are a priority population. Thus, social desirability bias would have been likely whereby fishermen may have reported that they tested for HIV or took Praziquantel when in fact they had not done so. For both HIV and schistosomiasis, distance to the nearest health facility may be an important factor which was not included in the data reported here.

The study findings are generalizable to Malawi fishermen over 18 years of age and the large sample size was critical in reducing random errors. However, following this baseline study, there will be a cluster-randomized trial which will enhance both the internal and external validity of the study outcomes.