The Knowledge, Attitudes and Practices of Malaria and The Risk of Malaria Infection Among Chinese Population in Sierra Leone

Background: The risk of malaria importation from malaria hyperendemic regions has threatened the achievement of the malaria elimination goal of China. However, few studies have focused on malaria control interventions among Chinese population in Africa. The aims of this study were to assess the knowledge, attitudes and practices (KAP) of malaria and the risk of malaria infection among Chinese population in Sierra Leone, then to improve the knowledge of malaria among Chinese population in Sierra Leone through health education interventions. Methods: Cluster random sampling method was undertaken to select the overseas Chinese from 27 Chinese institutions as respondents in Sierra Leone. Cross-sectional surveys of malaria KAP and the risk of malaria infection were performed on respondents by trained investigators. Health education training were conducted to educate respondents knowledge of malaria after the surveys. The same questionnaires of malaria KAP as before the training were used to evaluate the effect of health education interventions. Correlation analyses of results were performed by T test, ANOVA, Chi-Square and Logistics regression model. Results: A total of 134 respondents fully completed questionnaires were analyzed before health education training with mainly engaged in (73.88%) outdoor work. Majority of participators (82.84%) were from 20 Chinese provinces. About half of participators (49.25%) had not received malaria health education before going abroad. The practices of prevention malaria were used in most respondents, 84.33% (113/134) used mosquito net every day, 90.30% (121/134) were equipped with screen doors and Windows in their dwellings, 73.88% (99/134) used mosquito repellent when going out, and 74.63% (100/134) used mosquito insecticide at home. The average awareness rate of malaria knowledge of respondents without malaria training before going abroad (41.69 %) was signicantly lower than that of with malaria training (53.41%) (T =3.337, P=0.001).According to Logistics regression analysis, age (OR=2.6, 95%CI(1.0,8.8)) and male (OR=3.2, 95%CI(1.1,9.4)) were the main factors whether the awareness rate of malaria knowledge reaches 60% before the training. After health education training, the awareness rate


Introduction
In 2018, malaria was endemic in 91 countries and regions, with most malaria cases and deaths concentrated in sub-Saharan Africa, among which Sierra Leone is one of the ten countries with the highest malaria burden [1].Sierra Leone was located in west Africa, south of the Sahara Desert, north latitude 8~11° and west of the Atlantic Ocean. It has a tropical rain forest climate. Anopheles mosquitoes breed rapidly and plasmodium spreads widely. By contrast, China has not reported local malaria cases for three consecutive years since 2017 [2,3], and malaria has been eliminated in all epidemic provinces. In recent years, with the launch of global business, the number of Chinese going to sierra leone and other African countries for international assistance, exchange, investment, business and other activities has been increasing rapidly. There are still about 3,000 imported malaria cases every year, among which Africa has become the main source of imported malaria in China [4][5][6][7][8][9]. Chinese were not generally susceptible to falciparum malaria in China, so oversee travelers infected with falciparum malaria without treatment in time easily deteriorated into severe malaria with serious complications, resulting in about 30 imported malaria deaths in China every year [10].
Recent decades a large number of Chinese people went to Africa for work. By the end of 2018, there were 997,000 Chinese labor cooperation personnel working overseas, of which about 281,000 are in Africa [11].
And 1,398 Chinese labor service workers in Sierra Leone in 2018 [12]. If private business and tourism included, the estimated number of Chinese in Sierra Leone was around 3,000. From 2016 to 2019, 30-60 malaria cases imported from Sierra Leone each year in China, with no signi cant downward trend [8,13].
However, most Chinese in Africa were not well educated and lack of knowledge about malaria with malaria hyperendemic environment, weak public health infrastructure and high risk of malaria infection, which have brought great challenges to China's imported malaria prevention and control [12]. Therefore, China needs to move forward the line of defense for imported malaria.
In order to understand the risk of malaria and their KAP of malaria among overseas Chinese, this study conducted KAP about malaria and malaria risk survey and performed malaria health education interventions for Chinese in Sierra Leone from September to October 2019, then evaluated the interventions'effect and provided a basis for carrying out effective interventions in a targeted way.

Methods
The respondents were randomly selected by cluster random sampling method from 21 Chinese institutions in Sierra Leone from 11 Chinese-funded institutions, covering 200 people, for investigation and cognitive intervention. The minimum sample size of 96 cases (a = 0.05, = 0.1, P = 0.4) was calculated by the formula sample formula of cross-sectional investigation. The actual number of 134 people participated in KAP survey and health education training, and the response rate was 97.8% after the training.
The questionnaire of malaria KAP and malaria risk Surveys were designed by the epidemiologist expert group, which included basic information of respondents, knowledge and attitude of malaria and malaria prevention measures. The surveys were carried out by 4 investigators and supervised by 2 coordinators before health education training. The following was teaching respondents the knowledge of malaria and mosquito vector by using face to face teaching, and lecturer showed the samples of Anopheles, Culex and Aedes mosquitoes by 2 malaria experts. Simultaneously, the general situation of malaria infection in Sierra Leone, breeding habits of mosquitoes, the basic knowledge of plasmodium, and the speci c measures of mosquito and malaria prevention were included the training contents. After health education training, questionnaires on malaria KAP were carried out and the training effect was evaluated by 4 investigators and 2 coordinators.
Double entry method was used for data entry by Epidata3.0 software. Version 4.0.2 of the R statistical software (R Foundation for Statistical Computing, Vienna, Austria) was used to conduct statistical analysis and plot the distribution of respondents' migration. Knowledge of malaria was calculated by the number of correct answers compared with the total number of questions, and the awareness rate of malaria knowledge reached 60% that denoted as up to standard. The results were performed as description analysis, and the difference of the awareness rate of malaria between before and after health education training were conducted by T test, ANOVA, Chi-Square. Correlation analysis were used by Chi-Square and Logistics regression model. For Logistics regression analysis, selected variables were dichotomized into two categories with presence of certain characters/conditions =1 and absence = 0. The factors on the awareness rate of malaria knowledge and the risk of malaria infection with univariate analysis statistically signi cant were selected into Logistics regression model. P < 0.05 indicated that the difference was statistically signi cant. Centers for Disease Control(CDC) institutions, and 6.06% (4/66) were hospitals and other places. Among 134 respondents, most of their exit customs (82.84%) were in Beijing, whereas others were scattered in 7 cities, including Guangzhou, Xi an, Zhengzhou, Qingdao, Shanghai, Chongqing and Chengdu ( Figure 1).

Practices of malaria prevention
At least 2 measures among mosquito nets, screen doors and Windows, repellents and insecticides were used in all respondents. 84.33% of 134 respondents used mosquito net every day, 90.30% were equipped with screen doors and Windows in their dwellings, and 73.88% used repellent when going out, and 74.63% used mosquito repellent or insecticide at home.

Malaria Knowledge between before and after health education training
Before health education training, the average awareness rate of malaria knowledge of respondents without malaria control training (40.93%) was signi cantly lower than that of having malaria control training (47.98%) (T=2.333, P=0.021).The awareness rate of malaria knowledge training of males 42.43% was lower than that of females (55.0%,) with difference signi cantly (T=3.077,P=0.003).The awareness rate of malaria knowledge of respondents aged 45 or above (39.74%) was lower than that of respondents aged below 45 years (47.36%)(T=2.462,P=0.015).The awareness rate of malaria knowledge of respondents dispatched from private enterprises (41.69%)was lower than that of dispatched government institutions(53.41%) (T =3.337,P=0.001).The higher the degree of respondents have the higher awareness rate of malaria knowledge (T=6.152, P=0.046). Whether to use mosquito nets every day and the difference type of work were no statistically signi cant (P > 0.05).According to Logistics regression analysis, age (OR=2.6, 95%CI(1.0,8.8)) and male (OR=3.2, 95%CI(1.1,9.4)) were the main factors in uenced whether the awareness rate of malaria knowledge reaches 60% before health education training (Table 2 ).
After health education training, the awareness rate of malaria knowledge of 134 respondents dramatically increased to 87.62% that were signi cantly higher than 44.4% before training (P < 0.05).After the training, the awareness rate of malaria knowledge of respondents aged 45 or above was still lower than that of respondents aged below 45 years(T=5.139,P=0.000); the lower awareness rate of malaria knowledge of respondents were degree below junior college or below(78.28%), worker and businessmen(86.33%) with statistics signi cantly(P < 0.05). (table 1) Risk and factors of malaria infection 29.10% of 134 respondents had infected malaria in the past year, which the average frequency of infected malaria was 1.46 times (1-6 times). 37.37% (37/99) of outdoor workers were infected with malaria, which was signi cantly higher than 5.71% (6/35) of indoor workers (χ 2 =12.561, P=0.000).35.37% (29/82) of those aged below 45 years had infected malaria in the past year, signi cantly higher than 19.23% (10/52) of those aged 45 or above (χ 2 =4.015, P=0.045).For occupation, 35.24%(37/105) of workers and business had infected malaria in the past year, which was higher than 6.9%(2/29) of teachers, medical workers and researchers (χ 2 =8.846, P=0.003). 36.89%(38/103) of private enterprises or individuals had infected malaria in the past year, which was higher than that of government departments and public institutions (3.22%(1/31) )( χ 2 =13.090, P=0.000).However, there was no signi cant correlation among gender differences, whether they had received malaria knowledge training before going abroad, whether to use mosquito net every day, whether to use repellent when going out , whether to use mosquito pesticides and whether to install screen doors and Windows at home (P < 0.05), as shown in Table 1.
According to Logistics regression analysis, outdoor work was the main risk factor for malaria infection (OR=6.5, 95%CI (1.3,31.7)). Table 3 for details.

Discussion
With many years endeavor, no autochthonous malaria cases have reported since 2017 in China Mainland [9]. Nevertheless, the goal of achieving elimination malaria by 2020 in China, has been challenged by the steady stream of imported malaria cases. To prevent resurgences of indigenous cases, it is critical to implement and effective surveillance systems, to stop the transmission by detecting all possible malaria cases in a timely manner. Effective surveillance systems may be not decrease imported malaria effectively in China, and China have stable number of imported malaria cases from 2016 to 2019.This is where the important role if community involvement and the practices of the population [14]. This study is the rst time to explore the situation of malaria KAP and the infection risk of malaria among Oversea Chinese in Africa, so as to provide considerations to future prevention and control measure.
Most imported malaria cases still infected in Africa and Southeast Asia, and a number of studies have shown that the awareness rate of malaria knowledge among oversea labors was low [8,15,16]. Finding from this study shows that the awareness rate of malaria knowledge among Chinese population in Sierra Leone was low (44.4%), and who was male aged 45 years or above with less education had a low awareness of malaria knowledge, which was similar to other studies in China [16]. At present, most of Chinese labor workers and businessman from government institutes and large international corporation travelled to African countries would receive training on malaria prevention before going abroad, but most private companies seldom carried out health education training related malaria before going abroad [17].In Sierra Leone, most Chinese received health education training of malaria from dispatch agency, but less was from Entry-Exit Inspection and Quarantine (EIQ) and CDC. Health education training is so professional that different people should be take different training methods and strategies. The training effect would be threatened by the absence of professional organizations in health education training, which directly affect malaria knowledge of trainees. So professional health education training for overseas labors and cross-border travelers should be provided by public health authorities. In addition, Oversea Chinese had trained before going abroad and most parts of China had not reported local malaria cases since 2010 [18,19]. So, less education oversea labors were hard to realize the harmfulness of malaria and the way to prevent malaria. After living and working in malaria hyperendemic regions for a period of time, those who went abroad would take the initiative to acquire education of malaria prevention, then it is more conducive to conduct health education. Chinese ights to Africa are mainly concentrated in big cities such as Beijing, Shanghai, Guangzhou and so on. Therefore, cooperation and information exchange between various departments should be strengthened at the ports with a large number of inbound and outbound travelers to African countries, and the publicity of malaria prevention and control before going abroad and that in Africa should be carried out and strengthened.
In this study, through various forms of malaria knowledge training, the awareness rate of malaria knowledge among Chinese population in Sierra Leone increased from 44.4-87.63%, which indicated signi cantly this health education interventions improved knowledge of malaria. This study investigated the mosquito breeding places of environment surrounding to learn about dwelling environment before the survey, so as to emphasize the different way to remove mosquito breeding places. Meanwhile, health education training from this study focused on the knowledge of mosquito control at different topography and the identi cation of malaria-mosquito specimens to strengthen mosquito control. And using life science video presentation and interactive mode of questions and answer, respondents are easier to understand the training contents when they have some experience on malaria endemic area. The Chinese in Sierra Leone have deepened their understanding of malaria prevention through local work and life, and also created many new problems and puzzles. Targeted solutions have been made to solve problems and signi cantly improved the effect of training. Chinese overseas workers in Africa, the places they worked generally lack medical resources with a weak public health foundation, and they are limited by language barrier and other factors, making it di cult to access local public health and medical services [20].There are great difference between different regions in Africa at malaria epidemics and the distribution of malaria-mosquito [21][22][23], hence, anti-malaria measures and health education should be carried out in the light of local conditions. In areas where transportation is di cult, domestic public health institutions may consider using the online "Internet + health service platform" to conduct distance health education and regular malaria prevention training for overseas workers, so as to improve the awareness and ability of self-protection to prevent malaria.
This study shows that the malaria infection rate of Chinese in Sierra Leone was 29.1%, which was basically close to the local malaria infection rate of 32.0% [1], and outdoor work was the key risk factors for infecting malaria. In the past ve years, the infection rate of malaria in Sierra Leone has been around 35% [1] with a high prevalence of malaria, showing no trend of remission. Most of the study respondents were from the Freetown area of Sierra Leone, but the rate of malaria infection is likely to be higher in other rural areas of Sierra Leone where the natural environment is harsh and living conditions are di cult. Although in sierra leone in the vast majority of Chinese have used mosquito nets, installed screen door and window screens and used other anti-mosquito measures, but anopheles breeding ground is very ubiquitous with giving priority to with Gambia anopheles. More worryingly, the lack of mosquito control measures and the heavy burden of mosquito-borne disease control [24][25][26][27][28][29] aggravate a high incidence of malaria. The high temperature made it impossible for workers to wear long clothes and trousers outdoors all the time, and it is di cult to use mosquito repellents for long periods, thus outdoor workers in Sierra Leone are unable to avoid mosquito bites completely with a higher risk of malaria infection. Lack of medical resources and low access to medical services made it di cult for Chinese employees infected malaria to receive timely treatment, and infected cases easily became sources of infection and passed on to their peers. At present, it is generally accepted that the three major means of malaria prevention are mosquito control, physical and chemical measures to avoid bites and drug prevention [30].Therefore, for overseas Chinese, it is necessary to strengthen the economic input and implementation of malaria prevention and control, especially to take strict anti-mosquito measures in outdoor work.
In 2018-2019, among the imported malaria cases reported in China, labor workers and businessmen with mainly male young accounted for the rst place, who spent more time in outdoor work with a higher risk of contracting malaria [14], and it was consistent with the characteristics of the malaria-infected population found in this study. In addition, the Chinese in Sierra Leone were mainly treated in local Chinese medical teams and private Chinese clinics for malaria. The data of these cases have not been reported or recorded in China's infectious disease reporting system, which is a blind spot in the management of imported cases. For example, the prevalence rate of malaria among Chinese population labor workers in Guinea was as high as 91%, and most of them are infected overseas [29]. Malaria cases with foreign travel history found in China are recorded as imported cases [31], but most malaria cases infected overseas are not monitored. In order to reduce the incidence of imported malaria from the source, the measures of preventing malaria should move forward to overseas Chinese population, and health education and health input prevention should be strengthened among overseas Chinese.

Conclusions
In short, the Chinese in Sierra Leone were lack of knowledge of malaria with an inadequate training of malaria, and their awareness of malaria knowledge has been signi cantly improved through professional health education training. The rate of malaria infection among Chinese population in Sierra Leone with inadequate outdoor prevention was basically the same as that in the local area.   The Sankey diagram of health education training of malaria and outbound migration among Chinese population in Sierra Leone