High Mobility and STIs/HIV among Women Informal Cross Border Traders in Southern Mozambique: Exploring Knowledge, Risk Perception, and Sexual Behaviors

High circular mobility creates vulnerability and elevates risk for sexually transmitted infections (STIs) including Human Immunodeficiency Virus (HIV). We aim to explore knowledge, perceptions of risk, and sexual behaviors in relation to STIs/HIV, in Mozambican women involved in an informal cross border trade (ICBT) and residing in South Mozambique. A cross-sectional quantitative study, in 200 women cross border traders (WICBT), affiliated to the Mukhero Association, using a structured, face-to-face questionnaire, was conducted. Descriptive statistics and Pearson’s Chi-square test were used. The median age of participants was 37.0 years (interquartile range (IQR): 31.0–43.0), 100% were literate, travelled on average six times a month. WICBT with a high education level were more likely to have awareness of Gonorrhea, Syphilis, and Candidiasis; to self-perceive being at risk of getting HIV, Syphilis, and Human Papilloma Virus (HPV); and to test for HIV and Syphilis. Those with a low education level were more likely to have misconceptions about HIV and ever have sex in exchange for money/goods/services. Married participants were more likely to know how to prevent HIV. Participants with a high income were more likely to know about HPV; to self-perceive being at risk of getting Syphilis; to point sex workers as being at higher risk of getting HPV; and to ever test for HIV. WICBT with a low income were more likely to have sex in exchange for money/goods/services. Low and inconsistent knowledge and misconceptions of STIs/HIV, high sexual risky behavior, low perception of risk of getting STIs/HIV among this neglected and key population suggests their increased vulnerability to the STIs/HIV.


Introduction
The involvement of women in Informal Cross-Border Trading (ICBT) in the context of high mobility and circular migration has become an increasing phenomenon in the sub-Saharan Africa, especially the Western, Eastern, and Southern Africa (SADC) sub-regions [1,2].
In Mozambique, two national population-based surveys, INSIDA (2009) (INSIDA: Inquérito Nacional de SIDA (AIDS National Survey)-first population based survey carried out in 2009) [24] and IMASIDA (IMASIDA: Inquérito de Indicadores de Imunização, Malária e SIDA (Nacional Survey for Indicators for Imunization, Malaria and AIDS)-population based survey carried out in 2015) (2015) [25], showed an overall prevalence of 11.5% and 13.2% among men and women aged 15-49 years, respectively. The disproportionate impact of the HIV epidemic in women has been attributed to: Poverty; multiple sexual partners; transactional sex; inconsistent or no use of condoms; gender inequality; violence against women; cultural practices; and migration [22]. For example, the results of the study held in the Chókwè district, Southern Mozambique, showed that the prevalence of HIV was 29.4%, and it was associated with migrant labor patterns, placing all active women at a higher risk for HIV infection [26].
The levels of knowledge about HIV were high among men and women, in the general population aged 15-49 years in Mozambique. However, there was a low percentage (32%) of adults with comprehensive knowledge about the HIV/AIDS [24]. Moreover, a study conducted by the IOM (2010) [27] in the SADC region involving South African and Mozambican migrant workers in the Limpopo and Mpumalanga provinces, showed that there was low knowledge and low perception of risk and vulnerability about HIV/AIDS, high prevalence of risk behaviors, inconsistent condom use, and increased vulnerability of women.
The debate about the need to intensify the promotion of the simultaneous use of contraceptive methods including the condom is increasing, with a view to confer dual protection against STIs and unwanted pregnancies in women with a high risk to STIs/HIV [28].
Several studies were carried out in Mozambique on economics, socio-anthropologic, and on health issues concerning the transmission of STIs/HIV among migrant's miners, truck-drivers, and sex workers. However, there is scarcity of published studies on women involved in ICBT. In particular, knowledge is lacking on context and practices that put these women involved in ICBT at higher risk of STIs/HIV and unwanted pregnancies. Thus, with this study, we aimed to explore knowledge, perceptions of risk, and sexual behaviors in relation to STIs/HIV, in Mozambican women involved in an informal cross border trade (ICBT) and residing in Southern Mozambique.

Study Design and Participants
This was a cross-sectional quantitative study conducted from February to September 2015. The study involved 200 cross-border informal trade women (Mukheristas) aged 18 to 49, members of the Mukhero Association, who cross the borders of Ressano Garcia, (border post with South Africa), Namaacha and Goba (both bordering Eswatini), living in Maputo City (country capital) and Maputo Province, southern Mozambique.
Maputo City is the capital of Mozambique, with 1,120,867 inhabitants, corresponding to 4% of the general population, of which 52% are women. Maputo Province, which is a satellite of Maputo city, is inhabited by about 1,968,906 people (7.1%) [29]. It is in this province that the four borders are located, Ressano Garcia, Namaacha, Goba, and Ponta de Ouro, through which Mukheristas women cross to neighboring countries such as Eswatini and South Africa (see Figure 1).

Data Collection
Data collection took place at the Mukhero Association. Initially, a pilot study was conducted involving 10 women Mukheristas reselling their wares in the Fajardo market in Maputo City. This study was done to test our research instrument for further refinement. A systematic random sampling was used, based on the records of the Mukhero Association database. The women were interviewed at the Mukhero Association headquarters, in the markets where they sell and resell their imported products, freight unloading terminals, warehouses, in their homes, car parks, through face-to-face and a structured questionnaire in Portuguese language, by a previously trained team.

Measures
The question consisted of sociodemographic characteristics and Mukhero activities that included age, marital status, education level, household size, main occupation, income from Mukhero, motivations for practicing Mukhero, start of the practice of Mukhero, and number of monthly trips. Other questions evaluated the knowledge of STI/HIV such as if they have heard about HIV, Syphilis, HPV, Gonorrhea, Trichomoniasis and Candidiasis (Yes/No); ways of transmission of STIs, and ways of prevention; sexual risk behavior (Yes/No); multiple sexual partners, ever had sex in exchange for money/goods/services, and no use of condom (Yes/No); risk perception of getting STI/HIV (High risk/Low risk); reported lifetime STI's testing (Yes/No); and signs and symptoms (Yes/No).

Data Analysis
Data were analyzed with SPSS (Statistical Package for Social Sciences) version 23 (IBM Corp., Armonk, New York, NY, USA). Descriptive statistics looking at the distribution of the variables such as frequencies, means, and median (interquartile range = IQR), were performed. Then, Chi-square (χ 2 ) tests were calculated to understand the significance of the relationships found between variables. Differences were considered significant at a p-value of 0.05 or less.

Ethical Considerations
The research protocol was submitted and approved by the Ethics Committees of both the Institute of Hygiene and Tropical Medicine in Portugal and the National Bioethics Committee for Health in Mozambique (Ref. 169/CNBS/2014). The research was conducted on the basis of informed consent of the participants. After the data were collected, they were anonymized to ensure their confidentiality. In this way, we guarantee that there were no risks for the participants in the study.

Data Collection
Data collection took place at the Mukhero Association. Initially, a pilot study was conducted involving 10 women Mukheristas reselling their wares in the Fajardo market in Maputo City. This study was done to test our research instrument for further refinement. A systematic random sampling was used, based on the records of the Mukhero Association database. The women were interviewed at the Mukhero Association headquarters, in the markets where they sell and resell their imported products, freight unloading terminals, warehouses, in their homes, car parks, through face-to-face and a structured questionnaire in Portuguese language, by a previously trained team.

Measures
The question consisted of sociodemographic characteristics and Mukhero activities that included age, marital status, education level, household size, main occupation, income from Mukhero, motivations for practicing Mukhero, start of the practice of Mukhero, and number of monthly trips. Other questions evaluated the knowledge of STI/HIV such as if they have heard about HIV, Syphilis, HPV, Gonorrhea, Trichomoniasis and Candidiasis (Yes/No); ways of transmission of STIs, and ways of prevention; sexual risk behavior (Yes/No); multiple sexual partners, ever had sex in exchange for money/goods/services, and no use of condom (Yes/No); risk perception of getting STI/HIV (High risk/Low risk); reported lifetime STI's testing (Yes/No); and signs and symptoms (Yes/No).

Data Analysis
Data were analyzed with SPSS (Statistical Package for Social Sciences) version 23 (IBM Corp., Armonk, New York, NY, USA). Descriptive statistics looking at the distribution of the variables such as frequencies, means, and median (interquartile range = IQR), were performed. Then, Chi-square (χ 2 ) tests were calculated to understand the significance of the relationships found between variables. Differences were considered significant at a p-value of 0.05 or less.

Ethical Considerations
The research protocol was submitted and approved by the Ethics Committees of both the Institute of Hygiene and Tropical Medicine in Portugal and the National Bioethics Committee for Health in Mozambique (Ref. 169/CNBS/2014). The research was conducted on the basis of informed consent of the participants. After the data were collected, they were anonymized to ensure their confidentiality. In this way, we guarantee that there were no risks for the participants in the study. Table 1 shows the sociodemographic characteristics, motivation for the practice of Mukhero and trips' frequency. This study showed that for a total of 200 women enrolled in the study, the majority had an average age of 37 (IQR = 31.0-43.8) years, and they are married or live in common law marriage (59.5%), all can read and write. The main motivations for Mukhero's practice were: Lack of schooling (13.5%), unemployment (24.5%), increasing in family income (23%), and low partner wage (14.5%). Most of the participants started the activity of Mukhero between 5-10 years and make between three and six trips per month. The main occupation (80.0%) of most of the participants is the Mukhero activity and they make from their business the equivalent of up to three minimum wages for their survival. Note that the minimum wage at that time in Mozambique was 4.851.84 Meticais, where 1 USD was equal to 44.37 Meticais.  Table 2 shows that all participants have heard about HIV/AIDS and 87% have heard about gonorrhea. While 56% and 41% have heard about cervical cancer and syphilis, respectively, and only a minority (19%) have heard about candidiasis and trichomoniasis (15%).  According to Table 3, 94% of respondents know that HIV can be sexually transmitted, have unprotected sexual intercourse (96%), and using of contaminated needles (91.5%). However, we have to point out that although a majority (63%) of the participants stated that mosquito bites are not the common form of HIV transmission, 22% of participants think it is possible. On the other hand, only 17% of Mukheristas know how syphilis is transmitted and more than ninety percent of our interviewees do not know how it is transmitted or how one can be prevented from being infected by HPV. In relation to testing, the majority (85%) of the participants underwent HIV testing. However, it turns out that only 10% of respondents reported having tested syphilis and HPV, although syphilis screening was offered to all pregnant women in Mozambique.

Knowledge about Sexually Transmitted Infections including HIV/AIDS
As for prevention, more than 90% of participants know that condoms and having a single uninfected sex partner prevent HIV transmission. However, it should be noted that 19% of the Mukheristas reported that having sex with virgin girls and boys was one of the forms of prevention. On the other hand, only 18% and 8% of participants know how to prevent syphilis and HPV, respectively.

Perception of Risk to STIs
Regarding the level of self-perception about the possibility of contracting HIV within the Mukheristas, 66.5% of the interviewees consider that there is a lot of possibility, 27.5%, little possibility, and 6% did not answer. Considering also the possibility of contracting syphilis and HPV among the Mukheristas, 82.5% and 86.3% respectively did not know how to answer the question, as illustrated by Table 4.

Sexual Risk Behaviors, Reported Signs, and Symptoms of STIs
Regarding the number of sexual partners per woman in the 30 days prior to the survey, Table 5 shows that 78% of our respondents had one sexual partner, 11% had two partners or more. Fifteen percent (15%) had occasional sex, of these, only 53.3% used the condom.
Analyzing the question "if they ever had sex in exchange for money, goods or services?", 7.5% said yes. Of these, 99.5% was in exchange for services (facilitation of goods crossing at the border level, cargo loading, and long truck drivers). Moreover, in the 30 days prior to the survey, 19% of the participants reported pain in the lower abdomen, 17% vaginal discharge, 9% genital pruritus (itching), and 3% ulcer/wound/genital tumor.  The bivariate relationships between level of education, marital status, income from Mukhero, and knowledge, risk perception, lifetime STI's testing, risky sexual behaviors about STIs/HIV, using Pearson chi-square independent tests, are shown in Table 6. We only presented the results that are statically significant.

Knowledge about STIs/HIV and Marital Status
Participants that were not currently married were more likely to hear about Trichomoniasis (21.8% vs. 11.1%, p = 0.028) and Candidiasis (24.4% vs. 11.1%, p = 0.021), and were more likely to know how to prevent HIV (97.5% vs. 86.6%, p = 0.047). Meantime, participants that were currently married showed misconceptions such as having sexual intercourse with virgin young boys prevents HIV (26.5% vs. 8.3%, p = 0.038).

Knowledge, Risk Perception, Lifetime STI's Testing, Sexual Behaviors about STIs/HIV, and Income from Mukhero
Finally, women Mukheristas with a high income from Mukhero were also more likely to have heard about HPV (57.1% vs. 56.4%, p < 0.001), to self-perceive to be at high risk of getting HPV (76.6% vs. 76.2%, p = 0.041) and Syphilis ((31.1% vs. 10.5%, p = 0.022), to point sex workers to be at high risk of getting HPV (100% vs. 93.8%, p = 0.036), and to ever test for HIV (93.1% vs. 84.1%, p = 0.011) than those with low income from Mukhero. Contrarily, participants who had a low income were more likely to know that having sex with one uninfected partner prevents Syphilis (95.2% vs. 79.3%, p = 0.027) and to have sex in exchange for money/goods/services (8.8% vs. 0%, p = 0.042).

Discussion
The mobility of women informal cross border traders in Mozambique is locally well-known but not yet documented in the literature from a socio-epidemiological point of view. While the behavior, STIs/HIV risk factors of mobile men (trucks drivers, miners) as well the sexual workers, knowledge, sexual behaviors, perceptions of risk and vulnerability, reported signs and symptoms, and reported testing in relation to STIs/HIV, in Mozambican women involved in an informal cross border trade in Southern Mozambique, remain largely unknown.
Our study on high mobility and circular migration showed that these women made an average of six trips per month which is consistent with those seen among highly mobile populations in other researches. Surprisingly, we did not observe any significant relationship between numbers of trips with knowledge, sexual behaviors, perceptions of risk and vulnerability, reported signs and symptoms, and reported testing in relation to STIs/HIV. However, frequency of travel may repeatedly expose these women to the risk of contracting sexually transmitted infections including HIV, gender-based violence, and sexual harassment [3,5,6,8].
Contrary to what has been stereotyped in relation to these women with high mobility and circular migration, according to our findings the majority of them are married or in common law marriage, and almost had universal complete secondary school, although they referred to the lack of schooling, as motivation for the practice of Mukhero. Similar profiles were founded in the studies in Lesotho, Nigeria, and Portugal [9,30,31], where women who travelled frequently and made five or more trips were more likely to be married and have a higher level of education, compared to non-migrant. In our context, on the one hand, it may have been due to the massification of literacy campaigns among women made after the country's independence, in 1975. On the other hand, it might be explained by the nature of their activity. These characteristics could result in high levels of knowledge that would assist them in the adoption of safe sexual behavior and a greater perception of risk and vulnerability to sexually transmitted infections during the process of high mobility.
Our results revealed that HIV was the most commonly heard infection among STIs, followed by Gonorrhea and HPV. However, knowledge about the ways of transmission and prevention of HIV was inconsistent. Women with a low level of education presented more misconceptions and myths towards HIV transmission and prevention than those with a high education level. Misconceptions such as the mosquito's bite spreads HIV, having sex with virgin young boys and girls prevent HIV were higher among low literate participants. Similar evidence has been found in other studies [32][33][34].
Despite considerable numbers (54.5%) of participants had already heard about the HPV, the majority of participants were unaware of the forms of transmission and prevention, the causative agent of the disease, and they did not perform screening. In line with our findings, a recent study [35] held in Mozambique, where knowledge about cervical cancer (CC) and vaccine acceptability in young adolescents aged 10-19 years has been evaluated, found that most of the participants had already heard about CC, only one third knew the causative agent.
HIV-HPV co-infection in sub-Saharan Africa, where STIs/HIV prevalence is high, may exacerbate the dynamics of control of the HIV epidemic in the subcontinent, especially in the SADC region [17,21,23]. This situation may delay the ambitious UNAIDS "90-90-90" targets that aim to end the HIV/AIDS epidemic by 2030, that is, 90% of all HIV-positive persons will know their HIV status, 90% of those with a diagnosis of HIV infection will receive sustained ART, and 90% of persons receiving ART will have viral suppression [36].
Although syphilis testing is a routine in the consultations of pregnant women seeking public pre-natal care in Mozambique, less than half of our study participants have heard about it, and only a minority reported having screened the agent that causes syphilis. This contrast may indicate that women attending these services have probably not been adequately explained about these procedures, emphasizing the importance of good communication in the care of these women. Study [37] in another context, but with Africans migrants, showed that communication difficulties between health professionals and migrant patients due to language differences and cultural practices of migrant women, were evident in stereotyped attitudes, discriminatory aspects, and lack of preparation of some health professionals.
The self-perceived risk to acquiring HIV is relatively high in participants with a high educational level. A previous published study in the Asian context [32], showed that respondents who had high knowledge on STIs/HIV might have felt more at risk because they knew that they might get infected, and they might apply their knowledge to reduce transmission, increase prevention, and behavior exchange.
On the other hand, the majority of the Mukheristas participating in this study demonstrated a low level of self-perception in relation to other STIs. When we addressed "who could be in danger of contracting syphilis, gonorrhea, infection by HPV and trichomoniasis" among the following groups: Female sex workers, long truck-drivers, people who travel a lot, as is the case of Mukheristas, more than 80% of the participants in the study did not answer this question. Surprisingly, self-perception toward HPV and syphilis was low in women Mukheristas with a high income from Mukhero. They are not perceived to be at risk and vulnerability of contracting STIs/HIV, especially HPV, when they point greater risk and vulnerability to other mobility women, for example, sex workers. They also see the HIV and HPV infection as distant, confirming the idea of "other's illness" "impossible or unlikely to happen to them". They deny the risk, believing that HIV/AIDS and HPV threaten others and they exclude themselves from danger. A low level of vulnerability perception was observed in other contexts [31,35]. Women who self-identified themselves as high risk and vulnerability of contracting STIs/HIV were more likely to use condoms than those who were perceived as at low risk for contracting STIs/HIV [38].
Our study identified some sexual risk behaviors among women informal cross border traders, including multiple sexual partners and not using a condom. All participants with a low level of education, and low income were more likely to have had sex with multiple partners than other counterparts, most in exchange for money, goods, or services (facilitation of border crossings, cargo loading), without using a condom. These findings are consistent with another study carried out in another African country [11], and one study carried out in Mozambique [26].
Several reasons, which were not explored in this study, for poor adherence and inconsistent condom use have been mentioned in the literature: Enjoying sexual pleasure; familiarization of partner trust/having the habit with the client; coercive sex and rape; willingness to have children and religious beliefs; fear that the condom will break during sexual intercourse; and fear of itching and burns [39][40][41][42]. The national results of INSIDA (2009) [24] showed a low prevalence of condom use in Mozambique. Only 8% of women and 16% of men aged 15-49 who had sex in the last 12 months prior to the survey used condoms in the last sexual intercourse. Moreover, the recent national results of IMASIDA (2015) show that only 3% of women aged 15-49 years had two or more sexual partners in the last 12 months and 72% did not use condoms [25]. The lack of decision-making power that is noted in these women in relation to condom use, manifested by the transfer of responsibilities to partners, in a context of multiple and concomitant sexual partners and experiences of violence and sexual harassment during the high mobility process, has been the great challenge that these women face [43]. Therefore, condom use in the context of high mobility, where risk behaviors and vulnerabilities are increased, is a fundamental factor in the simultaneous prevention of STIs and unwanted pregnancies.
Few participants reported signs and symptoms of STIs 30 days before the study. On the one hand, it may be that participants are not able to recognize those symptoms. On the other hand, many STIs happen without signs and symptoms that force them to stop their business. In addition, addressing sexuality and sexually transmitted diseases in the African context, particularly Mozambican, is extremely complex, namely due to the myths and cultural practices related to the sexuality [44]. For example, our participants showed many reservations to answer the questions related to gonorrhea.
The results of this study have a useful dimension. The evidence now produced can serve as a baseline for the design of STD education campaigns adapted to this population of high cross-border mobility, which seem to be urgent. Furthermore, health promotion measures designed according to the needs of these populations will be useful to prevent infections.
This study must acknowledge some limitations. Firstly, these findings cannot be generalized, because the cross-sectional nature of our data can only demonstrate relationships between the variables. Secondly, we worked with the Hard-to-survey population. Thirdly, the sensibility of this topic among the WICBT in the African context, some sexual behavior may be under-reported, because we used self-reported data. Fourthly, the relatively law age and mixed gender of the enquirers could be influenced. Despite these limitations, our study provided insight about this topic that is yet unexplored in our country.

Conclusions
This study revealed that women involved in an informal cross-border trading in the context of high mobility and circular migration in Southern Mozambique, present relatively high levels of formal education and high incomes, despite referring to the lack of schooling, poverty, and unemployment as motivation for the practice of Mukhero. These characteristics seem to have contributed to their social rise and could result in high levels of knowledge about STIs/HIV that would assist them in the adoption of safe sexual behavior and perception of risk and vulnerability to sexually transmitted infections, during the process of high mobility. However, low and inconsistent knowledge and misconceptions of STIs/HIV, high sexual risky behavior, low perception of risk of getting STIs/HIV, and low reported STIs symptoms, were demonstrated mostly among participants with a low education level and low income from Mukhero, suggesting increased risk and vulnerability to the STIs/HIV. Health promotion programs and strategies for empowerment with the knowledge for the behavioral change, contextualized to the socioeconomic and epidemiological profiles of the country, are needed to promote prevention and reduce STIs/HIV transmission targeted to this neglected and key population.