Knowledge gaps of STIs in Africa; Systematic review

Sexually Transmitted Infections (STIs) are ambiguous burden of tremendous health, social and economic consequences. The current systematic review was conducted in order to determine awareness and knowledge of Africans toward sexually transmitted infections, not only concerning HIV/AIDS, but also other STIs such as gonorrhea, syphilis, HBV, HCV and HPV. A systematic review of literature was conducted, studies were retrieved and selected after fulfilling the inclusion criteria as well as passing the assessment procedure. Related data was extracted, quantitative analysis was conducted among participants who responded to questions related to HIV, HBV, HCV, HPV or STIs knowledge, sensitivity analysis as well as subgroup analysis were also conducted. Seventy four articles addressing knowledge among 35 African countries were included and 136 questions were analyzed and synthesized. The question “does using condom reduces HIV transmission?” was answered by 1,316,873 Africans in 35 countries, 66.8% [95% Cl; 62.6, 70.9] answered yes. While the question “is sexual contact a possible route of HBV transmission?” was answered by 7,490 participants in 5 countries; 42.5% [95% Cl; 20.4, 64.7] answered yes. The differences observed among populations are highlighting the possibility for improvement by directing light toward specific populations as well as addressing specific awareness knowledge to ensure that the general as well as the related specific preventive knowledge is improved.


Introduction
Sexually transmitted Infections (STIs) are ambiguous burden of tremendous health, social and economic consequences. Many STIs are hidden because many people may feel stigmatized when addressing them. Moreover, the committee on prevention and control of sexually transmitted diseases in USA estimated that the annual costs of selected major STDs are approximately $10 billion or, if sexually transmitted HIV is included, $17 billion [1]. a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 According to UNAIDS; almost 37 million people globally were living with HIV in 2017, sub-Saharan Africa accounted for 66% of the cases, 68% of new adult HIV infections, 92% of new infections in children and 72% of all AIDS-related deaths. Earlier in 2009, Swaziland topped the world's HIV epidemic countries with a 26% prevalence among adults, while South Africa was the country with the world's largest prevalence of people living with HIV as 5.6 million [2,3].
On the other hand and according to WHO; an estimated 257 million people are living with HBV infection with the highest prevalence in the Western Pacific Region and the African Region as 6.2% and 6.1% of the adult population are infected, respectively. About 1% of persons living with HBV infection (2.7 million people) are also infected with HIV. Moreover, approximately 399,000 people die each year from hepatitis C infection. Furthermore, the estimated global HPV prevalence is 11.7% with the Sub-Saharan Africa having the largest burden as well(24.0%) [4][5][6].
Africa is considered the continent with the lowest Gross Domestic Product (GDP) as most African countries fall within the lower-middle to low income countries classification. In March 2013, despite of the predicted uprising in African economy in the following decades, Africa was identified as the world's poorest inhabited continent; Africa's entire combined GDP is estimated to be barely a third of the United States', this could straightforwardly influencescreening opportunities, medical consultations as well as treatment options. Taking that under consideration; a strategyfor STIs containment in Africa should primarily emphasize prevention and its related knowledge. Chan and Tsai in their study represented STIs related awareness levels based on data collected from 33 sub-Saharan African countries. Although their study determined the estimated awareness according to data collected from 2003 to 2015 as well as a knowledge trend among each participated country was illustrated, awareness of five questions were assessed regarding HIV only. The current systematic review was conducted in order to determine awareness and knowledge of Africans of sexually transmitted infections, not only concerning HIV/AIDS, but also other STIs such as, gonorrhea, syphilis, HBV, HCV and HPV and concerning all awareness determinants that are reported in the literature [7,8].

Search strategy
To identify relevant studies; a systematic review of the literature was conducted in the 1 st of December 2018. The review was regulated in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement [9] (S1 Table). A comprehensive search was operated in PubMed, Embase, Google scholar, Scopus, Index Copernicus, DOAJ, EBSCO-CINAHL, Cochrane databases without language limits (studies written in French were later excluded). To obtain a current situation evidence; only studies published in or after 2010 were included. Furthermore, all studies where the data collection process took place before 2010 were also excluded, the only exception was if the collection process started before 2010 and ended in 2010 or afterwards. The keywords used in PubMed was as follow: ( Moreover, to optimize our search, hand searches of reference lists of included articles were also performed. Study selection and data extraction. All authors independently assessed titles and abstracts for eligibility, and any disagreement was resolved through discussion. A copy of the full text was obtained for all research articles that were available and approved in principle to be included. Abstraction of data was in accordance with the task separation method; method and result sections in each study were separately abstracted in different occasions to reduce bias. Moreover, data abstraction was conducted with no consideration of author's qualifications or expertise as described in details previously [10]. Studies assessed the knowledge of parasitic infections as well as studies conducted among healthcare workers (clinicians, laboratory specialists, nurses, dentists and midwives) were excluded. If a data regarding the period of conduction is missing; the reference list was crossed, if any cited study wasfound to bepublished after 2010;authors of the current review agreed to predict that the study is conducted after 2010 and hence it was considered for inclusion, and it was designed to be addressed later in the review as (conducted after 2010), otherwise the study was excluded. All studies measuring awareness level with scores or if it is generally good or moderate or poor without determining further details were also excluded. Each research article was screened for all relevant information and recorded in the data extraction file (Microsoft Excel), as one article may report outcome of awareness and/or knowledge and/or attitude toward specific sexually transmitted infection or toward several STIs, in a single population or among several ones. Moreover, data from each method section was extracted using a predefined set of variables; study characteristics, type of participants, study population size, geographical region and the period of the study conduction.
Assessment of quality. Each included article was evaluated based on a framework for making a summary assessment of the quality. The related published literature was crossed, then a framework was structured specifically to determine the level of representativeness of the studied population and to judge the strength of the estimates provided. Six questions were to be answered in each article, each answer represent either 1 score for yes, 0 score for No or 0 score for not available; a total score for risk of bias and quality was calculated by adding up the scores in all six domains, resulting in a score of between 0 and 6. The highest score indicates the highest quality, studies with a score for quality greater or equal to 3 (higher quality) were included in the review.
The six domains were: is the study objective clearly defined?, is the study sample completely determined?, is the study population clearly defined and specified?, is the response rate of participants above 70%?, is the methodology rigorous? and is the data analysis rigorous?
Trim and Fill method was used to assess the risk of publication bias in each question responses in the included studies [11]. Publication bias was assessed separately for each question-corresponding responses only if the question was addressed and answered in studies equal or greater than ten.
Quantitative analysis. Meta-analysis was performed-whenever possible using Review Manager Software (Version 5.3). In studies where the Standard Error (SE) is not reported; the following formula was used to calculate it: SE = p p (1-p)/ n where p stands for Prevalence. The software automatically provided the Confidence Interval (CI) according to the calculated SE, if the CI is provided in a study; it was introduced accordingly. The heterogeneity of each meta-analysis was assessed as described in details previously [10], the random effect was favored over the fixed effect model in all meta-analysis established as variations between studies is predicted to be probable due to the diversity of the study populations. Sensitivity analysis was also approached to determine the effect of studies conducted in populations proposed to behave in indifference manners or proposed to be more aware on the overall pooled prevalence. Moreover, subgroup analysis was also conducted -whenever suitable to determine awareness level in specific country or population. A question to take part in the meta-analysis has to be included in at least two studies. Moreover, for providing a better image as well as emphasizing potential research gaps; all HIV-related questions that are proposed to be of interest according to the objective of the current review, and was answered by at least 1,000 Africans, but included only in one study, were also provided alongside their related references. Nevertheless, questions related to other STIs were provided regardless of the number of participants due to their minority. Questions with similar outcome were proposed to be the same (e.g: the question "do you think sexual intercourse will increase the risk of HIV transmission?" and the question "is HIV sexually transmitted?" were considered as one question).

Studies included
A total of 7,540 articles were identified from the search strategy including hand searches of reference lists of included original research articles and reviews. From these, 7,453 articles were excluded. Seventy four articles met our inclusion criteria and passed the quality assessment procedure [8,. The articles reported specific awareness determinants and/or knowledge and/or attitudes of an African population regarding STIs as general and/or HBV and/or HCV and/or HPV and/or HIV. (Fig 1) illustrates the PRISMA flow diagram. The included articles are depicted in (Table 1). Assessment of the quality of included studies is depicted in (S2 Table).

Study characteristics
The characteristics of the included studies are depicted in (Table 1), among which the oldest were published in 2010 while the most recent ones were published in 2018. Fifty one research articles determining HIV awareness level and/or knowledge and/or attitudes were included, while 14 articles determining HBV awareness level and/or knowledge and/or attitudes were included. Furthermore, 6 and 9 articles concerned of awareness level and/or knowledge and/ or attitudes level regarding HCV and HPV were included, respectively. Seven articles determining STIs awareness level and/or knowledge and/or attitudes as general were also included. Two hundred questions were summarized among which 136 questions were analyzed and synthesized from included studies including the subgroup analysis. Publication bias assessment indicated no major asymmetry.
nine in South Africa [24,27,29,34,37,42,46,82,84], five in each of Ghana [19,31,65,66,68] and Ethiopia [21,73,77,78,80], four in Uganda [13,55,72,75], three in Mozambique [22,26,30], two in each of Namibia [45,76]and Cameroon [59,67], one in each of Congo [25], Sudan [33], Senegal [39], Morocco [47], Gambia [50], Tanzania [53], Madagascar [71] and Egypt [74] while a   Fig 2). Heterogeneity was high in all questions (I 2 more than 80%), except for the question "Is TB associated with HIV infection?" where I 2 = 0%. Knowledge gaps of STIs in Africa; Systematic review     [60]. Two studies were nationally representative and participants were from different States [38,83]. The oldest among the study included were conducted in 2010 while the newest were conducted in 2013 (S3 Table). Population under study  Knowledge gaps of STIs in Africa; Systematic review was found to be mainly students and adolescents (6/11), while one was toward each of pregnant women, religious leaders, general population, female sex workers and community dwelling women (S3 Table). Majority of studies were conducted among both genders (7/11), three studies were toward females only while one study included only males. Age of respondents ranged from 12 to 49 years.  (Table 3). Heterogeneity was high in all questions (I 2 more than 80%). South Africa. Nine included studies in regard to HIV were conducted among South Africans representing a total population of 17,320 participants; two studies were conducted in KwaZulu-Natal province [24,37] and one was conducted in each of Gauteng Province [29], Northern Cape province [42], North West province [34], two studies were toward online internet users [27,82], one study was conducted in Eastern Cape, Western Cape, Free State and Gauteng Provinces [46]while another study was nationally representative [84] (S4 Table). The oldest among the study included was conducted in 2010 while the newest was conducted after 2010. Population under study was distributed among circumcised males, men who have sex with men or indicated interest in men, general population and home-based carers (S3 Table). Majority of studies were conducted among both genders (5/9), while four were toward males only (S4 Table). Age of respondents was from 15 to more than 25 years. Thirty two questions were asked to the participants that are related to the knowledge and awareness of HIV as general, transmission routes, clinical symptoms and prevention attitude, among which 16 questions were analyzed and synthesized. The question 'Does using condom reduces HIV transmission?" was answered by 3  characteristics data, the pooled prevalence and the confidence intervals are depicted in (Table 4). Heterogeneity was high in all questions (I 2 more than 80%).
Adolescents and young people. The study participants' age were greater than 14and less than 25 years in thirteen HIV-related included studies, representing a total population of 5,908 participants; five studies were conducted in Nigeria [14,[16][17][18]63], three in Ghana [19,31,66], two in Mozambique [26,30], and one in each of Cameroon [59], Madagascar [71]and Uganda [72]. Majority of studies were toward students and adolescents (11/13) while two studies were conducted among pregnant women. Majority of studies were conducted among both genders  (Table 5). Heterogeneity was high in all questions (I 2 more than 80%). Awareness of HIV related to demographic characteristics. Media (as general) was the main source of information of participants reported in several studies [17,47,74]. However, other studies among students reported that school is the main source of information not media [22,75]. Health professionals was the least mentioned source of information in the study of Saleh and colleagues [74]. Chaquisse and colleagues in their recently published study (2018) determined women's age as not significantly associated with HIV and HBV knowledge. Moreover, they determined thatto have heard about HIV/AIDS, Syphilis, Gonorrhoea, Hepatitis B or Hepatitis C, was associated with better knowledge about HIV transmission modes [26].
Two studies indicated a statistically significant difference in the HIV/AIDS knowledge scores and the marital/ relationship status [38,65]. Nevertheless, another study indicated that no relation exists [55]. This last study also reported that stigma toward HIV was significantly associated with knowledge scores of HIV, education level and sex, while place of residence (rural versus urban) is not [55].
One study concluded that Comprehensive knowledge of HIV is significantly associated with more media items and fewer children at home [30].
Regarding religion, Christians compared to Muslims have been found to significantly have better knowledge of HIV/AIDS. Nevertheless, another study found that Muslim students scored higher on HIV/AIDS knowledge than Christian students [65,81]. Several studies indicated that the level of education and age have a significant association with the knowledge of HIV transmission [21,39,48]. Additionally, one study [81] agreed that only education level is associated, while another agreed that only age is associated [77]. Nevertheless, Faye and colleagues only concluded that marital status is associated to the knowledge of HIV transmission [39].
Seyoum and colleagues concluded that female participants who heard about HIV was significantly higher than that of the male participants. Moreover, there was a significant difference between males and females who suggested unsafe sexual intercourse as mode of transmission of HIV [77]. However, Yaya and colleagues found that the majority (82.5%) of participants (females) (N = 32,123) believe on contracting the virus via supernatural means [83].

Hepatitis B virus (HBV)
Fourteen included studies assessed the awareness of 9,446 Africans in regard to HBV, three studies were conducted in each of Nigeria [61,62,64], Cameroon [20,40,58] and Ghana [12,15,28], two in Ethiopia [32,52], one in each of Kenya, Mozambique and Madagascar [26,57,71]. The oldest among the study included was conducted in 2010 while the newest was conducted in 2016 (Table 1). Population under study was found to be mainly students and adolescents and pregnant women (10/14), one study was targeting each of non medical staff of health facilities, general population, barbers and traders ( Table 1). Majority of studies were conducted among both genders (8/14), five studies were toward females only (pregnant women) while one study included only males (barbers). Age of respondents ranged from 10 to 75 years. Fifteen questions were asked to the participants that are related to the knowledge and awareness of HBV as general, transmission routes, clinical symptoms, pathological consequences and prevention attitude, among which 13 questions were analyzed and synthesized. The question ''Do you know HBV?" was answered by 4,066 participants in Ghana, Mozambique, Ethiopia, Nigeria and Madagascar; 53.8% [95% Cl; 27.6, 79.9] answered yes. The question ''Does sexual contact is a possible route of HBV transmission?" was answered by 7,490 participants in Ghana, Mozambique, Ethiopia, Cameroon and Nigeria; 42.5% [95% Cl; 20.4, 64.7] answered yes. Questions asked, their corresponding articles' data, the pooled prevalence and the confidence intervals are depicted in (Table 6). Heterogeneity was high in all questions (I 2 more than 80%).
Awareness of HBV related to demographic characteristics. Abdulai and colleagues in their study among pregnant women determined that level of education and occupation are significantly associated to hepatitis B awareness [12]. Frambo and colleagues among the same population concluded that education is significantly associated to the level of awareness as well [40]. Furthermore, Ngaira and colleagues assessed the awareness as well as vaccination status among the same population (pregnant women) and indicated a significant difference between vaccine uptake and education [57].
Noubiap and colleagues assessed HBV vaccine uptake but among medical students, and indicated that duration of study but not age or vaccination status are significantly correlated. Nevertheless Okonkwo and colleagues in their study among traders concluded that knowledge of the nature of HBV virus varied significantly according to age [58,61].

Hepatitis C virus (HCV)
Sixincluded studies assessed the awareness of 2,306 Africans in regard to HCV, two studies were conducted in Egypt [74,79] and one in each of Ghana [15], Mozambique [26], Ethiopia [32] and Madagascar [71]. The oldest among the study included was conducted after Knowledge gaps of STIs in Africa; Systematic review 2010while the newest was conducted in 2015 (Table 1). Population under study was distributed among students and adolescents, general population, HCV positive patients, pregnant women and barbers (Table 1). Four studies were conducted among both genders, one toward females only and one toward males only ( Table 1). Age of respondents range from 18 to 80 years. Seventeen questions were asked to the participants that are related to the knowledge and awareness of HCV as general, transmission routes, clinical symptoms, pathological consequences and prevention attitude, among which 10 questions were analyzed and synthesized. The question ''Is sexual contact a possible route of HCV transmission?" was answered by  (Table 7). Heterogeneity was high in all questions (I 2 more than 80%). Awareness of HCV related to demographic characteristics. Adoba and colleagues conducted their study among barbers-sharp objects-related career, nevertheless, the radio was the major source of information about HCV infection (25.0%) [15]. Demsiss and colleagues in 2018 conducted a study among medicine and health science students in Ethiopia and determined that student's residence as well as department significantly associates to level of knowledge toward transmission and prevention of hepatitis B and C infections [32].

Human papillomavirus (HPV)
Nineincluded studies assessed the awareness of 5,157 Africans in regard to HPV, three studies were conducted in Nigeria [35,36,41] and one in each of Madagascar, Morocco, Mali, South Africa and Senegal [43,49,51,54,70,71]. The oldest among the study included was conducted in 2010 while the newest was conducted in 2016 (Table 1). Population under study was found to be mainly adolescents and students (6/9), while two studies was targeting general population and one was targeting HIV positive and negative females ( Table 1). Majority of studies were conducted among both genders (6/9), while three studies were toward females only. Age of respondents ranges from 15 to older than 67 years. Fifteen questions were asked to the participants that are related to the knowledge and awareness of HPV as general, transmission routes, clinical symptoms, pathological consequences and prevention attitude, among which 13 questions were analyzed and synthesized. The question ''Do you know HPV?" was answered by 5 (Table 8). Heterogeneity was high in all questions (I 2 more than 80%).
Awareness of HPV related to demographic characteristics. Funmilayo and colleagues in their study detected a statistically significant association between level of awareness and vaccine acceptance as well as the level or class of students [41]. Supporting this finding; Makwe and colleagues indicated the same association [49].
Massey and colleagues in Senegal reported that respondents who indicated living most of their lives in a rural area demonstrated a greater percentage of ever having heard of HPV, and that fathers' education level is significantly associated with the willingness of HPV vaccination. Mouallif and colleagues in Morocco concluded that mothers who agreed with the statement 'Whatever happens to my health is God's will', believed that the vaccine was expensive and believed that they had insufficient information about the vaccine were significantly less likely to accept the vaccine [51,54].

Sexually transmitted infections (STIs)
Sevenincluded studies assessed the awareness of 2,986 Africans in regard to STIs as general, three studies were conducted in Nigeria [17,18,44] and one in each of Madagascar, Morocco, Mali and Uganda [47,56,70,71]. The oldest among the study included was conducted after 2010 while the newest was conducted in 2014. Population under study was found to be mainly adolescents and students (5/7), while one study was targeting seafarers and another targeting women in reproductive age ( Table 1). Majority of studies were conducted among both genders (5/7), one was toward males only while another was targeting females only ( Table 1). Age of respondents range from 14 to older than 45 years. Thirty five questions were asked to the participants that are related to the knowledge and awareness of STIs general knowledge, transmission routes, clinical symptoms, pathological consequences and prevention attitude, among which 14 questions were analyzed and synthesized. The question ''Is Genital ulcer a symptom of having STIs?" was answered by 2,322 participants in Morocco and Uganda; 23.5% [95% Cl; 3.8, 43.2] answered yes. The question ''Do you know gonorrhea?" was answered by 1,123 participants in Nigeria and Madagascar; 22.8% [95% Cl; 5.1, 40.5] answered yes. questions asked, their corresponding articles' data, the pooled prevalence and the confidence intervals are depicted in (Table 9). Heterogeneity was high in all questions (I 2 more than 80%).
Awareness of STIs related to demographic characteristics. Akokuwebe and colleagues reported that Media (as general) was the main source of information 57.0% followed by friends 30.0%, and association between source of information about STDs is significantly related to age. Moreover, Laraqui and colleagues concluded that during the year prior to the study, 73.2% of participants (seafarers) were informed about the prevention of STI/HIV/AIDS through different ways, mainly the media (73% via TV and 45.6% via radio). Amu and colleagues provided more specific information in regard to source of knowledge as they determined that there are three major sources of information; the radio and television 343 (68.7%); teachers 340 (68.1%); and newspapers 224 (44.9%). Nevertheless, Nawagi and colleagues in Knowledge gaps of STIs in Africa; Systematic review  [17,47,56]. Joda and his colleagues in Nigeria conducted a study to assess the level of knowledge of STIs among students from different schools and concluded that there is no statistically significant differences in the responses obtained from various schools. Moreover, Reuter and colleagues conducted a study to assess the difference of STIs related knowledge between university students of Madagascar and USA, and concluded that there is no statistically significant differences [44,71].
In spite of the study populations' differences, five studies reported a significant association between knowledge of STIs and the level of education [30,38,68,81,82]. Considering age as a factor influencing level of awareness; four studies report it to be significantly valid [38,50,65,81], while two studies appose [26,59]. Living in an urban area was found to be significantly associated with awareness level in several studies [38,68,83].

Discussion
The current study was the first of its kind-to our knowledge, as not general assessment of knowledge is studied, but the specific awareness determinants. The presented outcomes are believed to be the best inputs for organizing effective preventive measures,planning and conducting awareness raising campaignsas well as identifying potential research gaps.
The current study highlights the specific levels of STIs-related knowledge, practices and prevention attitudes among different African populations. The pooled prevalence estimates showed that even though more than 90% of the population had heard about STIs (94.5%) in general and HIV(92.2%) in particular, (79.7%) had never heard about HCV. These results are consistent with earlier studies in Eastern Europe, Victoria, Lao People's Democratic Republic and Iran [85][86][87][88]. Moreover, (25.1%) of the population knows HPV. However, a study conducted among adolescents and adult women in one of the developed countries (USA) reported that only18% had heard about the virus [89]. Nevertheless, the confounders among participants are to be considered when comparing the studies.
In the contrary to the expectations in regard to HIV-related signs and symptoms knowledge in such epidemic countries; this review revealed that almost only (14.4%), (17.0%) and (17.7%) of South Africans know that oral candidiasis, herpes zosters and constant diarrhea could be associated with HIV infection, respectively. Consistently, UNAIDS recently (2018) reported that less than (20.0%) of the same population consider TB to be associated with AIDS [90].
The current findings of knowledge related to vertical HIV transmission during pregnancy (57.0%), delivery (66.0%) or breastfeeding (73.0%) corroborate with other studies, although they slightly concluded higher proportions [91,92]. Furthermore, these findings are in line with the results reported in UAE and Greece. Nevertheless, in India; Pratibha Gupta and colleagues reported knowledge rates as low as (8.85%) and (23.8%) regarding the transmission during delivery and breastfeeding, respectively [93][94][95].
The findings clearly demonstrate that HIV preventative knowledge of South Africans are higher than that of Nigerians. For instance; using condom (64.4% versus52.6%) and having one sexual partner (83.1% versus 57.6%) are known to reduce HIV transmission by South African and Nigerian populations, respectively. Bangladeshi women were reported to have knowledge similar to South Africans. However, other studies conducted in Vietnam, Italy and USA reported higher proportions [96][97][98][99].
It has been reported that increased HIV knowledge resulted in a reduction of risky sexual behaviors among adolescents [100]. Notably, current findings revealed that adolescents in Africa were-for some extend aware of the facts associated with epidemics, transmission and prevention of HIV infection. Approximately (60.7%) believe that a healthy person can be HIV infected, similar finding was reported among Russians as well. Nevertheless, higher awareness rates were also reported in Iran and USA [101][102][103]. More than (50.0%) were found to be of good knowledge level about HIV transmission through Sexual intercourse (67.8%), Sharing sharp unsterilized objects (54.2%) and using intravenous needles (53.32%). This knowledge is higher when compared to Southern Brazilian adolescent's. However, adolescents from India, USA, Lao People's Democratic Republic and Iraq were reported to possess higher knowledge scores [86,97,[104][105][106].
Despite the finding that most of adolescents in Africa are aware of HIV transmission routes, they still express extensive misconceptions; nearly the half believe that HIV could be contracted through mosquitoes (43.5%), toilet seats(43.7%),sharing cups/plates (33.5%) and through hugging or kissing (25.8%). Studies carried out among nursing students in Greece and among men who have sex with men in Finland illustrate similar findings as well. However, higher misconceptions rates(76.0%)for kissing and (100%) for each of sharing dishes, hot springs and mosquito bites were reported in Taiwan and Japan, respectively [95,[107][108][109].
HIV-related stigma and discrimination persists as major obstacle to an effective HIV response in all parts of the world. Almost (37.4%) of South Africans consider stigma is a barrier to HIV testing. Generally speaking, Africans' attitude toward HIV/AIDS patients is in need for enforcement. For example, (62.9%) would care for a relative with HIV in household, (57.1%) would buy vegetables from an HIV infected vendor, and only (44.8%) would allow a person with HIV to teach. Similar results were found to be reported in Sri Lanka. However, Janahi and colleagues in their findings reported that more than half of the adult participants (n = 1,630) in Bahrain would avoid sitting near, hugging or even shaking HIV infected people's hand [110][111][112].
The findings presented in this study regarding HBV illustrate that the knowledge of Africans is moderate; (61.4%) know about the consequences of liver damage. Moreover, reusing needles(52.7%), sexual contact(42.5%) and toothbrush sharing(49.0%)were considered to be possible routs of HBV transmission. Furthermore, (72.3%) correctly believe in the existence of vaccination. A prior study conducted among Asian Americans in USA reported almostsimilar knowledgerates [113].
Regarding HCV;almost(68.8%) of Africansbelieve that transmission of HCV through reusing needles can occur. However, nearlythe half (42.0%) incorrectly believe in the existence of vaccination. Taiwanese dental students also believe that there is an effective vaccine for HCV but in low misconception rate as (15.0%) [107].
The pooled prevalence of the African knowledge regarding the association between HPV and cervical cancer was found to be mostly (43.8%), this is consistent with a study conducted in USA. Moreover, nearly (26.1%) of South Africans were aware of a vaccine for HPV prevention, lower knowledge rate (10.8%, N = 1,177) was reported in Berlin, Germany recently (2018). However, the fact that the later study was conducted among students and young adults is needed to beconsidered when comparing the results [114,115].
Implementations of educational awareness programs in schools will have its impacts in the near future. Moreover, knowledge raising campaigns at the continent level or nationally, in urban and rural regions, targeting infected or non infected individuals, applying traditional sittings or integrating new online tools are needed to be initiated for enhancing awareness and willingness for testing and for decreasing STIs transmission and discriminations.

Strengths and limitations
The strengths of this review are that we systematically identified and included awareness estimates from 2010. Moreover, we have conducted meta-analysis to derive pooled prevalence estimates of all questions related. Furthermore, we carried out a quality assessment of the included studies based on criteria specifically developed to determine the quality of included studies.
Nevertheless, several limitations are to be considered when interpreting study results; grey literature evidence was not assessed. Moreover, African journals that are not indexed in the screened databases was not considered for inclusion as well, although all included studies are of good quality, several good studies might have be missed. Furthermore, another parameter that should be considered is that the limited number of participants in some questions can be observed for which the outcome might not be suitable to be generalized to the continent/country/population level. Lastly, the heterogeneity was high among the majority of questions analyzed and for the sake of this review the similar questions were considered exactly the same despite of the possibility of bias in the interview or the data collection process.

Conclusion
The current study findings indicate that awareness is needed to be enforced. The differences observed among populations are highlighting the possibility for improvement by directing effort toward specific populations as well as addressing specific awareness determinants to ensure that gaps of weaknesses are filled.
Supporting information S1