We are living in the era of the greatest human mobility ever recorded in history. According to the United Nations Secretariat [1
], the number of international migrants is estimated at 244 million, representing approximately 3.3% of the world population. Although they are harder to quantify, undocumented migrants are estimated to be 15–30 million worldwide (International Labor Organization, ILO) [2
]. In Italy, there were 5 million migrants in 2012, and approximately 23.7% of them were living in the Lombardy Region [3
Nearly half of all international migrants are women and girls, more and more of whom are migrating independently of the male population [4
]. Therefore, migration is a factor to be considered in issues related to women, as it may lead to the worsening or improvement of women’s health. The conditions of migration, the extent of integration into the host society, the social status of the woman and the health regulations in force in the host country are all factors that affect the well-being of women. Women who migrate from low-income to high-income countries [5
] are more likely to benefit from the host country’s health system, provided that they can speak the language of the host country and are employed. However, women are usually completely dependent on their husbands/partners and may not be able to access the health system to obtain adequate information and health care due to lack of health insurance and problems of male dominance [6
]. In fact, migrants often move with their culture and traditional norms and this is a particular challenge for women. For example, cultural norms may prevent women from accepting care from male practitioners. Moreover, educational levels, misconceptions and prejudices hinder their access to and the success of health prevention programs. In addition, the lack of language skills can be a major barrier to understanding health care procedures and the functioning of the health system [7
]. Therefore, in order to improve the welfare of the female migrant population, an appropriate education related to all aspects of women’s health is required, particularly in the field of reproductive and sexual health.
Sexually transmitted infections (STIs) are one of the main public health problems affecting migrant women [11
]. Most STIs are asymptomatic, but they can cause acute illnesses, chronic infections and serious delayed sequelae, such as infertility, ectopic pregnancies, cancer, long-term disability and premature deaths. Undocumented migrants are often denied access to public health services or are reluctant to use services that are available for them for fear of being deported. Even migrants who are legally entitled to health care may face various obstacles to utilizing these services [9
]. In Italy, very few data are available regarding STI surveillance among migrant women, especially undocumented women [12
]. Furthermore, although under Italian law health care is available to all migrants, including illegal migrants, no national preventive action targeted at the sexual health of female migrants has been implemented. Consequently, their access to screening is almost inexistent and the admission to medical care is limited to emergencies, when the disease has become symptomatic. In order to overcome these problems and to gain insight on sexual health in migrant women, we implemented a counseling and a preventive strategy for controlling STIs in undocumented migrant women (i.e., foreign-born person not having the official documents that are needed to enter, live in, or work in a country legally), in Milan. Urine sampling, which is non-invasive and easy to collect, was selected in order to avoid gynaecological examinations that may run counter to socio-cultural and religious beliefs, as well as to improve screening coverage.
In particular, we focused on two of the most common STIs worldwide [11
], Human papillomavirus (HPV) and Chlamydia trachomatis
) infections. As a secondary aim, we performed a pilot study to investigate the spread of another two STI infections, Neisseria gonorrhoeae
) and Trichomonas vaginalis
) in the same population.
2.1. Study Population and Acceptability to the Study
From June 2012 to December 2013, 757 undocumented migrant women attending the NAGA Centre in Milan (Italy) [15
], were invited to take part in the study, regardless of the reason (medical or otherwise) for their visit to the Centre. Informed consent, a questionnaire regarding their socio-demographic profile and sexual and reproductive health behaviour, as well as a first void urine sample were obtained from each participant. Overall, 537 women, aged 18–65 years, agreed to participate in the study. Therefore, the acceptability rate was 70.9% (95% Confidence Interval, 95% CI 67.7–74.1). Lack of time was the main reason that women (198/757; 26%) gave for refusing to participate. Twenty-two women refused to complete the questionnaire and give informed consent to the study due to the prevailing decisions of husbands/partners. This reason could have created a potential selection bias, but the proportion (22/757; 2.9%) was very low.
2.2. Socio-Demographic and Sexual Health Characteristics
The 537 women enrolled had a median age of 36 years (InterQuartile Range, IQR: 28–47). Subdividing for age-classes, 15.4% (n = 83) of women aged <25 years, 30% (n = 161) 25–34 years, 24.4% (n = 131) 35–44 years, 19.2% (n = 103) 45–54 years, and 11% (n = 59) ≥ 55 years. Regarding geographical origin, the women came from 39 different countries belonging to six World Health Organization (WHO) Regions: 45.6% (n = 245) of them were from Latin America [in particular, 38% from Peru, 20% from El Salvador, 17% from Ecuador, 9% from Brazil and 8% from Bolivia]; 30.7% (n = 165) came from Eastern Europe (47% from Romania, 22% from Ukraine, 11.5% from Albania, 9% from Moldova, 8% from Bulgaria, 2.5% from Kazakhstan, Serbia and the Russian Federation). The remaining 23.7% were from Eastern Mediterranean countries (8% (n = 43), for the most part from Morocco (67%)); Western Pacific (6.7% (n = 36), for the most part from Philippines (72%)), Africa (6.3% (n = 34), 32% of whom from Nigeria), and; Southeast Asia (2.6% (n = 14), all from Sri Lanka).
summarizes the socio-demographic and sexual-reproductive health characteristics of the women included in the study.
A total of 46.4% of the undocumented women had been living in Italy for more than 5 years, 57.4% were married or had stable partners, and 70.4% had a high level of education (high school or degree). As for the risk factors associated with sexual health, 44.3% of women first had sexual intercourse between 16 and 19 years of age. As regards to geographical origin, women from the Eastern Mediterranean, Western Pacific, Africa and Southeast Asia first had sexual intercourse later in life (>19 years, p = 0.05). 65.2% of women reported to have stable sexual partners and 64.8% did not use contraceptive methods. Seventy percent of the women had had at least one pregnancy, 26.4% reported to have had any Sexually Transmitted Disease (STD) in the past. Specifically, 6.7% reported mycosis and 6.9% reported bacterial vaginosis.
2.3. Evaluation of DNA Quality
The β-globin gene was amplified from all 537 urine samples collected, thus confirming the suitability of the extraction protocol.
2.4. HPV Detection and Genotyping
Overall, the prevalence of HPV infection was 24.2% (95% CI: 20.7–28; 130/537). By subdividing for geographical origin, the percentages of HPV DNA positive women were: 29.4% (95% CI: 24.1–35.6; 72/245) for those from Latin America, 27.8% (95% CI: 15–44; 10/36) from Western Pacific, 21.4% (95% CI: 5.8–47.9; 3/14) from Southeast Asia, 21% (95% CI: 10.2–33.5; 9/43) from the Eastern Mediterranean, 18.2% (95% CI: 12.8–24.6; 30/165) from Eastern Europe, and 17.6% (95% CI: 7.5–33.1; 6/34) from Africa. Comparisons of HPV DNA positivity among the geographical groups showed a statistically significant difference for women from Latin America versus those from Eastern Europe (29.4% vs. 18.2%, p = 0.009).
The median age of HPV DNA positive women was 37 years (IQR: 28–47). The age-stratified HPV prevalence showed a peak among women <25 years (32.5%; 95% CI: 23.4–43.2; 27/83) while it was constantly lower in the other age groups (21.7%, 26%, 21.3%, and 20.3% in women aged 25–34, 35–44, 45–54 and ≥55 years, respectively).
No meaningful comparison can be made regarding the prevalence of HPV infection by age and geographical origin, since the women under analysis were randomly recruited (Table 2
Overall, 77.7% (101/130) of HPV DNA positive samples were suitable (strong polymerase chain reaction (PCR) signal) for Restriction Fragment Length Polymorphism (RFLP) typing. A total of 34 different HPV types were identified from the urine samples, 18 belonging to the High Risk-clade (HR-clade: 52.9%) and 16 being Low Risk (LR) types (47.1%). Among typed infections, 85.2% (86/101) were caused by a single HPV type, while 14.8% (15/101) were multiple infections. On the whole, 67.3% (68/101) of infections were sustained by at least one type belonging to Group 1, which includes types classified as being carcinogenic for humans [16
Among the 508 women enrolled (excluding 29 women with untyped HPV DNA), HPV-56 was the most frequent type in Group 1, with a frequency of 2.0% (10/508), followed by HPV-16 and HPV-52 (7/508, 1.4% each). HPV-18 was only detected in 0.2% (1/508) of the women enrolled (Figure 1
2.5. C. trachomatis Detection and Genotyping
Overall, the prevalence of Ct infection was 7.8% (95% CI: 5.8–10.3; 42/537). Among the infected women, 16.3% (95% CI: 7.4–29.6; 7/43) were from the Eastern Mediterranean region, 9.8% (95% CI: 6.5–14; 24/245) from Latin America, 8.8% (95% CI: 2.3–22.2; 3/34) from Africa, 5.6% (95% CI: 0.9–17.2; 2/36) from Western Pacific, and 3.6% (95% CI: 1.5–7.4; 6/165) from Europe. Comparisons of geographical groups showed higher percentages of Ct DNA positivity among women from the Eastern Mediterranean and Latin America versus European women (16.3% vs. 3.6% and 9.8% vs. 3.6%, p = 0.007 and p = 0.01, respectively).
The median age of positive women was 28.5 years (IQR: 24.2–36). The prevalence peak was observed in women <25 years (13.2%, 95% CI: 7.2–21.9) with a decrease according to age (11.2%, 4.6%, 3.9%, and 5% among women aged 25–34, 35–44, 45–54 and ≥55 years, respectively).
For the same reason mentioned above, no meaningful comparisons can be made regarding the prevalence of Ct
infection by age and geographical origin (Table 3
Fifty percent (21/42) of Ct DNA positive samples were successfully genotyped. Seven different genovars, belonging to biovar trachoma, were identified: genovar E was the most frequently found infecting seven samples (33.3%), followed by genovar G (19%, four samples), by genovar D and F (14.3%, three samples each), H (9.5%, two samples), Ia and Ja (4.8%, one sample each).
2.6. HPV/C. Trachomatis Co-Infections
Among the 537 undocumented migrant women, 17 (3.2%; 95% CI: 1.9–5) were HPV/Ct co-infected. There were no specific socio-demographic or sexual/reproductive health characteristics, or features of the infecting pathogen, associated with co-infection.
2.7. Diagnostic and Therapeutic Follow-Up
All of the 155 HPV- and/or Ct-infected women were contacted by phone in order to inform them of their STI status and to make a medical appointment. Overall, 28 (18.1%) women did not answer the phone despite repeated attempts, 60 (38.7%) did not attend the medical appointment for work, logistical, and/or personal reasons, and 67 (43.2%) agreed to undergo a gynaecological examination and to have suitable treatment. The outcome of the Pap test carried out on 58 HPV DNA positive women was: negative cytology in 77.6% (45/58) and atypical squamous cells of undetermined significance (ASC-us) in 32.4% (13/58). Six women (6/13; 46.2%) with ASC-us were infected with HPV types belonging to the HR-clade (HPV-16, -26, -51, -56, -66 and -82, respectively) and 7 (53.8%) were infected with LR HPV types. Nine Ct infected women received specific antibiotic treatment.
The flowchart with the design of the study and the main results is reported in Figure 2
2.8. N. gonorrhoeae and T. vaginalis Detection
T. vaginalis and N. gonorrhoeae DNA was detected in the anonymous residual aliquots from the 537 samples collected in the pivotal study.
The overall percentage of Tv DNA positivity was 4.8% (95% CI: 3.3–7.0; 26/537), with the highest infection rate (11.6%; 95% CI: 5.1–24.5; 5/43) among women from the Eastern Mediterranean region, and the lowest among those from Latin America (2.4%; 95% CI: 1.1–5.2; 26/245) (p = not significant). The proportion of women infected with Tv was 7.9% (95% CI: 4.7–13.0; 13/165) and 5.6% (95% CI: 1.5–18.1; 2/36) in Europe and in the Western Pacific, respectively. None of the 14 women from Southeast Asia were infected with Tv.
The median age of infected women was 39.5 years (IQR: 29.5–46.5) and the prevalence increased according to age up to 54 years (3.6%, 4.3%, 6.1%, 6.8% among women aged <25, 25–34, 35–44, 45–54 years, respectively). Seven women Tv DNA positive (1.3%; 95% CI: 0.6–2.7; 7/537) were also HPV and/or Ct co-infected: 3 women had a Tv/HPV co-infection, 3 a Tv/Ct co-infection and one woman had a triple infection Tv/HPV/Ct. There were no women infected with Ng.
Most of the United Nations member states have ratified treaties recognizing the right to equal and equitable access to health care for all persons, notwithstanding their legal standing within a government system [8
]. In Europe, much attention has been paid to the health of migrants due to the intensification of human mobility across continents especially in recent years. However, accurate information on migrants and their health status are not available in many European countries. In addition, both existing epidemiological and health data may have been underestimated due to difficulties in including undocumented migrants [17
]. Health care access for undocumented migrants varies considerably between countries, and they are generally less likely to gain access to it than legal residents [8
]. Not having access to appropriate health care can lead to severe outcomes that could otherwise be managed or treated. Among the migrant population, women are the most vulnerable to health problems and well-being. In this context, reproductive and sexual health and STIs in particular are the main public health issues affecting migrant women.
In some European countries, such as Austria, Denmark, Finland, Ireland, Luxembourg, and Sweden, undocumented migrants are only legally entitled to receive emergency health care, even if they pay for it, and do not have access to family planning or to regular sexual and reproductive health check-ups and screening for STIs [7
]. Furthermore, in other countries, restrictive policies ban or impose restrictions on the over-the-counter sale of emergency contraception. For example, in Hungary, emergency contraception requires a prescription, which is often inaccessible for undocumented migrant women [7
In Italy, although health care is available to all migrants under Italian law, including those who lack legal documents, no national prevention strategy is directed to female migrants, therefore they do not have access to screening programs.
The aim of this study was to outline and evaluate STI screening and to gain knowledge on the spread of HPV and C. trachomatis infections among undocumented migrant women living in Milan, who attend the NAGA Centre.
A large number of women participated in the study with an acceptance rate of 70.9%. This percentage of participation in molecular screening (HPV DNA testing) is much higher than that observed in previous offers of conventional cytological screening (Pap test) at the NAGA Centre (estimated acceptance rate of approximately 4%, unshown data).
Patient counseling and self-collected urine samples proved to be preferable for these women and contributed to the successful outcome of the study. During counseling women received information on the diagnosis, prevention, screening and treatment of sexually transmitted infections and diseases. This strategy has helped women to overcome their fears and prejudices related to sexual health and they were therefore more willing to undergo free screening for HPV and C. trachomatis
infections. Urine sampling, a methodology already tested and validated by us [18
], thus avoiding gynecological examination as well as socio-cultural and religious implications, proved to be non-invasive, easy and quick, and therefore a good alternative to conventional cervical brush for Pap screening. Furthermore, the offer of a “real time” STI screening may have been the tipping point for participation.
This was not the case for the next step of diagnosis or treatment after screening. In fact, a high loss to follow-up was observed, since only 43.2% (a low, yet significant proportion) of women positive for HPV and/or C. trachomatis
DNA agreed to undergo further investigation. This was probably due to the long interval between the actual screening and the follow-up appointment at the medical centre, to work commitments or change of residence. LILT Health care is a voluntary medical centre with a limited availability of appointments, which was the main cause of the long period between sample collection and examination. As recommended by WHO, the screen-and-treat approach is probably the only effective preventive strategy for these women at high risk and who are hard to reach [20
The results from this study have provided baseline data regarding the epidemiology of HPV and C. trachomatis
infections in undocumented migrant women in Milan. The overall HPV and C. trachomatis
prevalence were 24.2% and 7.8%, respectively, and peaks were observed in younger women, aged <25 years (32.5% and 13.2%, respectively). Nearly 70% of HPV positive women were infected by types known to be at high oncogenic risk; the most detected type was HPV-56 (2.0%), followed by HPV-16 and HPV-52 (1.4% each). These HR-HPV types are known to be the most common in women with normal cytology worldwide [21
]. The prevalent genovar
positive women was genovar
E (33.3%), known to have a biological advantage over the other genovars
thanks to its ability to escape the immune response and to have specific virulence factors, able to facilitate the transmission and infectious processes [22
The study population was enrolled among women who freely and randomly had access to the NAGA Centre during the study period three days per week. It is therefore not representative of the geographical area of origin, especially for the small number of women from some areas compared to those from Latin American and Eastern Europe, but it reflects the migratory movement across a large urban area of Lombardy, which is the region with highest percentage of immigrants in Italy.
The prevalence of HPV and C. trachomatis infections detected in this cohort of irregular immigrants are not comparable to the prevalence data reported for these two STIs in both the countries of origin and the host country.
Regarding HPV infection, a meta-analysis [16
] that included 194 studies on approximately one million women with normal cytological findings worldwide showed the highest HPV infection rates for women in Sub-Saharan Africa (24.0%), Eastern Europe (21.4%), and Latin America (16.1%). As observed in our study, there is a peak in the age-specific HPV distribution for young women (<25 years) [21
The percentage of undocumented migrant women infected with HPV was higher than that reported for the Italian female population with normal cytology (HPV DNA prevalence: 15.8%) [23
], but lower than the prevalence reported in other studies on migrant women in Italy (42–47.8%) [12
]. However it is important to note that the women included in these studies came from two geographical areas at high prevalence of HPV infection (Africa and Eastern Europe), or had a history of prostitution. The discrepancies are probably due to various socio-demographic characteristics and risk factors.
The prevalence of C. trachomatis
infection observed in this cohort of undocumented migrant women was slightly higher than that reported for Italian women (7.8% vs. 5.2%) [19
]. However, this prevalence is equal to that observed in another study conducted on 233 Eastern European and Western African immigrant women in Southern Italy (7.7%) [24
Lastly, the availability of residual DNA aliquots from urine samples collected for the main study enabled us to investigate the spread of the two other common curable STIs, T. vaginalis
and N. gonorrhoeae
infections, in the same population. An overall prevalence of 4.8% was observed for Tv
infection, while no women among the undocumented migrants in Milan were infected by Ng
. These are the first data obtained in Italy for this high-risk cohort and are comparable to the data reported in women of the general population worldwide (Tv
prevalence: 4.0–6.4%; Ng
prevalence: 0.6–1.0%) [25
As regards to the migrant population, data on the prevalence of T. vaginalis
are not available. The European prevalence data for N. gonorrhoeae
infection are similar to that observed in the native population, but active surveillance should be continued due to the increase of this infection among migrant women in recent years (2000–2010) [25
]. In addition, both infections are a major public health problem since they can cause acute inflammatory disease, premature rupture of membranes and premature birth, and increase the risk of contracting HIV [25
Our results show an overall high prevalence of STIs in undocumented migrant women. The epidemiological profile varies according to geographical origin, since women from Latin America showed the highest rate of HPV infection while women from the Eastern Mediterranean area had the highest Ct and Tv infection rates.