Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae in women of the Czech Republic armed forces

Overview

Background: Sexually transmitted infections (STIs) are a serious health problem with global impact, more prominently in women. Their prevalence is increasing, and the preventive measure options are not being sufficiently innovated.

The military environment is historically characterized by a higher incidence of STIs. A prospective cross-sectional study was conducted in order to analyze prevalence of common STIs in women of the Czech Republic armed forces.

Material and methods: Chlamydia trachomatis (C. trachomatis) and Neisseria gonorrhoeae (N. gonorrhoeae) detection was performed in 231 women between August 2020 and December 2023. Participants were divided into three groups according to their military status. Group A –⁠ recruits (n = 84), Group B –⁠ active soldiers (n = 43) and Group C –⁠ control civilian group (n = 104).

Cervical smears were used to diagnose pathogens and data evaluating medical history and the occurrence of risk factors in women were obtained using a detailed questionnaire.

Results: Ch. trachomatis prevalence was 6.0% (5/84) in group A, 2.3% (1/43) in group B and 2.9% (3/104) in group C. There was no statistically significant difference between the groups (p = 0.601). No case of N. gonorrhoeae was recorded across the study (0/231). Regarding known STI factors, the groups differed significantly in age. The median age in group A was 26 years while it was 29 years in groups B and C similarly (p < 0.001). There was also significant in-between-groups difference in age of coitarche 16.0 vs. 16.0 vs.

17.0 years (p = 0,015). Women from group A reported more frequent absence from regular pap-smear attendance compared to other groups (12.0% vs. 16.3% vs. 3.9%) (p = 0.032).

Conclusion: This study did not show any significant difference in prevalence of C. trachomatis and N. gonorrhoeae in females of the Czech Republic Armed Forces compared to civilian women. Higher prevalence of selected STIs‘ risk factors were reported in recruits and active soldiers compared to civilian women.

Although not conclusively, shown findings should be considered a reason to foster the research on STIs in the military environment and to enhance preventive measures among women in the armed forces to limit impact of known STIs‘ risk factors.

Keywords:

Chlamydia trachomatis – Neisseria gonorrhoeae – army – sexually transmitted infection – military

BACKGROUND

Sexually transmitted infections (STIs) are a serious health issue affecting both women and men worldwide. Their incidence has an increasing tendency. The most common bacterial pathogens include Chlamydia trachomatis (Ch. trachomatis) and Neisseria gonorrhoe­ ae (N. gonorrhoeae). The WHO estimates that there were 128.5 million new cases of Ch. trachomatis worldwide in 2020 with a prevalence of 4.0% in women and 2.5% in men aged 15–49 years. There were 82.4 million estimated new cases worldwide in 2020 in the case of N. gonorrhoeae [1].

Even though these diseases are preventable and treatable, their effect on health can be devastating. The infection is often asymptomatic and affects women more than men [2]. The disease can lead to damage of reproductive organs and risk of deterioration of the individual’s fertility. Complicated infections may even result in life-threatening conditions such as tubo-ovarian abscess in women.

The military environment has historically been associated with a higher prevalence of STIs. Specific army factors, stress, community composition and availability of medical care may play a role [3, 4]. Available data on the incidence of Ch. trachomatis and N. gonorrhoeae in the military are acquired mainly from large United States (US) army registries [5]. Studies on European military units are usually limited to their extent. The range of reported rates of STIs incidence in published manuscripts is wide ranging from 3.1% to 8.2% in case of Ch. trachomatis and from 0.1% to 1.3% for N. gonorrhoeae [6, 7]. However, most of the studies assess the STIs in soldiers without gender stratification or in men only. Data on female soldiers‘STIs epidemiology are scarce. For these reasons we decided to conduct a study that aimed to evaluate the epidemiology of STIs in women of the Czech Armed Forces. The pilot phase of our study did not show significant difference in prevalence of Ch. trachomatis and N. gonorrhoeae between recruits and active soldiers of the Czech Armed Forces compared to civilian women [8]. In this recent study we publish complete epidemiological data together with STIs risk factors evaluation.

Obtained data were numerically pseudo anonymized. In women who were tested positive for STIs, a medical follow-up was provided with an antibiotic therapy prescribed.

Statistical analysis was performed in SPSS Statistics v.21. The Fisher exact test and standard chi-square test were used to determine difference in the STIs prevalence between the groups. Kruskal-Wallis test or chisquare/Fisher exact test were used to evaluate if the groups differed in exposure to risk factors for STIs. For statistically significant results the post hoc test or Bonferroni correction were applied. The level of statistical significance was p < 0.05.

 

RESULTS

Prevalence of Chlamydia Trachomatis and Neisseria Gonorrhoeae

A total of 231 women was enrolled in the study. Recruits in group A (n = 84), active soldiers in Group B (n = 43) and civilian women in control Group C (n = 104). Answers from 229 (99.1%) women who completed the questionnaire were collected.

Ch. trachomatis was detected in 5/84 (6.0%) women in group A, 1/43 (2.3%) in group B and 3/104 (2.9%) in group C. There was no statistically significant difference in Ch. tra­ chomatis prevalence between the groups (p = 0.601).

No case of N. gonorrhoeae was recorded across the study (0/231).

Demographic Data and STIs Risk Factors

Regarding known STI risk factors, the groups differed significantly in age. The median age in group A was 26 years while it was 29 years in groups B and C, similarly (p < 0.001).

The recorded median age of coitarche was 16 years in group A, 16 years in group B and 17 years in group C. This in-between-groups difference was statistically significant with lowest age of coitarche reported in group A participants (p = 0,015). Groups did not differ significantly either in number of lifetime sexual partners or number of sexual partners last year (p = 0.415; p = 0.053) (Table 1).

Regular Pap-smear attendance reported 73/83 (88.0%) women from group A, 36/43 (83.7%) women from group B and 99/103 (96.1%) women from group C (p = 0.032). Significantly more women from civilian group underwent Pap-smear regularly compared to recruits and active soldiers. The study did not show any significant in-between-group difference in personal history of STI (p = 0.107), cervical disease (p = 0.075), usage of condom or other contraceptive methods (p = 0.875), addictive substances usage (p = 0.830), smoking (p = 0.054) or marital status (p = 0.197) (Table 2).

 

Table 1. Analysis of ordinal STIs risk factors in groups

Group		Age (years)	Age of coitarche (years)	Number of lifetime sexual partners	Number of sexual partners in last year
A	Median	26.0	16.0	8.0	1.0
	Average	26.1	16.4	9.7	1.7
	SD	5.7	1.8	8.6	1.6
	N	84	79	78	79
B	Median	29.0	17.0	7.0	1.0
	Average	28.7	17.1	9.3	1.8
	SD	5.7	1.9	7.0	3.0
	N	43	43	41	43
C	Median	29.0	17.0	6.0	1.0
	Average	28.9	17.3	9.2	1.4
	SD	4.6	2.4	8.4	1.4
	N	103	102	99	101
Kruskal-Wallis a post hoc tests	χ²	17.8	8.4	1.8	5.9
	Degrees of freedom	2	2	2	2
	p-value	<0.001	0.015	0.415	0.053
	A-B	0.021	0.132	X	X
	A-C	0.000	0.017	X	X
	B-C	1.000	1.000	X	X

Explanations:

Bold: statistically significant results; N –⁠ number of subjects; SD –⁠ standard deviation; χ² –⁠ test statistics; A –⁠ Group A, military recruits; B –⁠ Group B, active soldiers; C –⁠ Group C; civilian women; X –⁠ not calculated

 

Table 2. Analysis of nominal STIs risk factors in groups

STIs risk factors	Category	Group A N	Group B N	Group C N	Test statistics	Degrees of freedom	p-value
Pap-smear in last 2 years	0	10	7	4	6.9	2	0.032
	1	73	36	99
History of STI	0	76	36	83	4.5	2	0.107
	1	7	7	20
History of cervical disease	0	69	37	69	5.2	2	0.075
	1	13	6	13
Contraception usage	0	60	30	62	5.8	X	0.875
	Oral contraceptive pill	14	8	20
	Intrauterine device	3	3	8
	Vaginal ring	2	0	3
	Condom	3	2	7
	Sterilization	0	0	1
Smoking	0	51	35	79	7.8	X	0.054
	1	26	7	18
Drug abuse	0	76	42	95	0.8	X	0.830
	1	2	0	2
Marital status	Single	63	31	72	7.7	X	0.197
	Married	12	7	23
	Divorced	2	4	2

Explanations:

Bold: statistically significant results; N –⁠ number of subjects; Category 0 –⁠ negative answer; Category 1 –⁠ positive answer; X –⁠ not calculated

 

DISCUSSION

The main aim of this study was to determine prevalence of Ch. trachomatis and N. gonorrhoeae in women of the Czech armed forces. Observed prevalence of Ch. trachomatis was higher, although not significantly, in recruits compared to active female soldiers and civilian controls. This is in line with high prevalence of Ch. tra­ chomatis in military recruits shown by Gaydos et al. and Boyer et al. respectively [9, 10]. High seroprevalence of STIs in recruits compared to civilians was also shown by Agan et al., even though in men only and for HPV [11]. Higher Ch. trachomatis prevalence in military personnel was reported in several studies during last decades. Duron et al. published a study on French military service members with Ch. trachomatis prevalence 8.2% and 3.0% in females and males respectively [7]. Data from US military also showed increased Ch. trachomatis prevalence in soldiers [4, 12]. However, our study did not show any significant increase of Ch. trachomatis prevalence in active female soldiers. This is consistent with an Austrian study which reported Ch. trachomatis in 3.2% of male soldiers and none female soldiers, although only 15 women were included in the study [13]. Similar prevalence (3.1%) of Ch. trachomatis was shown by a study on German paratroopers and marines (155 males and 5 females) or by large Israeli study on female soldiers (3.3%) [6, 14]. These data show that different military settings vary in prevalence of Ch. trachomatis and cannot simply be perceived as risky and problematic altogether.

Population data on Ch. trachomatis epidemiology in the Czech Republic are limited. Study performed on pregnant asymptomatic women reported prevalence rate of 2.2% [15]. Another study from Central Europe region showed Ch. trachomatis prevalence 2.3% in German 18–24 years old women [16]. There were 1810 new cases of Ch. Trachomatis infection reported in the Czech republic during the 2023 year [17].

No case of N. gonorrhoeae was detected in our study. Low prevalence of N. gonorrhoeae is in accordance with German cross-sectional study which reported prevalence of 1.3% in soldiers [16]. Previously mentioned large Israeli study showed detection of N. gonorrhoeae in 1.1% of female soldiers [14]. Study on French service members discovered only 1 case in 925 participants (0.1%) [7].

Prevalence of N. gonorrhoeae in the study on population of the Czech pregnant women was 0.0% [15]. However, a slow increase in rates of N. gonorrhoeae is documented across Europe and this trend will surely reach also the military environment [18]. Preliminary data for Czech population reveal 2562 new cases of N. gonorrhoeae in 2023 [17].

Groups in our study differed significantly in median age of participants with youngest in the Group A. We consider this a main limitation of the study. The difference could prove crucial as it is well established that STIs‘ prevalence is age-dependent with maximum peak in age groups < 25 years old [19, 20]. Age standardization was not applied due to limited number of positive detections. However, considering the character of in-between-group age difference, the disparity in STIs prevalence between the groups would be even smaller if standardization was applied.

Military recruits were shown to be at higher risk in two of evaluated STIs risk factors. Group A recorded the lowest age of coitarche and together with active soldiers also lower rate of regular preventive PAP-smears. The low age of coitarche in recruits could be explained by high-risk behavior in military service-women shown by Goyal et al. [21]. Simultaneously, early coitarche is often associated with risky sexual behavior, a higher number of sexual partners, substance use, and less frequent use of barrier contraception [22]. A Swedish study investigating risk factors associated with coital initiation showed that earlier onset of menstruation and a higher perceived social age may lead to earlier initiation of sexual activity. Women with earlier coitarche are also more likely to be victims of sexual violence [23].

The second main limitation of this study is the sample size and group distribution. The power of statistical analysis was limited with the smallest number (n = 43) of participants in the active soldiers group. Authors consider this to be caused partly by concerns of active soldiers regarding the results of STIs detection in relation to the employment and partly by unavailability of active soldiers due to their deployment across the units out of the health care facility region.

Authors believe that strong point of this study is its focus on female soldiers‘STIs epidemiology separately from males. This is important as women are generally more affected by STIs and most of the studies refer to male soldiers or combined cohorts without clear gender distribution.

CONCLUSION

This was the first study to analyze the epidemiology of Ch. trachomatis and N. gonorrhoeae in women of the Czech Republic Armed Forces. It did not demonstrate significant differences in the prevalence of the pathogens compared to civilian women, but it did emphasize a possibly increased STIs risks in the context of military service. The results should therefore serve as an incentive for further research and consideration of preventive measures to minimize the risks of military service for female soldiers‘ fertility health.