Spatiotemporal Distribution Of Parasitic Infections In Al-Najaf Al-Ashraf Governorate And Its Association With Age, Sex, And Seasonal Factors Distribusi Spasial-Waktu Infeksi Parasit di Provinsi Al-Najaf Al-Ashraf dan Hubungannya dengan Usia, Jenis Kelamin, dan Faktor Musiman Al-ali Hawraa Mohammed hawraa.mohammed.iku@atu.edu.iq Al-Furat Al-Awsat Technical University Iraq 07 03 2026 05032026 <bold id="_bold-7">Introduction</bold>

Parasitic infections represent one of the biggest public health challenges in the world today, particularly in emerging nations and subtropics. Due to their integral relation to environmental hygiene, water quality, public health awareness, climatic parameters that promote the parasite's life cycle and distribution, they represent a significant health and economic challeng [1],[2],[3]. Parasitic infections can be detected in the intestines, skin, and blood in Iraq, where a large epidemiological problem that can be addressed with continued monitoring due to environmental changes and infrastructure developments. Many studies have demonstrated that intestinal parasites remain a persistent prevalence problem in several governorates, including Erbil, Salah al-Din, southern Iraq, as well as some others[4],[5],[6].

Najaf Governorate stands out from all governorates, becoming a growing mega city-town and a holy city of global attraction for many people who have visited the governorates and other countries for the past few years, with millions coming in visiting annually from outside. Such a moving nature and high population density, as described in a study from Ethiopia, make the complex epidemiological settings possible and possibly impact the transmission dynamics for parasitic infection, very consistent with patterns seen in other low and middle income settings with high population movement[2],[7].

Understanding transmission dynamics does not merely depend on examining infection rates, but also requires a thoughtful use of time and space. Spatial analysis is important in disease outbreak identification and risk-category categorization, both at individual level, geographic level, as well as between rural and urban areas. Instead, temporal analysis draws attention to time-series epidemiological patterns, enabling prediction of the probability of disease outbreak and evaluation of control response[8].

Demographic factors, especially age and sex play a critical role including differences in health behaviors, natural immunity, and exposure to pathogens between humans of different genders and ages, play a pivotal role in susceptibility. Research conducted on the prevalence of parasitic infections has shown high prevalence of transmission of disease in school-age children due to higher prevalence of exposure and vulnerability in the school-aged children[8],[9].

Concomitantly, temperature, humidity and rainfall are some of the seasonal factors that determine the parasitic and vector activity and these factors contribute to the yearly trend in infection rates over the life of the whole season. These environmental factors are specially meaningful in subtropical and arid environments such as Iraq and the Middle East as a whole where water supply and sanitation practices depend on a particular season[1],[3]. While previous research has investigated and investigated parasites in Iraq, there are few such studies that combine epidemiological or comparative analyses with complex spatial and temporal analyses in Najaf population, particularly studies that link these factors with changes in the season of climate during the last year. Hence, this study is very significant as it aims to evaluate the epidemiological condition of the spread of parasite in Najaf Governorate, its geographical and temporal distribution, and the demographic variables (age and gender) as well as seasonal factors. The aim here is to develop a powerful database that should assist health policymakers in devising clearer and more effective measures to prevent and control disease or infection at the population level, and to support the overall improvement of prevention and control strategies.

 <bold id="_bold-8">Methodology</bold>

Data Collection: Data were collected from the Parasitology and Helminthology Unit at the Al-Sadr Teaching Hospital Laboratories, Najaf, Iraq for this study. Data were collected from July to November 2025. This data covered protozoan and helminthic infections, as well as sex and age differences, including individuals aged 1 to 45 years. In this period of analysis 422 patients were evaluated, and 292 were confirmed to have parasitic infections.

Statistical Analysis: The study data were assessed by descriptive analysis of the data, and frequencies and percentages were given to show the pattern of parasitic infection. The distribution of each parasite was analysed based on age, sex, the month of sample collection, place of residence (urban or rural), and the prevalence of the organisms investigated. No inferential statistics were used as this project's main focus was descriptive. These results are displayed in tables to clearly display the patterns and the proportions of the detected parasitic infections.

 Result

A recent research study on the health condition in Najaf, Iraq, found that there were five forms of parasitic infections Entamoeba histolytica/disparcomplex, Giardia lamblia, Trichomonashominis, Hymenolepis nana andTrichomonasvaginalis. A systematic analysis of 422 samples showed that 292, or 69.19% of the total samples, tested positive for parasitic infections. The other 130 samples, representing 30.81%, produced no infection (Table 1).

<bold id="_bold-13">Table 1: The Number Of</bold> <bold id="_bold-14">positive And Negative Samples</bold>

Samples No. Percentages %
Positive Of Parasite 292 %69.19
Negative Of Parasites 130 %30.81
Total 422 %100

The extent of different parasites found in the positive samples is detailed in Table 2. Five specific parasites were studied: Entamoeba histolytica/dispar complex, G. lamblia, T. hominis, H. nana, and T. vaginalis. Positive samples numbered 292, including all instances of being found at all. Entamoeba histolytica/dispar complex was the most common parasite shown in the data, in 159 samples (54.45%) of the total samples. After this, G. lamblia was detected in 117 samples, which is 40.07%. The prevalence of T. hominis, H. nana, and T. vaginalis was comparatively smaller, corresponding to 6 (2.05%), 2 (0.68%) and 8 (2.74%) samples respectively.

<bold id="_bold-21">Table 2: </bold> <bold id="_bold-22">Studied Parasitic Infections </bold> <bold id="_bold-23">Frequency And Percentage Distribution </bold>

Parasite Infections Entamoeba histolytica/dispar complex G.Lambilia T.Hominis H.Nana T.Vaginalis Total
No. 159 117 6 2 8 292
Percentages % 54.45% 40.07% 2.05% 0.68% 2.74% 100%

Examining the data presented in Table 3, a clear pattern emerges concerning the distribution of parasitic infections across various age demographics. The individuals for the study fell into three groups: 1–14 years of age, 15–44 years, and 45 years old or older. Of note, the youngest cohort among participants aged 1–14 showed the highest prevalence rate of infections. In this group, an impressive 189 positive samples were collected, representing an enormous 64.73% of all positive cases. The next age range, aged 15–44, exhibited less incidence, with 69 positive samples, representing 23.63%. The older cohort (45+) had the fewest infections with 34 positively isolated samples, representing 11.64% of positive estimates.

Scrutiny of the table indicates the different species of parasites within the age range. Regarding Entamoeba histolytica/dispar complex, approximately two-thirds (100 or 62.89%) of the positive samples originated in ages 1–14. The 15–44 age group represented 40 samples [25.16% of all samples] and the 45 and older group represented 19 samples [11.95% of all samples]. For G. lamblia, the 1–14 age group also showed the most number of cases with 81 samples or 69.23%.

There were 21 (17.95%) samples for the 15–44 age group, and 15 (12.82%) samples for 45 and older age groups. T.hominis and H. nana were isolated exclusively in the 1–14 age group. A total of 6 samples (100%) were labeled as T.hominisand 2 samples (100%) were labeled as H. nana Neither of these parasites was found in the older age groups. In contrast, all 8 cases of T. vaginalis described in the literature were within the 15–44 age range accounting for 100% of all cases reported.

<bold id="_bold-34">Table 3: Age-Wise Distribution Of Parasitic Infections</bold>

Parasite Infections Entamoeba histolytica/dispar complex G.Lambilia T.Hominis H.Nana T.Vaginalis Total
1-14 100(62.89%) 81(69.23%) 6(100%) 2(100%) 0(0%) 189(64.73%)
15-44 40(25.16%) 21(17.95%) 0(0%) 0(0%) 8(100%) 69(23.63%)
45≥ 19(11.95%) 15(12.82%) 0(0%) 0(0%) 0(0%) 34(11.64%)
Total 159(54.45%) 117(40.07%) 6(2.05%) 2(0.68%) 8(2.74%) 292(100%)

The distribution of the parasitic infections among the positive samples (divided, in terms of gender, into male and female groups) is summarized in Table 4. A table summarizes the prevalence of the actual infection for each parasite type, the ratio of each parasite type within each gender type, and the total for each category. Of the positive samples, 173 were from males accounting for 59.25% of the total positive samples. Females had 119 positive samples, which is 40.75% of the total.

The table provides additional information for each parasite type by sex. For instance, in the case of Entamoeba histolytica/dispar complex, 94 samples were from males (59.12%) and 65 samples were from females (40.88%). For G. lamblia 73 samples came from males (62.39%) and 44 from females (37.61%). In relation to T. hominis of the population, 4 samples were detected in males (66.67%) and 2 samples in females (33.33%). Regarding H. nana, 2 samples (100%) were identified in males (2 in total), and not in females (none of those were detected). Lastly, all cases of T. vaginalis (8 samples, 100%) were exclusively found in females, with no instances in males.

<bold id="_bold-47">Table 4: Distribution Of Parasitic Infection According To Sexes</bold>

Parasite Infections Entamoeba histolytica/dispar complex G.Lambilia T.Hominis H.Nana T.Vaginalis Total
Male 94(59.12%) 73(62.39%) 4(66.67%) 2(100%) 0(0%) 173(59.25%)
Female 65(40.88%) 44(37.61%) 2(33.33%) 0(0%) 8(100%) 119(40.75%)
Total 159(54.45%) 117(40.07%) 6(2.05%) 2(0.68%) 8(2.74%) 292(100%)

Table 5 Monthly breakdown of parasitic infections of positive samples identified using positive samples is shown from July to November. It explains the amount of positive samples per parasite type, the monthly percentage of each parasite and total positive samples per month.

There were 83 positive samples, each containing 28.42% of the total taken in July. These were 45 of Entamoeba histolytica/dispar complex (28.30%), 35 of G. lamblia (29.91%) and 2 of T. hominis (33.33%). There was also one case of T. vaginalis (12.5%), no H. nana In August 77 samples were positive – or 26.37%.

This included 42 cases of Entamoeba histolytica/dispar complex (26.42%), 30 of G.lamblia (25.64%), 2 of T. hominis (33.33%), 1 of H. nana (50.0%) and 2 of T. vaginalis (25.0%). For the September period, a total of 63 positive samples (21.58%) were recorded, of which 35 E. histolytica/dispar complex (22.01%), 25 G. lamblia (21.37%), and single isolated T. hominis (16.67%), H. nana (50.0%) and T. vaginalis (12.5%).

In October, 46 positive samples (15.75%) were obtained, including 25 (15.72%), 18 (15.38%), and single instances of T. hominis (16.67%) and T. vaginalis (25.0%) respectively. No H. nana was detected in this month.

in November, 23 positive samples (7.88%) were obtained in total, including 12 of Entamoeba histolytica/dispar complex (7.55%), 9 of G. lamblia (7.69%) and 2 of T. vaginalis (25.0%). No T. hominis nor H. nana were found in the samples for this month.

<bold id="_bold-59">Table 5: Distribution Of Parasitic Infections According To Months</bold>

Months Entamoeba histolytica/dispar complex G.Lambilia T.Hominis H.Nana T.Vaginalis Total
July 45(28.30%) 35(29.91%) 2(33.33%) 0(0%) 1(12.5%) 83(28.42%)
August 42(26.42%) 30(25.64%) 2(33.33%) 1(50.0%) 2(25.0%) 77(26.37%)
September 35(22.01%) 25(21.37%) 1(16.67%) 1(50.0%) 1(12.5%) 63(21.58%)
October 25(15.72%) 18(15.38%) 1(16.67%) 0(0%) 2(25.0%) 46(15.75%)
November 12(7.55%) 9(7.69%) 0(0%) 0(0%) 2(25.0%) 23(7.88%)
Total 159(54.45%) 117(40.07%) 6(2.05%) 2(0.68%) 8(2.74%) 292(100%)

Table 6 presents the distribution of positive samples with different samples from urban and rural populations showing parasitic infections. The table shows count of positive samples per identified parasite species with number of percentage/s per category. In rural samples, 176 positive samples were recorded, comprising 60.27% of positive cases. Of these, 95 samples were positive for Entamoeba histolytica/dispar complex, accounting for 59.75% of rural cases, and 70 samples were positive for G. lamblia (59.83%). T. hominis was found in 4 (66.67%) samples, H. nana in 2 (100%), and T. vaginalis in 5 (62.5%) samples. The urban area had 116 positive samples, 39.73% of the whole number. Among the samples from this group: 64 were positive for Entamoeba histolytica/dispar complex (40.25%), 47 for G. lamblia (40.17%); T. hominis found in 2 samples (33.33%), and T. vaginalis in 3 samples (37.5%). As we noted, there were no cases of H. nana in the urban population.

<bold id="_bold-74">Table 6: Distribution Of Parasitic Infections According To Residence</bold>

Residence Entamoeba histolytica/dispar complex G.Lambilia T.Hominis H.Nana T.Vaginalis Total
Rural 95(59.75%) 70(59.83%) 4(66.67%) 2(100%) 5(62.5%) 176(60.27%)
Urban 64(40.25%) 47(40.17%) 2(33.33%) 0(0%) 3(37.5%) 116(39.73%)
Total 159(54.45%) 117(40.07%) 6(2.05%) 2(0.68%) 8(2.74%) 292(100%)
<bold id="_bold-86">Discussion</bold>

Intestinal parasites is prevalent in Najaf Governorate (69.19% infection rate of this stage) according to the present study. This relates to a recent study reporting the common occurrence of E. histolytica and G. lamblia in the governorate, which found it caused by insufficient water and sanitation facilities and low health consciousness[10]. This percentage is significantly higher than the reported number used for a study in Zakho Governorate in which 18.65% of protozoan parasites were recorded, and the population of E. histolytica was significantly higher than that of G. lamblia It underlines the influence of various environmental and social factors in the two governorates[11]. Note that these percentages belong to the study sample of Najaf Governorate and thus might differ if larger samples have been taken or it was from another area. By parasitic species distribution, researchers found E. histolytica to be more prevalent (54.45%) than G. lamblia (40.07%).

For one, Iraqi population studies have reported E. histolytica as the most prevalent parasite, although the rates of the infection vary for different places and seasons[6]. A previous study from Mosul also reported that E. histolytica was more common in children that have diarrhea than G. lamblia [12]. The frequency is also confirmed by studies that have reported high infection rates in rural and neighbouring peripheral localities[13]. In terms of the age distribution of infections, the most infections were seen in 1–14 years old and that in children the general tendency was noted to reflect the study found in Duhok who found that children were more prone to E. histolytica than G. lamblia [14].

This can be linked to the underdeveloped immune system of children and to inadequate sanitary environments, as described in previous studies to estimate the disease burden of primary parasites in the surrounding areas[11]. As for the distribution by sex and region, the prevalence of infection was in males in the most of the intestinal parasites in the present study could be partly affected by the type of life-day environment and also by the greater environmental factors exposure of rural areas. Hymenolepis nana as a parasite was also found to be endemic in rural areas, especially among male adolescents, reflecting poor personal hygiene practices, exposure to sources of contamination, and overcrowded housing[15],[16],[17].

While the incidence of Trichomonas vaginalis was recorded in a ruralised manner, this infection was more concentrated in a rural setting, suggesting an increased epidemiologic specificity of the sexually transmitted parasite. Indeed, a lack of healthcare services and health education programs among the rural populations that have been recently studied in the governorates of Najaf, Babylon and Wasit were associated with the high incidence of infection also[18],[19],[20],[21]. Analysis of the pattern of seasonal distribution showed an alarming increase in infection during summer months, such as July and August. Indeed, this may be due to high temperatures and humidity, which favour a habitat for parasitic cysts to survive outside and in which water and food contaminated water can be more exposed to[6]. Most importantly, the findings indicated that rural communities showed significantly greater rates of infection than urban ones, which is in accordance with previous results that have correlated rural housing, inadequate water and sanitation facilities and risk for intestinal parasite infection suggesting environmental and social factors are playing important roles in the spread of infection[10],[13].

<bold id="_bold-87">Conclusion</bold>

The results of this study demonstrated the high prevalence of parasitic infections in the Najaf region of Iraq. The most popular parasites found were Entamoeba histolytica/dispar complex and G. lamblia. The number of such infections seemed to fluctuate, depending on, for example, the age and sex of those who were infected, the season and the area where they lived. Infection frequencies were greater among children (aged 1–14 yrs), males and those residing in the countryside. These results underscore the persistent public health risk associated with parasitic infections in this area and indicate that focused interventions are warranted.

Recommendations

Based on this study, it would be useful to initiate health education programs inside the community. This can mean emphasizing aspects of personal hygiene, the prevention of parasitic infections in these programs, and encouraging people to maintain such measures. Simultaneously, sanitation infrastructure must also be improved to minimize the risk of exposure to parasitic infections, especially in rural areas. Furthermore, the researchers recommend screening, especially at an early stage, in children and populations at risk, such as children and residents in rural areas. And long-term monitoring of parasitic infections is also critical in formulating effective public health measures, and interventions.

Ethics Statement

Oral informed consent was obtained from all participants prior to their inclusion in the study. Participants were told that they did not have to take part, and data collected could only be used for scientific research purposes.