Leishmaniasis is a vector –born disease distributed worldwide and affects more than 88 countries. Leishmania is a protozoan disease with flagella and belongs to the class Zoomastigophora, Order Kinetoplastida and the family of Trypanosomatidae [1]. The disease has three primary forms: cutaneous, subcutaneous and visceral Leishmaniasis [2,3]. Leishmaniasis is considered one of the severe public health problems, especially in developing countries. Despite the advances in treatment and diagnosis, the disease is still a concerning matter for public health [4,5]. The World Health Organization (WHO) 2014 highlighted Leishmania as an increasing threat vector-borne disease [6]. Cutaneous Leishmaniasis (CL), also called oriental sore, Baghdad boil, tropical sore, Uta, Chiclero ulcer, Delhi boil, Aleppo button and Baure ulcer, includes L.tropica, L. aethiopica, L. infantum and L. major were found to be responsible for the transmission of cutaneous Leishmaniasis in the old- world. On the other hand, the sandflies accountable for transmitting the disease included Lutzomyia in New World and Phlebotomus in the Old World (Table 1) [7-10]. It has been estimated that 1.5-2 million people are infected each year and 15 million are already infected, while 350 million are at risk of infection by Leishmania [11,12]. 

Two mainly different cell morphology of Leishmania can be found, the first is the promastigote in the sand fly and the second is the Amastigote in the mammalian host. Many stages are involved in the cycle of Leishmania, starting in the sand fly by ingesting amastigotes during blood feeding, then it turns to the Procyclic stage in the midgut. Procyclic converted to nectomonad in the microvilli. In the thoracic midgut and stomodeal valve, the nectomonad is turned into a nectomonad which can be converted into a haptomonad. Finally, leptomonad turned to the infective stage metacyclic that transmit during blood feeding on mammalian (Figure 1) [13].

More than one-third of Leishmaniasis cases are reported in the three epidemiological regions. West Asia starts from the Middle East to Central Asia, the Mediterranean basin and the Americas. Interestingly, ten countries count 70 – 75 % of the estimated global cases, which included Ethiopia, Iran, Syria, Brazil, Algeria, Colombia, Afghanistan, North Sudan, Pure and Costa Rica [14]

Figure 1: Schematic Elucidates the Two Central Cells' Different Shapes with All Stages in The Gut of the Sand Fly and The Mammalian During the Life Cycle. The Image Was Adapted from [13]

There are two primary clinical forms of the disease, the cutaneous and the visceral Leishmaniasis, also called Kala-azar, black fever and dumdum fever. Visceral Leishmaniasis is characterized by compromised internal organs leading to death in untreated patients. While cutaneous Leishmaniasis shows ulcers in the exposed body parts leading to permanent scars. Furthermore, the mucocutaneous form, also called American Leishmaniasis, espundia, Forest yaws and bois, can destroy the mucous membrane of the nose and the upper respiratory tract, causing distortions and physiological problems [14, 15]. This study aims to focus on the incidence of infection of this disease in Thi-Qar province from 2019 to 2022 and shows that the local governorate must take action to fight the vector in all the province regions.

Leishmaniasis is still a severely neglected disease and needs more research focusing on vector control, diagnosis processes, treatment options and public education.

Table 1: Exposes the Origin, Vector and Leishmania Species, Adapted from[10]

Data Collection

Data from the current study was kindly provided by the Ministry of Health, Public Health Directorate and Public health department of the Thi-Qar health directorate. Data included all clinically diagnosed cases of cutaneous Leishmaniasis from the province regions from 2019 to 2022. All samples were diagnosed clinically by a dermatologist according to the clinical features and symptoms of the disease. Collected swabs were collected and transported to the reference laboratory, the general public health laboratory, Baghdad, to confirm the diagnosis. Data included age, Gender, region, occupation, number of the boil and finally, type of ulcer (wet or day).

Laboratory Diagnosis of Cutaneous Leishmaniasis

A Direct Microscopy, Culture and Histopathology: Amastigotes stage of the parasite from skin scraping can be directly identified by Gemisa-stained by direct microscopy examination. Amastigote is an oval or round body with (2-4 µm) diameter, including kinetoplasts and nuclei Figure 2 [16,17]. Samples can be collected from the lesion site and cultured on a Novey-MacNealle medium using a tube. This method is time consuming and needs a septic technique to prevent contamination [18]. The sensitivity of the culture technique was 95.4% and the specificity was 100%, with the disadvantage of the inability to determine the specific type[19].

Immunological Diagnosis Methods

Many immunological techniques are used to diagnose cutaneous Leishmaniasis, including Enzyme-Linked Immune sorbent assay (ELISA), direct agglutination assay, lateral flow assay and western blot assay. The disadvantage of the immunological methods in diagnosing cutaneous Leishmaniasis is the weak humoral immune response to this form of infection leading to low sensitivity [20,21].

Skin Test of Cutaneous Leishmaniasis

This types usually use in vaccine studies and epidemiological surveys. This test is called the Montenegro skin test (MST) or Leishmania intradermal skin test (LST). The test relies on the principle of the delay-type hypersensitivity of cellular immune response to identify the cutaneous form of Leishmania with high sensitivity from 86.4%-100%. Skin reaction is adverse if reactive skin size is less than 5 mm, while positive if more than or equal to 5 mm [22, 23]. The disadvantage of this technique is the inability to differentiate between the current and the past infection. Also, preparing the antigen requires aseptic culture facilities [24].

Polymerase Chain Reaction (PCR)

This technique is preferable for diagnosing cutaneous Leishmaniasis (CL) with better sensitivity than other serological and culture methods. Non-invasive sample collection following DNA extraction and detection of Leishmania and their species according to the DNA sequencing technique make this method easy and sensitive for diagnosis CL [16].

Figure 2: Showing The Intracellular Location of Amastigotes in The Skin Scraping Sample Stained by Giemsa. The Image Was Adapted from [16]

Statistical Analysis

Graph-Pad Prism version 9.1 software is used in this study. A p-value more than 0.05 was considered not statistically significant, while a P value less than 0.05 was statistically significant.

Total Cases of Cutaneous Leishmaniasis from 2019 to 2022 were Distributed Among Females and Males Within the Different Age Groups

The total estimated cases of cutaneous Leishmaniasis beginning from 2019 to 2022 were 520 cases. Females showed 190 (36.54%) and males 330 (63.46%). Age groups included (1-79 years). There was no significant difference between males and females (p = 0.292) in Figure 3. The highest incidence of infection was 156 (30%) in the age group 1-9 years and 141 (27.12%) in the age group 10-19 years, both males and females (Table 2).

Cutaneous Leishmaniasis is Distributed According to Regions and Occupations from 2019 to 2022

Distribution of cutaneous Leishmaniasis according to occupation revealed that students recorded 163(31.35%) and children 113(21.73%). While soldiers and earners were 163(31.35%) and 77(14.81%) respectively. Interestingly, urban regions showed a high incidence of infection of CL 400 (76.92%) compared to rural regions 120 (23.08%) Figure 4. Statistical analysis showed a significant difference between rural and urban regard (p = 0.028) (Table 3).

The Incidence of Infection in Females and Males Was Distributed Among Age Groups in 2019

The total number of cases recorded from 2019 to 2022 was 520 cases. The total number of cases in 2019 was 199, involving 63 females (31.66%) and 136 males (68.34%). The incidence of infection was high among the ages group (10-19 years) was 66 (33.17%), while 42 (21.11%) among the ages group (1-9 years). Low incidence cases in the age group (70-79 years) showed three patients (1.51%) in Figure 5. Statistical analysis showed no significant difference between both sexes (p = 0.140) (Table 4).

The Incidence of Infection in Females and Males Was Distributed Among Age Groups in 2020

Cutaneous Leishmaniasis distributed among females and males in 2020 showed that females incidence was 26 (36.11%) while males were 46 (63.89%) out of the total reported cases 72 (100%). Included age groups were (1-49 years). The age group (20-29 years) has a high incidence rate of 20 (27.78%) while the lower was in age 940-49 years) 5 (6.94%) figure-6. Statistical analysis showed no significant difference between females and males (p = 0.160) (Table 5).

The Incidence of Infection in Females and Males Was Distributed Among Age Groups in 2021

Data on CL in the year 2021 showed a total of 202 cases (100%) and out of the total, 82(40.59%) cases were registered in females compared to 120(59.41%) in males. High incidence was noticed in the age group (1-9 years) with 82(10.59%), while a lower number of cases was 3 (1.49%) in both age groups (50-59 years) and (60-69 years) Figure 7. Statistical analysis showed no significant difference between females and males (p = 0.493) (Table 6).

Table 2: Total Cases of Cutaneous Leishmaniasis from 2019 to 2022 were Distributed Among Females and Males Within the Different Age Groups

Table 3: Cutaneous Leishmaniasis is Distributed According to Regions and Occupations from 2019 to 2022

Table 4: The Incidence of Infection in Females and Males Was Distributed Among Age Groups in 2019

Table 5: The Incidence of Infection in Females and Males Was Distributed Among Age Groups in 2020

Table 6: The Incidence of Infection in Females and Males Was Distributed Among Age Groups in 2021

Table 7: The Incidence of Infection in Females and Males Was Distributed Among Age Groups from January 9 To September 2022

The Incidence of Infection in Females and Males Was Distributed Among Age Groups from January 9 To September 2022

From January to September 2022, the total reported cases count was 47(100%). Females showed 20(42.55%) and males 27(57.45%). The age group (10-19 years) has a high incidence of CL and the age group (70-79 years) showed a lower incidence of reported cases compared to other age groups Figure 8. Statistical analysis showed no significant difference between females and males (p = 0.577) (Table 7).

Figure 3: Elucidate the Total Reported Cases of Cutaneous Leishmaniasis in Thi-Qar Province from 2019 To 2022, Distributed According to Sex and Age Group

Figure 4: Elucidates Total Reported Cases of Cutaneous Leishmaniasis in Thi-Qar Province from 2019 To 2022, Distributed According to Region and Occupation

Figure 5: Shows the Reported Cases of Cl Among Males and Females in Addition to The Age Groups in 2019

Figure 6: Reveals the Incidence of Infection of Cl Among Both Sex, Males and Females, In Addition to The Age Groups in 2020

Figure 7: Reveals the Incidence Of Infection Of Cl Among Both Sex, Males And Females, In Addition To The Age Groups In The Year 2021

Figure 8: Elucidates the Incidence of Infection of Cl Among Both Sex, Males and Females, In Addition to The Age Groups till September 2022

Cutaneous Leishmaniasis (CL) is an endemic vector-borne disease in more than 80 countries worldwide. It is estimated that 1.5–2 million infected cases of CL are documented every year and most patients are concentrated in Pakistan, Syria, Algeria, Peru and Saudi Arabia [25-27]. The current study data showed 520 cases of CL distributed 190 (36.54%) in females and 330 (63.64%) in males from 2019 to 2022.

Total cases were 199 (38.27%), 72 (13.85%), 202 (38.84%) and 47 (9.04%) in 2019,20120,2021 and 2022, respectively. The global COVID-19 pandemic that started at the beginning of 2020 has impacted the reported and documented cases due to the lockdown during the pandemic. Moreover, occupations involved children, earners, employees, farmers, homemakers, soldiers and students were involved in the current study. 

Data showed the incidence of CL among types of occupations for children 113 (21.73%), earners 77 (14.81%), employees 25 (4.81%), farmers 2 (0.38%), housewives 64 (12.31%), soldiers 76 (14.62%) and students 163 (31.35%). A case report showed that U.S. military soldiers reported two cases of CL after returning from Iraq [28]. Also, two cases in CL were in British Forces soldiers who served in Iraq [29]. Another study from 2004 to 2005 conducted in Alhaweja, Tikrit, Iraq, registered 107 CL cases. Males were 57% and age groups were (1-60 years) with an incidence rate was 45 cases per 10,000 [30]. Another study conducted by [31] in Basrah, south Iraq, reported 35 CL distributed for females 12 (34.28%) and males 233 (65.71%). Different incidence of CL according to the regions involves the other people's lifestyles and the geographical location that includes marshes and swamps, which act as a reservoir for the vector. 

Interestingly, a study conducted in Mosul city, Iraq, showed 1539 CL cases. Females' total cases of CL were 755(49.1%), while males were 784(50.9%). Regarding occupation, the study reported 363(23.6%), 285(18.5%), 151 (9.9%), 41 (2.7%), 54 (3.5%), 636 (41.2%) for housewives, students, workers, farmers, soldiers, policeman and other respectively [32]. Furthermore, a study by [33] from December 2018 to March 2019 involved 294 children with confirmed CL cases in Sinjar city, Iraq. Data showed no significant difference between sex and region.

Finally, to control the spreading of the disease, many actions need to be conducted and the prevalence of CL infection depends on many essential factors, including lifestyle, region, rural or urban and economic factors. The government's actions in fighting the vector reservoir like swamps and pools containing the sand fly is a crucial step to eliminating the disease.

The current study aims to spotlight the prevalence of CL among the population in different regions in the Thi-Qar governorate. Many necessary steps need to be followed by the public health department in the Thi-Qar directorate, including education and providing diagnostic kits and materials in addition to the treatment options in faraway medical centers. Furthermore, authorized facilities must use pesticides regularly to control insect replication.

Acknowledgement

We want to thank all medical staff of the public health department, Thi-Qar health directorate. For their kind support and for providing all information and documents for four years.

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