Plasmodium, Haemoproteus, and Leucocytozon, belonging to the phylum Apicomplexa, specifically the order Haemosporida, are among the most important causes of blood infections in birds. More than 200 known species have been described within this group, with thousands of other undescribed species likely to exist. Despite displaying a high degree of genetic diversity, most of these parasites display remarkable similarity in morphological characteristics, which limits the ability to rely solely on morphological characteristics to distinguish between different species [1-3]. These parasites can lead to significant increases in mortality rates among some wild bird species [4].

Hemoproteus parasites are unable to reproduce in the bird's peripheral blood, making their transmission to new birds through direct blood inoculation unlikely, unlike Plasmodium parasites, which commonly rely on this method. Instead, the development of their sexual stages is restricted to the louse fly, making this insect the crucial intermediary for transmission and ensuring the continuity of the parasite's life cycle between hosts [5]. Of the more than 100 described species of Plasmodium, Plasmodium relectum is the most common infecting birds, each characterized by varying degrees of host specificity and a specific geographic range. These parasites represent a group of blood pathogens, which include proteiosis, avian malaria, and avian leukemia, and exhibit a remarkable ability to influence the physiological and biological functions of their avian hosts. The effects of these parasites range from minor hematological disturbances to severe effects on survival and reproduction [6-8].

Birds infected with haemosporid parasites exhibit marked deterioration in their physiological and behavioral characteristics. Evidence indicates a marked reduction in lifespan and its ability to survive, as well as its reduced ability to mate and produce eggs, with increased susceptibility to secondary microbial infections. Studies also indicate that malaria parasites contribute to the decline in physical health of birds, reflecting the overall negative impact of these parasites on host fitness [9-11]. In many cases, bird deaths are attributed to the destructive effects of parasites on internal tissues, outside the red blood cells, where death may occur suddenly and without previous clinical signs [12].

Budgerigars are among the most common [traded] and widespread birds in various parts of the world, belonging to the parrot family. Their popularity as pets lies in a combination of their aesthetic and behavioral characteristics, including their bright colors, quiet voices, and ability to interact with humans and mimic words [13,14]. Although most parrot species are at risk of extinction, budgerigars have stable populations and are not considered a threatened species. These birds typically live between ten and fifteen years and have a relatively short breeding period [15,16].

Although the budgerigar M. undulatus, Shaw is native to Australia, its range has now spread to many regions around the world. This bird is known for its a large increase in bird numbers can cause overcrowding in cages, negatively impacting their overall health and increasing the likelihood of disease, especially parasitic diseases., if environmental and nutritional conditions are not carefully observed [17]. 

It comes right after common pets like cats and dogs, budgies (M. undulatus) have captured the hearts of pet lovers global thanks to their small build, playful spirit, and low cost. These intelligent birds are not only beautiful in color; they also possess an amazing ability to learn sounds even after reaching adulthood, making them a wonderful partner for human interaction and a unique model for scientific studies on auditory and vocal learning and development. Each budgie possesses a personality that is both curious and playful, making them an unforgettable addition to any home [18-20].

Hemoprotozoa injury are insect-borne diseases in parrots, with Plasmodium and Hemoproteus parasites playing a major role in their spread. Molecular studies have revealed a great diversity of Leucocytozoan species, which are the main cause of death in these birds [21]. The parasite Plasmodium relictum causes malaria in birds, deaths occur in parrots and cause widespread pathogenic effects on many bird species worldwide [22]. Microscopy continues to be the primary tool for detecting parasites in blood and tissue samples [23]. The current study, conducted in Maysan Governorate, aims to examine blood parasites in M. undulatus, determine infection rates of the most common species, and evaluate differences in infection rates between females and males.

Between February 2024 and March 2025, a total of 53 parrots (M. undulatus) of genders together were collected from the shops in Maysan Governorate. Following sample collection, thin blood smears were prepared and allowed to air dry for approximately 20–35 seconds. These smears were then fastened by pure methanol within 10 to 30 minutes on the day of the examination. After drying, the slides were dyed with (1:10) giemsa staining solution and placed inside paper strips for preservation. The slides were examined under a microscope at 100x oil magnification for two to eight hours to identify blood parasites, including Plasmodium, Haemoproteus, and Leucocytozoon species [24,25]. Microscopic images were obtained by two different digital cameras mounted on a photic microscope: AmScope MU1003 (10 M.P.) and Tomaltic/Hayear (12 M.P.). The parasite diagnosis was made using [26-29].

The outcomes showed that the overall incidence of blood parasites among budgerigars in Maysan Governorate was 30.18% (Table 1). 

Table 1: Evaluation of the Incidence of Haemosporidian in M. Undulatus in Maysan Governorate

It was also found that these birds their bodies are exposed to three different genera of parasites: Haemoproteus spp., Plasmodium spp., and Leucocytozoon spp. 18.75% for the first type, 68.75% for the second type, and 25% for the third type (Table 2, Figure 1). 

Figure 1: Haemoproteus spp., A, B: Gametocytes, Leucocytozoon spp., C, D: Gametocytes, Plasmodium spp., E: Schizont, F-H: Gametocytes

Table 2: The Level of Infection of Budgies Infected with Blood Parasites

It was noted that the infection rate was more pronounced in females than in males. On the other hand, single infections constituted the largest percentage, amounting to 68.75%, while double infections did not exceed 43.75% (Table 3). 

Table 3: Haemosporidian Prevalence Rates in Parrots According to Infection Type

Overall, a higher infection rate was recorded in females, amounting to 68.75%, compared to 45.45% in males (Table 4).

Table 4: Prevalence Rates of Blood Parasites among Male and Female Budgerigars

Many wild and domestic birds are infectived with various species of haemosporidian, which constitute a source of transmission to other species. Despite the importance of these birds in transmitting infection, there are few studies on these parasites in Iraq. When comparing the infection rate in our current study, which indicated that budgerigars (M. undulatus) were infectived with three genera of haemosporidian, with the rates in other studies, there is only one study by Khalaf [29] on this species of bird in Erbil, with a higher infection rate of 35.48% and two types of blood parasites. In New Zealand, Baron et al. [30] conducted their study on M. undulatus, and the infection rate in the same species was 30% with Plasmodium spp., while in the current study, the infection rate was 73.33%.

The infection rate in the current study is lower than in several studies, including Dimitrov et al. [31], who reported a 58% infection rate across several bird species. Ali et al. [32] reported a 60% infection rate in partridges. Berthová et al. [33] reported a 33.9% infection rate across several bird species in Slovakia. However, the rate was lower than in several studies, including Marzal et al. [34], who reported that 18.15% of parrots were infected with blood parasites. Rodríguez and Mata [35] reported that 15.9% of birds were infected with blood parasites in Colombia. Mohammad and Al-Moussawi [36] reported a 10.5% infection rate in passerines

Regarding the Leucocytozoon parasite, the infection rate was higher than that recorded by Lotta et al. [28] at 1.2% in South America, and Mirzaei et al. [37] at 11.64% in Iranian birds. There are several factors that control differences in infection rates in birds, including the season, the bird's sex, and the bird's geographic location, as well as the birds' ages and susceptibility to infection, in addition to feeding areas and the presence of vectors [38].

The current study found that ornamental birds (Melopsittacus undulatus) were infected with several types of haemosporidian, it falls under three species: Plasmodium, Haemoproteus, and Leucytozoon, with an infection rate of 30.18%. Females were more affected than males, and the incidence of double infection was lower than single infection.

Declaration of conflict of interest

The authors certify that this study is free from any conflict of interest in the context of its publication.

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