Filarial worms: a systematic review and meta-analysis of diversity in animals from Iran with emphasis on human cases

Abstract

Current systematic review and meta-analysis demonstrate the prevalence reports of filariasis in animals in Iran along with human cases. Studies were screened, relevant papers were selected and the random-effect model was used by forest plot with 95% confidence interval (CI). Of 17 records of human case-reports, particularly from Khuzestan province (5 cases), Dirofilaria repens was the most detected parasite (10 cases) with higher involvement of the right eye (7 cases) than other organs. Eleven animal species were reported to be parasitised by filarioids in Iran. The prevalence of Dirofilaria immitis in canids was 14.69% (95% CI: 10.33–19.67), with highest rates (20.92%; 95% CI: 13.84–29.03) in free-ranging dogs. Male (10.07%; 95% CI: 5.10–16.47) and more than 1-year old (20.77%; 95% CI: 8.66–36.42) dogs were more likely to be found infected. The frequency of other filarioids of zoonotic interest was: Acanthocheilonema reconditum in dogs 2.15% (95% CI: 0.71–4.33), Dipetalonema evansi in camels 10.16% (95% CI: 4.73–17.34), Onchocerca cervicalis in horses 3.63% (95% CI: 1.44–6.75%) and Onchocerca fasciata 16.57% (95% CI: 10.12–24.24%) in camels. Still, our knowledge on parasitic filariae in Iran is limited and more investigation is needed in both human and animal populations.

Canine microfilaraemia in some regions of Iran

“…3 Distribution of D. immitis , D. repens and A. reconditum in dogs and humans of Iran. See Table 3 for data about dogs and references [ 8 , 9 , 70 ] for data about human cases …”

Lymphatic filariasis in Asia: a systematic review and meta-analysis

“…Dirofilaria spp. was reported in humans in Iran (Ashrafi et al 2010;Ghasemi et al 2020;Jamshidi et al 2008;Tavakolizadeh and Mobedi 2009), Israeli (Gutierrez et al 1995), and Taiwan (Li et al 2013), although these cases are not considered NTDs. Because the aim of the study was to document the situation of LF only in humans, the many studies that reported animal filariasis in Asia were excluded from the present analysis.…”

Geographic Spatial Distribution Patterns of Dirofilaria immitis and Brugia pahangi Infection in Community Dogs in Chiang Mai, Thailand

“…The prevalence of D. immitis infection in dogs worldwide was 10.91% (95% CI = 10.18-11.65) in 2020. The prevalence of D. immitis in dogs varies across countries and continents, e.g., 22.68% in Australia, 12.07% in Asia, 11.60% in the Americas, 10.45% in Europe, and 7.57% in Africa [1]. Over the past few decades, the regional prevalence of D. immitis infection in dogs in Thailand has been reported as 10-58% in Bangkok [16,[29][30][31], 23-25% in the southern region [32], and 6-25% in the northern region [19,[33][34][35].…”

“…According to the World Health Organization (WHO) roadmap (WHO 2020), the goal of eliminating filariasis is expected to be achieved by 2030. Filarial infections are currently common in companion animals worldwide [1]. Specifically, in Southeast Asia, lymphatic filariasis caused by Brugia malayi (Brugian or Malayan filariasis), Wuchereria bancrofti (bancroftian filariasis) and Brugia timori is considered a significant human health problem.…”