Loiasis in sub-Saharan migrants living in Spain with emphasis of cases from Equatorial Guinea

Abstract

Background: Loiasis is an uncommon and poorly understood parasitic disease outside endemic areas of Africa. The aim of this study was to describe the clinical and biological patterns and treatment of imported loiasis by sub-Saharan migrants diagnosed in Madrid, Spain.Methods: A retrospective study was conducted with sub-Saharan immigrants seen at the Tropical Medicine Unit of the Carlos III Hospital in Madrid, Spain, a reference center, over 19 years. Categorical variables were expressed as frequency counts and percentages. Continuous variables were expressed as the mean and standard deviation (SD) or median and interquartile range (IQR: Q3-Q1). Chi-square tests were used to assess the association between categorical variables. The measured outcomes were expressed as the odds ratio (OR) with a 95% confidential interval. Continuous variables were compared by Student's t-tests or Mann-Whitney U tests. Binary logistic regression models were used. P < 0.05 was considered a statistically significant difference. Results:One hundred thirty-one migrants from tropical and subtropical areas with loiasis were identified. Forty-nine patients were male (37.4%). The migrants' mean age (±SD) was 42.3 ± 17.3 years, and 124 (94.7%) were from Equatorial Guinea. The median time (IQR) between arrival in Spain and the first consultation was 2 (1-7) months. One hundred fifteen migrants had eosinophilia, and one hundred thirteen had hyper-IgE syndrome. Fifty-seven patients had pruritus (43.5%), and thirty patients had Calabar swelling (22.9%). Seventy-three patients had coinfections with other filarial nematodes (54.2%), and 58 migrants had only Loa loa infections (45.8%). One hundred two patients (77.9%) were treated; 45.1% (46/102) patients were treated with one drug, and 54.9% (56/102) patients were treated with combined therapy. Adverse reactions were described in 14 (10.7%) migrants.Conclusions: Our patients presented early clinical manifestations and few atypical features. Thus, physicians should systematically consider loiasis in migrants with a typical presentation. However, considering that 72.5% of the patients had only positive microfilaremia without any symptoms, we suggest searching for microfilaremia in every migrant from endemic countries for loiasis presenting with eosinophilia.

The impact of Loa loa microfilaraemia on research subject retention during a whole sporozoite malaria vaccine trial in Equatorial Guinea

“… 25 , 26 Typically, all patients had eosinophilia, which resolved in most cases with anti-filarial treatment. 26 , 27 Although treatment with DEC has been associated with adverse reactions such as pruritus, Calabar swelling, dizziness, headache, arthralgias, fever and even encephalopathy, 8 , 9 , 25 , 27 , 28 it was well tolerated in our patients.…”

Characterising co-infections with Plasmodium spp., Mansonella perstans or Loa loa in asymptomatic children, adults and elderly people living on Bioko Island using nucleic acids extracted from malaria rapid diagnostic tests

“…Between 1978 and 2020, a total of 20 publications described Mansonellosis, Loasis, Onchocerciasis, and lymphatic filariasis in the context of Equatorial Guinea (S1 Table ). Five of these publications described L. loa and M. perstans infections among Equato-Guineans living in Spain [28][29][30][31] or Singapore [32], while three were case reports of foreigners returning from Equatorial Guinea [33][34][35]. One cross-sectional study investigated the prevalence of L. loa and M. perstans on Bioko Island using microscopy and qPCR-based detection [36].…”

Comparison of three PCR‐based methods to detect Loa loa and Mansonella perstans in long‐term frozen storage dried blood spots

“…Loa Loa, the parasite that causes loiasis (also known as African eye worm) [9], is endemic in 11 African countries, according to the Rapid Assessment Procedure for Loiasis (RAPLOA) [6,8,10,11]. The recent increased interest in L. loa began when severe adverse events (SAE) were recorded after treatment of people heavily infected with L. loa microfilariae (>30,000 microfilariae per millilitre, mf/ml) with ivermectin in regions where loiasis is coendemic with onchocerciasis and/or lymphatic filariasis (LF).…”

“…Mansonella perstans is considered the most common of the mansonellosis parasites and is endemic in a large portion of sub‐Saharan Africa, as well as in the northern part of the Amazon rainforest stretching from equatorial Brazil to the Caribbean coast of South America. M. perstans is co‐endemic with L. loa in some African regions, like Cameroon, Equatorial Guinea or Democratic Republic of the Congo [7–9, 11, 14]. In those endemic regions where O. volvulus , W. bancrofti , L. loa and M. perstans are co‐endemic, accurate and effective diagnostic tools for parasite detection are crucial for the success of any filariasis control programme.…”