Langlebiges Souvenir aus Kamerun – persistierende, massive Hypereosinophilie bei amikrofilarämischer Infektion mit Loa loa

Lisa Meffert; Friederike Schmitz; Jana Ziob

doi:10.1055/a-1500-6375

Langlebiges Souvenir aus Kamerun – persistierende, massive Hypereosinophilie bei amikrofilarämischer Infektion mit Loa loa

DMW - Deutsche Medizinische Wochenschrift ◽

10.1055/a-1500-6375 ◽

2021 ◽

Vol 146 (15) ◽

pp. 1005-1008

Author(s):

Lisa Meffert ◽

Friederike Schmitz ◽

Jana Ziob

Keyword(s):

Loa Loa

Zusammenfassung Einleitung Die Diagnosestellung einer seltenen polysymptomatischen Parasitose erfordert eine Zusammenarbeit von Internisten, Tropenmedizinern, Parasitologen und Dermatologen. Anamnese Es wird der Krankheitsverlauf einer 66-Jährigen mit regelmäßigen Aufenthalten in Kamerun aufgezeigt, die sich mit massiver Hypereosinophilie und Pruritus bei urtikariellen Schwellungen präsentierte. Untersuchungen und Diagnose Mittels interdisziplinärer Diagnostik wurde anhand Reiseanamnese, klinischen Symptomen und Laborergebnissen die Arbeitsdiagnose einer okkulten, amikrofilarämischen Loa-loa-Infektion mit immunologischer Hyperreaktion gegen das Parasitenantigen, reaktiver Hypereosinophilie und hoher Anti-Filarien-Antikörperkonzentration gestellt. Therapie und Verlauf Die anthelminthische Therapie erfolgte mit Ivermectin und Diethylcarbamazin. Unter Ivermectin kam es zur prompten Symptomregredienz und Abfall der Eosinophilen- und Antikörperwerte. Folgerung Parasitosen wie die L.-loa-Infektion sind in Europa extrem selten, sollten jedoch bei entsprechender Reiseanamnese und klinischem Erscheinungsbild frühzeitig als Differenzialdiagnosen beachtet werden. Es mangelt an standardisierten Therapie- und Nachsorgeempfehlungen. Eine präzise Erfassung aller Neudiagnosen mit Therapieverlauf/-ansprechen in einem internationalen Register sollte etabliert werden.

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Évaluation de l’efficacité et de la tolérance du lévamisole chez des patients microfilarémiques à Loa loa : essai clinique contrôlé randomisé à dose et intensité d’infection croissantes

Infectious Diseases Now ◽

10.1016/j.idnow.2021.06.172 ◽

2021 ◽

Vol 51 (5) ◽

pp. S81-S82

Author(s):

J. Campillo ◽

F. Missamou ◽

S. Pion ◽

C. Montavon ◽

M. Boussinesq ◽

...

Keyword(s):

Loa Loa ◽

Essai Clinique

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Validation of loop-mediated isothermal amplification for the detection of Loa loa infection in Chrysops spp in experimental and natural field conditions

Parasites & Vectors ◽

10.1186/s13071-020-04506-3 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Glory Ngongeh Amambo ◽

Raphael Awah Abong ◽

Fanny Fri Fombad ◽

Abdel Jelil Njouendou ◽

Franck Nietcho ◽

...

Keyword(s):

Lamp Assay ◽

Isothermal Amplification ◽

Field Conditions ◽

Infection Rates ◽

Loa Loa ◽

Significant Drop ◽

Natural Field ◽

North West ◽

Loop Mediated Isothermal Amplification ◽

The North

Abstract Background The mass drug administration of ivermectin for onchocerciasis control has contributed to a significant drop in Loa loa microfilaria loads in humans that has, in turn, led to reduction of infection levels in Chrysops vectors. Accurate parasite detection is essential for assessing loiasis transmission as it provides a potential alternative or indirect strategy for addressing the problem of co-endemic loiasis and lymphatic filariasis through the Onchocerciasis Elimination Programme and it further reflects the true magnitude of the loiasis problem as excess human mortality has been reported to be associated with the disease. Although microscopy is the gold standard for detecting the infection, the sensitivity of this method is compromised when the intensity of infection is low. The loop-mediated isothermal amplification (LAMP) assay of parasite DNA is an alternative method for detecting infection which offers operational simplicity, rapidity and versatility of visual readout options. The aim of this study was to validate the Loa loa LAMP assay for the detection of infected Chrysops spp. under experimental and natural field conditions. Methods Two sets of 18 flies were fed on volunteers with either a low (< 10 mf/ml) or high (> 30,000mf/ml) microfilarial load. The fed flies were maintained under laboratory conditions for 14 days and then analysed using LAMP for the detection of L. loa infection. In addition, a total of 9270 flies were collected from the north-west, east, and south-west regions (SW 1 and 2) of Cameroon using sweep nets and subjected to microscopy (7841 flies) and LAMP (1291 flies plus 138 nulliparous flies) analyses. Results The LAMP assay successfully detected parasites in Chrysops fed on volunteers with both low and high microfilariaemic loads. Field validation and surveillance studies revealed LAMP-based infection rates ranging from 0.5 to 31.6%, with the lowest levels in SW 2 and the highest infection rates in SW 1. The LAMP assay detected significantly higher infection rates than microscopy in four of the five study sites. Conclusion This study demonstrated the potential of LAMP as a simple surveillance tool. It was found to be more sensitive than microscopy for the detection of experimental and natural L. loa infections in Chrysops vectors.

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Feasibility of onchocerciasis elimination using a “test-and-not-treat” strategy in Loa loa co-endemic areas

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1829 ◽

2020 ◽

Author(s):

David J Blok ◽

Joseph Kamgno ◽

Sebastien D Pion ◽

Hugues C Nana-Djeunga ◽

Yannick Niamsi-Emalio ◽

...

Keyword(s):

Adverse Events ◽

Drug Administration ◽

Mass Drug Administration ◽

Treatment Duration ◽

Loa Loa ◽

Serious Adverse Events ◽

Endemic Areas ◽

The Individual ◽

The Impact ◽

Main Strategy

Abstract Background Mass drug administration (MDA) with ivermectin is the main strategy for onchocerciasis elimination. Ivermectin is generally safe but associated with serious adverse events in individuals with high Loa loa microfilarial densities (MFD). Therefore, ivermectin MDA is not recommended in areas where onchocerciasis is hypo-endemic and L. loa is co-endemic. To eliminate onchocerciasis in those areas, a test-and-not-treat (TaNT) strategy has been proposed. We investigated whether onchocerciasis elimination can be achieved using TaNT and the required duration. Methods We used the individual-based model ONCHOSIM to predict the impact of TaNT on onchocerciasis microfilarial (mf) prevalence. We simulated pre-control mf prevalence levels from 2-40%. The impact of TaNT was simulated under varying levels of participation, systematic non-participation and exclusion from ivermectin due to high L. loa MFD. For each scenario, we assessed the time to elimination, defined as bringing onchocerciasis mf prevalence below 1.4%. Results In areas with 30-40% pre-control mf prevalence, the model predicted that it would take between 14 and 16 years to bring the mf prevalence below 1.4% using conventional MDA, assuming 65% participation. TaNT would increase the time to elimination by up to 1.5 years, depending on the level of systematic non-participation and the exclusion rate. At lower exclusion rates (≤2.5%), the delay would be less than six months. Conclusions Our model predicts that onchocerciasis can be eliminated using TaNT in L. loa co-endemic areas. The required treatment duration using TaNT would be only slightly longer than in areas with conventional MDA, provided that participation is good.

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Lymphatic filariasis and loa loa

Principles of Medicine in Africa ◽

10.1017/cbo9780511751660.049 ◽

2013 ◽

pp. 453-456

Author(s):

Camilla Rothe ◽

Christopher J. M. Whitty ◽

Eldryd Parry

Keyword(s):

Lymphatic Filariasis ◽

Loa Loa

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Semiannual Treatment of Albendazole Alone is Efficacious for Treatment of Lymphatic Filariasis: A Randomized Open-label Trial in Cote d'Ivoire

Clinical Infectious Diseases ◽

10.1093/cid/ciab194 ◽

2021 ◽

Author(s):

Allassane F Ouattara ◽

Catherine M Bjerum ◽

Méité Aboulaye ◽

Olivier Kouadio ◽

Vanga K Marius ◽

...

Keyword(s):

Lymphatic Filariasis ◽

Primary Outcome ◽

Central Africa ◽

Wuchereria Bancrofti ◽

Bancroftian Filariasis ◽

Loa Loa ◽

Open Label ◽

Treatment Groups ◽

Open Label Trial ◽

To Receive

Abstract Background Ivermectin (IVM) plus albendazole (ALB), or IA, is widely used in mass drug administration (MDA) programs that aim to eliminate lymphatic filariasis (LF) in Africa. However, IVM can cause severe adverse events in persons with heavy Loa loa infections that are common in Central Africa. ALB is safe in loiasis, but more information is needed on its efficacy for LF. This study compared the efficacy and safety of three years of semiannual treatment with ALB to annual IA in persons with bancroftian filariasis. Methods Adults with Wuchereria bancrofti microfilaremia (Mf) were randomized to receive either three annual doses of IA (N=52), six semiannual doses of ALB 400mg (N=45), or six semiannual doses of ALB 800mg (N=47). The primary outcome amicrofilaremia at 36 months. Findings IA was more effective for completely clearing Mf than ALB 400mg or ALB 800mg (79%, CI 67-91; vs. 48%, CI 32-66 and 57%, CI 41-73, respectively). Mean % reductions in Mf counts at 36 months relative to baseline tended to be greater after IA (98%, CI 88-100) than after ALB 400mg (88%, CI 78-98) and ALB 800mg (89%, CI 79-99) (P=0.07 and P=0.06, respectively). Adult worm nest numbers (assessed by ultrasound) were reduced in all treatment groups. Treatments were well tolerated. Interpretation Repeated semiannual treatment with ALB is macrofilaricidal for W. bancrofti and leads to sustained reductions in Mf counts. This is a safe and effective regimen that could be used as MDA to eliminate LF in areas ivermectin cannot be used.

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