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Trends in Parasitology Aug 2015
Topics: Animals; Filariasis; Humans; Molecular Diagnostic Techniques; Population Surveillance
PubMed: 26166751
DOI: 10.1016/j.pt.2015.06.005 -
Frontiers in Immunology 2022Filariae are parasitic roundworms, which can cause debilitating diseases such as lymphatic filariasis and onchocerciasis. Lymphatic filariasis, also known as... (Review)
Review
Filariae are parasitic roundworms, which can cause debilitating diseases such as lymphatic filariasis and onchocerciasis. Lymphatic filariasis, also known as elephantiasis, and onchocerciasis, commonly referred to as river blindness, can lead to stigmatizing pathologies and present a socio-economic burden for affected people and their endemic countries. Filariae typically induce a type 2 immune response, which is characterized by cytokines, i.e., IL-4, IL-5 and IL-13 as well as type 2 immune cells including alternatively activated macrophages, innate lymphoid cells and Th2 cells. However, the hallmark characteristic of filarial infections is a profound eosinophilia. Eosinophils are innate immune cells and pivotal in controlling helminth infections in general and filarial infections in particular. By modulating the function of other leukocytes, eosinophils support and drive type 2 immune responses. Moreover, as primary effector cells, eosinophils can directly attack filariae through the release of granules containing toxic cationic proteins with or without extracellular DNA traps. At the same time, eosinophils can be a driving force for filarial pathology as observed during tropical pulmonary eosinophilia in lymphatic filariasis, in dermatitis in onchocerciasis patients as well as adverse events after treatment of onchocerciasis patients with diethylcarbamazine. This review summarizes the latest findings of the importance of eosinophil effector functions including the role of eosinophil-derived proteins in controlling filarial infections and their impact on filarial pathology analyzing both human and experimental animal studies.
Topics: Animals; Humans; Eosinophils; Elephantiasis, Filarial; Onchocerciasis; Immunity, Innate; Lymphocytes; Filarioidea; Eosinophilia
PubMed: 36389745
DOI: 10.3389/fimmu.2022.983812 -
Parasites & Vectors Jan 2023The diurnal periodicity of Loa loa microfilaraemia is well known but few studies have documented the short- and long-term stability of microfilarial density. It seems...
BACKGROUND
The diurnal periodicity of Loa loa microfilaraemia is well known but few studies have documented the short- and long-term stability of microfilarial density. It seems stable over time at the community level, but significant variations have been observed at the individual level.
METHODS
We assessed the temporal variability of L. loa microfilaraemia at 5-day, 1-month and 16-month intervals and analyzed the influence of sex, age, level of microfilaraemia, temperatures and time of sampling on this variability.
RESULTS
At the community level, L. loa microfilaraemia is very stable over time at 5-day, 1-month and 16-month intervals (Pearson correlation coefficients of 0.92, 0.91 and 0.78, respectively, all three with P < 0.001). However, some individuals had significant variations of up to ± 50% of their initial microfilaraemia at 5-day (33.0%), 1-month (36.5%) and 16-month (62.6%) intervals, even in individuals with an initial microfilaraemia density > 20,000 mf/ml (7.7, 23.1 and 41.4%, respectively, for 5 days, 1 month and 16 months). We do not highlight any external factors that have a major impact on this variability.
CONCLUSION
Although at the community level, microfilaria density is very stable, we highlight some individuals with large variations in both the short and long term, which may have an important impact on onchocerciasis control campaigns and longitudinal studies evaluating the impact of an intervention on L. loa microfilaraemia.
Topics: Animals; Humans; Loa; Loiasis; Onchocerciasis; Endemic Diseases; Microfilariae
PubMed: 36691079
DOI: 10.1186/s13071-022-05612-0 -
PLoS Neglected Tropical Diseases Oct 2022Malaria and filariasis are significant vector-borne diseases that are co-endemic in the same human populations. This study aims to collate the evidence, probability, and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Malaria and filariasis are significant vector-borne diseases that are co-endemic in the same human populations. This study aims to collate the evidence, probability, and characteristics of malaria and filariasis co-infections in participants among studies reporting the co-occurrence of both diseases.
METHODS
We searched for potentially relevant articles reporting the co-occurrence of malaria and filariasis in five electronic databases (Embase, PubMed, Scopus, Medline, and CENTRAL) from inception to May 22, 2022. We estimated the pooled prevalence and probability of malaria and filariasis co-infections among study participants using random-effects meta-analyses and synthesized the characteristics of patients with co-infections narratively.
RESULTS
We identified 951 articles, 24 of which (96,838 participants) met eligibility criteria and were included in the systematic review. Results of the meta-analysis showed a pooled prevalence of malaria and filariasis co-infections among participants of 11%. The prevalence of co-infections was 2.3% in Africa, 0.2% in Asia, and 1.6% in South America. The pooled prevalences of malaria and Wuchereria bancrofti, malaria and Loa loa, malaria and Mansonella perstans co-infections were 0.7%, 1.2%, and 1.0%, respectively. The meta-analysis results showed that the co-infections between two parasites occurred by probability (P = 0.001). Patients with co-infections were at increased risk of having an enlarged spleen, a lower rate of severe anemia, lower parasite density, and more asymptomatic clinical status. Patients with co-infections had decreased levels of C-X-C motif chemokine 5, tumor necrosis factor-α, interleukin-4, c4 complement, and interleukin-10. In addition, patients with co-infections had a lower interleukin-10/tumor necrosis factor-α ratio and higher interleukin-10/interleukin-6 ratio.
CONCLUSION
The present study showed that the prevalence of malaria and filariasis co-infections was low and varied between geographical areas in the selected articles. Co-infections tended to occur with a low probability. Further studies investigating the outcomes and characteristics of co-infections are needed.
Topics: Animals; Humans; Prevalence; Interleukin-10; Interleukin-4; Coinfection; Tumor Necrosis Factor-alpha; Interleukin-6; Filariasis; Mansonelliasis; Malaria; Probability; Complement C4; Chemokines
PubMed: 36269701
DOI: 10.1371/journal.pntd.0010857 -
Parasitology Research Dec 2021Filariae are vector-borne parasitic nematodes that are endemic worldwide, in tropical and subtropical regions. Important human filariae spp. include Onchocerca volvulus,... (Review)
Review
Filariae are vector-borne parasitic nematodes that are endemic worldwide, in tropical and subtropical regions. Important human filariae spp. include Onchocerca volvulus, Wuchereria bancrofti and Brugia spp., and Loa loa and Mansonella spp. causing onchocerciasis (river blindness), lymphatic filariasis (lymphedema and hydrocele), loiasis (eye worm), and mansonelliasis, respectively. It is estimated that over 1 billion individuals live in endemic regions where filarial diseases are a public health concern contributing to significant disability adjusted life years (DALYs). Thus, efforts to control and eliminate filarial diseases were already launched by the WHO in the 1970s, especially against lymphatic filariasis and onchocerciasis, and are mainly based on mass drug administration (MDA) of microfilaricidal drugs (ivermectin, diethylcarbamazine, albendazole) to filarial endemic areas accompanied with vector control strategies with the goal to reduce the transmission. With the United Nations Sustainable Development Goals (SDGs), it was decided to eliminate transmission of onchocerciasis and stop lymphatic filariasis as a public health problem by 2030. It was also requested that novel drugs and treatment strategies be developed. Mouse models provide an important platform for anti-filarial drug research in a preclinical setting. This review presents an overview about the Litomosoides sigmodontis and Acanthocheilonema viteae filarial mouse models and their role in immunological research as well as preclinical studies about novel anti-filarial drugs and treatment strategies.
Topics: Acanthocheilonema; Animals; Elephantiasis, Filarial; Filarioidea; Humans; Loiasis; Male; Mice; Models, Animal
PubMed: 33547508
DOI: 10.1007/s00436-020-07026-2 -
Biomedicine & Pharmacotherapy =... May 2021Human filarial infections are vector-borne nematode infections, which include lymphatic filariasis, onchocerciasis, loiasis, and mansonella filariasis. With a high... (Review)
Review
Human filarial infections are vector-borne nematode infections, which include lymphatic filariasis, onchocerciasis, loiasis, and mansonella filariasis. With a high prevalence in developing countries, filarial infections are responsible for some of the most debilitating morbidities and a vicious cycle of poverty and disease. Global initiatives set to eradicate these infections include community mass treatments, vector control, provision of care for morbidity, and search for vaccines. However, there are growing challenges associated with mass treatments, vector control, and antifilarial vaccine development. With the emergence of genome editing tools and successful applications in other infectious diseases, the integration of genetic editing techniques in future control strategies for filarial infections would offer the best option for eliminating filarial infections. In this review, we briefly discuss the mechanisms of the three main genetic editing techniques and explore the potential applications of these powerful tools to control filarial infections.
Topics: Animals; CRISPR-Associated Protein 9; CRISPR-Cas Systems; Clustered Regularly Interspaced Short Palindromic Repeats; Filariasis; Filaricides; Filarioidea; Gene Editing; Genetic Therapy; Humans; Protozoan Vaccines
PubMed: 33581654
DOI: 10.1016/j.biopha.2021.111292 -
Trends in Parasitology Jul 2022Mass drug administration (MDA) of ivermectin is currently the main strategy to achieve elimination of transmission (EoT) of onchocerciasis. Modelling suggests that EoT... (Review)
Review
Mass drug administration (MDA) of ivermectin is currently the main strategy to achieve elimination of transmission (EoT) of onchocerciasis. Modelling suggests that EoT may not be reached in all endemic foci using annual MDA alone. Onchocerciasis and loiasis are coendemic in forest areas of Central Africa where ivermectin treatment can lead to severe adverse events in individuals with heavy loiasis load, rendering MDA inappropriate. Vector control has been proposed as a complementary intervention strategy. Here, we discuss (i) achievements and pitfalls of previous interventions; (ii) epidemiological impact, feasibility, and combination with MDA to accelerate and/or protect EoT; (iii) role of modelling; (iv) opportunities for innovative methods of vector monitoring and control; and (v) strengthening entomological capacity in endemic countries.
Topics: Humans; Ivermectin; Loiasis; Mass Drug Administration; Onchocerciasis
PubMed: 35379556
DOI: 10.1016/j.pt.2022.03.003 -
Tropical Medicine & International... Nov 2014Several cases of lymphatic filariasis (LF) have been reported in non-endemic countries due to travellers, military personnel and expatriates spending time in and... (Review)
Review
OBJECTIVE
Several cases of lymphatic filariasis (LF) have been reported in non-endemic countries due to travellers, military personnel and expatriates spending time in and returning from endemic areas, as well as immigrants coming from these regions. These cases are reviewed to assess the scale and context of non-endemic presentations and to consider the biological factors underlying their relative paucity.
METHODS
Cases reported in the English, French, Spanish and Portuguese literature during the last 30 years were examined through a search of the PubMed, ProMED-mail and TropNet resources.
RESULTS
The literature research revealed 11 cases of lymphatic filariasis being reported in non-endemic areas. The extent of further infections in recent migrants to non-endemic countries was also revealed through the published literature.
CONCLUSIONS
The life-cycle requirements of Wuchereria and Brugia species limit the extent of transmission of LF outside of tropical regions. However, until elimination, programmes are successful in managing the disease, there remains a possibility of low rates of infection being reported in non-endemic areas, and increased international travel can only contribute to this phenomenon. Physicians need to be aware of the signs and symptoms of lymphatic filariasis, and infection should be considered in the differential diagnosis of people with a relevant travel history.
Topics: Adult; Aged; Animals; Child; Disease Transmission, Infectious; Elephantiasis, Filarial; Emigrants and Immigrants; Endemic Diseases; Female; Humans; Male; Middle Aged; Togo; Travel; Wuchereria bancrofti
PubMed: 25145445
DOI: 10.1111/tmi.12376 -
Annals of Parasitology 2015Despite the considerable progress of medicine, parasitic diseases still pose a great threat to human health and life. Among parasitic diseases, those transmitted by... (Review)
Review
Despite the considerable progress of medicine, parasitic diseases still pose a great threat to human health and life. Among parasitic diseases, those transmitted by vectors, mainly arthropods, play a particular role. These diseases occur most frequently in the poorest countries and affect a vast part of the human population. They include malaria, babesiosis, trypanosomiasis, leishmaniasis and filariasis. This study presents those vector-transmitted diseases that are responsible for the greatest incidence and mortality of people on a global scale. Attention is focused primarily on diseases transmitted by mosquitoes, flies, Hemiptera and ticks.
Topics: Animals; Arthropod Vectors; Babesiosis; Culicidae; Diptera; Filariasis; Hemiptera; Humans; Leishmaniasis; Malaria; Parasitic Diseases; Ticks; Trypanosomiasis; Zoonoses
PubMed: 26568987
DOI: 10.17420/ap6103.01 -
The Indian Journal of Medical Research Jun 2019Onchocerciasis and lymphatic filariasis (LF) are human filarial diseases belonging to the group of neglected tropical diseases, leading to permanent and long-term... (Review)
Review
Onchocerciasis and lymphatic filariasis (LF) are human filarial diseases belonging to the group of neglected tropical diseases, leading to permanent and long-term disability in infected individuals in the endemic countries such as Africa and India. Microfilaricidal drugs such as ivermectin and albendazole have been used as the standard therapy in filariasis, although their efficacy in eliminating the diseases is not fully established. Anti-Wolbachia therapy employs antibiotics and is a promising approach showing potent macrofilaricidal activity and also prevents embryogenesis. This has translated to clinical benefits resulting in successful eradication of microfilarial burden, thus averting the risk of adverse events from target species as well as those due to co-infection with loiasis. Doxycycline shows potential as an anti-Wolbachia treatment, leading to the death of adult parasitic worms. It is readily available, cheap and safe to use in adult non-pregnant patients. Besides doxycycline, several other potential antibiotics are also being investigated for the treatment of LF and onchocerciasis. This review aims to discuss and summarise recent developments in the use of anti-Wolbachia drugs to treat onchocerciasis and LF.
Topics: Adult; Albendazole; Animals; Anti-Bacterial Agents; Doxycycline; Drug Therapy, Combination; Elephantiasis, Filarial; Humans; India; Neglected Diseases; Onchocerciasis; Tropical Medicine; Wolbachia
PubMed: 31496523
DOI: 10.4103/ijmr.IJMR_454_17