Density Of Microfilariae Research Articles

Eosinophils, basophils and myeloid-derived suppressor cells in chronic Loa loa infection and its treatment in an endemic setting.

Chronic infection by Loa loa remains an unsolved immunological paradox. Despite harboring subcutaneously migrating adult worms and often high densities of microfilariae, most patients experience only relatively mild symptoms, yet microfilaricidal treatment can trigger life-threatening inflammation. Here, we investigated innate cell populations hypothesized to play a role in these two faces of the disease, in an endemic population in Gabon. We analyzed numbers and activation of eosinophils and basophils, as well as myeloid-derived suppressor cell (MDSC) subsets and associated circulating cytokine levels by flow cytometry in sex- and age-matched L. loa-uninfected (LL-), -amicrofilaraemic (MF-) and -microfilaraemic (MF+) individuals (n = 42), as well as microfilaraemic individuals treated with albendazole (n = 26). The percentage of eosinophils was lower in LL- (3.0%) than in the combined L. loa-infected population, but was similar in MF+ (13.1%) and MF- (12.3%). Upon treatment of MF+, eosinophilia increased from day 0 (17.2%) to day 14 (24.8%) and had decreased below baseline at day 168 (6.3%). Expression of the eosinophil activation marker CD123 followed the same pattern as the percentage of eosinophils, while the inverse was observed for CD193 and to some extent CD125. Circulating IL-5 levels after treatment followed the same pattern as eosinophil dynamics. Basophil numbers did not differ between infection states but increased after treatment of MF+. We did not observe differences in MDSC numbers between infection states or upon treatment. We demonstrate that both chronic infection and treatment of L. loa microfilaraemia are associated with eosinophil circulation and distinct phenotypical activation markers that might contribute to inflammatory pathways in this setting. In this first ever investigation into MDSC in L. loa infection, we found no evidence for their increased presence in chronic loiasis, suggesting that immunomodulation by L. loa is induced through other pathways.

Current Status of Lymphatic Filariasis in Three Selected Communities in Sagbama Local Government Area of Bayelsa State, Nigeria

Current status of lymphatic filariasis in three selected communities in Sagbama LGA Bayelsa State, Nigeria was conducted between July and October, 2019. Descriptive Cross-Sectional study was carried out to determine LF prevalence, microfilaria density and W. bancrofti in mosquitoes. Blood samples were collected at night through vein puncture and examined using Giesma staining and Knott concentration techniques. Indoor resting mosquitoes were collected using pyrethrum spray technique and dissected for filarial worms. Out of 274 participants 37(13.5%) were infected of LF, Adagbabiri had the highest prevalence of 21(21.4%) followed by Sagbama 11(12.6%) and 5(5.6%) in Tungbabiri. The females were more infected than males, 22(59.5%) and 15(40.5%) respectively, there was no significant difference (P>0.05) between sex. The highest prevalence of 19.4% were recorded in ages 40-49yrs and least prevalence of 5.3% in 10-19yrs. Low microfilaria density 0.08,0.04 and 0.08 were observed among age groups, 0.10 and 0.20 between sex across 3 communities. There was no significant difference (P>0.05) of mean filarial density among age groups and sex. Participants knowledge on LF was very low but a good perception on socio economic consequences of LF was recorded across the three communities. No filaria larvae was discovered in mosquitoes of Anopheles gambiae and Culex quniquifasciatus dissected. In conclusion, although low prevalence was observed. Therefore, there is need for control programs and surveillance of LF in Sagbama Local Government Area.

Is the antiparasitic drug ivermectin a suitable candidate for the treatment of epilepsy?

There are only a few drugs that can seriously lay claim to the title of "wonder drug," and ivermectin, the world's first endectocide and forerunner of a completely new class of antiparasitic agents, is among them. Ivermectin, a mixture of two macrolytic lactone derivatives (avermectin B1a and B1b in a ratio of 80:20), exerts its highly potent antiparasitic effect by activating the glutamate-gated chloride channel, which is absent in vertebrate species. However, in mammals, ivermectin activates several other Cys-loop receptors, including the inhibitory γ-aminobutyric acid type A and glycine receptors and the excitatory nicotinic acetylcholine receptor of brain neurons. Based on these effects on vertebrate receptors, ivermectin has recently been proposed to constitute a multifaceted wonder drug for various novel neurological indications, including alcohol use disorders, motor neuron diseases, and epilepsy. This review critically discusses the preclinical and clinical evidence of antiseizure effects of ivermectin and provides several arguments supporting that ivermectin is not a suitable candidate drug for the treatment of epilepsy. First, ivermectin penetrates the mammalian brain poorly, so it does not exert any pharmacological effects via mammalian ligand-gated ion channels in the brain unless it is used at high, potentially toxic doses or the blood-brain barrier is functionally impaired. Second, ivermectin is not selective but activates numerous inhibitory and excitatory receptors. Third, the preclinical evidence for antiseizure effects of ivermectin is equivocal, and at least in part, median effective doses in seizure models are in the range of the median lethal dose. Fourth, the only robust clinical evidence of antiseizure effects stems from the treatment of patients with onchocerciasis, in which the reduction of seizures is due to a reduction in microfilaria densities but not a direct antiseizure effect of ivermectin. We hope that this critical analysis of available data will avert the unjustified hype associated with the recent use of ivermectin to control COVID-19 from recurring in neurological diseases such as epilepsy.

Temporal variability of Loa loa microfilaraemia

BackgroundThe 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.MethodsWe 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.ResultsAt 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.ConclusionAlthough 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.Graphical

The Domestic Dog as a Laboratory Host for Brugia malayi.

Of the three nematodes responsible for lymphatic filariasis in humans, only Brugia malayi is actively maintained in research settings owing to its viability in small animal hosts, principal among which is the domestic cat. While the microfilaremic feline host is necessary for propagation of parasites on any significant scale, this system is plagued by a number of challenges not as pronounced in canine filarial models. For this reason, we investigated the capacity in which dogs may serve as competent laboratory hosts for B. malayi. We infected a total of 20 dogs by subcutaneous injection of 500 B. malayi third-stage larvae (L3) in either a single (n = 10) or repeated infection events (125 L3 per week for four weeks; n = 10). Within each group, half of the individuals were injected in the inguinal region and half in the dorsum of the hind paw. To track the course of microfilaremia in this host, blood samples were examined by microscopy biweekly for two years following infection. Additionally, to identify cellular responses with potential value as predictors of patency, we measured peripheral blood leukocyte counts for the first year of infection. A total of 10 of 20 dogs developed detectable microfilaremia. Peak microfilaria density varied but attained levels useful for parasite propagation (median = 1933 mL−1; range: 33–9950 mL−1). Nine of these dogs remained patent at 104 weeks. A two-way ANOVA revealed no significant differences between infection groups in lifetime microfilaria production (p = 0.42), nor did regression analysis reveal any likely predictive relationships to leukocyte values. The results of this study demonstrate the competence of the dog as a host for B. malayi and its potential to serve in the laboratory role currently provided by the cat, while also clarifying the potential for zoonosis in filariasis-endemic regions.

POPULATIONS AND SITE SELECTION OF DIROFILARIA URSI (NEMATODA: ONCHOCERCIDAE) IN AMERICAN BLACK BEARS (URSUS AMERICANUS).

A total of 4,846 (84.5±87.15, 3-429: mean±SD, range) subadult or adult Dirofilaria ursi were recovered from 56 American black bears (Ursus americanus) in Ontario, 1975-77. Yearling bears had fewer worms than older bears; age classes greater than 2.5 yr had similar numbers of worms. Dead worms comprised 3.7% of all worms. There was one dead worm in total in 10 yearling bears and consistently more dead worms in older bears. The occurrence of worms within local sites in bears differed over time. Increasing numbers of worms appeared first in peritracheal sites (Site 1) following 1-3 seasons of transmission, in abundance in perirenal sites (Site 2) following the second season of transmission, and in lateral and ventral trunk and abdomen plus medio-proximal legs (Site 3) following three and four seasons of transmission. Few worms occupied other sites (Site 4). The proportion of worms recovered from the four sites was 46, 30, 19.8, and 3.9%, respectively. Dead worms comprised only 3.2% of worms in the first three definitive sites but 14% of worms in other sites. These data are consistent with primary, secondary, and tertiary site preferences for mature D. ursi in this species. Circulating microfilaremia in peripheral blood was periodic in 7/10 experiments and revealed a pattern of variable numbers during the day, highest in the evening and lowest during the night. The time of high density of microfilariae in peripheral blood was synchronous with the feeding cycle of Simulium venustum, the vector of D. ursi. Immediately postmortem, microfilariae were at highest densities in blood of lungs regardless of their relative density in peripheral blood. These data can direct diagnostic efforts to maximize detection of adult D. ursi in tissues and larvae in blood samples of naturally infected bears.

Effect of a single dose of 8 mg moxidectin or 150 μg/kg ivermectin on O. volvulus skin microfilariae in a randomized trial: Differences between areas in the Democratic Republic of the Congo, Liberia and Ghana and impact of intensity of infection.

Our study in CDTI-naïve areas in Nord Kivu and Ituri (Democratic Republic of the Congo, DRC), Lofa County (Liberia) and Nkwanta district (Ghana) showed that a single 8 mg moxidectin dose reduced skin microfilariae density (microfilariae/mg skin, SmfD) better and for longer than a single 150μg/kg ivermectin dose. We now analysed efficacy by study area and pre-treatment SmfD (intensity of infection, IoI). Four and three IoI categories were defined for across-study and by-study area analyses, respectively. We used a general linear model to analyse SmfD 1, 6, 12 and 18 months post-treatment, a logistic model to determine the odds of undetectable SmfD from month 1 to month 6 (UD1-6), month 12 (UD1-12) and month 18 (UD1-18), and descriptive statistics to quantitate inter-interindividual response differences. Twelve months post-treatment, treatment differences (difference in adjusted geometric mean SmfD after moxidectin and ivermectin in percentage of the adjusted geometric mean SmfD after ivermectin treatment) were 92.9%, 90.1%, 86.8% and 84.5% in Nord Kivu, Ituri, Lofa and Nkwanta, and 74.1%, 84.2%, 90.0% and 95.4% for participants with SmfD 10-20, ≥20-<50, ≥50-<80, ≥80, respectively. Ivermectin's efficacy was lower in Ituri and Nkwanta than Nord Kivu and Lofa (p≤0.002) and moxidectin's efficacy lower in Nkwanta than Nord Kivu, Ituri and Lofa (p<0.006). Odds ratios for UD1-6, UD1-12 or UD1-18 after moxidectin versus ivermectin treatment exceeded 7.0. Suboptimal response (SmfD 12 months post-treatment >40% of pre-treatment SmfD) occurred in 0%, 0.3%, 1.6% and 3.9% of moxidectin and 12.1%, 23.7%, 10.8% and 28.0% of ivermectin treated participants in Nord Kivu, Ituri, Lofa and Nkwanta, respectively. The benefit of moxidectin vs ivermectin treatment increased with pre-treatment IoI. The possibility that parasite populations in different areas have different drug susceptibility without prior ivermectin selection pressure needs to be considered and further investigated. Registered on 14 November 2008 in Clinicaltrials.gov (ID: NCT00790998).

Mapping Spatial Variation and Impact of the National MDA Program on Lymphatic Filariasis Elimination in Ghana: An Initial Study

Lymphatic filariasis (LF) is a public health menace, especially in developing countries. A periodic review of mass drug administration (MDA) performance is critical to monitoring elimination progress. However, investigating the spatial pattern of LF with respect to MDA intervention is yet to be documented. This is essential to appreciating the transmission dynamics across LF-endemic communities and how it is spatially impacted by MDA programs. The aim of this study was to map and explore the spatial variation and hotspots of LF infection among endemic communities and evaluate the impact of the MDA intervention program on its spatial pattern in Ghana. Relative risks, clustering and clusters, prevalence odds ratios, and their confidence intervals were studied with community-level LF data prior to intervention and post intervention periods. The overall risk of LF infection was 0.12% and 0.02% before and after MDA, respectively, suggesting reduced transmission. Using empirical Bayesian smoothing to map the relative risk, a substantial variation in the spatial distribution of the relative risk of LF among endemic communities was observed. Most of the excess prevalence communities were unexpectedly visible even after years of MDA. The Empirical Bayesian Moran’s Index for global clustering showed a reduction in clustering of LF prevalence after MDA with IM = 0.455 and 0.119 for before and after MDA, respectively. Furthermore, examining risks associated with ecological zones, it was observed that the Guinea Savannah and the Transition Zone were the most vulnerable zones for LF infection with prevalence odds ratios 18.70- and 13.20-fold higher than in the reference Moist evergreen zone, respectively. We observed a drastic reduction in risk in the Wet evergreen zone after MDA, while the Guinea Savannah sustained high levels of risk even after MDA. These findings should prompt public health officials to adopt stratified cluster sampling in LF-endemic regions to monitor the rate and density of microfilaria.

EVALUATION OF LYMPHATIC FILARIASIS AFTER TWO ROUNDS OF MASS DRUG ADMINISTRATION IN LAU LOCAL GOVERNMENT AREA OF TARABA STATE NIGERIA

This study was undertaken to evaluate the effects of Mass Drug Administration (MDA) on Wuchereria bancrofti (microfilariae) after two rounds of combined Ivermectin and Albendazole distribution. A total of 221 participants were recruited in three communities in Lau Local Government Area of Taraba State by convenience sampling method. Questionnaires and physical examinations were used to assess clinical manifestations associated with the infection. Blood samples were collected by finger prick method and stained with Giemsa stain for examination to establish the presence of W. bancrofti while immunochromatographic card test was performed to determine the presence of filarial antigen in serum. Previous data were used to determine the pre-drug prevalence of the parasite. The results showed that the drug did not significantly reduce the clinical manifestations reported among the patients. The microfilariae prevalence and microfilaria mean density after two rounds of drug administration was 19.5% and 1.49%, while the pre- MDA prevalence and microfilaria mean density was 27.8% and 2.44% respectively. There was a statistically significant decrease of microfilaria prevalence (P&lt;0.05) after two rounds of MDA. There was no significant effect of MDA by age, sex and occupation-related microfilariae prevalence in the study area. In conclusion, the study reveals that microfilaria prevalence and load decreased after two rounds of MDA of combined Ivermectin and Albendazole distribution amongst the studied populations. Routine evaluation of the MDA is required to assess the impact of the drug for the eventual elimination of the infection.

Impact of Lymphatic Filariasis on Married Women from Rural Areas of Bankura District, West Bengal, India

In third world countries like India, women play a vital role in building and maintaining the family and the society. Lymphatic Filariasis (LF) among married women may inflict a deep impact on the society. Present study was focused to study the impact of LF on married women of some rural areas of Bankura district in West Bengal, India. Night blood-samples of 1202 married women were examined to detect the presence of microfilariae. They were examined clinically and also asked for any hidden filarial manifestation. Affected subjects were also interrogated to understand the impact of LF on their lives. Microfilaria rate, mean microfilaria density and disease rate among the married women of the area were assessed as 6.16%, 10.89% and 11.98% respectively. 95.83% of the diseased subjects were of opinion that the disease had imposed some or many adverse effects on their lives. The diseased women suffer from disability, loss of efficiency and social stigma. They are often neglected and abstain themselves from intimating their problems to the family members and seeking help for various reasons. Awareness level is poor and presumably the situation is same in the rural areas of other under developed and developing countries.

Effect of Ivermectin Treatment on the Frequency of Seizures in Persons with Epilepsy Infected with Onchocerca volvulus.

A clinical trial performed in the Democratic Republic of Congo (DRC), among persons with epilepsy (PWE) infected with Onchocerca volvulus treated with anti-seizure medication suggested that ivermectin reduces the seizure frequency. We assessed the effect of ivermectin treatment on seizure frequency in PWE with and without anti-seizure medication in three onchocerciasis endemic areas (Maridi, South Sudan; Aketi, DRC; and Mahenge, Tanzania). Pre- and 3–5 months post-ivermectin microfilariae densities in skin snips and seizure frequency were assessed. After ivermectin, the median (IQR) percentage reduction in seizure frequency in the study sites ranged from 73.4% (26.0–90.0) to 100% (50.0–100.0). A negative binomial mixed model showed that ivermectin significantly reduced the seizure frequency, with a larger decrease in PWE with a high baseline seizure frequency. Mediation analysis showed that ivermectin reduced the seizure frequencies indirectly through reduction in microfilariae densities but also that ivermectin may have a direct anti-seizure effect. However, given the short half-life of ivermectin and the fact that ivermectin does not penetrate the healthy brain, such a direct anti-seizure effect is unlikely. A randomized controlled trial assessing the ivermectin effect in people infected with O. volvulus who are also PWE on a stable anti-seizure regimen may be needed to clarify the causal relationship between ivermectin and seizure frequency.

Microfilaria-dependent thoracic pathology associated with eosinophilic and fibrotic polyps in filaria-infected rodents

BackgroundPulmonary manifestations are regularly reported in both human and animal filariasis. In human filariasis, the main known lung manifestations are the tropical pulmonary eosinophilia syndrome. Its duration and severity are correlated with the presence of microfilariae. Litomosoides sigmodontis is a filarial parasite residing in the pleural cavity of rodents. This model is widely used to understand the immune mechanisms that are established during infection and for the screening of therapeutic molecules. Some pulmonary manifestations during the patent phase of infection with L. sigmodontis have been described in different rodent hosts more or less permissive to infection.MethodsHere, the permissive Mongolian gerbil (Meriones unguiculatus) was infected with L. sigmodontis. Prevalence and density of microfilariae and adult parasites were evaluated. Lungs were analyzed for pathological signatures using immunohistochemistry and 3D imaging techniques (two-photon and light sheet microscopy).ResultsMicrofilaremia in gerbils was correlated with parasite load, as amicrofilaremic individuals had fewer parasites in their pleural cavities. Fibrotic polypoid structures were observed on both pleurae of infected gerbils. Polyps were of variable size and developed from the visceral mesothelium over the entire pleura. The larger polyps were vascularized and strongly infiltrated by immune cells such as eosinophils, macrophages or lymphocytes. The formation of these structures was induced by the presence of adult filariae since small and rare polyps were observed before patency, but they were exacerbated by the presence of gravid females and microfilariae.ConclusionsAltogether, these data emphasize the role of host-specific factors in the pathogenesis of filarial infections.

Implications for annual retesting after a test-and-not-treat strategy for onchocerciasis elimination in areas co-endemic with Loa loa infection: an observational cohort study

SummaryBackgroundA test-and-not-treat (TaNT) strategy has been developed to prevent people with high concentrations of circulating Loa loa microfilariae (>20 000 microfilariae per mL) developing serious adverse events after ivermectin treatment during mass drug administration to eliminate onchocerciasis. An important question related to cost and programmatic issues is whether annual retesting is required for everyone. We therefore aimed to investigate changes in L loa microfilarial densities during TaNT campaigns run 18 months apart.MethodsIn this observational cohort study, we assessed the participants of two TaNT campaigns for onchocerciasis. These campaigns, which were run by a research team, together with personnel from the Ministry of Health and community health workers, were done in six health areas (in 89 communities) in Okola health district (Cameroon); the first campaign was run between Aug 10, and Oct 29, 2015, and the second was run between March 7, and May 26, 2017. All individuals aged 5 years and older were invited to be screened for Loa loa microfilaraemia before being offered ivermectin (unless contraindicated). L loa microfilarial density was measured at the point of care using the LoaScope. All those with a L loa microfilarial density of 20 000 microfilariae per mL or less were offered treatment; in the first 2 weeks of the 2015 campaign, a higher exclusion threshold of 26 000 microfilariae per mL or less was used. At both rounds of the intervention, participants were registered with a paper form, in which personal information were collected. In 2017, we also recorded whether each individual reported participation in the 2015 campaign. The primary outcome, assessed in all participants, was whether L loa microfilarial density was above or below the exclusion threshold (ie, the criteria that guided the decision to treat).FindingsIn the 2015 TaNT campaign, 26 415 people were censused versus 29 587 people in the 2017 TaNT campaign. All individuals aged 5 years and older without other contraindications to treatment (22 842 people in 2015 and 25 421 people in 2017) were invited to be screened for L loa microfilaraemia before being offered ivermectin. In 2015, 16 182 individuals were examined with the LoaScope, versus 18 697 individuals in the same communities in 2017. 344 (2·1%) individuals were excluded from ivermectin treatment because of a high L loa microfilarial density in 2015, versus 283 (1·5%) individuals in 2017 (p<0·0001). Records from 2017 could be matched to those from 2015 for 6983 individuals (43·2% of the 2015 participants). In this cohort, in 2017, 6981 (>99·9%) of 6983 individuals treated with ivermectin in 2015 had L loa microfilariae density below the level associated with neurological serious adverse events.InterpretationIndividuals treated with ivermectin do not need to be retested for L loa microfilaraemia before the next treatment, provided that they can be re-identified. This adjusted approach will enable substantial cost savings and facilitate reaching programmatic goals for elimination of onchocerciasis in areas that are co-endemic for loiasis.FundingBill & Melinda Gates Foundation, Division of Intramural Research (National Institute of Allergy and Infectious Diseases, US National Institutes of Health).

Epidemiology of epilepsy in Cameroon: A review

More than 10 million people with epilepsy live in Africa. Many patients in Sub-Saharan Africa do not received appropriate treatment due to socio-economic and cultural factors. Cameroon has one of the highest prevalence in the world. We systematically reviewed research articles, original papers, abstract on PubMed, Google Scholars, African Journals Online (AJOL), ResearchGate with no limitation of period until 2018. The terms of research were “epilepsy” “Cameroon” “epileptic seizures” “convulsions” and regions of the countries. We reviewed 20 publications but only 15 were used for this review. The prevalence of epilepsy in Cameroon varies from 35.4 to 134.5‰. Children are mostly affected. There is a light male predominance, that could be explained by risk behavior in young male. Incidence of epilepsy varies from 98 to 222.7 per 100000 PY especially in village closed to the Sanaga river which are endemic zone of onchocerciasis. This Incidence is highly associated to microfilaria density. This leads to a new entity called Onchocerciasis associated epilepsy. Many studies reported etiologies of epilepsy: poor pregnancy follow-up, CNS infections, stroke and head trauma. The relative risk of mortality in 6.2 times for people with epilepsy compare to people without epilepsy due mainly to: status epilepticus and SUDEP. Consequences of epilepsy include: stigmatization, exclusion, socioprofessional disabilities, burns and neuropsychiatric disorders. Epilepsy is a major public health problem. Many causes and risk factors could be identified and prevented. That is why we should improve awareness and advocacy.

IL-4 receptor dependent expansion of lung CD169+ macrophages in microfilaria-driven inflammation.

Lung disease is regularly reported in human filarial infections but the molecular pathogenesis of pulmonary filariasis is poorly understood. We used Litomosoides sigmodontis, a rodent filaria residing in the pleural cavity responsible for pleural inflammation, to model responses to human filarial infections and probe the mechanisms. Wild-type and Th2-deficient mice (ΔdblGata1 and Il-4receptor(r)a-/-/IL-5-/-) were infected with L. sigmodontis. Survival and growth of adult filariae and prevalence and density of microfilariae were evaluated. Cells and cytokines in the pleural cavity and bronchoalveolar space were characterized by imaging, flow cytometry and ELISA. Inflammatory pathways were evaluated by transcriptomic microarrays and lungs were isolated and analyzed for histopathological signatures. 40% of WT mice were amicrofilaremic whereas almost all mutant mice display blood microfilaremia. Microfilariae induced pleural, bronchoalveolar and lung-tissue inflammation associated with an increase in bronchoalveolar eosinophils and perivascular macrophages, production of mucus, visceral pleura alterations and fibrosis. Inflammation and pathology were decreased in Th2-deficient mice. An IL-4R-dependent increase of CD169 was observed on pleural and bronchoalveolar macrophages in microfilaremic mice. CD169+ tissue-resident macrophages were identified in the lungs with specific localizations. Strikingly, CD169+ macrophages increased significantly in the perivascular area in microfilaremic mice. These data describe lung inflammation and pathology in chronic filariasis and emphasize the role of Th2 responses according to the presence of microfilariae. It is also the first report implicating CD169+ lung macrophages in response to a Nematode infection.

Projected Number of People With Onchocerciasis-Loiasis Coinfection in Africa, 1995 to 2025.

BackgroundOnchocerciasis elimination through mass drug administration (MDA) is hampered by coendemicity of Loa loa, as people with high L. loa microfilariae (mf) density can develop serious adverse events (SAEs) after ivermectin treatment. We assessed the geographical overlap of onchocerciasis and loiasis prevalence and estimated the number of coinfected individuals at risk of post-ivermectin SAEs in West and Central Africa from 1995 to 2025.MethodsFocusing on regions with suspected loiasis transmission in 14 countries, we overlaid precontrol maps of loiasis and onchocerciasis prevalence to calculate precontrol prevalence of coinfection by 5 km2 × 5 km2 pixel, distinguishing different categories of L. loa mf intensity. Using statistical and mathematical models, we predicted prevalence of both infections and coinfection for 2015 and 2025, accounting for the impact of MDA with ivermectin.ResultsThe number of people infected with onchocerciasis was predicted to decline from almost 19 million in 1995 to 4 million in 2025. Of these, 137 000 people were estimated to also have L. loa hypermicrofilaremia (≥20 000 L. loa mf/mL) in 1995, declining to 31 000 in 2025. In 2025, 92.8% of coinfected cases with loiasis hypermicrofilaremia are predicted to live in hypoendemic areas currently not targeted for MDA.ConclusionsLoiasis coinfection is a major concern for onchocerciasis elimination in Africa. We predict that under current strategies, at least 31 000 coinfected people still require treatment for onchocerciasis in 2025 while being at risk of SAEs, justifying continued efforts in research and development for safer drugs and control strategies.

PO 8382 CLINICAL AND LABORATORY ASSESSMENT OF LOA LOA INFECTIONS IN GABON

BackgroundLoiasis is a parasitic infection highly endemic in West and Central Africa. Previously often considered as a benign infection, recent studies have suggested that high microfilaria loads in loiasis patients may be associated with increased mortality. The true impact of loiasis on affected communities is unknown. Reports on clinical symptoms and changes in laboratory values due to loiasis infection are focused mostly on returning travellers. Assessments in endemic populations have scarcely been performed. Laboratory alterations such as eosinophilia are thought to be present mostly in patients from non-endemic areas.MethodsThis cross-sectional study was performed in rural Gabon to investigate the clinical symptoms and laboratory changes caused by loiasis in an endemic population. Inclusion criteria were local residency for at least two years and an age above two years. Participants were interviewed with a questionnaire covering loiasis-specific symptoms, exploratory questions and history of eye worm. Local vocabulary was employed if needed. At the same time L. loa microfilaria diagnostics were performed including thick blood smear preparation and concentration techniques. Additionally, differential blood count and haemoglobin measurements were performed. Peripheral blood withdrawals were done between 10 am and 3 pm.ResultsA total of 1030 participants were recruited, of whom 56% were female; they were between 2 and 98 years of age. L. loa microfilariae were detectable in 27% of all participants. Microfilariae densities ranged from 1 to 76 250 Mf/mL. Overall a positive history of eye worm was reported in 56%, with 25% of participants reporting eye worm passage and 36% Calabar swelling within the last year. Also, an analysis of laboratory parameters in comparison to clinical data and infection status was performed.ConclusionLoiasis infection should receive more attention by the scientific community and further studies are needed, as the disease causes substantial morbidity in endemic populations.

Distribusi Filariasis Brugia timori dan Wuchereria bancrofti di Desa Kahale, Kecamatan Kodi Balaghar, Kabupaten Sumba Barat Daya, Nusa Tenggara Timur

Lymphatic filariasis is still a health problem in the East Nusa Tenggara province. Southwest Sumba District is filariasis endemic area. It is found 35 chronic cases in Kodi Balaghar subdistrict. Although implementation of mass drug adminsitration was held in 2011 but drug coverage had been poor and not reach Kodi Balaghar subdistrict. The purpose of this study were to measure the prevalence and distribution, determine the density and type of parasite and mapping cases in the Kodi Balaghar subdistrict. This research was a descriptive study with cross sectional approach which conducted in the Kahale Village, Kodi Balaghar Subdistrict in 2012. Five hundred people were checked. The results of the examination found that 21 positive microfilariae cases, Mf rate was 4.2%. Two species of microfilariae that found were Wuchereria bancrofti and Brugia timori. The distribution filariasis cases is higher in men and higher in reproductive age (15-45 years). There were three types of infection, an infection by B. timori, W. bancrofti, and mixed infections both the microfilariae. The density of microfilariae in the area was 190.86 mf/ml, the density W. bancrofti was 160.04 mf/ml, B. timori was 115.97 mf/ml. Filariasis cases distributed near to potential breeding places of mosquito .

Gambaran Angka Prevalensi Mikrofilaria di Kabupaten Banyuasin Pasca Pengobatan Massal Tahap III

Filariasis is a chronic infectious disease that can cause permanent disability. One effort to interrupt transmission of filariasis is the Mass Drug Administration filariasis (MDA filariasis) in endemic areas of filariasis for 5 years. In 2012, MDA filariasis was carried out in all regions of Banyuasin. After treatment the 3rd year, it is necessary to evaluate the prevalence of microfilaria and microfilaria density. This activity was conducted by finger blood survey to people who’s living in sentinel and spot villages. This study selected 930 people for SDJ activities The test results obtained 4 positive of microfilaria Brugia malayi. The prevalence or microfilaria rate (Mf rate) in the village of sentinel was 0,96 with microfilaria density were 938/mL of blood, Mf rate in spot village was 0.31 with a microfilaria density were 217.75/mL of blood, while the Mf rate district was 0.43 with a microfilaria density were 716.06/mL of blood. People who suffer filiariasis mostly are farmers/fishermen. The prevalence of microfilariae in Banyuasin decreased, but the risk of transmission can still occur because of the density of microfilariae found&gt; 50/mL of blood.

In Southern Nigeria Loa loa Blood Microfilaria Density is Very Low Even in Areas with High Prevalence of Loiasis: Results of a Survey Using the New LoaScope Technology.

Ivermectin treatment can cause central nervous system adverse events (CNS-AEs) in persons with very high-density Loa loa microfilaremia (≥ 30,000 mf/mL blood). Hypoendemic onchocerciasis areas where L. loa is endemic have been excluded from ivermectin mass drug administration programs (MDA) because of the concern for CNS AEs. The rapid assessment procedure for L. loa (RAPLOA) is a questionnaire survey to assess history of eye worm. If ≥ 40% of respondents report eye worm, this correlates with ≥ 2% prevalence of very high-density loiasis microfilaremia, posing an unacceptable risk of CNS-AEs after MDA. In 2016, we conducted a L. loa study in 110 ivermectin-naïve, suspected onchocerciasis hypoendemic villages in southern Nigeria. In previous RAPLOA surveys these villages had prevalences between 10% and 67%. We examined 10,605 residents using the LoaScope, a cell phone-based imaging device for rapidly determining the microfilaria (mf) density of L. loa infections. The mean L. loa village mf prevalence was 6.3% (range 0-29%) and the mean individual mf count among positives was 326 mf/mL. The maximum individual mf count was only 11,429 mf/mL, and among 2,748 persons sampled from the 28 villages with ≥ 40% RAPLOA, the ≥ 2% threshold of very high Loa mf density could be excluded with high statistical confidence (P < 0.01). These findings indicate that ivermectin MDA can be delivered in this area with extremely low risk of L. loa-related CNS-AEs. We also concluded that in Nigeria the RAPLOA survey methodology is not predictive of ≥ 2% prevalence of very high-density L. loa microfilaremia.