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"Klarmann-Schulz, Ute"
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Immunoepidemiological Profiling of Onchocerciasis Patients Reveals Associations with Microfilaria Loads and Ivermectin Intake on Both Individual and Community Levels
2014
Mass drug administration (MDA) programmes against Onchocerca volvulus use ivermectin (IVM) which targets microfilariae (MF), the worm's offspring. Most infected individuals are hyporesponsive and present regulated immune responses despite high parasite burden. Recently, with MDA programmes, the existence of amicrofilaridermic (a-MF) individuals has become apparent but little is known about their immune responses. Within this immunoepidemiological study, we compared parasitology, pathology and immune profiles in infection-free volunteers and infected individuals that were MF(+) or a-MF. The latter stemmed from villages in either Central or Ashanti regions of Ghana which, at the time of the study, had received up to eight or only one round of MDA respectively. Interestingly, a-MF patients had fewer nodules and decreased IL-10 responses to all tested stimuli. On the other hand, this patient group displayed contrary IL-5 profiles following in vitro stimulation or in plasma and the dampened response in the latter correlated to reduced eosinophils and associated factors but elevated neutrophils. Furthermore, multivariable regression analysis with covariates MF, IVM or the region (Central vs. Ashanti) revealed that immune responses were associated with different covariates: whereas O. volvulus-specific IL-5 responses were primarily associated with MF, IL-10 secretion had a negative correlation with times of individual IVM therapy (IIT). All plasma parameters (eosinophil cationic protein, IL-5, eosinophils and neutrophils) were highly associated with MF. With regards to IL-17 secretion, although no differences were observed between the groups to filarial-specific or bystander stimuli, these responses were highly associated with the region. These data indicate that immune responses are affected by both, IIT and the rounds of IVM MDA within the community. Consequently, it appears that a lowered infection pressure due to IVM MDA may affect the immune profile of community members even if they have not regularly participated in the programmes.
Journal Article
Occurrence of Lymphatic Filariasis infection after 15 years of mass drug administration in two hotspot districts in the Upper East Region of Ghana
by
Adu Mensah, Derrick
,
Obeng, Prince
,
Opoku, Vera Serwaa
in
Biology and Life Sciences
,
Medicine and Health Sciences
,
People and Places
2022
Lymphatic filariasis (LF) causes chronic morbidity, which usually manifests as lymphedema or hydrocele. Mass drug administration (MDA) began in Kassena Nankana East Municipal (KNEM) and Nabdam, two hotspot districts in the Upper East Region in Ghana, in 2000 and 2005, respectively. This cross-sectional study evaluated the impact of 15 years of MDA on the control of LF as determined by circulating filarial antigen (CFA) and microfilariae assessment in the KNEM and the Nabdam districts.BACKGROUNDLymphatic filariasis (LF) causes chronic morbidity, which usually manifests as lymphedema or hydrocele. Mass drug administration (MDA) began in Kassena Nankana East Municipal (KNEM) and Nabdam, two hotspot districts in the Upper East Region in Ghana, in 2000 and 2005, respectively. This cross-sectional study evaluated the impact of 15 years of MDA on the control of LF as determined by circulating filarial antigen (CFA) and microfilariae assessment in the KNEM and the Nabdam districts.A total of 7,453 participants from eight sub-districts in the two hotspot districts (KNEM: N = 4604; Nabdam: N = 2849) were recruited into the study. The overall CFA prevalence as determined by the FTS was 19.6% and 12.8% in the KNEM and Nabdam districts, respectively. Manyoro, a sub-district on the border with Burkina Faso, recorded the highest CFA prevalence of 26% in the KNEM. Assessment of microfilariae and Og4C3 antigen was done from 1009 (KNEM: N = 799 (79.2%); Nabdam: N = 210 (20.8%)) randomly selected FTS-positive (N = 885) and FTS-negative (N = 124) individuals. The Og4C3 antigen was found in 22.6%/23.0% of the selected individuals (KNEM/Nabdam), whereas the night blood revealed microfilariae in only 0.7%/0.5%.METHODOLOGY/PRINCIPAL FINDINGSA total of 7,453 participants from eight sub-districts in the two hotspot districts (KNEM: N = 4604; Nabdam: N = 2849) were recruited into the study. The overall CFA prevalence as determined by the FTS was 19.6% and 12.8% in the KNEM and Nabdam districts, respectively. Manyoro, a sub-district on the border with Burkina Faso, recorded the highest CFA prevalence of 26% in the KNEM. Assessment of microfilariae and Og4C3 antigen was done from 1009 (KNEM: N = 799 (79.2%); Nabdam: N = 210 (20.8%)) randomly selected FTS-positive (N = 885) and FTS-negative (N = 124) individuals. The Og4C3 antigen was found in 22.6%/23.0% of the selected individuals (KNEM/Nabdam), whereas the night blood revealed microfilariae in only 0.7%/0.5%.Using the WHO endorsed FTS, CFA prevalence exceeded the long-standing <2% threshold-which may need revision and validation. Surprisingly, the Og4C3 ELISA showed positive results in only about one-fifth of the FTS positive samples. However, even this result would not have met the <2% CFA criteria for LF elimination. In contrast, projections from the microfilariae results revealed a halt in LF transmission. The global elimination target was due in 2020 but has been extended to 2030 since this could not be met. Focused MDA intervention intensification on seasonal migrants and non-compliers, and implementation of alternative treatment strategies may suffice for the elimination of the disease.CONCLUSIONS/SIGNIFICANCEUsing the WHO endorsed FTS, CFA prevalence exceeded the long-standing <2% threshold-which may need revision and validation. Surprisingly, the Og4C3 ELISA showed positive results in only about one-fifth of the FTS positive samples. However, even this result would not have met the <2% CFA criteria for LF elimination. In contrast, projections from the microfilariae results revealed a halt in LF transmission. The global elimination target was due in 2020 but has been extended to 2030 since this could not be met. Focused MDA intervention intensification on seasonal migrants and non-compliers, and implementation of alternative treatment strategies may suffice for the elimination of the disease.
Journal Article
Tropical leg lymphedema caused by podoconiosis is associated with increased colonisation by anaerobic bacteria
2023
The non-filarial and non-communicable disease podoconiosis affects around 4 million people and is characterized by severe leg lymphedema accompanied with painful intermittent acute inflammatory episodes, called acute dermatolymphangioadenitis (ADLA) attacks. Risk factors have been associated with the disease but the mechanisms of pathophysiology remain uncertain. Lymphedema can lead to skin lesions, which can serve as entry points for bacteria that may cause ADLA attacks leading to progression of the lymphedema. However, the microbiome of the skin of affected legs from podoconiosis individuals remains unclear. Thus, we analysed the skin microbiome of podoconiosis legs using next generation sequencing. We revealed a positive correlation between increasing lymphedema severity and non-commensal anaerobic bacteria, especially
Anaerococcus provencensis
, as well as a negative correlation with the presence of
Corynebacterium
, a constituent of normal skin flora. Disease symptoms were generally linked to higher microbial diversity and richness, which deviated from the normal composition of the skin. These findings show an association of distinct bacterial taxa with lymphedema stages, highlighting the important role of bacteria for the pathogenesis of podoconiosis and might enable a selection of better treatment regimens to manage ADLA attacks and disease progression.
Journal Article
Changes in circulating filarial antigen status in previously positive individuals: Lessons for treatment monitoring and pre-transmission assessment surveys
2025
The Global Programme to Eliminate Lymphatic Filariasis has made significant gains through mass drug administration (MDA) of Ivermectin/Albendazole. Periodic evaluation of the MDA programme in lymphatic filariasis elimination is particularly useful in determining end points for stopping the programme. This is a follow-up study that sought to examine the effects of additional time and MDA intake on antigenemia seroreversion in persons who had previously tested positive for LF using the Filarial Test Strip (FTS) and the TropBio ELISA over a period of 1-5 years.
A total of 542 individuals, from the Kassena Nankana East Municipal (N = 340) and Nabdam districts (N = 202) in the Upper East Region of Ghana, who had previously tested either positive (N = 446) or negative (N = 96) for FTS-CFA, participated in the study. Two follow-up visits were conducted; 1-4 years (follow-up-1) and 2-5 years (follow-up-2) after the baseline visit. Of the 446 FTS-CFA positives, 175 (39.2%) did not receive additional MDA (ivermectin/Albendazole) after the baseline visit. Overall, from the two follow-up visits, 159/175 (90.9%) FTS-CFA+ participants who did not receive any additional Ivermectin/Albendazole and 226 out of the 271 (83.4%) with additional MDA treatment became CFA negative. A total of 120 randomly selected baseline FTS-CFA+ samples were tested with Og4C3 TropBio ELISA and only 44/120 (36.7%) were found positive. Of these 44 participants, 12 (27.3%) completely became CFA negative and an additional 18 (40.9%) had reduced antigen levels during the follow-up. Likewise, all three previously/baseline microfilariae positive persons had become amicrofilaremic.
In the present work, it has been shown that >90% of the previous CFA positive individuals seroreverted in 1 to 5 years post-baseline without additional MDA. The FTS is a more sensitive diagnostic tool that plausibly detects residual CFA in blood. The impact and influence of time as compared to additional ivermectin/Albendazole intake, on CFA seroreversion in this study was significant (p < 0.001).
Journal Article
Humoral immune response to COVID-19 vaccines in onchocerciasis-infected individuals: a field study from Ghana
by
Ahiadorme, Monica
,
Parcina, Marijo
,
Osei-Mensah, Jubin
in
Adolescent
,
Adult
,
Antibodies, Helminth - blood
2025
COVID-19 vaccines are the most successful medical interventions to reduce disease severity and mortality. Various vaccine platforms with unique properties have been developed. The course of the pandemic was contrary to the initial predictions, relatively mild in sub-Saharan Africa. Besides other contributing factors, helminths may also play a role due to their immunomodulatory properties. This study aimed to investigate antibody responses in onchocerciasis-infected individuals after multiple doses of different COVID-19 vaccines, comparing mRNA and vector-based vaccines, accounting for co-infections, and contrasting the findings with those from healthy endemic controls..
For this purpose, samples of onchocerciasis-infected individuals (n=110) from a larger and ongoing clinical trial were collected during the COVID-19 pandemic (December 2022) in northwestern Ghana. Participants were grouped according to their COVID-19 vaccine status as unvaccinated, incomplete (1 dose), and complete (2 doses). Helminth-specific and SARS-CoV-2-specific antibodies were quantified using ELISA, while a multiplex immunoassay was used to determine SARS-CoV-2 variant-specific neutralizing antibodies. Non-parametric statistical tests including Kruskal-Wallis and Mann-Whitney-U test were used for group comparison.
The data indicated a high SARS-CoV-2 seroprevalence among both, COVID-19 unvaccinated and vaccinated participants, despite the lack of a confirmed infection. Unvaccinated participants (n=44) showed 86% and 77% seropositivity for spike-specific IgA and IgG, respectively. Incompletely (n=22) and completely (n=36) COVID-19 vaccinated groups showed 63% and 50% nucleocapsid seropositivity, indicating viral exposure. The study identified elevated antibody levels following COVID-19 vaccination despite underlying onchocerciasis infection compared to the unvaccinated control group. However, comparable SARS-CoV-2 IgG levels were detected among mRNA and vector-based vaccinated individuals, as well as a higher breakthrough infection rate (NCP-seropositivity) in mRNA vaccinees. Interestingly, active-infected onchocerciasis individuals (Microfilaria positive) showed a reduced vaccine-induced IgG response after complete COVID-19 vaccination. Moreover, helminths may modify the vaccine- or infection-induced SARS-CoV-2 IgG subclass response, as the lack of IgG1 and the expression of IgG4 was associated with microfilaria and soil-transmitted helminth seropositivity.
The study concluded that COVID-19 vaccines trigger a strong humoral immune response despite underlying onchocerciasis infection. However, parasitic status or microfilaria load may dampen vaccine-induced responses. These findings highlight the complexity of investigating vaccine responses in the presence of an undeterminable infection history, co-infections and polyparasitism in helminth-endemic areas and emphasize the need to further explore parasite-immunomodulatory mechanisms on COVID-19 vaccine efficacy for future vaccine development.
Journal Article
The design and development of a study protocol to investigate Onchocerca volvulus, Loa loa and Mansonella perstans-mediated modulation of the metabolic and immunological profile in lean and obese individuals in Cameroon
by
Andrew, Beng Amuam
,
Ehrens, Alexandra
,
Nchang, Lucy Cho
in
Analysis
,
Antiparasitic agents
,
Biology and Life Sciences
2023
Life-style metabolic diseases are steadily rising, not only in developed countries, but also in low- and middle-income countries, presenting a global health problem. Metabolic disorders like type 2 diabetes and cardiovascular diseases are among the ten leading causes of death defined by the WHO in 2019. Results from animal and observational human studies suggest a connection between the decline in human helminth infections and rise of life-style-associated metabolic diseases in developing regions. This trial was designed to investigate filarial infections and their impact on metabolic diseases in Cameroon. We hypothesize that the induction of regulatory immune responses during filarial infection reduces obesity-induced low-grade inflammatory immune responses and thereby improves metabolic parameters, whereas anthelmintic treatment abolishes this protective effect.
Participants infected with Mansonella perstans, Onchocerca volvulus and/or Loa loa being lean (BMI <25), overweight (BMI >25 and <30) or clinically obese (BMI ≥30) from Littoral regions of Cameroon will be evaluated for their parasitological, immunological, metabolic and biochemical profile before and after treatment of their parasitic infections. Anthropomorphic measurements and a detailed questionnaire will complement our analysis. The investigation will assess blood immune cell populations, serum adipokines and cytokines that could be influenced by the parasite infection and/or metabolic diseases. Further, parameters like blood glucose, homeostatic model assessment of insulin resistance (HOMA-IR), circulating lipids and circulating makers of liver function will be monitored. Parameters will be assessed before treatment, 12 and 18 months after treatment.
The focus of this study is to obtain a comprehensive metabolic profile of the participants in rural areas of Cameroon and to investigate the relationship between filarial immunomodulation and metabolic diseases. This study will elucidate the effect of anti-filarial treatment on the metabolic and immunological parameters that partake in the development of insulin resistance, narrowing in on a potential protective effect of filarial infections on metabolic diseases.
doi.org/10.1186/ISRCTN43845142, ISRCTN43845142 February 2020 Trial title Effects of filarial parasite infection on type 2 diabetes Issue date: 27.10.22, V.1.
Journal Article
Comparison of Doxycycline, Minocycline, Doxycycline plus Albendazole and Albendazole Alone in Their Efficacy against Onchocerciasis in a Randomized, Open-Label, Pilot Trial
2017
The search for new macrofilaricidal drugs against onchocerciasis that can be administered in shorter regimens than required for doxycycline (DOX, 200mg/d given for 4-6 weeks), identified minocycline (MIN) with superior efficacy to DOX. Further reduction in the treatment regimen may be achieved with co-administration with standard anti-filarial drugs. Therefore a randomized, open-label, pilot trial was carried out in an area in Ghana endemic for onchocerciasis, comprising 5 different regimens: the standard regimen DOX 200mg/d for 4 weeks (DOX 4w, N = 33), the experimental regimens MIN 200mg/d for 3 weeks (MIN 3w; N = 30), DOX 200mg/d for 3 weeks plus albendazole (ALB) 800mg/d for 3 days (DOX 3w + ALB 3d, N = 32), DOX 200mg/d for 3 weeks (DOX 3w, N = 31) and ALB 800mg for 3 days (ALB 3d, N = 30). Out of 158 randomized participants, 116 (74.4%) were present for the follow-up at 6 months of whom 99 participants (63.5%) followed the treatment per protocol and underwent surgery. Histological analysis of the adult worms in the extirpated nodules revealed absence of Wolbachia in 98.8% (DOX 4w), 81.4% (DOX 3w + ALB 3d), 72.7% (MIN 3w), 64.1% (DOX 3w) and 35.2% (ALB 3d) of the female worms. All 4 treatment regimens showed superiority to ALB 3d (p < 0.001, p < 0.001, p = 0.002, p = 0.008, respectively), which was confirmed by real-time PCR. Additionally, DOX 4w showed superiority to all other treatment arms. Furthermore DOX 4w and DOX 3w + ALB 3d showed a higher amount of female worms with degenerated embryogenesis compared to ALB 3d (p = 0.028, p = 0.042, respectively). These results confirm earlier studies that DOX 4w is sufficient for Wolbachia depletion and the desired parasitological effects. The data further suggest that there is an additive effect of ALB (3 days) on top of that of DOX alone, and that MIN shows a trend for stronger potency than DOX. These latter two results are preliminary and need confirmation in a fully randomized controlled phase 2 trial.
ClinicalTrials.gov #06010453.
Journal Article
Morbidity management and surveillance of lymphatic filariasis disease and acute dermatolymphangioadenitis attacks using a mobile phone-based tool by community health volunteers in Ghana
2020
Morbidity burden of lymphatic filariasis (LF) relies on the information from the Mass Drug Administration (MDA) programme where Community Health Volunteers (CHVs) passively report cases identified. Consequently, the exact prevalence of morbidity cases is not always accurate. The use of mobile phone technology to report morbidity cases was piloted in Ghana using a text-based short messaging service (SMS) tool by CHVs. Though successful, illiterate CHVs could not effectively use the SMS tool. The aim of this study was to evaluate the use of a mobile phone-based Interactive Voice Response System (mIVRS) by CHVs in reporting LF morbidity cases and acute dermatolymphangioadenitis (ADLA) attacks in Ghana. The mIVRS was designed as a surveillance tool to capture LF data in Kassena Nankana Districts of Ghana. One hundred CHVs were trained to identify and report lymphedema and hydrocele cases as well as ADLA attacks by calling a hotline linked to the mIVRS. The system asked a series of questions about the disease condition. The ability of the CHV to report accurately was assessed and the data from the mIVRS were compared with the paper records from the CHVs and existing MDA programme records from the same communities and period. Higher numbers of lymphedema and hydrocele cases were recorded by the CHVs using the mIVRS (n = 590 and n = 103) compared to the paper-based reporting (n = 417 and n = 76) and the MDA records (n = 154 and n = 84). Female CHVs, CHVs above 40 years, and CHVs with higher educational levels were better at paper-based reporting ( P = 0.007, P = 0.001, P = 0.049 respectively). The system, when fully developed and linked to national databases, may help to overcome underreporting of morbidity cases and ADLA attacks in endemic communities. The system has the potential to be further expanded to other diseases.
Journal Article
The viability of utilising phone-based text messages in data capture and reporting morbidities due to lymphatic Filariasis by community health workers: a qualitative study in Kilwa district, Tanzania
by
Ogondiek, John
,
Mandara, Wilfred
,
Horn, Sacha
in
Cellular telephones
,
Chemotherapy
,
Community
2022
Background
Globally, there is recognition of the value of using mobile phones among health providers in improving health systems performance. However, in many Low- and Middle-income countries where there is shortage of health providers, Community Health Workers have assumed some responsibilities especially relating to identifying and reporting on health problems within their communities. Despite the known benefits of using mobile phone technology to deliver health services, there is limited information on the extent to which Community Health Workers are able to effectively use the technology in data collection and reporting. The aim of this study was to determine the feasibility of utilizing phone-based text messages on Lymphatic Filariasis morbidity surveillance by Community Health Workers.
Methods
This was a cross sectional study whose data was collected through key informant interviews and focused group discussions among community health workers, health providers and staff of neglected tropical diseases control program. Collected transcripts were analysed through Thematic content analysis as it allowed for the identification of data codes through inductive reasoning.
Results
The use of mobile phone-based text messages in data collection and reporting lymphatic filariasis morbidity cases by Community Health Workers was perceived by study participants to be a relevant tool and feasible due to the ease of use of the technology. The tool was reported by end-users to significantly increase their performance and efficiency was gained in terms of reduced paper work, increased the number of patients accessing health care services and the ability to report in real-time. All respondents were confident that Community Health Workers were the right persons to interact with communities in tracking and reporting morbidity cases using mobile technology.
Conclusion
Mobile phone-based text messages have proven to be effective in routine workflows such as, data collection and reporting on Lymphatic Filariasis morbidity cases, patient to provider communication, decision making and supportive supervision. Mobile phones have also improved efficiency and general performance of end users in terms of increased number of cases identified and efficiency gained in terms of reduced paper work and the ability to collect and report in real-time.
Journal Article
Phenotypical characterization, and antibiotics susceptibility patterns of skin bacteria found in podoconiosis patients in the North West Region of Cameroon
by
Ndzeshang, Bertrand Lontum
,
Bonekeh, John
,
Fombad, Fanny Fri
in
Ampicillin
,
Antibiotic
,
Antibiotics
2023
Background
Podoconiosis, a non-infectious disease originating from long-term exposure of bare feet to irritant red clay soil is a lifelong, disabling disease with no specific diagnostic tool, classified into 5 stages based on the severity of leg swelling (lymphoedema). Secondary bacterial infections have been suggested to cause acute dermatolymphangioadenitis (ADLA) attacks and drive disease progression. Although the North West Region of Cameroon has a proven history of podoconiosis endemicity, the bacterial composition of lymphoedema due to this condition has not been studied. Thus, this study investigated the leg bacterial diversity of patients who suffered from the lymphoedema and their susceptibility pattern to selected antibiotics.
Methods
A cross-sectional study was carried out in which podoconiosis affected and non-lymphoedema individuals living in the same community were purposively selected. Samples were collected by swabbing the skin between the toes and around the anklebone, then cultured and sub-cultured on nutrient agar to obtain pure isolates. The cultured isolates were then morphologically and biochemically classified using microscopy and analytic profile index test kits, respectively. The disk diffusion technique was used to determine antibiotic susceptibility.
Results
Thirty-three participants were recruited, and 249 bacterial isolates were characterized into 29 genera, 60 species; with 30 (50%) being gram positive rods, 19 (31.7%) gram positive cocci, and 11 (18.3%) gram negative rods. Thirteen gram positive rods, fifteen gram positive cocci, and eight gram negative rods of bacterial species were found only in podoconiosis individuals among which
Cellulomonas spp / Microbacterium
spp. (2.8%),
Staphylococcus lentus
(3.3%), and
Burkholderia cepacia
(4.0%) dominated. 90% (90%) of the bacterial isolates were sensitive to doxycycline, whereas ampicillin had a high level of intermediate resistance, and penicillin G had the greatest resistant profile.
Conclusion
Our findings show that 94 (37.8%) out of 249 described bacterial isolates were exclusively found in the legs of podoconiosis individuals, and their susceptibility pattern to antibiotics was similar to that of others.
Journal Article