Elimination of gambiense human African trypanosomiasis (gHAT) as a public health problem has been reached or is in sight in a number of endemic foci and the next step is now to reach the elimination of transmission. The ability to detect Trypanosomabruceigambiense (T.b.gambiense) in both the last human cases and in a suspected animal reservoir becomes increasingly important to reach this goal. We have evaluated here the diagnostic performance of the AnTat A/B and LiTat A/B primers in comparison with the TBR, TgsGP and nested TgsGP PCRs that are currently used for the molecular diagnosis of gHAT. The evaluation was based on serial DNA dilutions from two T.b.gambiense strains for sensitivity, purified reference strains for specificity and field strains isolated from pigs in Côte d'Ivoire for field application. Results showed that the two PCRs (AnTat A/B and LiTat A/B) are not specific for T.b.gambiense, limiting their relevance for studies on suspected animal reservoirs. However, they could represent complementary tools to improve the molecular diagnosis of gHAT in the elimination process even if the detection limit was lowest than for the TgsGP PCR. The results also once more suggest that nested TgsGP PCR should be interpreted with caution as they may lead to an over-estimation of the T.b.gambiense prevalence particularly in animal studies.

Toxoplasma gondii, responsible for toxoplasmosis, is one of the worldwide prevalent parasitic zoonoses infecting warm-blooded animals including humans with cats being the definitive host. Congenital transmission can occur and leads to congenital toxoplasmosis, which may result in foetal or neonatal death, or severe malformations. In this study, we aimed to determine the seroprevalence and associated factors among pregnant women in a rural setting of Burkina Faso. We conducted a cross-sectional study from December 2020 to March 2021 in the Nanoro health district area. Women attending antenatal care for the first time at the selected health centers were enrolled in the study. For each participant, socio-demographic and clinical data were collected through a questionnaire. In addition, venous blood was drawn for the detection and avidity determination of IgG antibodies to T. gondii by enzyme-linked immunosorbent assay. Logistic regression was used to identify factors associated with seropositivity. Out of 416 participants, 37.3

Seasonal malaria chemoprevention (SMC) is an effective malaria preventive intervention in sub-Sahara Africa. However, as with any other drug-based intervention, the large-scale deployment of this strategy could lead to Amodiaquine plus Sulfadoxine-Pyrimethamine (AQSP) drug pressure on the circulating parasites population with selection for specific alleles that could compromise the impact of the intervention in the near future. This study aimed to assess the distribution of the Pfmdr1 mutation involved in resistance to AQ before and after the annual campaign of SMC in the health district of Nanoro. Randomly selected dried blood spots collected prior (n = 100) and after (n = 100) the 2021 SMC campaign were used for the detection of mutation in codons 86 and 184 of the Pfmdr1 gene using a nested PCR with restriction fragment length polymorphism approach. No significant change in the prevalence of Pfmdr1 N86Y mutation was observed before and after the SMC campaign (p = 0.28). The mutant allele 86Y was observed at low prevalences, representing only 2.17

The skin is an anatomical reservoir for African trypanosomes, yet the prevalence of extravascular parasite carriage in the population at risk of gambiense Human African Trypanosomiasis (gHAT) remains unclear. Here, we conducted a prospective observational cohort study in the HAT foci of Forecariah and Boffa, Republic of Guinea. Of the 18,916 subjects serologically screened for gHAT, 96 were enrolled into our study. At enrolment and follow-up visits, participants underwent a dermatological examination and had blood samples and superficial skin snip biopsies taken for examination by molecular and immuno-histological methods. In seropositive individuals, dermatological symptoms were significantly more frequent as compared to seronegative controls. Trypanosoma brucei DNA was detected in the blood of 67% of confirmed cases (22/33) and 9% of unconfirmed seropositive individuals (3/32). However, parasites were detected in the extravascular dermis of up to 71% of confirmed cases (25/35) and 41% of unconfirmed seropositive individuals (13/32) by PCR and/or immuno-histochemistry. Six to twelve months after treatment, trypanosome detection in the skin dropped to 17% of confirmed cases (5/30), whereas up to 25% of unconfirmed, hence untreated, seropositive individuals (4/16) were still found positive. Dermal trypanosomes were observed in subjects from both transmission foci, however, the occurrence of pruritus and the PCR positivity rates were significantly higher in unconfirmed seropositive individuals in Forecariah. The lower sensitivity of superficial skin snip biopsies appeared critical for detecting trypanosomes in the basal dermis. These results are discussed in the context of the planned elimination of gHAT.

Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense cause human African trypanosomiasis (HAT), a neglected tropical disease that constitutes an important public health issue in sub-Saharan Africa. In the absence of a vaccine, only chemotherapy and vector control has been used to combat the disease. Environmental factors, such as exposure to infected tsetse files, and genetic factors such as variants in the APOL1 gene have been shown to contribute to the risk of developing HAT. However, the known factors only explain a small part of the risk of developing trypanosomiasis. We have undertaken a genome wide association study (GWAS) using 3813 samples from T. b. gambiense and T.b. rhodesiense HAT foci in Guinea, Côte d’Ivoire, Cameroon, DRC, Malawi and Uganda. 2141 samples were genotyped on the H3Africa SNP chip followed by a genotyping a validation cohort of an additional 1,627 samples at candidate loci. After the primary and validation studies we identified a novel locus near SMOC2 with genome-wide significance. We also identified suggestive associations near NXN, NTNG1 and NCKAP5 that have stronger associations with disease susceptibility than the APOL1 loci that has been previously identified by hypothesis driven approaches. These genes offer new entry points for future studies of the underlying genetic mechanisms of HAT.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThis work was supported by Human Heredity and Health in Africa (H3Africa) programme under Wellcome Trust grant number 099310/Z/12/Z and H3Africa grant number H3A-18- 004. H3Africa is managed by the Science for Africa Foundation (SFA Foundation) in partnership with Wellcome, NIH and AfSHG. The views expressed herein are those of the author(s) and not necessarily those of the SFA Foundation and her partners.### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The Minister de la Sante Publique (Democratic Republic of Congo) gave ethical approval for this work No 1/2013; Ministere de la Sante et de la Lutte Contre le SIDA of Cote d'Ivoıre gave ethical approval for this work; Uganda Vector Control Division Research Ethics Committee (Ministry of Health), gave ethical approval for this work ; Uganda National Council for Science and Technology HS 1344 gave ethical approval for this work; Comite Consultatif de Deontologie et d'Ethique [CCDE] de l'Institut de Recherche pour le Developpement: gave ethical approval for this work; 1-22/04/2013; Cameroon (Le Comite National d'Ethique de la Recherche pour la Sante Humain: 2013/364/L/CNERSH/ SP), Comite National D'Ethique et de la Recherche 2014/No 38/ MSLS/CNER-dkn) gave ethical approval for this work Malawi National Health Sciences Research Committee, protocol numbers NHSRC15/4/1399 and Malawi 1213 gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors

Asymptomatic carriers of Plasmodium falciparum represent important parasite reservoirs maintaining malaria transmission in the community. This study aimed on the one hand to screen the other household members living with children under seasonal malaria chemoprevention (SMC) coverage in order to determine the level of malaria infection in this population and on the other hand to determine the appropriate type of rapid diagnostic test (RDT) for this screening to detect these asymptomatic carriers in the community. During the 2022 SMC campaign (July to October), a cross-sectional survey was carried out in 745 participants who were screened by ultrasensitive rapid diagnostic test (usRDT), standard rapid diagnostic test (rRDT) and microscopy. Out of them, 395 had microscopy results available and were included in the data analysis. The prevalence of asymptomatic carriers of asexual forms of Plasmodium falciparum was 26.58% (105/395) while sexual forms were found in 5.32% (21/395) of the study population. Children from 5 to 15 years had the highest prevalence of P. falciparum asexual forms 35.76% (59/165) compared with older participants. Malaria positivity rate for rRDT and usRDT was 29.40% (219/745) and 40.49% (305/745) respectively. The usRDT had a higher sensitivity than the rRDT (72.38% (95% CI 62.8-80.66) vs. 60.95% (95% CI 50.94-70.33)). In terms of specificity, rRDT had a higher specificity 82.41% (95% CI 77.53-86.62) versus 69.66% (95% CI 64.01-74.89) for usRDT. This study reports a high prevalence of parasite carriers in household members of children under SMC coverage in Nanoro, Burkina Faso. In conclusion, usRDT seems more appropriate for strategies based on detection and treatment of parasite carriers within the community.

Trichinellosis is a serious zoonotic disease with worldwide distribution caused by parasitic nematodes of the genus Trichinella. If not well managed, this can lead to complications and death. Data in Burkina Faso are scarce. Therefore, this study aimed to assess the seroprevalence and risk factors of Trichinella infection in Burkina Faso. This was a cross-sectional study where pregnant women attending antenatal care were enrolled after signature of an informed consent. Serum samples of 418 pregnant women were collected and stored at the Clinical Research Unit of Nanoro. Anti-Trichinella spiralis IgG Human ELISA Kit was used to test the samples at the Luxembourg Institute of Health. Anthropometric, clinical and socio-demographic data were collected using a structured questionnaire and Chi-square and Student t-tests were used to compare groups. The p-value significance threshold was set at 0.05. Overall, the seroprevalence of Trichinellosis was 2.4% (10/418). The baseline characteristics analysis showed associations between Trichinella seropositive pregnant women and factors such as body mass index (BMI) and gravidity. Individuals identified as Trichinella seropositive were not previously diagnosed and have not been treated for Trichinella infection with any specific therapy. A low seroprevalence of Trichinella infection was found in our study area. Efforts for continuous education in trichinellosis prevention are necessary.

Introduction: Human filariasis causes high morbidity and severe illness. There is a link between helminth infection and anemia. The objective of this study was to estimate the prevalence of blood-dwelling microfilariae among pregnant women in Burkina Faso using a molecular technique and attempt to find an association between anemia and filarial infection. Methods: A total of 1018 dried blood spot samples (DBS) were collected from pregnant women at the Health District of Nanoro. The DNA was isolated from DBS samples using a rapid and simple method. Afterward, the isolated DNA was assayed using the Filaria real-time PCR (F-RT-PCR) method. Results: Ten F-RT-PCR-positive samples were obtained as follows: two W. bancrofti (0.2%), four L. loa (0.39%), and four M. perstans (0.39%). No concomitant filarial infections were detected, as well as no coinfections between filarial disease and malaria. There was no link between the presence of W. bancrofti, L. loa, or M. perstans and anemia in pregnant women. Conclusions: The prevalence and intensity of human filariasis in this study were low for all of the samples in which microfilariae were detected. The F-RT-PCR can be a confirmatory test for diagnosis in remote areas due to its effectiveness in detecting and differentiating, both sensitively and specifically, a wide range of filarial parasites.

Background Human African trypanosomiasis (HAT) is an important disease of sub-Saharan Africa that is approaching elimination in many regions. However, the disease has previously returned from similarly low case numbers in the past, making it important to identify issues that hinder elimination efforts. One important factor is likely to be the recent characterization of individuals with latent HAT infections that are able to tolerate HAT with few symptoms and to control blood parasitaemia to levels that are undetectable by microscopy. Although animal trypanotolerance has been examined in detail, it is unclear how the latent phenotype is maintained in humans.Methods To identify immune components involved in latent HAT, we used targeted RNASeq to examine the expression of 495 immune-related transcripts in blood collected from 287 individuals at active disease foci in Guinea. These samples included latent infections, HAT clinical cases, and uninfected controls. The in vivo effects of IL21 functional blockade was investigated using a murine model of trypanosomiasis.Results Differential expression analysis revealed transcripts involved in T cell activation and B cell development that associated with trypanosome infection, including PD1 , CD70 , and CD80 . In particular, IL21 was found to be elevated in infected individuals, although it was significantly higher in clinical cases relative to latent infections. This pattern was replicated at the protein level when patient sera were examined by ELISA. Reducing IL21 pathway activity in mice infected with Trypanosoma brucei led to increased survivorship and reduced parasitaemia in the model animals.Conclusion Our data show that IL21 is a potential biomarker of Human African Trypanosomiasis and is a cause rather than a consequence of symptoms severity. Further investigation of IL21 will contribute to understanding the factors involved in developing latent HAT, improving control efforts to identify and predict such infections. In the future, the factors identified in this study may also serve as intervention targets to control the symptoms of trypanosomiasis.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementPC, AC, AML were funded by a Wellcome Senior Fellowship to AML (209511/Z/17/Z). BB was funded by IRD. WJK, HN and HI, were supported through the Human Hereditary and Health in Africa (H3Africa) [H3A/18/004]. The second phase of the Wellcome component of H3Africais being implemented by the African Academy of Sciences (AAS) and the NEPAD Agency's Alliance for Accelerating Excellence in Science in Africa (AESA) in partnership with Wellcome.### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:All investigations on humans were conducted in accordance with the Declaration of Helsinki. Participants were identified through healthcare providers, community engagement and active surveillance campaigns led by the national contral program, Ministry of Health Guinea. Written informed consents for sample collection, analysis and publication of anonymised data was obtained from all participants by trained local healthcare workers. Subjects or their legal guardian gave consent as a signature or a thumbprint after receiving standardized information in French or their local langage as preferred. Ethical approvals for the study was obtained from within the TrypanoGEN Project following H3Africa Consortium guidelines for informed consent and from Comite Consultatif de Deontologie et ethique (CCDE) at the Institut de recherche pour le Developpent (IRD; 10/06/2013). Research procedures were also approved by the University of Glasgow MVLS Ethics Committee for Non-Clinical Research Involving Human Subjects (Reference no. 200120043). All animal experiments were approved by the University of Glasgow Ethical Review Committee and performed in accordance with the UK Home Office guidelines, UK Animals (Scientific Procedures) Act, 1986 and EU directive 2010/63/EU. All experiments were conducted under SAPO regulations and UK Home Office project licence number PC8C3B25C to Dr. Jean Rodgers. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors and the TrypanoGEN network (H3Africa)

Abstract Background Passive diagnosis of human African trypanosomiasis (HAT) at the health facility level is a major component of HAT control in Guinea. We examined which clinical signs and symptoms are associated with HAT, and assessed the performance of selected clinical presentations, of rapid diagnostic tests (RDT), and of reference laboratory tests on dried blood spots (DBS) for diagnosing HAT in Guinea. Method The study took place in 14 health facilities in Guinea, where 2345 clinical suspects were tested with RDTs (HAT Sero-K-Set, rHAT Sero-Strip, and SD Bioline HAT). Seropositives underwent parasitological examination (reference test) to confirm HAT and their DBS were tested in indirect enzyme-linked immunoassay (ELISA)/Trypanosoma brucei gambiense, trypanolysis, Loopamp Trypanosoma brucei Detection kit (LAMP) and m18S quantitative PCR (qPCR). Multivariable regression analysis assessed association of clinical presentation with HAT. Sensitivity, specificity, positive and negative predictive values of key clinical presentations, of the RDTs and of the DBS tests for HAT diagnosis were determined. Results The HAT prevalence, as confirmed parasitologically, was 2.0% (48/2345, 95% CI: 1.5–2.7%). Odds ratios (OR) for HAT were increased for participants with swollen lymph nodes (OR = 96.7, 95% CI: 20.7–452.0), important weight loss (OR = 20.4, 95% CI: 7.05–58.9), severe itching (OR = 45.9, 95% CI: 7.3–288.7) or motor disorders (OR = 4.5, 95% CI: 0.89–22.5). Presence of at least one of these clinical presentations was 75.6% (95% CI: 73.8–77.4%) specific and 97.9% (95% CI: 88.9–99.9%) sensitive for HAT. HAT Sero-K-Set, rHAT Sero-Strip, and SD Bioline HAT were respectively 97.5% (95% CI: 96.8–98.1%), 99.4% (95% CI: 99.0–99.7%) and 97.9% (95% CI: 97.2–98.4%) specific, and 100% (95% CI: 92.5–100.0%), 59.6% (95% CI: 44.3–73.3%) and 93.8% (95% CI: 82.8–98.7%) sensitive for HAT. The RDT’s positive and negative predictive values ranged from 45.2–66.7% and 99.2–100% respectively. All DBS tests had specificities ≥ 92.9%. While LAMP and m18S qPCR sensitivities were below 50%, trypanolysis and ELISA/T.b. gambiense had sensitivities of 85.3% (95% CI: 68.9–95.0%) and 67.6% (95% CI: 49.5–82.6%). Conclusions Presence of swollen lymph nodes, important weight loss, severe itching or motor disorders are simple but accurate clinical criteria for HAT referral in HAT endemic areas in Guinea. Diagnostic performances of HAT Sero-K-Set and SD Bioline HAT are sufficient for referring positives to microscopy. Trypanolysis on DBS may discriminate HAT patients from false RDT positives. Trial registration The trial was registered under NCT03356665 in clinicaltrials.gov (November 29, 2017, retrospectively registered https://clinicaltrials.gov/ct2/show/NCT03356665 ) Graphical Abstract

Abstract Background In rural African settings, most of the children under the coverage of Seasonal Malaria Chemoprevention (SMC) are also undernourished at the time of SMC delivery, justifying the need for packaging malarial and nutritional interventions. This study aimed at assessing the impact of SMC by coupling the intervention with nutrients supplementation for preventing malaria in children less than 5 years old in Burkina Faso. Methods A randomized trial was carried out between July 2020 and June 2021 in the health district of Nanoro, Burkina Faso. Children (n = 1059) under SMC coverage were randomly assigned to one of the three study arms SMC + Vitamin A (SMC-A, n = 353) or SMC + Vitamin A + Zinc (SMC-AZc, n = 353) or SMC + Vitamin A + PlumpyDoz(tm) (SMC-APd, n = 353)-a medium quantity—lipid-based nutrient supplement (MQ-LNS). Children were followed up for one year that included an active follow-up period of 6 months with scheduled monthly home visits followed by 6 months passive follow-up. At each visit, capillary blood sample was collected for malaria diagnosis by rapid diagnosis test (RDT). Results Adding nutritional supplements to SMC had an effect on the incidence of malaria. A reduction of 23% (adjusted IRR = 0.77 (95%CI 0.61–0.97) in the odds of having uncomplicated malaria in SMC-APd arm but not with SMC-AZc arm adjusted IRR = 0.82 (95%CI 0.65–1.04) compare to control arm was observed. A reduction of 52%, adjusted IRR = 0.48 (95%CI 0.23–0.98) in the odds of having severe malaria was observed in SMC-APd arm compared to control arm. Besides the effect on malaria, this combined strategy had an effect on all-cause morbidity. More specifically, a reduction of morbidity odds of 24%, adjusted IRR = 0.76 (95%CI 0.60–0.94) in SMC-APd arm compared to control arm was observed. Unlike clinical episodes, no effect of nutrient supplementation on cross sectional asymptomatic infections was observed. Conclusion Adding nutritional supplements to SMC significantly increases the impact of this intervention for preventing children from malaria and other childhood infections. Trial registration: NCT04238845.

Background Elimination of gambiense Human African Trypanosomiasis (gHAT) as public health problem has been achieved in countries like Côte d’Ivoire and Burkina Faso. The World Health Organization (WHO) has set targets for interruption of transmission of gHAT by 2030. In this context, the performance of diagnostic algorithms for early detection of HAT re-emergence remains to be assessed. Methods Our study represents a further step in the analysis on 8,648 dried blood spots collected during HAT rapid diagnostic tests (RDT) screening in gHAT historical foci in South West Burkina Faso and Centre West Côte d’Ivoire. We assessed the specificity of three molecular tests on 1,000 randomly selected samples from each country. We performed the Trypanozoon subgenus-specific m18S qPCR and RIME LAMP and the Trypanosoma brucei gambiense-specific TgsGP qPCR. Results No parasites were detected using parasitological investigations. The overall seroprevalence based on positivity to at least one RDT was 1.19% (103/8648, (0.83–1.55%). The specificities of m18S qPCR and TgsGP qPCR were 99% (990/1,000, 98.9–99.8%) and 99.8% (998/1,000, 95.5–100%) respectively. The RIME LAMP test was negative for all 1,000 specimens (specificity 100%). Conclusion All molecular tests qPCR m18S, qPCR TgsGP and RIME LAMP showed high diagnostic specificity. A previous study demonstrated low analytical sensitivities for qPCR m18S and qPCR TgsGP (respectively 1,000 and 10,000 trypanosomes/mL) while that of the RIME LAMP (100 trypanosomes/mL) was in the range of parasitaemias commonly observed in HAT patients. However, none of the three tests was entirely suitable for high-throughput use. To decide what is the best algorithm for HAT post-elimination monitoring, data on costs for all possible algorithms including serological and parasitological diagnostics need to be considered, according to the epidemiological context. Funding from the EDCTP2 Programme supported by the European Union (Project DRIA-2014-306-DiTECT-HAT).

Background The burden of MiP remains high with adverse effects on the health of both women and their offspring. In endemic areas, pregnant women are generally asymptomatic with low parasitemia which can be missed by malaria RDTs, but affecting the pregnancy course. We postulate that proactive screening with highly-sensitive RDTs (HS-RDT) and treatment of those found infected using dihydroartemisinin piperaquine (DP), in addition to standard intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) could improve maternal and infant health. Methods Pregnant women with gestational age of 16 to 24 weeks were randomized to receive screening and treatment with DP and IPTp-SP or IPTp-SP alone until delivery. Biological samples were collected for participant management and study purposes. Primary and secondary end- points were the prevalence of placental malaria, maternal anemia, maternal peripheral infection, and low birth weight. Results Malaria infection was detected in almost one on four (1/4) of the pregnant women at recruitment. No difference was found between study arms in terms of placental malaria infection (adjusted odds ratio, 1.54 [95% confidence interval, 0.95–2.53]; P = 0.082). At delivery, the prevalence of peripheral maternal infection was slightly lower in the intervention group compared to the one of the control group but the difference was not statistically significant. Increasing number of IPTp-SP doses was associated with a significantly lower risk of peripheral malaria infection and low birth weight. Conclusion Pregnant women should initiate antenatal care as soon as possible in order to fully benefit of malaria preventives measures. Strategies addressing late attendance to ANC with early start of IPTp-SP among eligible pregnant women should be developed and implemented. Funding: This project is part of the EDCTP2 programme supported by the European Union (grant number TMA2018CDF-2397-ASSER MALARIA)

Seasonal Malaria chemoprevention (SMC) is one of the large-scale life-saving malaria interventions initially recommended for the Sahel subregion, including Burkina Faso and recently extended to other parts of Africa. Initially, SMC was restricted to children 3 to 59 months old, but an extension to older children in some locations was recently recommended. Further characterization of SMC population profile beyond age criterion is necessary for understanding factors that could negatively impact the effectiveness of the intervention and to define complementary measures that could enhance its impact. Children were assessed through a cross-sectional survey during the first month of the 2020 SMC campaign (July-August 2020) as part of the SMC-NUT project in the health district of Nanoro. Parameters such as body temperature, weight, height, mid-upper arm circumference (MUAC) were assessed. In addition, blood sample was collected for malaria diagnosis by rapid diagnostic tests (RDT) and microscopy, and for haemoglobin measurement. A total of 1059 children were enrolled. RDT positivity rate (RPR) was 22.2%, while microscopy positivity rate (MPR) was 10.4%, with parasitaemia levels ranging from 40 to 70480/μL. RPR and MPR increased as patient age increased. Wasting was observed in 7.25% of children under SMC coverage while the prevalence of stunting and underweight was 48.79% and 23.38%, respectively. As the age of the children increased, an improvement in their nutritional status was observed. Finally, undernourished children had higher parasite densities than children with adequate nutritional status. In the health district of Nanoro, children who received Seasonal Malaria Chemoprevention (SMC) were mostly undernourished during the period of SMC delivery, suggesting the need for combining the SMC with synergistic interventions against malnutrition to achieve best impact.

The boom in Burkina Faso’s artisanal gold mining since 2007 has attracted populations from Côte d'Ivoire and Guinea, which are the West African countries most affected by human African trypanosomiasis (HAT) and therefore increases its risk of re-emergence. Our aim was to update the HAT data in Burkina Faso in the risk of the re-emergence context with the advent of artisanal gold mining. The study was carried out in the southwestern Burkina Faso where entomological surveys were conducted using biconical traps in March 2017. Follow by an active medical survey in April 2017, which was targeted the gold panners in 7 villages closer to artisanal gold sites, using CATT, mini-anion exchange centrifugation technique, trypanolysis test (TL) and ELISA test to measure human/tsetse contacts. The buffy coat technique and the TL were also applied in pigs to check their reservoir role of human trypanosomes. Our results have shown no case of HAT among 958 individuals tested and all the 50 pigs were also negative, but the level of antibodies against tsetse saliva evidenced by ELISA revealed low human/tsetse contact. Moreover, gold panners practise agriculture and breeding in an infected tsetse area, which are increased the risk. Our results illustrate that the risk of re-emergence is low. The passive surveillance system implemented in 2015 in southwestern Burkina Faso is needed to increase the sentinel sites to better cover this area by taking into account the gold mining. Finally, awareness-raising activities are needed among populations about HAT.

The World Health Organisation has targeted the elimination of human African trypanosomiasis (HAT) as zero transmission by 2030. Continued surveillance needs to be in place for early detection of re-emergent cases. In this context, the performance of diagnostic tests and testing algorithms for detection of the re-emergence of Trypanosoma brucei gambiense HAT remains to be assessed. We carried out a door-to-door active medical survey for HAT in the historical focus of Batié, South–West Burkina Faso. Screening was done using three rapid diagnostic tests (RDTs). Two laboratory tests (ELISA/T. b. gambiense and immune trypanolysis) and parasitological examination were performed on RDT positives only. In total, 5883 participants were screened, among which 842 (14%) tested positive in at least one RDT. Blood from 519 RDT positives was examined microscopically but no trypanosomes were observed. The HAT Sero-K-Set test showed the lowest specificity of 89%, while the specificities of SD Bioline HAT and rHAT Sero-Strip were 92% and 99%, respectively. The specificity of ELISA/T. b. gambiense and trypanolysis was 99% (98–99%) and 100% (99–100%), respectively. Our results suggest that T. b. gambiense is no longer circulating in the study area and that zero transmission has probably been attained. While a least cost analysis is still required, our study showed that RDT preselection followed by trypanolysis may be a useful strategy for post-elimination surveillance in Burkina Faso.

Background Malaria infection during pregnancy (MIP) is not only deleterious to the woman, but it also puts her fetus at increased risk of adverse outcomes, such as preterm delivery, low birth weight, and intrauterine growth retardation. Additionally, all-cause mortality during the first year of life in babies born to women with malaria during pregnancy is also increased. Many interventions such as IPTp-SP and long-lasting insecticidal nets have proven to be efficient at reducing malaria in pregnancy burden but adherence to recommended policies remains poor. In sub-Saharan Africa, malaria in pregnancy is often asymptomatic and many malaria infections may be missed due to the inadequate performance of the current rapid diagnostic test to detect low-level parasitemias. Therefore, additional strategies such as intermittent screening with ultrasensitive rapid diagnostic tests and treatment with an effective artemisinin-based combination therapy in addition to IPTp-SP could reduce placental malaria, peripheral malaria infection at delivery, and low birth weight. Methods This pilot 2-group randomized open trial with a nested qualitative social behavioral will be carried out in Nanoro district in which 340 pregnant women will be recruited. Pregnant women will be randomized into two groups and followed on a monthly basis until delivery. In the intervention group, monthly screening using ultrasensitive rapid diagnostic tests and treatment of those found to be infected with dihydroartemisinin-piperaquine will be performed. In addition, a reminder will be sent to increase the uptake of IPTp-SP doses per woman. During scheduled and unscheduled visits, malaria infection, hemoglobin level, and other clinical outcomes will be assessed and compared by the group. The primary feasibility outcome will evaluate the study site's capacity to enroll participants and the women’s perception and acceptability of the intervention. The primary clinical outcome will be the prevalence of placental malaria at delivery. Discussion The present protocol aims to evaluate the feasibility on a large-scale and also to demonstrate the impact and the operational feasibility of additional screening with ultrasensitive rapid diagnostic tests and treatment with DHA-PQ on placental malaria, low birth weight, and peripheral malaria infection at delivery in a high-burden setting in Burkina Faso. Trial registration ClinicalTrials.gov , ID: NCT04147546 (14 October 2019).

After intensive control efforts, human African trypanosomiasis (HAT) was declared eliminated in Côte d'Ivoire as a public health problem in December 2020 and the current objective is to achieve the interruption of the transmission (zero cases). Reaching this objective could be hindered by the existence of an animal reservoir of Trypanosoma (T.) brucei (b.) gambiense. In the framework of a study led in 2013 to assess the role of domestic animals in the epidemiology of HAT in the two last active foci from Côte d'Ivoire (Bonon and Sinfra), plasmas were sampled from four species of domestic animals for parasitological (microscopic examination by the buffy coat technique (BCT)), serological (immune trypanolysis (TL)) and molecular (specific PCR: TBR for T. brucei s.l., TCF for T. congolense forest type, TVW for T. vivax and PCR for T. b. gambiense) testing. In order to improve the understanding of the involvement/role of these animals in the transmission of T. b. gambiense, we have quantified in this study the IgG response to whole saliva extracts of Glossina palpalis gambiensis in order to perform an association analysis between anti-saliva responses and the positivity of diagnostic tests. Cattle and pigs had significantly higher rates of anti-tsetse saliva responses compared to goats and sheep (p < 0.01). In addition, the anti-tsetse saliva responses were strongly associated with the parasitology (BCT+), serology (TL+) and PCR (TBR+ and TCF+) results (p < 0.001). These associations indicate a high level of contacts between the positive/infected animals and tsetse flies. Our findings suggest that protecting cattle and pigs against tsetse bites could have a significant impact in reducing transmission of both animal and human trypanosome species, and advocates for a "One health" approach to better control African trypanosomosis in Côte d'Ivoire.

Abstract Background Plasmodium falciparum malaria remains a major public health concern in sub-Sahara Africa. Seasonal malaria chemoprevention (SMC) with amodiaquine + sulfadoxine-pyrimethamine is one of the most important preventive interventions. Despite its implementation, the burden of malaria is still very high in children under five years old in Burkina Faso, suggesting that the expected impact of this promising strategy might not be attained. Development of innovative strategies to improve the efficacy of these existing malaria control measures is essential. In such context, we postulate that screening and treatment of malaria in household members of children receiving SMC could greatly improve the impact of SMC intervention and reduce malaria transmission in endemic settings. Methods This randomized superiority trial will be carried out in the Nanoro health district, Burkina Faso. The unit of randomisation will be the household and all eligible children from a household will be allocated to the same study group. Households with 3–59 months old children will be assigned to either (i) control group (SMC alone) or (ii) intervention (SMC+ screening of household members with standard Histidin Rich Protein Rapid Diagnostic Test (HRP2-RDT) and treatment if positive). The sample size will be 526 isolated households per arm, i.e., around 1052 children under SMC coverage and an expected 1315 household members. Included children will be followed-up for 24 months to fully cover two consecutive malaria transmission seasons and two SMC cycles. Children will be actively followed-up during the malaria transmission seasons while in the dry seasons the follow-up will be passive. Conclusion The study will respond to a major public health concern by providing evidence of the efficacy of an innovative strategy to boost the impact of SMC intervention.

Background. The diagnosis of gambiense human African trypanosomiasis (gHAT) typically involves 2 steps: a serological screen, followed by the detection of living trypanosome parasites in the blood or lymph node aspirate. Live parasites can, however, remain undetected in some seropositive individuals, who, we hypothesize, are infected with Trypanosoma brucei gambiense parasites in their extravascular dermis. Methods. To test this hypothesis, we conducted a prospective observational cohort study in the gHAT focus of Forecariah, Republic of Guinea. Of the 5417 subjects serologically screened for gHAT, 66 were enrolled into our study and underwent a dermatological examination. At enrollment, 11 seronegative, 8 unconfirmed seropositive, and 18 confirmed seropositive individuals had blood samples and skin biopsies taken and examined for trypanosomes by molecular and immunohistological methods. Results. In seropositive individuals, dermatological symptoms were significantly more frequent, relative to seronegative controls. T.b. gambiense parasites were present in the blood of all confirmed cases (n = 18) but not in unconfirmed seropositive individuals (n = 8). However, T. brucei parasites were detected in the extravascular dermis of all unconfirmed seropositive individuals and all confirmed cases. Skin biopsies of all treated cases and most seropositive untreated individuals progressively became negative for trypanosomes 6 and 20 months later. Conclusions. Our results highlight the skin as a potential reservoir for African trypanosomes, with implications for our understanding of this disease's epidemiology in the context of its planned elimination and underlining the skin as a novel target for gHAT diagnostics.