Genomic investigation of atypical malaria cases in Kanel, northern Senegal.

BACKGROUND: The diagnosis of malaria cases in regions where the malaria burden has decreased significantly and prevalence is very low is more challenging, in part because of reduced clinical presumption of malaria. The appearance of a cluster of malaria cases with atypical symptoms in Mbounguiel, a village in northern Senegal where malaria transmission is low, in September 2018 exemplifies this scenario. The collaboration between the National Malaria Control Programme (NMCP) at the Senegal Ministry of Health and the Laboratory of Parasitology and Mycology at Cheikh Anta Diop University worked together to evaluate this cluster of malaria cases using molecular and serological tools. METHODS: Malaria cases were diagnosed primarily by rapid diagnostic test (RDT), and confirmed by photo-induced electron transfer-polymerase chain reaction (PET-PCR). 24 single nucleotide polymorphisms (SNPs) barcoding was used for Plasmodium falciparum genotyping. Unbiased metagenomic sequencing and Luminex-based multi-pathogen antibody and antigen profiling were used to assess exposure to other pathogens. RESULTS: Nine patients, of 15 suspected cases, were evaluated, and all nine samples were found to be positive for P. falciparum only. The 24 SNPs molecular barcode showed the predominance of polygenomic infections, with identifiable strains being different from one another. All patients tested positive for the P. falciparum antigens. No other pathogenic infection was detected by either the serological panel or metagenomic sequencing. CONCLUSIONS: This work, undertaken locally within Senegal as a collaboration between the NMCP and a research laboratory at University of Cheikh Anta Diop (UCAD) revealed that a cluster of malaria cases were caused by different strains of P. falciparum. The public health response in real time demonstrates the value of local molecular and genomics capacity in affected countries for disease control and elimination.

Molecular detection and quantification of Plasmodium falciparum gametocytes carriage in used RDTs in malaria elimination settings in northern Senegal.

BACKGROUND: Malaria surveillance requires powerful tools and strategies to achieve malaria elimination. Rapid diagnostic tests for malaria (RDTs) are easily deployed on a large scale and are helpful sources of parasite DNA. The application of sensitive molecular techniques to these RDTs is a modern tool for improving malaria case detection and drug resistance surveillance. Several studies have made it possible to extract the DNA of Plasmodium falciparum from RDTs. The knowledge of gametocyte carriage in the population is important to better assess the level of parasite transmission in elimination settings. The aim of this study was to detect P. falciparum gametocytes from used RDTs by quantitative PCR for molecular monitoring of malaria transmission. METHODS: DNA was extracted from 303 RDT devices (SD Bioline Malaria Pf) using the Chelex-100 protocol. qPCR was performed in a 20 µL reaction to detect and quantify transcripts of the pfs25 gene. The cycle threshold (Ct) was determined by the emission fluorescence corresponding to the initial amount of amplified DNA. RESULTS: The study found an overall prevalence of 53.47% with an average Ct of 32.12 ± 4.28 cycles. In 2018, the prevalence of gametocytes was higher in the Ranérou district (76.24%) than in the Saint-Louis district (67.33%) where an increase in the number of gametocyte carriers in 2018 was noted, in comparison with 2017. CONCLUSIONS: RDTs are a good source of DNA for molecular monitoring of gametocyte carriage. This method is a simple and effective tool to better understand the level of malaria transmission with a view to elimination.

Mass testing and treatment for malaria followed by weekly fever screening, testing and treatment in Northern Senegal: feasibility, cost and impact.

BACKGROUND: Population-wide interventions using malaria testing and treatment might decrease the reservoir of Plasmodium falciparum infection and accelerate towards elimination. Questions remain about their effectiveness and evidence from different transmission settings is needed. METHODS: A pilot quasi-experimental study to evaluate a package of population-wide test and treat interventions was conducted in six health facility catchment areas (HFCA) in the districts of Kanel, Linguère, and Ranérou (Senegal). Seven adjacent HFCAs were selected as comparison. Villages within the intervention HFCAs were stratified according to the 2013 incidences of passively detected malaria cases, and those with an incidence ≥ 15 cases/1000/year were targeted for a mass test and treat (MTAT) in September 2014. All households were visited, all consenting individuals were tested with a rapid diagnostic test (RDT), and, if positive, treated with dihydroartemisinin-piperaquine. This was followed by weekly screening, testing and treatment of fever cases (PECADOM++) until the end of the transmission season in January 2015. Villages with lower incidence received only PECADOM++ or case investigation. To evaluate the impact of the interventions over that transmission season, the incidence of passively detected, RDT-confirmed malaria cases was compared between the intervention and comparison groups with a difference-in-difference analysis using negative binomial regression with random effects on HFCA. RESULTS: During MTAT, 89% (2225/2503) of households were visited and 86% (18,992/22,170) of individuals were tested, for a combined 77% effective coverage. Among those tested, 291 (1.5%) were RDT positive (range 0-10.8 by village), of whom 82% were < 20 years old and 70% were afebrile. During the PECADOM++ 40,002 visits were conducted to find 2784 individuals reporting fever, with an RDT positivity of 6.5% (170/2612). The combination of interventions resulted in an estimated 38% larger decrease in malaria case incidence in the intervention compared to the comparison group (adjusted incidence risk ratio = 0.62, 95% CI 0.45-0.84, p = 0.002). The cost of the MTAT was $14.3 per person. CONCLUSIONS: It was operationally feasible to conduct MTAT and PECADOM++ with high coverage, although PECADOM++ was not an efficient strategy to complement MTAT. The modest impact of the intervention package suggests a need for alternative or complementary strategies.

Genetic evidence for imported malaria and local transmission in Richard Toll, Senegal.

BACKGROUND: Malaria elimination efforts can be undermined by imported malaria infections. Imported infections are classified based on travel history. METHODS: A genetic strategy was applied to better understand the contribution of imported infections and to test for local transmission in the very low prevalence region of Richard Toll, Senegal. RESULTS: Genetic relatedness analysis, based upon molecular barcode genotyping data derived from diagnostic material, provided evidence for both imported infections and ongoing local transmission in Richard Toll. Evidence for imported malaria included finding that a large proportion of Richard Toll parasites were genetically related to parasites from Thiès, Senegal, a region of moderate transmission with extensive available genotyping data. Evidence for ongoing local transmission included finding parasites of identical genotype that persisted across multiple transmission seasons as well as enrichment of highly related infections within the households of non-travellers compared to travellers. CONCLUSIONS: These data indicate that, while a large number of infections may have been imported, there remains ongoing local malaria transmission in Richard Toll. These proof-of-concept findings underscore the value of genetic data to identify parasite relatedness and patterns of transmission to inform optimal intervention selection and placement.

Correction to: Mass testing and treatment for malaria followed by weekly fever screening, testing and treatment in Northern Senegal: feasibility, cost and impact.

An amendment to this paper has been published and can be accessed via the original article.

Case investigation and reactive case detection for malaria elimination in northern Senegal.

BACKGROUND: Given progress in malaria control in recent years, many control programmes in sub-Saharan Africa will soon be required to strengthen systems for surveillance in order to further drive transmission to zero. Yet few practical experiences are available to guide control programmes in designing surveillance system components in low transmission, pre-elimination, and elimination phases. METHODS: A malaria case investigation programme was piloted for 12 weeks in 2012 in Richard Toll district of northern Senegal. Malaria infections (N = 110) were identified through facility-based passive case detection and investigated within three days. Rapid diagnostic tests (RDT) and a brief questionnaire were administered to 5,520 individuals living within the index case compound or within five neighbouring compounds. RESULTS: In comparison with family and neighbours, index cases were more likely to be male, age 15-49, and to report travel within the past 15 days that entailed an overnight stay. Twenty-three (0.4%) of family/neighbours were RDT-positive. Potential risk factors for infection among family and neighbours were examined, including: sex, age, occupation, travel history, bed net usage, and residence (index vs neighbouring compound). Adjusting for all factors, relative risk (RR) of infection was associated with residence in the index case household (RR = 3.18, p < 0.05) and recent travel, including travel to Dakar (RR = 19.93, p < 0.001), travel within the region (RR = 9.57, p < 0.01), and to other regions in Senegal (RR = 94.30, p < 0.001). Recent fever among RDT-positive family/neighbours was uncommon (30%). Modifications to testing criteria were examined to optimize the efficiency of secondary case investigations in this population. Limiting blood testing to residents of the index case compound and neighbours with recent travel or fever would have identified 20/23 (87%) of the infections through testing 1,173 individuals. Information on the remaining three infections suggests that additional screening for boarding school attendees may facilitate identification of all cases. CONCLUSIONS: The primary risk factor for malaria infection in the low transmission district of Richard Toll is travel. Additional intervention and monitoring strategies to target travellers at risk of malaria infection are needed in this region. Optimizing case investigation with specific targeted testing and treatment of at-risk family and neighbours strengthens the systems needed for continued progress towards malaria elimination in northern Senegal.

Traditional cooking practices and preferences for stove features among women in rural Senegal: Informing improved cookstove design and interventions.

Nearly half the world's population burns solid fuel for cooking, heating, and lighting. The incomplete combustion of these fuels is associated with detrimental health and environmental effects. The design and distribution of improved cookstoves that increase combustion efficiency and reduce indoor air pollution are a global priority. However, promoting exclusive and sustainable use of the improved stoves has proved challenging. In 2012, we conducted a survey in a community in rural Senegal to describe stove ownership and preferences for different stove technologies. This report aims to describe local stove and fuel use, to identify household preferences related to stove features and function, and to elicit the community perceptions of cleaner-burning stove alternatives with a focus on liquid propane gas. Similar to many resource-limited settings, biomass fuel use was ubiquitous and multiple stoves were used, even when cleaner burning alternatives were available; less than 1% of households that owned a liquid propane stove used it as the primary cooking device. Despite nearly universal use of the traditional open fire (92% of households), women did not prefer this stove when presented with other options. Propane gas, solar, and improved cookstoves were all viewed as more desirable when compared to the traditional open fire, however first-hand experience and knowledge of these stoves was limited. The stove features of greatest value were, in order: large cooking capacity, minimal smoke production, and rapid heating. Despite the low desirability and smoke emisions from the traditional open fire, its pervasive use, even in the presence of alternative stove options, may be related to its ability to satisfy the practical needs of the surveyed cooks, namely large cooking capacity and rapid, intense heat generation. Our data suggest women in this community want alternative stove options that reduce smoke exposure, however currently available stoves, including liquid propane gas, do not address all of the cooks' preferences.

Estimating pediatric asthma prevalence in rural senegal: A cross-sectional survey.

RATIONALE: In Senegal, the prevalence of childhood asthma and utilization of appropriate asthma therapies is unknown. METHODOLOGY: We used the International Study of Asthma and Allergies in Childhood (ISAAC) survey instrument to assess childhood respiratory health in rural Senegal. We interviewed the caregivers of children aged 5 through 8 years of age in the four largest Niakhar villages in August 2012. RESULTS: We interviewed 1,103 primary caregivers for 1,513 children, representing 91% of all age-eligible children in the study area. Overall, 206 (14%) children had wheeze at any time in the past, 130 (9%) had wheeze within the past year, and only 41 (3%) reported a clinical diagnosis of asthma. Among children with wheeze within the past year, 81 (62%) had symptoms of severe asthma. Nocturnal cough was reported in 186 (14%) children who denied any history of wheezing illness. Only four (3%) children with wheeze in the past year had ever received bronchodilator therapy. Children with wheeze in the past year were significantly more likely to seek medical care for respiratory symptoms and to be perceived as less healthy than their peers. Children of lower socioeconomic status were significantly more likely to have wheeze. CONCLUSIONS: Nearly one in ten children in Niakhar, Senegal had symptoms suggestive of asthma; however, few children have a diagnosis of asthma or use appropriate therapies. This study highlights an opportunity to raise community awareness of asthma in rural Senegal and to increase access to appropriate medical therapies. Pediatr Pulmonol. 2017;52:303-309. © 2016 Wiley Periodicals, Inc.

Feasibility of utilizing the SD BIOLINE Onchocerciasis IgG4 rapid test in onchocerciasis surveillance in Senegal.

As effective onchocerciasis control efforts in Africa transition to elimination efforts, different diagnostic tools are required to support country programs. Senegal, with its long standing, successful control program, is transitioning to using the SD BIOLINE Onchocerciasis IgG4 (Ov16) rapid test over traditional skin snip microscopy. The aim of this study is to demonstrate the feasibility of integrating the Ov16 rapid test into onchocerciasis surveillance activities in Senegal, based on the following attributes of acceptability, usability, and cost. A cross-sectional study was conducted in 13 villages in southeastern Senegal in May 2016. Individuals 5 years and older were invited to participate in a demographic questionnaire, an Ov16 rapid test, a skin snip biopsy, and an acceptability interview. Rapid test technicians were interviewed and a costing analysis was conducted. Of 1,173 participants, 1,169 (99.7%) agreed to the rapid test while 383 (32.7%) agreed to skin snip microscopy. The sero-positivity rate of the rapid test among those tested was 2.6% with zero positives 10 years and younger. None of the 383 skin snips were positive for Ov microfilaria. Community members appreciated that the rapid test was performed quickly, was not painful, and provided reliable results. The total costs for this surveillance activity was $22,272.83, with a cost per test conducted at $3.14 for rapid test, $7.58 for skin snip microscopy, and $13.43 for shared costs. If no participants had refused skin snip microscopy, the total cost per method with shared costs would have been around $16 per person tested. In this area with low onchocerciasis sero-positivity, there was high acceptability and perceived value of the rapid test by community members and technicians. This study provides evidence of the feasibility of implementing the Ov16 rapid test in Senegal and may be informative to other country programs transitioning to Ov16 serologic tools.

[Secretory breast carcinoma in a man. A case report with rapid evolution unfavorable]. / Carcinome sécrétoire du sein chez l'homme. A propos d'un cas d'évolution rapide.

Secretory carcinoma or juvenile carcinoma of the breast is a very rare tumor of male adults. Generally, it has a good prognosis after locoregional treatment. The authors report an observation of a secretory carcinoma occurring in a 20 year old man. The lesion presented as a voluminous tumor 12 cm in diameter with 3 positive lymph nodes; it was treated by mastectomy and axillary dissection. Tumor developed in a few months, with visceral metastasis and fatal issue. The cytological, histological and immuno-histochemical features necessary to the diagnosis are described. The rapid development of this case of secretory carcinoma is unusual. This leads the authors to propose the use of an additional treatment for adult secretory breast carcinoma with more than 3 positive lymph nodes.

Costs of meningitis sequelae in children in Dakar, Senegal.

BACKGROUND: Survivors of bacterial meningitis risk lifelong sequelae. In economic evaluations of vaccines protecting against meningitis, treatment and productivity costs due to meningitis sequelae are rarely included in studies from low-income countries, mainly due to lack of data. The aim of this study was to estimate the costs of meningitis sequelae in children in Senegal from the perspective of households. METHODS: Children who had suffered from bacterial meningitis were identified from a database at Albert Royer Hospital in Dakar. Sixty-eight children were located at their home and caregivers interviewed about costs during the acute meningitis episode and due to meningitis sequelae, including productivity loss from caring for a disabled child. Lifetime costs were predicted by assuming a life expectancy of 30 years for disabled children. RESULTS: Seventy-one percent of the children had either minor or major sequelae. Mean discounted lifetime sequelae costs amounted to US$ 34,895 (95% confidence interval: US$ 67-96,755) per child. Discounted childcare costs amounted to US$ 3158 (9%), treatment costs US$ 460 (1%) and productivity costs US$ 31,276 (90%). No children were receiving rehabilitation services by the time the study was conducted. CONCLUSION: The present study is the first to present data on household costs from families with disabled children in a low-income country setting. Caring for a disabled child is a considerable financial as well as emotional burden for the individual family. None of the families could afford the treatment they desired for their child.

Effectiveness of haemophilus influenzae type B conjugate vaccine for prevention of meningitis in Senegal.

A total of 24 cases of hospitalized, laboratory-confirmed Haemophilus influenzae type b (Hib) meningitis were identified through a regional pediatric bacterial meningitis surveillance system. Each case was matched by age and residence to 4 neighborhood controls. The adjusted vaccine effectiveness for ≥ 2 doses was 95.8% (95% confidence interval, 67.9%-99.4%). Hib vaccine appears to be highly effective in preventing Hib meningitis in Senegal.

Prospective cohort study of disabling sequelae and quality of life in children with bacterial meningitis in urban Senegal.

BACKGROUND: No studies have prospectively examined disabling sequelae and quality of life in children with bacterial meningitis in Sub-Saharan Africa. METHODS: Objectives were to (i) follow-up pediatric bacterial meningitis surveillance system children from urban Dakar, Senegal; (ii) use standardized tools to classify disabling sequelae (Global Burden of Disease classification system) and quality of life (Pediatric Quality of Life Inventory tool); and (iii) compare these sequelae with an age- and community-matched control group. RESULTS: Sixty-six cases and 66 controls had follow-up examinations. The odds of a major sequelae was 3 times greater in the cases (65.1%, 43/66) than the age- and community-matched control group (40.9%, 27/66) (adjusted odds ratio, 3.24; 95% confidence interval, 1.25-8.38). Hearing loss was the most common major sequelae in the cases (51.8%, 29/56) followed by cognitive deficit (40.0%, 26/65), seizures (21.2%, 14/66), and motor deficit (21.2%, 14/66). Of these cases, 34.9% (23/66) had multiple impairments. The risk of major sequelae was 79.2% (17/22) in children with previous pneumococcal meningitis, 59.1% (14/24) in Haemophilus influenzae type b meningitis, and 54.6% (6/11) in meningococcal meningitis. Total quality of life scores were significantly lower in cases (mean, 69.7; standard deviation, 25.6) than controls (mean, 84.0; standard deviation,: 14.4) (weighted mean difference, 12.98; 95% confidence interval, 6.15-19.82). CONCLUSIONS: Children with bacterial meningitis are at high risk of complex multiple impairments and impaired quality of life. Many of these disabilities could have been averted with use of the new conjugate vaccines against Haemophilus influenzae type b, pneumococcus, and meningococcus.

Hospital surveillance of childhood bacterial meningitis in Senegal and the introduction of Haemophilus influenzae type b conjugate vaccine.

Bacterial meningitis is an important cause of morbidity and mortality in children living in low-resource settings. Pediatric bacterial meningitis cases < 5 years of age were identified through a regional hospital surveillance system for 3 years after introduction of routine immunization with Haemophilus influenzae type b (Hib) conjugate vaccine in Senegal in July 2005. Cases from the national pediatric hospital were also tracked from 2002 to 2008. The regional surveillance system recorded 1,711 suspected pediatric bacterial meningitis cases. Of 214 laboratory-confirmed cases, 108 (50%) were caused by Streptococcus pneumoniae, 42 (20%) to Hib, and 13 (6%) to Neisseria meningitidis. There was a 98% reduction in the number of hospitalized Hib meningitis cases from Dakar Region in 2008 compared with 2002. The surveillance system provides important information to the Ministry of Health as they consider self-funding Hib vaccine and introducing pneumococcal vaccine.