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1.
Med Trop Sante Int ; 4(1)2024 03 31.
Article in French | MEDLINE | ID: mdl-38846122

ABSTRACT

Objective: To determine the etiology of cervico-vaginal infections by cytobacteriology and the efficacy of qPCR for the diagnosis of sensitive strains such as Streptococcus agalactiae, Borrelia crocidurae, Chlamydia trachomatis, Neisseria gonorrhoeae and Treponema pallidum. Methodology: This prospective cross-sectional study was performed between January and September 2021 in 346 women who were examined for cervico-vaginal infection at the Hôpital Principal de Dakar (HPD). Cytobacteriological (direct examination, agar culture) and molecular analyses were performed. Results: Vaginal flora imbalances predominated, with a rate of 72.3%. The proportion of type IV vaginal flora was 46.5%. Of the 199 germs isolated, Candida albicans (25.1%), Ureaplasma urealyticum (17.6%), S. agalactiae (7.8%), Gardnerella vaginalis (6.6%) and nonalbicans Candida (5.5%) were the main pathogens responsible for cervico-vaginal infections in patients. Among women tested for mycoplasma, U. urealyticum was identified in 43.3% of patients. Among those tested for C. trachomatis, the proportion of infected women was low (4%). The prevalence of C. albicans was higher in pregnant women (38.3%) than in nonpregnant women (19.2%). S. agalactiae strains showed high resistance to certain beta-lactam antibiotics (pristinamycin 100%, gentamycin 100%, ampicillin 92.5% and cefalotin 85.2%) and to a glycopeptide antibiotic (vancomycin 100%). The Staphylococcus aureus strain had good sensitivity to antibiotics except gentamycin (100%) and kanamycin (100%). The enterobacteria tested were all sensitive to phenicols, carbapenems, cephalosporins and aminoglycosides. However, E. coli showed high resistance to tetracycline. The different methods showed low prevalences of C. trachomatis and N. gonorrhoeae, so comparisons Test RapidChlamydia/qPCR for C. trachomatis and culture/qPCR for N. gonorrhoeae were not possible. For S. agalactiae, on the other hand, qPCR was more advantageous than culture. The χ2 test showed a significant difference (Yates χ2 = 33.77 and p = 1-7) for the diagnosis of S. agalactiae. S. agalactiae qPCR had a sensitivity of 40.7%, a specificity of 94%, and positive and negative predictive values of 36.7% and 94.9% respectively, as well as a kappa = 0.33. Conclusion: The methods applied enabled us to identify the pathogens that cause cervicovaginal infections. The results suggest that qPCR may be an alternative, at least for the diagnosis of S. agalactiae. However, culture remains indispensable for studying antibiotic sensitivity. In order to improve patient care, molecular techniques need to be integrated into the HPD testing toolbox. To broaden the repertoire of pathogens to be diagnosed by qPCR, targeted comparison studies will be needed to increase the probability of encountering infected individuals.


Subject(s)
Real-Time Polymerase Chain Reaction , Humans , Female , Senegal/epidemiology , Cross-Sectional Studies , Adult , Prospective Studies , Young Adult , Real-Time Polymerase Chain Reaction/methods , Middle Aged , Adolescent , Vaginitis/microbiology , Vaginitis/epidemiology , Vaginitis/diagnosis , Vaginitis/drug therapy
3.
J Infect Public Health ; 17(5): 922-928, 2024 May.
Article in English | MEDLINE | ID: mdl-38579539

ABSTRACT

BACKGROUND: The surveillance of respiratory pathogens in rural areas of West Africa has, to date, largely been focussed on symptoms. In this prospective study conducted prior to the COVID-19 pandemic, we aimed to assess the asymptomatic prevalence of respiratory pathogen carriage in a group of individuals living in a rural area of Senegalese. METHODS: Longitudinal follow up was performed through monthly nasopharyngeal swabbing during the dry season and weekly swabbing during the rainy season. We enrolled 15 individuals from the village of Ndiop. A total of 368 nasopharyngeal swabs were collected over a one-year period. We investigated the prevalence of 18 respiratory viruses and eight respiratory bacteria in different age groups using singleplex and multiplex PCR. RESULTS: In total, 19.56% of the samples (72/368) were positive for respiratory viruses and 13.60% of the samples (50/368) were positive for respiratory bacteria. Coronaviruses (19/72, 26.39%), adenoviruses (17/72, 23.61%), rhinoviruses (14/72, 19.44%), Streptococcus pneumoniae (17/50, 34%), and Moraxella catarrhalis (15/50, 30%) were the most frequently detected viruses. Interestingly, the carriage of respiratory pathogens was shown to be more frequent during the rainy season, as pluviometry was shown to be positively associated with the occurrence of respiratory viruses such as influenza (P = .0078, r2 =.523) and RSV (P = .0055, r2 =.554). CONCLUSIONS: Our results show a non-negligible circulation of respiratory pathogens in a rural area in Senegal (West Africa) with an underestimated proportion of asymptomatic individuals. This study highlights the fact that the circulation of viruses and bacteria in the community has been overlooked.


Subject(s)
Respiratory Tract Infections , Viruses , Humans , Infant , Seasons , Senegal/epidemiology , Prospective Studies , Pandemics , Nasopharynx , Bacteria
4.
Int J Infect Dis ; 141: 106952, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38336005

ABSTRACT

OBJECTIVES: Influenza is frequent among pilgrims participating in the Grand Magal de Touba (GMT), in Senegal, with a potential to spread to contacts when they return home. METHODS: Ill pilgrims consulting at a health care center in Mbacké city close to Touba during the 2021 GMT, pilgrims returning to Dielmo and Ndiop villages, and patients who did not travel to Touba and consulted at health care centers in these two villages in 2021 were tested for the influenza virus by polymerase chain reaction on nasopharyngeal samples. Next-generation sequencing and comparative and phylogenetic analyses of influenza A virus genomes were performed. RESULTS: A total of 62 of 685 patients tested positive for influenza A virus, including 34 of 53 who were consulted in Mbacké in late September, six of 129 pilgrims who returned home in early October, and 20 of 42 villagers from October 3 to 29. A total of 27 genomes were obtained. Four clusters were observed based on the phylogenetic analyses, suggesting that Mbacké patients and returned pilgrims may have shared closely related viral strains with patients inhabiting the villages who did not participate in the GMT. CONCLUSIONS: Villagers in Ndiop and Dielmo may have been infected with viral strains originating from the GMT and possibly imported by pilgrims who returned from the GMT.


Subject(s)
Influenza, Human , Humans , Influenza, Human/epidemiology , Senegal/epidemiology , Phylogeny , Epidemiologic Studies , Real-Time Polymerase Chain Reaction , Genomics
5.
EClinicalMedicine ; 67: 102379, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38188691

ABSTRACT

Background: Despite significant progress in malaria control over the past twenty years, malaria remains a leading cause of child morbidity and mortality in Tropical Africa. As most patients do not consult any health facility much uncertainty persists about the true burden of the disease and the range of individual differences in susceptibility to malaria. Methods: Over a 25-years period, from 1990 to 2015, the inhabitants of Dielmo village, Senegal, an area of intense malaria transmission, have been monitored daily for their presence in the village and the occurrence of diseases. In case of fever thick blood films were systematically examined through microscopy for malaria parasites and patients received prompt diagnosis and treatment. Findings: We analysed data collected in 111 children and young adults monitored for at least 10 years (mean 17.3 years, maximum 25 years) enrolled either at birth (95 persons) or during the two first years of life. A total of 11,599 episodes of fever were documented, including 5268 malaria attacks. The maximum number of malaria attacks in a single person was 112. Three other persons suffered one hundred or more malaria attacks during follow-up. The minimum number of malaria attacks in a single person was 11. The mean numbers of malaria attacks in children reaching their 4th, 7th, and 10th birthdays were 23.0, 37.7, and 43.6 attacks since birth, respectively. Sixteen children (14.4%) suffered ten or more malaria attacks each year at ages 1-3 years, and six children (5.4%) each year at age 4-6 years. Interpretation: Long-term close monitoring shows that in highly endemic areas the malaria burden is higher than expected. Susceptibility to the disease may vary up to 10-fold, and for most children childhood is an endless history of malaria fever episodes. No other parasitic, bacterial or viral infection in human populations has such an impact on health. Funding: The Pasteur Institutes of Dakar and Paris, the Institut de Recherche pour le Développement, and the French Ministry of Cooperation provided funding.

6.
Am J Trop Med Hyg ; 110(2): 391-398, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38109763

ABSTRACT

Respiratory infections, mainly due to viruses, are among the leading causes of worldwide morbidity and mortality. We investigated the prevalence of viruses and bacteria in a cross-sectional survey conducted in Dielmo, a village in rural Senegal with a population of 481 inhabitants. Nasopharyngeal sampling was performed in 50 symptomatic subjects and 101 asymptomatic subjects. Symptomatic subjects were defined as individuals presenting with clinical signs of respiratory infection, whereas asymptomatic subjects were recruited in the same households. The identification of pathogens was performed by polymerase chain reaction for 18 respiratory viruses and eight respiratory bacteria. The prevalence results for respiratory viruses detected in each study group demonstrated that 83.6% of symptomatic samples were positive for at least one respiratory virus, and 21.8% were detected in asymptomatic samples. Influenza A (P = 0.0001), metapneumovirus (P = 0.04), and enterovirus (P = 0.001) were significantly more prevalent in symptomatic patients. Overall, 82.0% of symptomatic subjects and 26.9% of asymptomatic subjects were positive for at least one respiratory bacterium. The most frequent pathogenic bacteria detected were Moraxella catarrhalis (56%) and Streptococcus pneumoniae (48.0%) among symptomatic individuals, whereas in asymptomatic subjects Corynebacterium propinquum was more prevalent (18%). A principal component analysis showed that parainfluenzas 2 and 4 were associated with asymptomatic subjects, whereas influenza A was associated with the presence of symptoms. Considering these results, a large epidemiological surveillance of the circulation of these respiratory pathogens in the general population should be conducted to provide a better understanding of their carriage and to potentially prevent epidemics.


Subject(s)
Influenza, Human , Microbiota , Respiratory Tract Infections , Viruses , Humans , Infant , Influenza, Human/epidemiology , Cross-Sectional Studies , Viruses/genetics , Nasopharynx , Bacteria/genetics
7.
Article in English | MEDLINE | ID: mdl-37578895

ABSTRACT

Bartonella species are involved in various human diseases, causing a range of clinical manifestations; animals are considered as the main reservoirs, transmitting diverse species of Bartonella through direct contact and haematophagous insects. Here, we characterize a new species, Bartonella raoultii sp. nov., within the genus Bartonella, using a taxonogenomic polyphasic approach. Strain 094T (= CSUR B1097T=DSM 28004T), isolated from the blood of an infected rodent (Mastomys erythroleucus) in Senegal, is an aerobic and rod-shaped bacterium. The annotated non-contiguous genome sequence is 1 952322 bp long and contains 37.2 mol% G+C content, 1686 protein-coding genes and 50 RNA genes, including seven rRNA genes.


Subject(s)
Bartonella , Animals , Humans , Senegal , Base Composition , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , Phylogeny , Sequence Analysis, DNA , Bacterial Typing Techniques , Fatty Acids/chemistry , Murinae/genetics
10.
Am J Trop Med Hyg ; 108(5): 968-976, 2023 05 03.
Article in English | MEDLINE | ID: mdl-36913922

ABSTRACT

In endemic malaria areas, Plasmodium is currently diagnosed mainly through the use of rapid diagnostic tests (RDTs). However, in Senegal, many causes of fever remain unknown. Tick-borne relapsing fever, an often-neglected public health problem, is the main cause of consultation for acute febrile illness after malaria and flu in rural areas. Our objective was to test the feasibility of extracting and amplifying DNA fragments by quantitative polymerase chain reaction (qPCR) from malaria-negative RDTs for Plasmodium falciparum (malaria Neg RDTs P.f) to detect Borrelia spp. and other bacteria. Between January and December 2019, malaria Neg RDTs P.f were collected on a quarterly basis in 12 health facilities in four regions of Senegal. The DNA extracted from the malaria Neg RDTs P.f was tested using qPCR and the results were confirmed by standard PCR and sequencing. Only Borrelia crocidurae DNA was detected in 7.22% (159/2,202) of RDTs. The prevalence of B. crocidurae DNA was higher in July (16.47%, 43/261) and August (11.21%, 50/446). The annual prevalence was 9.2% (47/512) and 5.0% (12/241) in Ngayokhem and Nema-Nding, respectively, health facilities in the Fatick region. Our study confirms that B. crocidurae infection is a frequent cause of fever in Senegal, with a high prevalence of cases in health facilities in the regions of Fatick and Kaffrine. Malaria Neg RDTs P.f are potentially a good source of pathogen sampling for the molecular identification of other causes of fever of unknown origin, even in the most remote areas.


Subject(s)
Borrelia , Malaria, Falciparum , Malaria , Relapsing Fever , Humans , Relapsing Fever/diagnosis , Relapsing Fever/epidemiology , Relapsing Fever/microbiology , Senegal/epidemiology , Rapid Diagnostic Tests , Borrelia/genetics , Malaria/diagnosis , Malaria, Falciparum/diagnosis , Fever , Polymerase Chain Reaction/methods , Diagnostic Tests, Routine
11.
Travel Med Infect Dis ; 52: 102515, 2023.
Article in English | MEDLINE | ID: mdl-36470351

ABSTRACT

BACKGROUND: Respiratory and gastrointestinal symptoms and febrile illness are the most common complaints among ill pilgrims attending the Grand Magal of Touba (GMT) in Senegal. METHODS: Patients presenting with respiratory or gastrointestinal symptoms or febrile systemic illnesses were recruited between 2018 and 2021 at a healthcare centre close to Touba. Respiratory, gastrointestinal and blood samples were tested for potential pathogens using qPCR. RESULTS: 538 patients were included. 45.5% of these were female, with a median age of 17 years. Of the 326 samples collected from patients with a cough, 62.8% tested positive for at least one virus, including influenza viruses (33.1%). A high positivity rate of bacterial carriage was observed for Haemophilus influenzae (72.7%), Streptococcus pneumoniae (51.2%) and Moraxella catarrhalis (46.0%). Of the 95 samples collected from patients with diarrhoea, 71.3% were positive, with high rates of bacterial carriage, ranging from 4.2% for Tropheryma whipplei to 45.3% for Entero-pathogenic Escherichia coli. Of the 141 blood samples collected from patients with fever, 31.9% were positive including Plasmodium falciparum (21.3%), Borrelia sp. (5.7%) and dengue virus (5.0%). CONCLUSION: This study provides insight into the aetiology of most common infections at the GMT on which to base therapeutic options.


Subject(s)
Respiratory Tract Infections , Streptococcus pneumoniae , Humans , Female , Adolescent , Male , Streptococcus pneumoniae/genetics , Bacteria , Moraxella catarrhalis/genetics , Polymerase Chain Reaction , Delivery of Health Care , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology
12.
Clin Infect Dis ; 76(8): 1382-1390, 2023 04 17.
Article in English | MEDLINE | ID: mdl-36571112

ABSTRACT

BACKGROUND: Louse-borne trench fever caused by Bartonella quintana is a neglected public health concern, known to be transmitted from body louse feces via scratching. No viable B. quintana have ever been isolated from head lice before; therefore, their role as a vector is still poorly understood. METHODS: In Senegal, the implementation of a permanent local surveillance system in a point-of-care laboratory (POC) allows the monitoring of emerging diseases. Here we used culture as well as molecular and genomic approaches to document an outbreak of trench fever associated with head lice in the village of Ndiop. Head lice and blood samples were collected from febrile patients between November 2010 and April 2015. Genomes of 2 isolated strains of B. quintana were sequenced and analyzed. RESULTS: A total of 2289 blood samples were collected in the 2010-2015 period. From 2010-2013, B. quintana DNA was detected by polymerase chain reaction (PCR) in 0.25% (4/1580). In 2014, 228 blood samples were collected, along with 161 head lice from 5 individuals. B. quintana DNA was detected in 4.4% (10/228) of blood samples, and in lice specimens collected from febrile patients (61.7%, 50/81) and non-febrile patients (61.4%, 43/70). Two B. quintana strains were isolated from blood and head lice from 2 different patients. Genomic sequence analysis showed 99.98% overall similarity between both strains. CONCLUSIONS: The presence of live B. quintana in head lice, and the genetic identity of strains from patients' blood and head lice during a localized outbreak in Senegal, supports the evidence of head lice vectorial capacity.


Subject(s)
Bartonella quintana , Lice Infestations , Pediculus , Trench Fever , Animals , Humans , Bartonella quintana/genetics , Pediculus/genetics , Trench Fever/epidemiology , Senegal/epidemiology , Lice Infestations/epidemiology , Disease Outbreaks , DNA
13.
J Infect Dis ; 226(6): 1075-1083, 2022 09 21.
Article in English | MEDLINE | ID: mdl-35776143

ABSTRACT

BACKGROUND: Rickettsia felis is emergent in tropical areas. Despite its high morbidity, its natural history has not yet been fully determined. We investigated the role of the common household booklouse, Liposcelis bostrychophila, recently found to harbor R. felis. METHODS: Blood samples from 372 febrile patients from Senegalese villages, as well as nasal and skin samples from 264 asymptomatic individuals, were tested for cat flea-associated and booklice-associated strains of R. felis. Dust samples from beds were collected to isolate booklice and R. felis. Mice were infected with aerosol of R. felis strain from naturally infected booklice. RESULTS: Forty febrile patients (11%) were infected by R. felis, including 26 (7%) by the booklice-associated strain. Nine nasal samples (3.4%) and 28 skin samples (10.6%) contained R. felis, including 7 and 24, respectively, with the booklice-associated strain. The presence of live L. bostrychophila was observed in 32 dust samples (16.8%); R. felis was identified in 62 dust samples (32.5%). Several mice samples were positive for R. felis; interstitial lymphohistiocytic infiltrates were identified in lungs. CONCLUSIONS: Liposcelis bostrychophila may be a reservoir of R. felis. The booklice-associated strain is pathogenic in mammals, causing pneumonia. Human infection may be acquired via inhalation of infected booklice particles.


Subject(s)
Felis , Pneumonia , Rickettsia felis , Animals , Dust , Humans , Mammals , Mice
14.
J Med Entomol ; 59(3): 1019-1032, 2022 05 11.
Article in English | MEDLINE | ID: mdl-35286393

ABSTRACT

Bed bugs are known to carry several microorganisms. The purpose of this study was to assess the prevalence of bed bug infestation in two rural areas of Senegal and determine the species present in the population. A screening was conducted to detect some arthropod associated pathogenic bacteria in bed bugs and to evaluate the prevalence of endosymbiont carriage. One survey took place in 17 villages in Niakhar and two surveys in Dielmo and Ndiop and surroundings area in the same 20 villages. Bed bugs collected were identified morphologically and by MALDI-TOF MS tools. Microorganisms screening was performed by qPCR and confirmed by sequencing. During the survey in the Niakhar region, only one household 1/255 (0.4%) in the village of Ngayokhem was found infested by bed bugs. In a monitoring survey of the surroundings of Dielmo and Ndiop area, high prevalence was found during the two rounds of surveys in 65/314 (21%) in 16/20 villages (January-March) and 93/351 (26%) in 19/20 villages (December). All bed bugs were morphologically identified as the species Cimex hemipterus, of which 285/1,637 (17%) were randomly selected for MALDI-TOF MS analysis and bacteria screening. Among the Bacteria tested only Wolbachia (Alphaproteobacteria, Rickettsiales, Rickettsiaceae) DNA was found in 248/276 (90%) of the bedbugs. We briefly describe a high level of non-generalized bed bug infestation in rural Senegal and the diversity of Wolbachia strains carried by C. hemipterus. This study opens perspectives for raising household awareness of bed bug infestations and possibilities for appropriate control.


Subject(s)
Bedbugs , Ectoparasitic Infestations , Wolbachia , Animals , Bedbugs/anatomy & histology , Senegal , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
16.
Vector Borne Zoonotic Dis ; 21(9): 659-666, 2021 09.
Article in English | MEDLINE | ID: mdl-34534024

ABSTRACT

Q fever and tick-borne borreliosis are two zoonotic diseases rarely diagnosed in Senegalese health facilities, particularly in rural areas. Our study aims to better understand the circulation of Coxiella burnetii and Borrelia spp. DNA on human skin and the domestic environment in rural areas. Cutaneous swabs were taken from febrile patients being treated for borreliosis and/or Q fever, the members of patients' households and control households in the Niakhar area. Dust samples were also collected from 90 households where 54 cases of borreliosis and Q fever were reported as well as from the households of members of control populations in Dielmo, Ndiop, and Niakhar. C. burnetii and Borrelia spp. DNA were detected by quantitative PCR in cutaneous swabs and dust samples targeting spacers IS1111_IS30A and Bor 16S gene. Of 1365 persons tested, 76 were shown to carry C. burnetii, 13 Borrelia spp., and 6 were identified as carrying both C. burnetii and Borrelia spp. The prevalence of Borrelia spp. DNA in households was 16.7% in Dielmo, 6.7% in Ndiop, and 23.3% in all other villages in the Niakhar area, and the presence of C. burnetii in the same localities was 10%, 13.3% and 66.7%, respectively. Furthermore, C. burnetii genotyping identified the presence of Multispacer Sequence Typing group 6. These results revealed for the first time the carriage on the skin of C. burnetii and Borrelia spp. DNA in humans and its wide distribution across households. Our findings suggest that many populations are exposed to these diseases, with frequent contaminating cases of infectious origin arising from the domestic environment.


Subject(s)
Borrelia , Coxiella burnetii , Q Fever , Animals , Borrelia/genetics , Coxiella burnetii/genetics , DNA , Dust , Humans , Q Fever/veterinary , Senegal/epidemiology
17.
PLoS Negl Trop Dis ; 15(6): e0009555, 2021 06.
Article in English | MEDLINE | ID: mdl-34185789

ABSTRACT

BACKGROUND: Severe acute malnutrition (SAM) is a major public health problem affecting children under the age of five in many low- and middle-income countries, and its resolution would contribute towards achieving the several sustainable development goals. The etiology of SAM is pluri-factorial, including delayed maturation of the gut microbiota, suboptimal feeding practices and dysfunctional breastfeeding. The recent serendipitous detection of Listeria monocytogenes in the breast milk of Malian women, in contrast to French women, suggests a possible association with SAM. METHODOLOGY/ PRINCIPAL FINDINGS: To investigate the possible association of L. monocytogenes carriage in breast milk and SAM, a case-control study was performed in Senegal, with subjects recruited from two areas. Using 16S amplicon sequencing, a culture independent method, 100% (152/152) of the mothers were positive for L. monocytogenes in their breast milk while qPCR analysis gave lower recovery rates. Interestingly, after enrichment in Fraser broth and seeding on PALCALM agar, all 10 isolated strains were isolated from the milk of 10 mothers who had SAM children which also had a significantly increased relative abundance of L. monocytogenes (0.34 (SD 0.35) vs 0.05 (SD 0.07) in controls, p<0.0001). The high genomic similarity between these strains and Malian breast milk strains from a previous study supports the hypothesis of endemic clone carriage in West Africa. Moreover, the in vitro growth inhibition of L. monocytogenes using breast milk samples was obtained from only 50% of the milk of mothers who had SAM children, in contrast to control samples which systematically inhibited the growth of L. monocytogenes with a higher inhibition diameter (15.7 mm (SD 2.3) in controls versus 3.5 mm (SD 4.6) in SAM, p = 0.0001). Lactobacillus and Streptococcus isolated from the breast milk of controls inhibit L. monocytogenes in a species-dependent manner. CONCLUSIONS/SIGNIFICANCE: Our study reveals a previously unsuspected carriage of L. monocytogenes in the breast milk of West African women, which is associated with SAM. The inhibitory effect of human selected lactic acid bacterial species against L. monocytogenes might provide new therapeutic and inexpensive options to prevent and treat this neglected public health issue.


Subject(s)
Listeria monocytogenes/isolation & purification , Listeriosis/epidemiology , Milk, Human/microbiology , Severe Acute Malnutrition/epidemiology , Adult , Case-Control Studies , Child, Preschool , Female , Humans , Infant , Lactobacillus , Listeria monocytogenes/genetics , Male , RNA, Ribosomal, 16S , Senegal , Streptococcus
18.
PLoS Negl Trop Dis ; 15(4): e0009184, 2021 04.
Article in English | MEDLINE | ID: mdl-33886571

ABSTRACT

BACKGROUND: Tick-borne relapsing fever (TBRF) is the most common vector-borne bacterial disease in humans in West Africa. It is frequently clinically confused with malaria. Our study aims to determine, on a micro-geographic scale, the conditions for the maintenance and spread of TBRF in the Niakhar district of Senegal. METHODOLOGY/PRINCIPAL FINDINGS: We conducted clinical, entomological and animal reservoir investigations. Field surveys were carried out in order to investigate the presence of Ornithodoros sonrai vector ticks and to detect Borrelia spp. by qPCR using the 16S rRNA and glpQ genes, respectively. Micromammal trapping series were carried out inside homes and Borrelia infection was detected using brain tissue qPCR. Capillary blood samples from febrile patients were also tested for Borrelia using qPCR. More than 97% (40/41) of the villages surveyed were infested with O. sonrai ticks. The prevalence of Borrelia spp. infections in ticks was 13% (116/910), and over 73% (85/116) were positively confirmed as being Borrelia crocidurae. Borreliosis cases accounted for 12% (94/800) of episodes of fever and all age groups were infected, with children and young people between the ages of 8-14 and 22-28 being the most infected by the disease (16% and 18.4%). TBRF cases occurred in all seasons, with a peak in August. In two species of small rodents that were found to be infected (Arvicanthis niloticus, Mus musculus), the proportion of Borrelia infection was 17.5% (10/57), and the highest prevalence of infection (40.9%, 9/22) was observed in A. niloticus. CONCLUSION/SIGNIFICANCE: Our study indicates that TBRF is an endemic disease in the Niakhar district, where children and young people are the most infected. Arvicanthis niloticus and O. sonrai ticks are massively present and appear to be the main epidemiological reservoirs causing its extensive spread to humans.


Subject(s)
Blood/microbiology , Borrelia/isolation & purification , Endemic Diseases , Relapsing Fever/veterinary , Animals , Borrelia/classification , Borrelia/genetics , Disease Vectors , Humans , Ornithodoros , Public Health , RNA, Ribosomal, 16S , Relapsing Fever/epidemiology , Rodentia , Senegal/epidemiology
19.
Int J Infect Dis ; 105: 470-471, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33434665

ABSTRACT

In the context of the coronavirus disease-2019 (COVID-19) pandemic, all mass gathering (MG) events have been cancelled. The Grand Magal took place on October 6, 2020, in Touba, Senegal, which was the only MG event organized in 2020. This Muslim pilgrimage gathers about four million Muslim Mourides from Senegal and beyond. No significant increase in COVID-19 cases was therefore observed at the national level in the weeks following the Grand Magal. This successful strategy is an invitation to better promote community commitments by public authorities in their various strategies.


Subject(s)
COVID-19/epidemiology , Islam , Pandemics , Communicable Disease Control , Crowding , Humans , Public Health , SARS-CoV-2 , Senegal/epidemiology , Travel
20.
Int J Mol Sci ; 21(21)2020 Oct 29.
Article in English | MEDLINE | ID: mdl-33138055

ABSTRACT

The symbiotic Wolbachia are the most sophisticated mutualistic bacterium among all insect-associated microbiota. Wolbachia-insect relationship fluctuates from the simple facultative/parasitic to an obligate nutritional-mutualistic association as it was the case of the bedbug-Wolbachia from Cimexlectularius. Understanding this association may help in the control of associated arthropods. Genomic data have proven to be reliable tools in resolving some aspects of these symbiotic associations. Although, Wolbachia appear to be fastidious or uncultivated bacteria which strongly limited their study. Here we proposed Drosophila S2 cell line for the isolation and culture model to study Wolbachia strains. We therefore isolated and characterized a novel Wolbachia strain associated with the bedbug Cimexhemipterus, designated as wChem strain PL13, and proposed Wolbachiamassiliensis sp. nov. strain wChem-PL13 a type strain of this new species from new supergroup T. Phylogenetically, T-supergroup was close to F and S-supergroups from insects and D-supergroup from filarial nematodes. We determined the 1,291,339-bp genome of wChem-PL13, which was the smallest insect-associated Wolbachia genomes. Overall, the wChem genome shared 50% of protein coding genes with the other insect-associated facultative Wolbachia strains. These findings highlight the diversity of Wolbachia genotypes as well as the Wolbachia-host relationship among Cimicinae subfamily. The wChem provides folate and riboflavin vitamins on which the host depends, while the bacteria had a limited translation mechanism suggesting its strong dependence to its hosts. However, the clear-cut distinction between mutualism and parasitism of the wChem in C. hemipterus cannot be yet ruled out.


Subject(s)
Bacterial Proteins/genetics , Bedbugs/microbiology , Genome, Bacterial , Symbiosis/genetics , Wolbachia/classification , Animals , Genomics , Phylogeny , Wolbachia/genetics , Wolbachia/isolation & purification
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