ABSTRACT
Rickettsiae may cause febrile infections in humans in tropical and subtropical regions. From Madagascar, no molecular data on the role of rickettsioses in febrile patients are available. Blood samples from patients presenting with fever in the area of the capital Antananarivo were screened for the presence of rickettsial DNA. EDTA (ethylenediaminetetraacetic acid) blood from 1020 patients presenting with pyrexia > 38.5 °C was analyzed by gltA-specific qPCR. Positive samples were confirmed by ompB-specific qPCR. From confirmed samples, the gltA amplicons were sequenced and subjected to phylogenetic analysis. From five gltA-reactive samples, two were confirmed by ompB-specific qPCR. The gltA sequence in the sample taken from a 38-year-old female showed 100% homology with R. typhi. The other sample taken from a 1.5-year-old infant was 100% homologous to R. felis. Tick-borne rickettsiae were not identified. The overall rate of febrile patients with molecular evidence for a rickettsial infection from the Madagascan study site was 0.2% (2/1020 patients). Flea-borne rickettsiosis is a rare but neglected cause of infection in Madagascar. Accurate diagnosis may prompt adequate antimicrobial treatment.
ABSTRACT
The occurrence of tick-borne relapsing fever and leptospirosis in humans in Madagascar remains unclear despite the presence of their potential vectors and reservoir hosts. We screened 255 Amblyomma variegatum ticks and 148 Rhipicephalus microplus ticks from Zebu cattle in Madagascar for Borrelia-specific DNA. Borrelia spp. DNA was detected in 21 Amblyomma variegatum ticks and 2 Rhipicephalus microplus ticks. One Borrelia found in one Rhipicephalus microplus showed close relationship to Borrelia theileri based on genetic distance and phylogenetic analyses on 16S rRNA and flaB sequences. The borreliae from Amblyomma variegatum could not be identified due to very low quantities of present DNA reflected by high cycle threshold values in real-time-PCR. It is uncertain whether these low numbers of Borrelia spp. are sufficient for transmission of infection from ticks to humans. In order to determine whether spirochaete infections are relevant in humans, blood samples of 1009 patients from the highlands of Madagascar with fever of unknown origin were screened for Borrelia spp. - and in addition for Leptospira spp. - by real-time PCR. No target DNA was detected, indicating a limited relevance of these pathogens for humans in the highlands of Madagascar.
Subject(s)
Arachnid Vectors/microbiology , Borrelia/genetics , DNA, Bacterial/blood , Ixodidae/microbiology , Leptospira/genetics , Leptospirosis/blood , Lyme Disease/blood , Animals , Cattle , DNA, Bacterial/genetics , Humans , Leptospirosis/microbiology , Lyme Disease/microbiology , Madagascar , Phylogeny , RNA, Ribosomal, 16S/genetics , Real-Time Polymerase Chain ReactionABSTRACT
Brucellosis, Q fever and melioidosis are zoonoses, which can lead to pyrexia. These diseases are often under-ascertained and underreported because of their unspecific clinical signs and symptoms, insufficient awareness by physicians and public health officers and limited diagnostic capabilities, especially in low-resource countries. Therefore, the presence of Brucella spp., Coxiella burnetii and Burkholderia pseudomallei was investigated in Malagasy patients exhibiting febrile illness. In addition, we analyzed zebu cattle and their ticks as potential reservoirs for Brucella and C. burnetii, respectively. Specific quantitative real-time PCR assays (qPCRs) were performed on 1020 blood samples drawn from febrile patients. In total, 15 samples (1.5%) were Brucella-positive, mainly originating from patients without travel history, while DNA from C. burnetii and Bu. pseudomallei was not detected. Anti-C. burnetii antibodies were found in four out of 201 zebu serum samples (2%), whereas anti-Brucella antibodies could not be detected. Brucella DNA was detected in a single zebu sample. Three out of 330 ticks analyzed (1%) were positively tested for C. burnetii DNA but with high Ct values in the qPCR assay. Our data suggest that zebus as well as Amblyomma and Boophilus ticks have to be considered as a natural reservoir or vector for C. burnetii, but the risk of cattle-to-human transmission is low. Since bovine brucellosis does not seem to contribute to human infections in Madagascar, other transmission routes have to be assumed.
Subject(s)
Brucellosis/epidemiology , Fever/etiology , Melioidosis/epidemiology , Q Fever/epidemiology , Animals , Antibodies, Bacterial/blood , Brucella , Brucellosis/pathology , Cattle , Coxiella burnetii , Humans , Madagascar , Melioidosis/pathology , Q Fever/pathology , Real-Time Polymerase Chain Reaction , ZoonosesABSTRACT
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) clones pose a significant threat to hospitalised patients because the bacteria can be transmitted by asymptomatic carriers within healthcare facilities. To date, nothing is known about the prevalence of S. aureus and MRSA among healthcare workers in Madagascar. The objective of our study was to examine the prevalence and clonal epidemiology of nasal S. aureus and MRSA among healthcare workers and non-medical University students in Antananarivo, Madagascar. METHODS: This cross sectional study screened nasal swabs taken from students and healthcare workers for S. aureus. Multiplex PCR was performed to identify S. aureus-specific (nuc), MRSA-specific mecA and mecC genes, Panton-Valentine leukocidin (PVL) (lukF-PV), and toxic shock syndrome toxin-1 (TSST-1) specific genes in methicillin-sensitive S. aureus (MSSA) and MRSA isolates. Staphylococcus protein A gene (spa) typing was performed for all confirmed MRSA isolates. The frequency distribution of nasal S. aureus and MRSA of healthcare workers and non-medical students was compared using Pearson's χ(2) test. RESULTS: Of 1548 nasal swabs tested, 171 (11 %) were positive for S. aureus; 20 (1.3 %) of these isolates were identified as MRSA. S. aureus was detected in 91 of 863 healthcare workers (10.4 %) and in 80 (11.8 %) of 685 students; however, 14 (1.5 %) healthcare workers carried MRSA compared with six (0.9 %) students. Nasal carriage of S. aureus and MRSA was more prevalent in women than in men, and 21 (11.7 %) S. aureus isolates were PVL-positive and 36 (21 %) were TSST-1 positive. The mecC gene was not detected in any isolates. Five different spa types were identified, with spa type t186 being the predominant MRSA clone (16/20). CONCLUSION: The results of the present study reveal a low frequency of S. aureus and MRSA nasal carriage in both students and healthcare workers from Antananarivo, Madagascar. The predominant MRSA clone (t186) was previously described in hospitalised patients in Madagascar.
Subject(s)
Methicillin-Resistant Staphylococcus aureus/genetics , Staphylococcal Infections/diagnosis , Staphylococcus aureus/genetics , Adult , Bacterial Toxins/genetics , Cross-Sectional Studies , DNA, Bacterial/isolation & purification , DNA, Bacterial/metabolism , Enterotoxins/genetics , Exotoxins/genetics , Female , Health Personnel , Humans , Leukocidins/genetics , Madagascar/epidemiology , Male , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Multiplex Polymerase Chain Reaction , Nasal Cavity/microbiology , Prevalence , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purification , Students , Superantigens/geneticsABSTRACT
BACKGROUND: Salmonella enterica serovar Typhi is a predominant cause of bloodstream infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance to ciprofloxacin have been reported from different parts of the world. However, data from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility of S. Typhi isolated from patients with febrile illness in SSA. METHODS: Febrile patients from 9 sites within 6 countries in SSA with a body temperature of ≥38.0°C were enrolled in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates were identified biochemically and confirmed by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin (MIC > 0.06 µg/mL) were screened for mutations in quinolone resistance-determining regions in target genes, and the presence of plasmid-mediated quinolone resistance (PMQR) genes was assessed by PCR. RESULTS: A total of 8161 blood cultures were performed, and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27 (0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible (22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected in any isolate. CONCLUSIONS: Salmonella Typhi with reduced susceptibility to ciprofloxacin was not distributed homogenously throughout SSA. Its prevalence was very high in Kenya, and was not observed in other study countries. Continuous monitoring of antimicrobial susceptibility is required to follow the potential spread of antimicrobial-resistant isolates throughout SSA.
Subject(s)
Anti-Bacterial Agents/pharmacology , Ciprofloxacin/pharmacology , Drug Resistance, Bacterial/genetics , Salmonella typhi/drug effects , Typhoid Fever/microbiology , Adolescent , Adult , Africa South of the Sahara/epidemiology , Child , Child, Preschool , Female , Humans , Infant , Male , Microbial Sensitivity Tests , Molecular Epidemiology , Salmonella typhi/genetics , Typhoid Fever/epidemiology , Young AdultABSTRACT
BACKGROUND: The burden of typhoid fever (TF) in sub-Saharan Africa is largely unknown but is increasingly thought to be high, given that water and sanitary conditions remain unimproved in many countries. To address this gap in information, the Typhoid Fever Surveillance in Africa Program (TSAP) founded a surveillance system for TF in 10 African countries. This study was a component of the TSAP surveillance project in Madagascar. METHODS: The study entailed a qualitative assessment of patients' experiences and perceptions of services for febrile symptoms at the studies' rural and urban sentinel public health clinics. The study examined influences on the use of these facilities, alternative sources of care, and providers' descriptions of medical consultations and challenges in providing services. Data were collected through semistructured and open-ended individual interviews and a focus group with patients, caregivers, and medical personnel. RESULTS: Thirty-three patients and 12 healthcare providers participated in the data collection across the 2 healthcare facilities. The quality of services, cost, and travel distance were key factors that enabled access to and use of these clinics. Divergent healthcare-seeking patterns were related to variability in the care utilized, socioeconomic status, and potential distance from the facilities : These factors influenced delivery of care, patient access, and the health facilities' capacity to identify cases of febrile illness such as TF. CONCLUSIONS: This approach provided an in-depth investigation and understanding of healthcare-seeking behavior at the study facilities, and factors that facilitated or acted as barriers to their use. Our findings demonstrate the relevance of these public health clinics as sites for the surveillance of TF in their role as central healthcare sources for families and communities within these rural and urban areas of Madagascar.
Subject(s)
Health Services Accessibility/statistics & numerical data , Typhoid Fever/epidemiology , Typhoid Fever/psychology , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Madagascar/epidemiology , Male , Middle Aged , Public Health Surveillance , Qualitative Research , Typhoid Fever/therapy , Young AdultABSTRACT
Tick-borne spotted fever group (SFG) rickettsioses are emerging infectious diseases in Sub-Saharan Africa. In Madagascar, the endemicity of tick-borne rickettsiae and their vectors has been incompletely studied. The first part of the present study was conducted in 2011 and 2012 to identify potential anthropophilic tick vectors for SFG rickettsiae on cattle from seven Malagasy regions, and to detect and characterize rickettsiae in these ticks. Amblyomma variegatum was the only anthropophilic tick species found on 262 cattle. Using a novel ompB-specific qPCR, screening for rickettsial DNA was performed on 111 A. variegatum ticks. Rickettsial DNA was detected in 96 of 111 ticks studied (86.5%). Rickettsia africae was identified as the only infecting rickettsia using phylogenetic analysis of ompA and ompB gene sequences and three variable intergenic spacers from 11 ticks. The second part of the study was a cross-sectional survey for antibodies against SFG rickettsiae in plasma samples taken from healthy, pregnant women at six locations in Madagascar, two at sea level and four between 450 and 1300m altitude. An indirect fluorescent antibody test with Rickettsia conorii as surrogate SFG rickettsial antigen was used. We found R. conorii-seropositives at all altitudes with prevalences between 0.5% and 3.1%. Our results suggest that A. variegatum ticks highly infected with R. africae are the most prevalent cattle-associated tick vectors for SFG rickettsiosis in Madagascar. Transmission of SFG rickettsiosis to humans occurs at different altitudes in Madagascar and should be considered as a relevant cause of febrile diseases.
Subject(s)
Antibodies, Bacterial/blood , Ixodidae/microbiology , Pregnancy Complications, Infectious/microbiology , Rickettsia Infections/microbiology , Rickettsia/isolation & purification , Adult , Animals , Female , Humans , Madagascar/epidemiology , Phylogeny , Pregnancy , Pregnancy Complications, Infectious/blood , Pregnancy Complications, Infectious/epidemiology , Rickettsia/genetics , Rickettsia Infections/epidemiologyABSTRACT
BACKGROUND: The clinical diagnosis of bacterial bloodstream infections (BSIs) in sub-Saharan Africa is routinely confused with malaria due to overlapping symptoms. The Typhoid Surveillance in Africa Program (TSAP) recruited febrile inpatients and outpatients of all ages using identical study procedures and enrollment criteria, thus providing an opportunity to assess disease etiology and pretreatment patterns among children and adults. METHODS: Inpatients and outpatients of all ages with tympanic or axillary temperatures of ≥38.0 or ≥37.5°C, respectively, and inpatients only reporting fever within the previous 72 hours were eligible for recruitment. All recruited patients had one blood sample drawn and cultured for microorganisms. Data from 11 TSAP surveillance sites in nine different countries were used in the analysis. Bivariate analysis was used to compare frequencies of pretreatment and BSIs in febrile children (<15 years old) and adults (≥15 years old) in each country. Pooled Cochran Mantel-Haenszel odds ratios (ORs) were calculated for overall trends. RESULTS: There was no significant difference in the odds of a culture-proven BSI between children and adults among inpatients or outpatients. Among both inpatients and outpatients, children had significantly higher odds of having a contaminated blood culture compared with adults. Using country-pooled data, child outpatients had 66% higher odds of having Salmonella Typhi in their bloodstream than adults (OR, 1.66; 95% confidence interval [CI], 1.01-2.73). Overall, inpatient children had 59% higher odds of pretreatment with analgesics in comparison to inpatient adults (OR, 1.59; 95% CI, 1.28-1.97). CONCLUSIONS: The proportion of patients with culture-proven BSIs in children compared with adults was similar across the TSAP study population; however, outpatient children were more likely to have Salmonella Typhi infections than outpatient adults. This finding points to the importance of including outpatient facilities in surveillance efforts, particularly for the surveillance of typhoid fever. Strategies to reduce contamination among pediatric blood cultures are needed across the continent to prevent the misdiagnosis of BSI cases in children.
Subject(s)
Bacteremia/epidemiology , Salmonella Infections/epidemiology , Typhoid Fever/prevention & control , Adolescent , Adult , Africa South of the Sahara/epidemiology , Age Factors , Bacteremia/diagnosis , Bacteremia/microbiology , Child , Child, Preschool , Female , Fever/etiology , Hospitalization , Humans , Inpatients/statistics & numerical data , Malaria/epidemiology , Male , Outpatients/statistics & numerical data , Prevalence , Salmonella Infections/microbiology , Salmonella typhi/isolation & purification , Time-to-Treatment , Typhoid Fever/epidemiology , Typhoid Fever/microbiology , Young AdultABSTRACT
This study assesses the nasal occurrence of ß-lactamase-producing Enterobacteriaceae both in patients in a hospital department of infectious diseases at admission and in healthy Madagascan students and health care workers. Nasal swabs from 681 students, 824 health care workers, and 169 patients were obtained in Antananarivo, Madagascar, and transferred to Germany. Screening for ß-lactamase (ESBL, ampC) producing Enterobacteriaceae was performed by cultural and molecular approaches, comprising Brilliance ESBL agar, E-testing, ABCD-testing, and commercial hyplex ESBL and SuperBug ID PCR. Regarding ESBL-positive strains and strains with resistance against at least three out of the four tested bactericidal antibiotic drugs, 0.3% (five out of 1541) of the students and health care workers group showed nasal colonization, whereas colonization was observed in 7.1% (12 out of 169) of the hospitalized patients at admission. No appreciably reduced detection rates after sample storage and intercontinental transport were observed. A considerable proportion of nasal colonization with cephalosporin-resistant Enterobacteriaceae was demonstrated in Madagascan hospital patients at admission, posing a risk of developing future endogenous infections. The nasal colonization of healthy individuals was negligible. Good storage and transport stability of Enterobacteriaceae will allow for future studies even in areas difficult to access.