Charles Emile Ramarokoto

Epidemiology of methicillin-susceptible Staphylococcus aureus lineages in five major African towns: high prevalence of Panton-Valentine leukocidin genes

The epidemiology of methicillin-susceptible Staphylococcus aureus (MSSA) in Africa is poorly documented. From January 2007 to March 2008, 555 S. aureus isolates were collected from five African towns in Cameroon, Madagascar, Morocco, Niger, and Senegal; among these, 456 unique isolates were susceptible to methicillin. Approximately 50% of the MSSA isolates from each different participating centre were randomly selected for further molecular analysis. Of the 228 isolates investigated, 132 (58%) belonged to five major multilocus sequence typing (MLST) clonal complexes (CCs) (CC1, CC15, CC30, CC121 and CC152) that were not related to any successful methicillin-resistant S. aureus (MRSA) clones previously identified in the same study population. The luk-PV genes encoding Panton-Valentine leukocidin (PVL), present in 130 isolates overall (57%), were highly prevalent in isolates from Cameroon, Niger, and Senegal (West and Central Africa). This finding is of major concern, with regard to both a source of severe infections and a potential reservoir for PVL genes. This overrepresentation of PVL in MSSA could lead to the emergence and spread of successful, highly virulent PVL-positive MRSA clones, a phenomenon that has already started in Africa.

Epidemiology of methicillin-resistant Staphylococcus aureus lineages in five major African towns: emergence and spread of atypical clones.

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Africa is poorly documented. From January 2007 to March 2008, we collected 86 MRSA isolates from five African towns, one each in Cameroon, Madagascar, Morocco, Niger and Senegal. Although one or two major clones, defined by the sequence type and staphylococcal cassette chromosome mec type, predominated at each site, genetic diversity (ten clones) was relatively limited in view of the large geographical area studied. Most of the isolates (n = 76, 88%) belonged to three major clones, namely ST239/241-III, a well-known pandemic clone (n = 34, 40%), ST88-IV (n = 24, 28%) and ST5-IV (n = 18, 21%). The latter two clones have only been sporadically described in other parts of the world. The spread of community-associated MRSA carrying the Panton-Valentine leukocidin genes is a cause for concern, especially in Dakar and possibly throughout Africa.

Case-control study of the etiology of infant diarrheal disease in 14 districts in Madagascar.

Background Acute diarrhea is a major cause of childhood morbidity and mortality worldwide. Its microbiological causes and clinico-epidemiological aspects were examined during the rainy seasons from 2008 to 2009 in 14 districts in Madagascar. Methods Stool specimens of 2196 children with acute diarrhea and 496 healthy children were collected in a community setting. Intestinal parasites were diagnosed by microscopy and bacteria by culturing methods. Rota-, astro and adenoviruses were identified using commercially available ELISA kits and rotaviruses were confirmed using reverse transcriptase polymerase chain reaction (RT-PCR). Results Intestinal microorganisms were isolated from 54.6% of diarrheal patients and 45.9% of healthy subjects (p = <0.01). The most common pathogens in diarrheic patients were intestinal parasites (36.5%). Campylobacter spp. and Rotavirus were detected in 9.7% and 6.7% of diarrheic patients. The detection rates of Entamoeba histolytica, Trichomonas intestinalis and Giardia lamblia were much greater in diarrheal patients than in non diarrheal subjects (odds ratios of 5.1, 3.2, 1.7 respectively). The abundance of other enteropathogens among the non diarrheal group may indicate prolonged excretion or limited pathogenicity. Conclusion In developing countries, where the lack of laboratory capacities is great, cross sectional studies of enteropathogens and their spatial distribution, including diarrheal and non diarrheal subjects, are interesting tools in order to advise regional policies on treatment and diarrheic patient management.

Morbidity assessment in urinary schistosomiasis infection through ultrasonography and measurement of eosinophil cationic protein (ECP) in urine.

Summary In a Schistosoma haematobium‐endemic village in western Madagascar we evaluated ultrasonography and Eosinophil Cationic Protein (ECP) in urine as means to detect the associated urinary tract pathology. 192 individuals were matched according to age and sex, and grouped into infected persons with bladder and, if present, kidney pathology (n= 96); infected persons without pathology (n= 48) and noninfected persons without pathology (n= 48). The median urinary egg count was significantly higher in individuals with ultrasonographically detectable urinary tract pathology (115 eggs/10 ml urine) than in infected persons without (45 eggs/10 ml of urine). At 136 ng/ml, the median ECP level was significantly higher in the 144 infected individuals than in the 48 noninfected persons (0.35 ng/ml). Egg excretion correlated positively with ECP level. The median ECP level was significantly higher in the group with ultrasonographically detectable urinary tract pathology than in the group without (183 ng/ml vs. 67 ng/ml). The results suggest that minor degrees of pathology, particularly at an early stage of infection with S. haematobium, might be overlooked by ultrasonography despite the presence of marked inflammation, as indicated by markedly increased urinary ECP levels in infected individuals without ultrasonographically detectable urinary tract pathology. ECP may therefore provide important information on the evolution of S. haematobium‐associated urinary tract morbidity.

Seroprevalence of hepatitis C and associated risk factors in urban areas of Antananarivo, Madagascar

BackgroundThe risk factors for the transmission of HCV vary substantially between countries and geographic regions. The overall prevalence in south and east Africa region has been estimated to be 1.6% but limited information about the epidemiology of HCV infection in Madagascar is availableMethodsA cross-sectional survey for hepatitis C antibodies was conducted in 2,169 subjects of the general population of Antananarivo to determine seroprevalence of hepatitis C and associated risk factors.ResultsThe overall seroprevalence was 1.2% (25/2,169). The prevalence did not differ significantly according to gender but it increased with age (Chi2 tendency test, p < 10-5). The variable history of hospitalization, previous therapeutic injections, dental treatment, intravenous drug use, and abnormal ALT and AST were statistically significantly related with the presence of HCV antibodies. No relationship with past history of blood transfusion was observed.ConclusionHCV prevalence in Madagascar seems to be similar to that in most other east African countries. Age appears to be an important risk factor. Iatrogenic causes of HCV transmission need to be further evaluated because all HCV cases had a history of receiving therapeutic injections and data suggested a cumulative effect in relation with therapeutic injections.

Serum concentrations of sICAM-1, sE-, sP- and sL-selectins in patients with Schistosoma mansoni infection and association with disease severity.

Increased serum concentrations of soluble intercellular adhesion molecule‐1 (sICAM‐1, CD54) and of soluble E‐ (CD62E), but not soluble P‐ (CD62P) and L‐ (CD62 L) selectins, were detected in Malagasy patients living in an hyperendemic focus of Schistosoma mansoni. Levels of sICAM‐1 remained elevated for several months after treatment with praziquantel. Serum levels of ICAM‐1, but not of other markers, were significantly correlated with the disease severity, as indicated by ultrasonographical data, and with some circulating fibrosis markers (at least hyaluronic acid). sICAM‐1 level may reflect endothelial inflammatory reactions, probably harmful, in the liver and may be useful for monitoring morbidity evolution in schistosomiasis mansoni.

Schistosoma haematobium infection in western Madagascar: morbidity determined by ultrasonography.

To assess the morbidity related to Schistosoma haematobium infection in western Madagascar, an ultrasonographic examination was performed of 574 inhabitants > 5 years old in a village in an old-established endemic area where no prior systematic antischistosomal treatment had been given. The overall prevalence of infection was 75.9% and the geometric mean egg count of positive individuals was 36 eggs/10 mL of urine. Recent haematuria had been experienced by 31.8% of individuals. Echographic abnormalities of the urinary tract were present in 50.5% of individuals: they were more frequent in males. Bladder wall lesions were observed in 93.1% of individuals with ultrasonographic changes, irregularities of the inner surface being the most common finding. Congestive changes were noted in 8.4% of kidneys, but we observed only 4 severe congestions. Bladder lesions and congestive changes in kidneys predominated in youth; their presence and severity were significantly correlated with egg excretion. In 12 inhabitants, grade 1 periportal fibrosis was observed, but no significant association was found with S. haematobium infection. In a control village, where the prevalence of S. haematobium infection was 7%, moderate congestion of kidneys was observed in 2% of examined inhabitants, and bladder changes in 6%, with a significant relationship with S. haematobium infection.

Sexual behavior and sexually transmitted infections in men living in rural Madagascar: implications for HIV transmission.

Background Madagascar is in the midst of a large HIV epidemic. Therefore, it is important to obtain relevant epidemiologic data that can be used to develop a preventive strategy. Goal The goal of the study was to assess sexual behavior and sexually transmitted infections (STIs) among men living in two coastal villages and one highland village with different levels of endemicity of urogenital schistosomiasis. Study Design Data were obtained from cross-sectional studies on male reproductive health. All men aged 15 to 49 years were offered enrollment. Results Of 401 men evaluated, 6.5% had used a condom and 45.6% reported having multiple partners in the previous 3 months. Symptoms of urethritis during the previous 7 days were reported by 128 men (31.9%). Urethritis was associated with the youngest age group (15–19 years) and the coastal villages, in which HIV antibodies were found in 0.9% and 2.5%, respectively. The prevalence of Schistosoma hematobium was 31.0% and 55.0% in these two villages, whereas none of the men in the highland village were infected. In bivariate analyses, urogenital schistosomiasis was associated with reported symptoms of urethritis, but it acted as a confounder in multivariate analyses. Conclusion Several risk factors for HIV propagation exist in these rural areas in Madagascar. Young men in particular should be targeted for HIV/STI prevention. Treatment of urogenital schistosomiasis could be considered part of the syndromic STI treatment in areas where S hematobium is endemic, for patients seeking primary care for urethritis.

Gynecological Manifestations, Histopathological Findings, and Schistosoma-Specific Polymerase Chain Reaction Results Among Women With Schistosoma haematobium Infection: A Cross-sectional Study in Madagascar

Background. The pathophysiology of female genital schistosomiasis (FGS) is only partially understood. This study aims to describe the histopathological findings, polymerase chain reaction (PCR) results, and gynecological manifestations of FGS in women with different intensities of Schistosoma haematobium infection. Methods. Women aged 15–35 years living in an S. haematobium-endemic area in Madagascar underwent pelvic and colposcopic examinations. Small biopsy specimens were obtained from lesions and examined histopathologically. Schistosoma PCR was done on urine, biopsy, cervicovaginal lavage, and genital mucosal surface specimens. Results. Sandy patches and rubbery papules were found in 41 of 118 women (35%). Rubbery papules reflected an intense cellular immune reaction dominated by eosinophils, epithelial erosion, and viable ova. There was a significant decrease in the prevalence of rubbery papules with age, even after adjustment for urinary ova excretion. The sandy patches with grains showed moderate cellular immune reaction and ova (viable and/or calcified). They were most prevalent in cases with low-intensity urinary S. haematobium infection. Forty-two percent of women with Schistosoma-negative urine specimens had at least 1 genital specimen test positive for Schistosoma by PCR. Conclusions. The results indicate a diversity of lesions caused by S. haematobium and a dynamic evolution of the genital lesions. Schistosoma PCR may give an indication of the diagnosis.

Rotavirus genotypes in children in the community with diarrhea in Madagascar.

In the context of the possible introduction of a preventive vaccine against rotaviruses in Madagascar, the G and P genotypes distribution of the rotaviruses circulating in the children in Madagascar was studied, and the presence of emerging genotypes and unusual strains were assessed. From February 2008 to May 2009, 1,679 stools specimens were collected from children ≤5 years old with diarrhea. ELISA was used for antigen detection, and molecular amplification of VP7 and VP4 gene fragments was used for genotyping. Rotavirus antigen was detected in 104 samples (6.2%). Partial sequences of VP7 and VP4 genes were obtained from 81 and 80 antigen‐positive stools, respectively. The most frequent G and P types combinations detected were G9P[8] (n = 51; 64.6%), followed by G1P[8] (n = 15; 18.9%), and G1P[6] (n = 8; 10.1%). A few unusual G‐P combinations, such as G4P[6] (n = 3; 3.8%), G9P[6] (n = 1; 1.3%), and G3P[9] reassortant feline human virus (n = 1; 1.3%) were identified. Both VP4 and VP7 sequences in one of the three G4P[6] isolates were closely related to those in porcine strains, and one was a reassortant human porcine virus. These findings give an overview of the strains circulating in Madagascar and should help public health authorities to define a vaccine strategy. J. Med. Virol. 85:1652–1660, 2013.