Chromoblastomycosis and sporotrichosis, two endemic but neglected fungal infections in Madagascar.

Chromoblastomycosis and sporotrichosis are endemic fungal infections of tropical and subtropical regions, including Madagascar. The causal fungi develop in the soil or on plants and infect humans through wounds, either directly (wounding by the plant, through thorns, for example), or through the contact of an existing wound with contaminated soil. For this reason, the lesions predominantly occur on the limbs, and these fungi principally infect people working outside with bare hands and/or feet. The subcutaneous lesions of chromoblastomycosis are initially nodular, subsequently becoming warty, tumoral, cauliflower-like and pruriginous, which promotes dissemination. The chronic nature of the infection and its progression over long periods lead to highly disabling lesions in essentially rural and agricultural populations. The lesions of sporotrichosis are also nodular, but more ulcerous, and they form an extended chain following the route of the lymph vessels. Pus, squamous or skin biopsy specimens are used for the mycological examination of these mycoses. Treatment depends on the severity and form of the lesions and is based on antifungal drugs sometimes combined with physical methods. There has been no study of these infections for more than two decades in Madagascar, despite the large numbers of cases seen by doctors in all parts of the island. The nature, diversity and distribution of the plants responsible for contamination have not been described in Madagascar. In this review, we described these two endemic mycoses in terms of their epidemiological, mycological, clinical and therapeutic characteristics, focusing particularly on Madagascar, which is one of the leading foci of these two infections worldwide.

[Epidemics of acute respiratory infections in Madagascar in 2002: from alert to confirmation]. / Epidémies d'infections respiratoires aiguës à Madagascar en 2002: de l'alerte à la confirmation.

UNLABELLED: An epidemiological investigation (Ministry of Health/Institut Pasteur de Madagascar (IPM)) was conducted in July 2002, in two districts of a same province (Fianarantsoa: Fianarantsoa II and Ikongo) considering the high frequency of deaths linked with acute respiratory infection (ARI). Morbidity and mortality data was collected in the Centre de Santé de Base (CSB) which gave the alert (village of Sahafata, district Fianarantsoa II). Analysis of monthly activity reports (MAR) allowed calculation of incidence rates of ARI/pneumonia in Fianarantsoa province. Virological data was based on the analysis of nasopharyngeal samples collected during the investigations. Clinical symptoms and homogeneity of laboratory results are consistent with an origin of these epidemics being related to the circulation of an influenza virus A subtype H3N2. Attack rates were very high. CFR was significantly higher in individuals of less than 1 year and more than 65 years. This data was confirmed by posterior investigations of teams from MoH/WHO. Surprisingly, this large epidemic was due to a known influenza virus that previously circulated in countries of northern hemisphere (the year before) and even in Antananarivo weeks before. Different hypothesis could be proposed to explain such phenomenon: great restriction of exchanges between different geographical zones, nutritional status.... CONCLUSION: The epidemic episodes of acute respiratory infections in Madagascar in July 2002 were due to an influenza virus A subtype H3N2 without any genotypic or phenotypic features. Various factors, could explain the importance of the epidemic and particular high lethality found in some age groups. This epidemic illustrates the relative incapacity for a developing country, to face and manage a flu epidemic caused by a classical influenza virus.

[Genetic variability of Poliovirus: typing of strains isolated in Madagascar by restriction fragment length polymorphism (RFLP) assay]. / Variabilité génétique des Poliovirus: étude du polymorphisme de la longueur des fragments de restriction enzymatique de souches isolées à Madagascar.

The differentiation of the vaccine or wild origin of Poliovirus at the laboratory is an important step towards the process of the poliomyelitis eradication. We report herein the results obtained from Poliovirus types 3 and 2, isolated in Madagascar in 1997 and 2002 from healthy children and cases of acute flaccid paralysis, respectively. The technique used is based on the amplification of genome (RT-PCR), followed by Restriction Fragment Length Polymorphism assay (RFLP), performed in 3 different regions of the genome. In the capsid region (VP3-VP1 and VP1-2A), RFLP analysis allowed us to differentiate without ambiguity the wild or vaccine origin of the Poliovirus type 3, and to identify Vaccine-Derived Poliovirus (VDPV) type 2. In the noncapsid region, including the RNA polymerase and 3' non coding region (3Dpol-3' NTR), the VDPV were found to be recombinant with other Enteroviruses. These results confirm that RFLP assay is a reliable tool for intratypic differentiation and to study the genetic drift and recombination of Poliovirus.

[Persistence of an endemic circulation of the West Nile virus in Madagascar]. / Persistance d'une circulation endémique du virus West Nile a Madagascar.

The wide geographic distribution of the West Nile virus and the increase in virulence observed since 1994 in the Mediterranean basin, central Europe and North America, with several outbreaks of lethal encephalitis, demonstrate the importance of regular surveillance of the epidemiological data regarding this virus in the world. The Institut Pasteur de Madagascar has shown between 1975 and 1990 that this arbovirus was most abundant in Madagascar, where it had an endemic circulation. There has been no further study since that time. In order to evaluate the level of circulation, the seroprevalence of anti-West Nile antibodies in children that are 15 or less was measured on two different collections of sera. These collections came from population studies realised respectively in the region of Ambositra in the Highlands in 1996 and in the city of Mahajanga on the north west coast in 1999. The seroprevalence were 2.1% and 10.6% respectively, these results indicate that the circulation of this climatic dependent virus is still significant.

Nouvelle methode de typage moleculaire des Enterovirus humains : caracterisation des souches malgaches non serotypables

"New method for molecular typing of human enteroviruses: characterization of ""untypeable"" strains isolated in Madagascar"" : Enteroviruses; members of the family icornaviridae;are responsible for a wide variety of diseases and represent a major public health hazard. Typing of non polio enterovirus (NPEV) infection is traditionally based on a serum neutralization assay. However; this method is time-consuming; labor-intensive; expensive; and may fail to identify antigenic variation. A new molecular typing involving partial sequencing of the genome has been recently developed. In this study; 46 NPEV strains were analyzed; including 37 antigenicaly ""untypeable"" viruses. Partial sequencing of the C-end of the viral capsid protein VP1 and pairwise identity with the prototype strains allow us to assign a serotype for all ""untypeable"" viruses. The result show a large number and wide variety of Coxsackieviruses A which belong to the HEV-C species and also Echoviruses and Coxsackieviruses B of the HEV-B species. This method may be useful to identify all NPEV serotypes in Madagascar and to assess the possible impact of circulating NPEV populations; as we enter the final stage of poliomyelitis eradication."

Epidemies d'infections respiratoires aigues a Madagascar en 2002 : de l'alerte a la confirmation

Epidemics of acute respiratory infections in Madagascar in 2002 : from alert to confirmation : An epidemiological investigation (Ministry of Health/Institut Pasteur de dagascar (IPM)) was conducted in July 2002; in two districts of a same province (Fianarantsoa : Fianarantsoa II and Ikongo) considering the high frequency of deaths linked with acute respiratory infection (ARI). Morbidity and mortality data was collected in the Centre de Sante de Base (CSB) which gave the alert (village of Sahafata; district Fianarantsoa II). Analysis of monthly activity reports (MAR) allowed calculation of incidence rates of ARI/pneumonia in Fianarantsoa province. Virological data was based on the analysis of nasopharyngal samples collected during the investigations. Clinical symptoms and homogeneity of laboratory results are consistent with an origin of these epidemics being related to the circulation of an influenza virus A subtype H3N2. Attack rates were very high. CFR was significantly higher in individuals of less than 1 year and more than 65 years. This data was confirmed by posterior investigations of teams from MoH/WHO. Surprisingly; this large epidemic was due to a known influenza virus that previously circulated in countries of northern hemisphere (the year before) and even in Antananarivo weeks before. Different hypothesis could be proposed to explain such phenomenon : great restriction of exchanges between different geographical zones; nutritional status

Variabilite genetique des Poliovirus : etude du polymorphisme de la longueur des fragments de restriction enzymatique de souches isolees a Madagascar

"Genetic variability of Poliovirus : typing of strains isolated in Madagascar by Restriction Fragment Length Polymorphism (RFLP) assay"". The differentiation of the vaccineor wild origin of Poliovirus at the laboratory is an important step towards the process of the poliomyelitis eradication. We report herein the results obtained from Poliovirus types 3 and 2; isolated in Madagascar in 1997 and 2002 from healthy children and cases of acute flaccid paralysis; respectively. The technique used is based on the amplification of genome (RT-PCR); followed by Restriction Fragment Length Polymorphism assay (RFLP); performed in 3 different regions of the genome. In the capsid region (VP3-VP1 and VP1-2A); RFLP analysis allowed us to differentiate without ambiguity the wild or vaccine origin of the Poliovirus type 3; and to identify Vaccine-Derived Poliovirus (VDPV) type 2. In the noncapsid region; including the RNA polymerase and 3' non coding region (3Dpol-3' NTR); the VDPV were found to be recombinant with other Enteroviruses. These results confirm that RFLP assay is a reliable tool for intratypic differentiation and to study the genetic drift and recombination of Poliovirus."

[New method of molecular typing in human Enteroviruses: characterization of Madagascar "untypable" strains]. / Nouvelle méthode de typage moléculaire des Entérovirus humains: caractérisation des souches malgaches "non sérotypables".

Enteroviruses, members of the family Picornaviridae, are responsible for a wide variety of diseases and represent a major public health hazard. Typing of non polio enterovirus (NPEV) infection is traditionally based on a serum neutralization assay. However, this method is time-consuming, labor-intensive, expensive, and may fail to identify antigenic variation. A new molecular typing involving partial sequencing of the genome has been recently developed. In this study, 46 NPEV strains were analyzed, including 37 antigenicaly "untypeable" viruses. Partial sequencing of the C-end of the viral capsid protein VP1 and pairwise identity with the prototype strains allow us to assign a serotype for all "untypeable" viruses. The results show a large number and wide variety of Coxsackieviruses A which belong to the HEV-C species and also Echoviruses and Coxsackieviruses B of the HEV-B species. This method may be useful to identify all NPEV serotypes in Madagascar and to assess the possible impact of circulating NPEV populations, as we enter the final stage of poliomyelitis eradication.

[African Swine Fever introduction into Madagascar, history and lessons from an emergence]. / Introduction de la Peste Porcine Africaine à Madagascar, histoire et leçons d'une émergence.

African Swine Fever (ASF) was diagnosed for the first time in Madagascar in 1998. ASF has apparently been introduced from the African continent to the southern part of the island with a subsequent spread to other regions except for areas in the north and in the west. The epidemic has had severe economic consequences for the home market of pork meat production. This article reviews the course of the epidemic with particular emphasis on the vectors involved in the transmission of the virus, such as the soft tick, Ornithodoros moubata porcinus. Presence of this vector and of the bushpig, Potamochoerus larvatus, as a potential wild reservoir, are some of the major obstacles in control of ASF in Madagascar. A veterinary disease surveillance system has to be urgently warranted.

Introduction de la peste porcine africaine à Madagascar : histoire et leçons d'une émergence

La Peste Porcine Africaine (PPA) a récemment fait son apparition à Madagascar.Officiellement diagnostiquée fin 1998, la PPA a vraisemblablement été introduite à Madagascar en 1997 dans le sud du pays à partir de virus provenant du continent africain. La PPA s'estensuite propagée dans la quasi-totalité du pays à l'exception de la région d'Antsiranana (Nord) et de Morondava (Ouest). La maladie a eu des conséquences économiques désastreuses et aentraîné la désorganisation de la filière porcine malgache.Nous rapportons ici l'histoire de cette émergence et l'existence de particularités locales comme la présence de vecteurs, les tiques du genre Ornithodoros - O. moubata porcinus - et de réservoirs sauvages potentiels comme le potamochère - Potamochoerus larvatus - qui compromettentl'éradication de la maladie.Ces faits renforcent la nécessité pour Madagascar de disposer d'un système d'alerte et de riposte rapide

[Seroprevalence of viral hepatitis B in the city of Mahajanga, Madagascar in 1999]. / Séroprévalence de l'hépatite virale B dans la ville de Mahajanga à Madagascar en 1999.

A seroepidemiological study was carried out to assess the prevalence of hepatitis B virus (HBV) in the city of Mahajanga, Madagascar in July 1999. A total of 654 serum samples were collected from randomly selected subjects over the age of 2 years. The ELISA technique was used to detect serum markers of HBV infection. Prevalence rates were 14.2 p. 100 for HBs, 1.4 p. 100 for HBe antigens, and 49.5 p. 100 for HBV infection as defined by the presence of at least one serum markers. HBs antigens were detected in 20.8 p. 100 of children between the ages of 2 and 4 years and 15.3 p. 100 of women of childbearing age. In the latter age group, 5.6 p. 100 demonstrated HBe antigens, which are considered as a replication marker. The findings of this study are in agreement with those of a previous study in Madagascar and indicate that an expanded program of immunization against hepatitis B virus is warranted.

[Circulation of the poliovirus in endemic zones with children vaccinated by the oral polio vaccine]. / Circulation des poliovirus dans les zones d'endémie chez les enfants vaccinés par le vaccin polio oral.

Strategies aiming to eradicate the poliovirus and poliomyelitis seek primarily to eliminate wild strains associated with the disease, by means of world wide vaccination campaigns using the oral attenuated vaccine (OPV). OPV contains attenuated viral strains which retain their replicating capacity in the digestive tract and thus induce the development of an antiviral local intestinal immunity and limit the circulation of the virus. In such a context, poliomyelitis surveillance laboratories should study above all cases of acute flaccid paralysis (AFP), highlighting the circulation of wild strains, identifying regional reservoirs and guiding vaccination strategies. Alongside circulation, there appear to be important genetic and phenotypic shifts in vaccinating strains, since the OPV is capable of preserving a reservoir of pathogenic stains and thereby impairing vaccination efficacy and the eradication of the virus. Furthermore, non-polio enteroviruses should be considered as a source of emerging pathogenic strains. These questions are being studied by the Pasteur Institute with the objective of determining the effects of OPV campaigns on the circulation of the poliovirus. We have studied the poliovirus vaccine and the circulation of wild strains in urban and peripheral urban areas in African countries known to be endemic for poliomyelitis (Central African Republic, Madagascar, Côte d'Ivoire). The study population consisted of children who had already been vaccinated and new-borns in the course of vaccination. We also evaluated the diffusion of the vaccine strains in their immediate environment. Genetic interchanges were taken into account. For children who received the 3-4 OPV doses, asymptomatic virus excretion was insignificant (0.4-2.4%). The rate of virus excretion in the surrounding environment of children in the course of being vaccinated was relatively low (1.76-5.3%). Our study also detected variant and recombinant strains.

[Pseudo-poliomyelitis paralysis caused by Echovirus 7]. / Paralysie pseudo-poliomyélitique associée à échovirus 7.

The authors describe one case of acute flaccid paralytic of lower limbs in a 10-year-old boy with Echovirus 7 isolated in the stool and a high titer of homologous antibodies (> or = 1,024). At the final stage of poliomyelitis program eradication, paralysis associated with non polio enterovirus may replace cases of paralytic poliomyelitis. In the present study, the authors highlight the needs to confirm virologically all suspect cases of acute flaccid paralytic. Aetiological function of the virus isolated and interpretation of the diagnostic methods are discussed.

[Hepatitis B virus infection: a public health problem in Madagascar]. / Infection par le virus de l'hépatite B: un problème de santé publique à Madagascar.

In this article, the authors summarize studies on hepatitis B virus infection in Madagascar. Estimated prevalence rate for acute or chronic HBs antigen infection is 23% among general population which classify the country in high endemicity area. Vertical and horizontal transmissions for the childhood are high with an estimated prevalence rate for HBs antigen infection of 10 to 35% among children under less than 5-year-old according to areas. This situation indicates that an expanded program of immunization against hepatitis B virus is warranted.

[Prevalence of hepatitis C virus infection in the general population of Madagascar]. / Prévalence de l'infection par le virus de l'hépatite C en population générale à Madagascar.

The achievement of a sera collection representative for the general population > or = 1 year in 1994 allowed the assessment of the seroprevalence of Hepatitis C virus infection (HCV) in Antananarivo and Toamasina provinces which represent 45% of the total population of Madagascar. The overall sero-prevalence was 1.2% among the 921 tested sera. The prevalence was not significantly different according to sex, but it increased according to the age. The absence of positive children was an argument in consideration of the low importance of mother-to-infant transmission in the epidemiology of HCV. A significant relationship was observed with past history of blood transfusion. This point is a well established idea that reminds the interest of the detection of positive individuals for anti-HCV antibodies. The seroprevalence observed in our study could be considered as moderate. It is close to the values recorded in Europe or in Japan, and much lower than those observed in Equatorial Africa.

[Poliomyelitis in Madagascar (1988-1996): current situation in the World Health eradication program by the year 2000]. / La poliomyélite à Madagascar (1988-1996): situation actuelle dans le cadre du programme mondial d'éradication d'ici l'an 2000.

The number of acute flaccid paralysis (AFP) cases reported to World Health Organization (WHO) decreased from 1988 (48 cases) to 1996 (8 cases), but the real endemic situation of poliomyelitis is unknown. Cases are under or misreported. Very often, notifications are delayed; virological investigations of the etiology could not be performed as well as the environment studies and the immunization ripostes. In 1996, only one AFP case was confirmed by isolation of wild poliovirus. The immunization coverage in children under one by OPV (3 doses) was 73.0% in 1996 from the statistics of the Public Health Services but only 54.7% from randomized studies. The eradication of poliomyelitis by the year 2000 has engaged Madagascar in the disease prevention by improving the immunization coverage within the Expanded Immunization Programme in association with the Organization of National Immunization Days in October and November 1997. Likewise, the Virological Unit of the Pasteur Institute was recognized as the National WHO Reference Centre for Polio.

[Serological markers for hepatitis A, B and C in Madagascar. First investigation in a rural area]. / Les marqueurs sérologiques des hépatites A, B et C à Madagascar. Première enquête en zone rurale.

The first serological survey of hepatitis A, B and C virus infection was carried out in Madagascar during 1993 in two rural villages (653 sera) of the middle-west. This study shows a high frequency of positivity of hepatitis A virus markers (94.9%). Hepatitis A is acquired in early childhood. The data show the high frequency of positivity of hepatitis B (HBV) markers: in the two villages 72.5% and 89.8% have one marker, and seroprevalence of HBs antigene is 18.9% and 30.5%. Hepatitis B also is acquired in early childhood. The data show that not only hepatitis A and B but also hepatitis C is highly prevalent (2.2% and 5.8%). There was an increase in HCV antibody prevalence with age.