[The immune structure against q fever and tick-bite spotted fever group rickettsioses in the population and domestic animals of the Republic of Guinea].

The circulation of the rickettsiae R.africae and C.brunetii, the causative agents of African tick-bite spotted fever and Q fever, was first ascertained throughout the territory of the Republic of Guinea. The immune stratum against R.africae among the population varied 1.1 to 25.4% or 10.6+/-0.7% on average and that among the livestock did 0.6 to 18.8% or 7.6+/-0.6% on average. The proportion of sera to C,brunettii in the population was in the rage from 0.8 to 10.5% or 2.4+/-0.3% on average; that in livestock was 3.2 to 18.7% or 8.0+/-0.6% on average. However, many aspects of the circulation of rickettsiae, the pathology and importance of these fevers in the structure of morbidity in Guinea remain still unclarified and call for further investigations, by applying the current laboratory diagnostic tests for rickettsiosial diseases.

[International collaboration of the E.I. Martsinovsky Institute of Medical Parasitology and Tropical Medicine: assistance for public health in the Republic of Guinea].

Within the framework of international collaboration, the E.I. Martsinovsky Institute of Medical Parasitology and Tropical Medicine (IMPTM), I.M. Sechenov First Moscow State Medical University, assisted the Public Health System of the Republic of Guinea in detecting, diagnosing, studying, and preventing tropical infections of viral, bacterial, and parasitic etiologies, and in training national scientific manpower. The work was under way in the Soviet-Guinea Research Microbiology and Virology Laboratory, USSR Ministry of Health, in the Republic of Guinea (now the Pasteur Institute in Guinea (PIG)) in 1978-1991. The circulation of pathogens of a number of tropical infections, the fauna of vectors and carriers of transmissible infections, and their involvement of the circulation of pathogens of these diseases were found in this period. Consultative-and-methodological and medical assistance was given; national higher- and middle-level brainpower trained. It is expedient to restore scientific ties between the IMPTM and the PIG.

[African trypanosomiasis in the Republic of Guinea].

The information on the Gambian form of African human trypanosomiasis (AHT), collected in Guinea, is analyzed. The fauna of tsetse flies currently numbers at least 8 species. Two species are the vectors of AHT. These include G.(N.) palpalis and G.(N.) tachinoides, the latter of which is the vector of animal trypanosomiasis ("nagana" cattle disease) as well. In the period of 1991 to 1997, the country's incidence of AHT was 9.6:100,000. The highest morbidity was established in the natural region of Lower Guinea (23.4:100,000, with mortality rates of 1.1 to 18.5%). A clinical study of the population of a few villages in this region revealed 6 patients with AHT. Its clinical diagnosis was parasitologically verified. Preliminary studies suggest the circulation of the pathogen of AHT in Guinea, the most active foci of which are in Lower Guinea. The epidemiological features of AHT and its epidemic significance for Guinea are yet to be studied.

[Characterization of contacts of the population of Guinea with synanthropic rodents as Lassa fever virus carriers].

Questionnaire surveys made in 17 villages from 3 ecological zones of Guinea have provided evidence for the population's contact with synanthropic rodents as Lassa fever virus carriers. Over 100 rodents are quarterly captured in the houses of the traditional type in the villages located in the savanna woodland. Less than 10 specimens are captured at the food warehouses. There are more than 100 rodents in the majority of houses of the traditional type in the villages located in the secondary forest. In the villages of rainy tropical forests, the capture rate is low--10 to 100 rodents. The main rodent capturers are boys and young men (aged 7 to 20 years) who are principal rodent meat eaters; although almost the whole population, particularly in rural areas, consumes this meat in varying degrees. The proportion of captured rats of the genus Mastomys (the carrier of Lassa fever virus) in the town of Kindia is 11%. In the rural area, it is much higher (as high as 94%) in the villages located in the rainy tropical forests. It is estimated that one trapper quarterly catches 0.2 (in the savanna woodland) to 6.9 (in the secondary forests) infected rats, which agrees with the data of a serological survey of Guinea's population. By and large, the majority of the Guinean population may be referred to as a group at risk for Lassa fever due to their permanent contacts with rodents.

[The mammals of Guinea as reservoirs and carriers of arboviruses].

A great body of data on the fauna and ecology of wild mammals and their participation in the circulation of arboviruses were collected when the ecology of the latter of the Republic of Guinea was studied in 1978 to 1989. A hundred and eighteen species belonging to 10 orders were identified. Over 2,000 biological specimens were virologically and serologically examined. Six arboviruses were isolated. These included Dugbe virus (from the hussar monkey Cercopithecus (Erythrocebus patas) and 5 viruses from chiropters: Rift valley fever, from Micropteropus pusillus, Miniopterus schreibersi, and Hipposideros caffer, Saboya, Fomede, and Ank 6909 from Nycteris gambiensis and Kolenter from Hipposideros sp. Fomede, Kolente, and Ank 6909 viruses turned out to be new species for science. Rodents were found to have viral antigens of Lass fever (Mastomys natalensis, Tatera valida kempi and Rattus rattus), Dugbe and Chikungunya fevers (M. natalensis) and West Nile fever (Mus sp.). A serological survey of mammals revealed that the latter had antibodies to 12 arboviruses. Thus, the mammals of Guinea participate in the circulation of 18 arboviruses, 13 of them are pathogenic for man.

[The problem of intoxication in the population of the Republic of Guinea due to venomous snake bites].

Intoxication of the population of Guinea due to venomous snake bites (100-150 intoxications per 100,000 with an 18% mortality rate) is a serious public health problem in the Republic of Guinea. Guinea's fauna of venomous snakes is diverse and numbers 20 species that are dangerous to human beings. The representatives of the family Elapidae (cobras and mambas) whose venom is highly toxic (LD50 5-12 mg) are responsible for the bulk (59.6%) of their bites. There has been recently an increase in the number of deaths from venomous snake bites, as high as 60% of the patients consulting a doctor being notified in one of the prefectures. At the same time the situation associated with the availability of antisnake serum is critical in the country due to its minute amount and to the inaccessibility of its high prices. By taking into account the great demand for the serum in Guinea, as everywhere over West Africa (thousands of doses every year), its manufacture may be profitable for potential investors and partners of the Pasteur Institute of Guinea.

[Contribution to the study of mosquitoes (Diptera: Culicidae) of Guinea: Fauna and distribution]. / Contribution à l'étude des moustiques (Diptera: Culicidae) de la Guinée. Faune et distribution.

The authors report the results of ten years of entomological research conducted in Guinea. During this period, 84,000 larvae and 66,000 adult mosquitoes belonging to 8 different genera were captured and identified according to species or species groups. Mosquito fauna in Guinea includes almost all the known vectors of malaria and filaria in West Africa (see tables I-IV) as well as many of the known vectors of arboviruses. Four methods were used for capturing the insects, the most efficient being the use of a net in vegetation which succeeded in trapping 83% of the species described.

[Blood-sucking mosquitoes (Diptera, Culicidae) of the prefecture of Kindia, the Republic of Guinea. 4. The genus Anopheles]. / Krovososushchie komary (Diptera, Culicidae) prefektury Kindiia, Respublika Gvineia. Soobshchenie 4. Rod Anopheles.

During a three-year survey on bloodsucking mosquitos in the Kindia prefecture (physico-geographical region of Middle Guinea) 17 of Anopheles mosquito species had been established. Two of them (An. demeilloni and An. swetzi) were noted in this region for the first time. The data on mosquitos biotope distribution, their seasonal dynamics of abundance and comparative effectiveness of collection methods were received as well. It had been concluded that it was reasonable to use the diverse capture methods on faunistic study of this mosquito genus.

[Ticks of the Ixodidae family as reservoir of arboviruses in the Republic of Guinea. II. Arboviruses]. / Les tiques de la famille Ixodidae comme réservoir d'arbovirus en République de Guinée. II. Les arbovirus.

From 1978 to 1985, 96,167 Ixodidae family were collected, from which 79 strains of the following arboviruses were isolated, i.e. 4 Bhanja strains, 9 CHF-Congo, 20 Dugbe, 24 Jos (viruses ecologically related to ticks), 10 Abadina, 7 Bluetongue, 1 Bunyamwera, 1 Chikungunya, (related to ticks for the first time), 1 Kindia and 2 Forecariah (new viruses). The main sources for arbovirus isolation were ticks of the Amblyomma variegatum genus (78.5%) followed by ticks of the Boophilus (12.6%), Rhipicephalus (7.6%) and Haemaphysalis (1.3%) genera. According to experimental data obtained in the laboratory and in the field involvement of A. variegatum as reservoir host for Abadina virus was established. The seasonal dynamics characteristics of the propagation of this virus and its pathogenicity for cattle were also noticed. Serological surveys on cattle (i.e. on about 7000 sera) showed that Abadina, Bluetongue, CHF-Congo, Dugbe viruses spread more actively, with 24-35% positive sera. The rate of positive sera against Bhanja, Forecariah, Jos and RVF viruses did not exceed 0.9%. During the study period, the arboviruses isolated from ticks did not play any important epidemiological role in human pathology of the Republic of Guinea.

[Indirect immunoenzyme method for the laboratory diagnosis of Lassa and Ebola hemorrhagic fevers]. / Nepriamoi immunofermentnyi metod dlia laboratornoi diagnostiki gemorragicheskikh likhoradok Lassa i Ebola.

Conditions for performing solid-phase indirect enzyme-immunoassay (SPEIA) for the detection of Lassa and Ebola virus antigens and antibodies to them using horseradish peroxidase-labeled antispecific globulins were developed. The method is highly sensitive, specific, and reproducible. By this method, antigens of Lassa and Ebola viruses could be detected in tissue culture fluid of the infected cell cultures and in animal organ suspensions. Detection of antibodies to Lassa and Ebola viruses in human convalescent sera and in normal donors by means of SPEIA opens possibilities for its use in large-scale diagnostic and seroepidemiological surveys.