Topical problems of rabies: natural foci, the methods of study and control in Central Russia

This analytical review is dealing with the origin and evolution of modern rabies as well as hypotheses concerning the natural foci of rabies infection, the formation of the Central European nosological area of rabies and its eastward shift due to the systematic oral vaccination of the main hosts. The epizootological problems connected with the character of the natural foci of rabies, as well as the methods and prospects of the vaccination of foxes on the territory of Central Russia, are discussed.     

Animal rabies in Poland: epidemiological situation and methods of control

The epidemiological situation and methods of control of animal rabies in Poland are presented. Registered data on rabies cases for the period from 1948 up to 1986 are discussed. Two species of animals, namely dogs and foxes, have played the major role in the epidemics of rabies. The undertaken measures have proved satisfactory to control rabies due to dogs as a vector but were found inadequate to control wild-life rabies. Since 1967 the fox has been the main vector of the epizootics of rabies.     

Current problems of the epidemiological surveillance of poliomyelitis

A uniform program of the epidemiological supervision of poliomyelitis must be worked out for every administrative territorial unit. This program should include the early and complete detection of all cases of this infection, irrespective of their severity; the analysis of the quality of vaccination; the determination of the immune status of the child population; the characteristic of the poliovirus circulation.     

A descriptive epidemiological study of raccoon rabies in a rural environment

A recent outbreak of rabies in raccoons, Procyon lotor (L.), in Loudoun County, Virginia (1981-82), prompted a study of the epidemiology of the disease. Parameters studied included the occurrence and movement of the disease over time, sex and age relationships, and behavior patterns of raccoons. During the 18 mo, 427 raccoons were tested, of which 75% were infected with rabies virus. Interpretation of rainfall data and the subsequent spatial occurrence of infected raccoons within the county indicated a cause and effect relationship. The submission rate of female raccoons was greater than that of males. The female raccoons (adult and juvenile) were also found to be infected with the virus more often than the males. Behavior of infected raccoons in a rural environment was similar to those observed in the southeastern United States during earlier epizootics of rabies. The presence of a skunky odor on infected raccoons may be a characteristic of raccoon rabies.     

Ecological and epidemiological studies of histoplasmosis in the United States of America

Histoplasmosis is a disease that is transmitted from nature to man. The causative agent,Histoplasma capsulatum, grows freely in the soil and the infection is spread by inhalation of the infectious spores. The infection is highly endemic in the central United States. Soil contaminated with fecal droppings of chickens, starlings, blackbirds, and other avian species is a principal source of infection.Paper read at the Eighth International Congresses for Tropical Medicine and Malaria, September 1968, Teheran (Iran).     

First human rabies case in French Guiana, 2008: epidemiological investigation and control

Background

Until 2008, human rabies had never been reported in French Guiana. On 28 May 2008, the French National Reference Center for Rabies (Institut Pasteur, Paris) confirmed the rabies diagnosis, based on hemi-nested polymerase chain reaction on skin biopsy and saliva specimens from a Guianan, who had never travelled overseas and died in Cayenne after presenting clinically typical meningoencephalitis.

Methodology/Principal Findings

Molecular typing of the virus identified a Lyssavirus (Rabies virus species), closely related to those circulating in hematophagous bats (mainly Desmodus rotundus) in Latin America. A multidisciplinary Crisis Unit was activated. Its objectives were to implement an epidemiological investigation and a veterinary survey, to provide control measures and establish a communications program. The origin of the contamination was not formally established, but was probably linked to a bat bite based on the virus type isolated. After confirming exposure of 90 persons, they were vaccinated against rabies: 42 from the case''s entourage and 48 healthcare workers. To handle that emergence and the local population''s increased demand to be vaccinated, a specific communications program was established using several media: television, newspaper, radio.

Conclusion/Significance

This episode, occurring in the context of a Department far from continental France, strongly affected the local population, healthcare workers and authorities, and the management team faced intense pressure. This observation confirms that the risk of contracting rabies in French Guiana is real, with consequences for population educational program, control measures, medical diagnosis and post-exposure prophylaxis.     

Modelling the natural history of HIV infection in individuals and its epidemiological implications

The variation of viraemia in the natural course of HIV infection is expected to have major influence on the probability of transmission and, consequently, on the epidemiology of HIV/AIDS. In this paper we propose a model which takes into account the time evolution of HIV viraemia (measured as HIV-RNA copies per ml of blood) in an infected individual and its impact on the threshold for the establishment of an endemic level, and mainly on the relative contribution of each of the clinical phases of the infection to the total transmission of HIV per infected individual. We consider that an infected individual passes through three phases of viraemia. The first phase, which lasts for 6–7 weeks, is characterized by very high viraemia. In the second phase, which lasts about 10 years, the viraemia is much lower, increasing again in the last phase, which lasts up to two years, and ends in full-blown AIDS. We show that the relative contribution of each phase to the total transmission of HIV is very sensitive to the model we assume for the dependence of the transmissibility of HIV on the viral load. For instance, if we assume that transmissibility is proportional to the decimal logarithm of viraemia, then the second phase predominates always. Due to the epidemiological importance of this fact, it is clear that further improvement on virological research to better understand the dependence of HIV transmissibility on the viral concentration in biological fluids is necessary.     

The epidemiological surveillance of poliomyelitis in the Ukraine]

Correlation has been revealed between the circulation of polioviruses among the population and environmental objects. A rise in the circulation of polioviruses, type I, was caused by a decrease in collective immunity to this virus type. Water supply and sewage system purification was found ineffective with respect to enteroviral contamination. Vaccinal prophylaxis, carried out for many years, did not lead to the elimination of poliovirus strains, genetically different from vaccine ones.