Comportamiento de los focos rábicos en la provincia La Habana / Behavior of rabies outbreaks in Havana province

Fundamento: para la salud pública y el desarrollo del mundo, las enfermedades como Dengue, Zika, Chikingunya, Fiebre amarrilla y rabia son reemergentes la mayoría de ellas son infecciones que han cruzado la barrera que existe entre las especies animales y los seres humanos.Objetivo: analizar el comportamiento de los focos rábicos en la provincia La Habana.Métodos: se realizó un estudio observacional descriptivo retrospectivo de los casos de especie animal positivos a rabia, examinados en el Centro Provincial de Higiene, Epidemiología y Microbiología de La Habana, desde el 2013 hasta el 2016. Se incluyó 51 muestras de cerebros de carnívoros, quirópteros y herbívoros estudiados en la provincia. Se empleó la técnica de inmunofluorescencia directa para el diagnóstico de rabia. La descripción de la positividad se realizó a partir de los sistemas de información Excel.Resultados: el municipio Boyeros con mayor índice de positividad seguido de Arroyo Naranjo, desplaza la rabia canina de casos positivos a la rabia por mangosta.Conclusiones: el mayor reporte de casos se notificó en el municipio periférico Boyeros ubicado al sur de la provincia La Habana y limítrofe con la provincia Artemisa(AU)

Background: for the public health and world development diseases such as Dengue, Zika, Chikungunya, Yellow fever and rabies are re-emergent and most of them are infections that have crossed the barrier that exists between animal species and humans.Objective: to analyze the behavior of rabies outbreaks in Havana province, from 2013 to 2016.Methods: a retrospective descriptive, observational study of rabies-positive animal species examined at the Provincial Center for Hygiene, Epidemiology and Microbiology of Havana was conducted from 2013 to 2016. 51 samples of brains from carnivores, bats, and herbivores studied in the province were included. The direct immunofluorescence technique was used for the diagnosis of rabies. The description of the positivity was carried out using the Excel information systems.Results: the municipality of Boyeros with the highest positivity index followed by Arroyo Naranjo, displaces canine rabies cases by mongoose.Conclusions: the largest report of cases was reported in Boyeros geographically located in the south Havana province and bordering with Artemisa province(AU)

From rabies to transmissible spongiform encephalopathies: an immune-mediated microbial trigger involving molecular mimicry could be the answer.

The concept of experimental allergic encephalomyelitis (EAE) being linked to both rabies post-vaccination encephalomyelitis and multiple sclerosis (MS) has raised the intriguing question whether animal studies carried out for the induction and transmission of transmissible spongiform encephalopathies (TSEs) using brain antigens including prions do have a similar immunopathogenetic mechanism. Although an essential link between autoimmunity and MS has been well established, its role in the pathogenesis of TSEs is generally lacking. However, auto-antibodies to myelin proteins and/or other neuronal antigens such as neurofilaments and prion proteins have been reported in animals with bovine spongiform encephalopathy (BSE) and scrapie as well as in patients with Creutzfeld-Jakob disease (CJD) and kuru. Acinetobacter has been suggested as a possible triggering microbial factor in the initiation of the autoimmune responses in these diseases because bacterial molecular sequences resemble brain antigens, especially in animals affected with BSE and patients with MS and CJD. These possibilities need to be evaluated further with longitudinal prospective studies carried out on larger numbers of animals or humans with such diseases. The transplantation of saline suspensions of brain homogenates will evoke immunological responses and therefore, the results in the study of MS and other neurological diseases have to be interpreted with caution.

Oral bacterial flora of dogs with and without rabies: a preliminary study in Thailand.

The authors studied the bacterial flora of the dog oral cavity and of bite wounds, Aerobic bacteria were isolated from mouth swabs of 16 normal and 5 rabid dogs as well as from infected dog-bite wounds from 18 patients. A total of 20 different microbial species were recovered from mouth swab cultures. The most frequently isolated organisms were Klebsiella pneumoniae ssp pneumoniae, Escherichia coli, Staphylococcus aureus, Citrobacter freundii, Enterobacter cloacae, Acinetobacter calcoaceticus, and Pasteurella species. There were no differences in the aerobic bacterial flora between rabid and nonrabid dogs. From the cultures of the bite wound swabs, the authors found that almost all of the organisms identified were part of the normal oral flora of the dog. One or more aerobic bacteria were isolated from the infected dog-bite wounds. Two patients had four, 3 had three, 4 had two, and 6 had one of the nine organisms in their wounds. The predominant species of bacteria involved in infection of bite wounds were, as follows: Staphylococcus aureus, Pasteurella multocida, E. coli, Moraxella species, Pasteurella canis, and Enterobacter cloacae. However, three wound cultures had no aerobic bacterial growth. The results of this study show that the infected bite wounds may contain a mixed bacterial flora that colonize human skin and the oral cavity of dogs.

[New data on the spread of P-41-positive strains of the rabies virus in arctic and extra-arctic regions]. / Novye dannye o rasprostranenii P-41 polozhitel'nykh shtammov rabicheskogo virusa v arkticheskom i vnearkticheskom regionakh.

271 strains of rabies virus, isolated in different regions of the former USSR, were studied with the use of monoclonal antibodies P-41 (Germany). All strains isolated in the arctic regions, as well as some of the strains isolated in nonarctic regions situated 300-1700 km south of the polar circle (the Baltic countries, Central Yakutia, the eastern part of the Transbaikal region), gave positive reaction with these antibodies. Cases of hydrophobia caused by virus with the 41 (+) marker were described. Information on the spread such strains in other parts of the world is presented.

Target cells of cytotoxic T lymphocytes directed to the individual structural proteins of rabies virus.

Target cells of cytotoxic T lymphocytes (CTL) directed to the individual structural proteins (except for the large polymerase (L) protein) of rabies virus were established by expressing only the respective protein in murine neuroblastoma (NA) and murine macrophage (J774-1) cell lines. Mice infected with the ERA strain of rabies virus developed CTL responses to all of these rabies virus proteins. The cytotoxic activity was abrogated by pretreatment of the effector cells with anti-CD8 monoclonal antibody (MAb) and complement but not with anti-CD4 MAb. Cell lysis by CTL was blocked in the presence of anti-major histocompatibility complex (MHC) class 1 antibodies in J774-1 cell lines. Rabies virus-infected cells express these proteins at the surface, which can be recognized and lysed by the respective CTL. Mice immunized with beta-propiolactone-inactivated virus induced a CTL response against glycoprotein but not against internal viral components. This assay system might be useful for further analysis of the possible contribution of these proteins in the cell-mediated immune protection against rabies.

Experimental rabies infection of non-nervous tissues in skunks (Mephitis mephitis) and foxes (Vulpes vulpes).

Non-neural tissues, from three male and four female stripped skunks (Mephitis mephitis), 5 to 7 months old, and one male and two female red foxes (Vulpes vulpes), 12 to 16 months old, experimentally infected with street rabies virus, were examined by light microscopic immunohistochemical and electron microscopic methods. This is the first report of ultrastructural lesions in rabies-infected adrenal medulla, cornea, and nasal glands. Using the streptavidin biotin peroxidase technique, antigen was detected in mucous cells and interstitial neurons and their processes in the submandibular salivary gland, in chromaffin cells of the adrenal medulla, in epidermal cells of the skin, in external root sheath cells of hair follicles, and in corneal epithelial cells. Electron microscopically, matrix (viral nucleocapsid), virions, and anomalous viral products were common in most tissues examined, but their relative proportions varied. The results suggested that replication with minimal accumulation of matrix and anomalous viral growth products was characteristic of growth in tissues (submandibular salivary gland) that frequently produce high titers of virus, whereas replication with large amounts of matrix and anomalous structures occurred in tissues (adrenal gland and nasal gland) that generally contained low or moderate titers of virus. Novel findings included viral budding into secretory granules, increase in microfilaments in infected mucogenic cells, and continuity of viral convoluted membranous profiles with rough endoplasmic reticulum of chromaffin cells and nasal glandular cells. The presence of viral antigen and developing virus in extra-neural tissues constitutes a potential risk of non-bite exposure to people in certain groups/occupations.

Further studies on the susceptibility of raccoons (Procyon lotor) to a rabies virus of skunk origin and comparative susceptibility of striped skunks (Mephitis mephitis).

Two raccoons (Procyon lotor) were inoculated in the masseter muscles with 10(5.9) mouse intracerebral lethal dose50 (MICD50) of a rabies virus isolated from a naturally infected Iowa (USA) striped skunk (Mephitis mephitis). Five striped skunks were inoculated with either 10(0.7) or 10(2.1) MICLD50 of the same isolate. All five skunks died within 35 days following inoculation. Both raccoons survived 273 days without adverse effects, and virus was not isolated from saliva samples taken at between 25 and 273 days following inoculation.

Occurrence of human rabies in peninsular Malaysia.

The occurrence of a case of human rabies in Peninsular Malaysia is reported. Despite the various control measures taken, sporadic cases of rabies have continued to occur in Peninsular Malaysia, especially in the northern states. Clinical awareness of the occurrence of rabies is therefore important and effective post-exposure prophylaxis should be instituted as soon as possible to prevent the possible occurrence of this dreaded disease.

Differentiation of two rabies strains in Estonia with reference to recent Finnish isolates.

We compared 24 rabies samples collected in Estonia in 1989 to 1992, to identify the kinds of rabies strains circulating in this country. Eleven of the strains came from the islands of Saaremaa, Hiiumaa and Muhu, off the Baltic coast; 13 came from the mainland. The mainland strains, like those from the 1988 to 1989 epizootic in Finland, were antigenically different from the 11 island isolates. The island isolates reacted negatively with monoclonal antibody W-187.5 as does the SAD B19 rabies vaccine strain, currently spread as baits to wildlife in Finland and other parts of Europe. In order to unambiguously distinguish the island isolates from the SAD B19 vaccine, we developed a polymerase chain reaction (PCR) protocol for rabies, followed by a single restriction enzyme digestion. This method enabled the island isolates to be differentiated with ease from the vaccine strain SAD B19 at the level of the nucleoprotein-coding region. Additionally, this method had the ability to distinguish other polar field isolates examined, as well as the laboratory challenge virus strain CVS, from SAD B19 vaccine. Modifications of the above PCR method may be used for epidemiological investigations of new outbreaks or of outbreaks involving different species.

Detection of rabies virus in different tissues of experimentally infected mice at preclinical and postclinical stages of the disease.

Rabies fixed virus (CVS) was passaged 10 times in mice by intramuscular (im) route followed by experimental inoculation of the titrated virus in 4 groups of mice with the dose of 0.1 ml of 1000 mouse (LD50 0.03 ml) using intracerebral (ic), intravenous (iv), intramuscular (im), intraocular (io), and intranasal (in) routes respectively. No marked variation in clinical signs due to variation of routes could be detected. Involvement of brain with io route could be detected even in preclinical stage. Although the virus could be detected in the postclinical stage in all the tissues under study (brain, skin, salivary gland and corneal impression), with io and ic routes spread of the virus was observed in comparatively higher concentrations.

[Experimental infection of sheep with a rabies virus of canine origin: study of the pathogenicity for that species]. / Infección experimental de ovinos por un virus de la rabia de origen canino: estudio del poder patógeno para esta especie.

The effects of the inoculation of a canine strain of rabies virus in sheep were studied using ten animals which received different amounts of this virus. Two subjects, inoculated with 10(5.4) mouse intracerebral lethal doses 50% (MICLD50), died from rabies after 19 and 40 days of incubation. Clinical signs were anorexia, emaciation, nervous reactions and prostration before death. The virus was recovered from different parts of the central nervous system and salivary glands with high titres. Only three animals showed an antibody response, at very low levels.

[A lyssavirus with an unusual antigenic structure isolated from a bat in southern Kyrgyzstan]. / Lissavirus s neobychnoi antigennoi strukturoi, vydelennoi ot letuchei myshi na iuge Kyrgyzstana.

Examination of 191 specimens of Chiroptera in Osh Province of Kyrgyzstan yielded 1 strain of lyssavirus from Myotis blythi, the isolate not belonging to serotype 1. The virus was designated Aravan by the area of its isolation. Its antigenic structure was studied using antinucleocapsid monoclonal antibodies of the Wistar Institute (Philadelphia, ISA) and Central Veterinary Laboratory of Great Britain (Waybridge, Great Britain). The paper presents its antigenic profile, brief characteristics of similarity and differences of the Aravan strain and known lyssavirus serotypes.

Epidemiologic and historical relationships among 87 rabies virus isolates as determined by limited sequence analysis.

Nucleotide sequence analysis of a 200-bp region of the nucleoprotein (N) gene of rabies virus differentiated unique genetic groups of rabies virus from samples collected in areas where dog rabies is enzootic in Asia, Africa, Europe, and the Americas. Patterns of nucleotide sequence identified for an outbreak area were conserved in samples collected over three decades. Epidemiologic relationships among isolates were determined by patterns of conserved nucleotide sequence, and the degree of sequence divergence between samples from separate outbreak areas were measured. This approach suggested that a historical reconstruction of events leading to the introduction of rabies into an area would be possible. In this broader view of rabies epidemiology, the cultural legacy of European exploration and colonization may have also included zoonotic disease.