Buffalopox.

Buffalopox is a contagious viral disease affecting milch buffaloes (Bubalus Bubalis) and, rarely, cows. The disease has zoonotic implications, as outbreaks are frequently associated with human infections, particularly in the milkers. Buffalopox is associated with high morbidity (80%). The clinical symptoms of the disease are characterized by wartline lesions on the udder, teats, inguinal region, base of the ears, and over the parotid. In the severe form, generalized rash is observed. Although the disease does not lead to high mortality, it has an adverse effect on the productivity and working capacity of the animals resulting in large economic losses. The outbreaks of buffalopox occurred frequently in India, Pakistan, Bangladesh, Nepal, Iran, Egypt, and Indonesia, where buffaloes are reared as milch animals. The buffalopox is closely related with other Orthopoxviruses. In particular, it is close to the vaccinia virus. There is a view that the buffalopox virus might be derived from the vaccinia virus. It is possible that it became pathogenic to humans and animals through adaptive evolution of the genome by obtaining the virulence genes. PCR is performed for the C18L gene for the purpose of specific detection and differentiation of the buffalopox virus from other orthopoxviruses. The C18L gene encodes the ankyrin repeat protein, which determines the virus host range. The open reading frame of this gene is only 150-nucleotide long as against 453 nucleotide in the vaccinia virus, 756 - in the camelpox virus, and 759 - in the cowpox virus. It can be concluded that a systematic study based on the epidemiology of the virus, existence of reservoirs, biological transmission, and the molecular organization of the buffalopox virus from buffalo, cow, and humans may pave the way to a better understanding of the circulating virus and contribute to the control of the disease using the suitable diagnostic and prophylactic measures.

[Vaccine-like viruses: peculiarities of circulation in the South America].

The peculiarities of the spread of vaccine-like viruses first revealed more than 50 years ago in the area of the South America was discussed. These viruses cause infective episodes among milk cattle and caretaking personnel. Cancellation of the smallpox vaccination in 1980 resulted in a decrease in the community immunity and increased the risks of human infection. This circumstance makes it necessary to activate monitoring of the properties of the vaccine-like viruses, the circle of hosts and possible changes in the pathogenicity for humans.

[Monkeypox: features of spread after cancellation of mandatory pox immunization].

Features of spread of monkeypox after eradication of smallpox and cancellation of mandatory pox immunization are examined. In the condition of cancellation of mandatory pox immunization, a decrease of population immunity to pox in the population, a lack of vigilance in most of the medical specialists to diseases caused by other pathogenic for human orthopoxviruses was noted. This situation complicates the prognosis of the development of possible outbreaks of infection of humans by monkeypox. In such situation only constant vigilance with respect to this zooanthroponosis, use of express diagnostics methods, as well as means of effective protection will allow to stop outbreaks of monkeypox at the early stages of the development.

[Cowpox: features of spread after cancellation of mandatory pox immunization].

Features of spread of cowpox in the contemporary conditions are examined. A decrease of population immunity to pox in the population of Russia caused by cancellation of pox immunization, hidden circulation of cowpox virus in various species of rodents, as well as lack of vigilance to pathogenic orthopoxviurses in healthcare workers were noted to create the real preconditions for the emergence of infection of humans caused by cowpox virus. Thereby presence of means of express laboratory diagnostics of cowpox and means of effective medical protection for the prevention of development of this disease in the population of Russia becomes an actual necessity.

[Smallpox is a dormant volcano].

The presence of rodent-associated natural foci containing at least 6 of the known 11 viruses belonging to the genus Orthopoxvirus (Poxviridae, Chordopoxvirinae) within the equatorial, tropical, subtropical, temperate, and subarctic climatic zones; the increasing aggravation of the monkey pox epidemic situation in equatorial Africa with an increase in human mortality by an average of 9.8% with a possibility of 2 to 8 passages in 30-70% of patients; the possible persistence of a virus in the human cadavers buried in the permafrost of Eurasia and America; bioterrorism threat due to the unaccounted viral reserves persisting somewhere or somebody; no postvaccinal human immunity since vaccination and vaccine manufacture stopped 30 years ago as recommended by the WHO, make the risk of the deteriorating epidemic situation with disastrous effects greater now and in the foreseeable future than it was 20-30 years ago. Health care academic circles and bodies do not know methods for rapid diagnosis in the field conditions of species-specific identification smallpox virus or preventive (low-reactogenic, effective vaccines, and those accessible for mass production) and therapeutic (nontoxic drugs, those satisfactory for mass production, inexpedient, effective ones when orally used) agents. Basic studies of biodiversity, functional properties of viral DNA and proteins, pathogenesis, and evolution are required. Live smallpox virus should be used at certain and particularly final stages for these studies that are of scientific and applied significance.

Comparison of the genetic maps of variola and vaccinia viruses.

The complete genetic map of the variola major virus strain India-1967 is built basing on the sequence data. The suggested map is compared with the maps of the sequenced genomic regions of Copenhagen and Western Reserve strains of vaccinia virus and Harvey strain of variola major virus. The principle differences revealed in the genomic organization of these viruses are discussed.

Nucleotide sequence analysis of variola virus HindIII M, L, I genome fragments.

DNA of the variola major virus strain India-1967 in the region of HindIII M, L, I fragments has been sequenced. Analysis of this sequence of 18029 bp revealed 19 potential open reading frames (ORFs). Four proposed proteins (L2R, H9R, L5L, L6R) contain metal-binding domains. Comparison of the variola virus (VAR) and vaccinia virus strain Copenhagen (COP) sequences show that the main differences are between proteins L1R and I5R. L1R contains 6 additional amino acid residues on the C-terminus. The protein I5R of VAR contains three Ca2+ binding domains but this COP has deletions in 2 of the 3 established domains. Possible functions of the predicted viral polypeptides are discussed.

Pox infection in white rats.

2 pox outbreaks among white rats in a breeding colony are described. The infection occurred in 3 different forms: pulmonary, dermal and mixed. Apparently healthy animals appeared to be virus carriers. The virus isolated belonged to the genus Orthopoxvirus of Poxviridae family, and was very close to cowpox virus. It differed from reference strains of cowpox virus in having a lower ceiling temperature and a higher pathogenicity for white rats.

A method for serological differentation of closely related poxviruses.

A two-step gel precipitation reaction with antiserum to vaccinia virus, based on sequential addition of two test viruses was elaborated for differentiation of closely related orthopoxviruses. The appearance of an additional precipitation line indicated differences in the antigenic structure of the viruses compared. Differences in the antigenic structure of vaccinia, variola and monkey pox viruses as well as the antigenic identity with cow pox virus of poxviruses isolated from carnivora, elephants and okapi were established.

Experimental infection of domestic cats by cowpox virus.

Infection of young domestic cats by cowpox virus isolated from sick rodents (family Muridae) revealed their high susceptibility to the virus; a severe disease with 100% lethality developed after oral inoculation as well as upon skin scarification. The disease in dermally infected animals was accompanied by eruptions on the site of inoculation. High concentration of the virus was detected in lungs of animals infected by either of inoculation routes. The data testify the possible participation of domestic cats as intermediate hosts in the circulation of cowpox virus.

New outlook on the biology of cowpox virus.

Analysis of cowpox outbreaks revealed an extremely wide range of virus pathogenicity including 9 orders of mammals. Recent serological and virological data support the hypothesis that wild rodents may be a natural reservoir of cowpox virus. Cowpox infection of humans occurring without any contact with infected cattle (registered in the U. K. and Poland) is especially interesting for medical and veterinary virology. Surveillance seems justified of the possible virus dissemination beyond its natural reservoir resulting in further infection of man and animals.

"White-wild" (variola-like) poxvirus strains from rodents in Equatorial Africa.

Strains of variola-like virus were isolated from rodents, namely 1 each from Mastomys coucha (fam. Muridae) and Helioscorus rufobrachium (fam. Sciuridae) in the Bumba zone of the Equatorial province of the Zaire Republic. Attempts to isolate the virus from 48 monkeys were negative. Neutralizing antibodies were found in 1 of 7 monkey (Cercopithecus ascanius schmidti) sera examined as well as in the serum of H. rufobrachium from which the virus was isolated.

Variola virus strains of 1960--1975: the range of intraspecies variability and relationship between properties and geographic origin.

A comparative study of 61 variola virus strains recovered from patients in various geographic regions of the world revealed significant intraspecies variability in some biological properties, established the range of this variability and demonstrated the existence of strains with atypical properties. There was a certain correlation between some laboratory markers of variola virus and the degree of its pathogenicity for man. The prevalence of more virulent and thermoresistant strains in the Hindustan subcontinent and the peculiarity and heterogeneity of the strains circulating in Africa were demonstrated. Alastrim virus was detected among the African isolates.

Standardization of ELISA for detection of antibodies to orthopoxviruses.

The experience with ELISA technique utilized at serological screening for orthopoxviruses in the Republic of Ivory Coast revealed factors reducing the sensitivity and the specificity of the test. It was found out that routine controls such as "positive" and "negative" sera as well as the accepted reading of the results by two-fold or higher increase of OD values as compared to the "negative" control may be not sufficient. A significantly enhanced sensitivity and specificity of reaction was achieved by simultaneous examination of each serum under study with a control antigen. Selection of optimal dilutions of each test component followed by spectrophotometric assay and calculation of results according to the given formula contributed to the same aim. As a result of these improvements the rate of antibody detection among revaccinees was enhanced from 19 to 78.8% and the titres of ELISA and virus neutralization tests correlated in 88% of cases.

Monoclonal antibodies to monkey pox virus: preparation and application.

Two fusion experiments with NSO myeloma cells yielded 30 hybrid cell lines which continuously and actively secreted monoclonal antibodies (MoAb) to monkey pox virus. Eight lines appeared to produce antibodies to specific antigenic determinants. The isotype and serologic reactivity of MoAb to monkey pox virus was characterized and the karyotype of several hybridomas determined. An enzyme labelled conjugate has been prepared from MoAb selectively reacting with monkey pox virus. This conjugate allowed the identification of monkey pox virus in the materials from patients. It also helped to determine that an orthopoxvirus isolated from wild squirrel in the Republic of Zaire was monkey pox virus.

Monkey pox in humans: current results.

The presented studies were performed at the WHO Collaboration Center for Smallpox in Moscow in the framework of the WHO monkey pox project. The authors recommend improved methods for rapid detection of orthopoxvirus antigen, namely passive haemagglutination (PHA) using dried stable red blood cells and ELISA in order to provide more rapid and efficient laboratory diagnosis under field conditions. Independent serologic diagnosis of monkey pox by ELISA-adsorption (ELISA-A) was proved of value for epidemiological studies and for detection of inapparent infections. The application range of the latter technique and its limitations were also determined.

[Comparative restriction enzyme analysis of the genome in variola virus strains from the Russian collection]. / Sravnitel'nyi restriktsionnyi analiz genomov shtammov virusa natural'noi ospy iz Rossiiskoi kollektsii.

Comparative RFLP analysis was for the first time performed for 21 variola virus (VARV) strains of the Russian collection with 20 amplicons covering the total VARV genome. The amplicons were synthesized in the long polymerase chain reaction. A database useful as a reference for identifying VARV strains was generated. VARV strains isolated in different geographical regions were compared and proved to vary mostly in variable genome regions. Each of the dendrograms constructed included three clusters of African, Asian, and VARV-alastrim isolates. The VARV-alastrim isolates differed to the greatest extent from the other strains. VARV strains isolated during an ecdemic variola burst in Moscow (1960) grouped with Asian isolates. Polymorphism of VARV strains was for the first time observed for a single variola burst with a few affected patients.

[Study of the structure-activity organization of the variola virus genome. II. Analysis of the nucleotide sequence of the HindIII region (C,E,R,Q,K and H)-DNA fragments of the India-1967 strain]. / Izuchenie strukturno-funktsional'noi organizatsii genoma virusa natural'noi ospy. II. Analiz posledovatel'nosti nukleotidov raiona HindIII (C,E,R,Q,K i H)-fragmentov DNK shtamma india-1967.

Sequencing of variola virus (VAR) genome region of 43069 bp was carried out. This area contains 42 potential genes. Computer analysis of proteins coding for these viral genes was done. We compared VAR proteins with the those of vaccinia virus. The region studied is conservative for orthopoxviruses.

[Study of the structural-functional organization of the natural variola virus genome. I. Cloning HindIII- and XhoI-fragments of viral DNA and sequencing HindIII -M, -L, -I fragments]. / Izuchenie strukturno-funktsional'noi organizatsii genoma virusa natural'noi ospy. I. Klonirovanie HindIII- i XhoI-fragmentov virusnoi DNK i sekvenirovanie HindIII-M, -L, -I fragmentov.

HindIII and XhoI genome fragments of variola major virus strain India-1967 were inserted into the bacterial plasmids and cosmid. Sequencing and computer analysis of the region of HindIII M, L, and I DNA fragments of the virus studied have been carried out.