Short communication: Parapoxvirus and Orthopoxvirus coinfection in milk of naturally infected cows

Abstract

Several studies have shown the occurrence of poxvirus infections associated with exanthematic lesions in cattle from many Brazilian states. Coinfection between viruses belonging to 2 genera, Orthopoxvirus (OPXV) and Parapoxvirus (PPV), was already identified from the lesions of affected cows and humans. The DNA and infectious viral particles of Vaccinia virus, an OPXV, have been detected in milk of naturally and experimentally infected cows. However, to date no reports have described the detection of Pseudocowpox virus, a PPV, in milk. Thus, we investigated the presence of PPV and OPXV in milk samples obtained from dairy cows from a Brazilian region with exanthematic disease outbreaks. From 2011 to 2014, 6 dairy farms with exanthematic disease outbreaks involving dairy cows, calves, and humans were visited. Twelve crusts of cows' teat lesions and 60 milk samples were collected. The crusts and milk samples were analyzed by PCR to detect OPXV or PPV DNA. According to the analyzed crusts, we detected PPV infection in 4 of the 6 visited farms, from which we investigated the PPV contamination in milk. From the 40 milk samples tested, PPV DNA was detected in 12 samples. Of these milk samples, 8 were positive for both PPV and OPXV. This is the first report of PPV DNA detection in milk samples from affected cows, indicating that the virus may be present in milk and potentially contaminating dairy products associated or not with OPXV. In addition to the lesions caused by direct contact, the presence of 2 or more poxvirus species in milk showed that the effect of zoonotic exanthematic diseases on public health and animal husbandry is relevant and cannot be overlooked.

Twenty Years after Bovine Vaccinia in Brazil: Where We Are and Where Are We Going?

“…The classic form of VACV transmission is through direct contact between the milkers and infected dairy cows, which characterizes BV as an occupational zoonosis [16]. Furthermore, the sick dairy workers are often removed from work, which results in disruption of the service in the affected rural properties, as well as additional expenses related to the replacement of human resources and decreases the familiar incomes of these affected milkers [13,20,22,23]. The following discussion of VACV and BV researches illustrates chronologically how they have become a very important part of virology and epidemiology history in Brazil during the past 20 years.…”

Low prevalence of anti‐Orthopoxvirus neutralizing antibodies in an urban population of Brazil

“…Seven unvaccinated individuals with detectable NA reported consumption of artisanal cheese and six of them reported consumption of made from raw milk, also suggesting the role of dairy products as alternative routes for zoonotic VACV transmission. Indeed, VACV has been detected in unpasteurized dairy products, however the effect of such contamination on VACV transmission to humans is still unknown 5,48–50 . Although the consumption of raw milk and artisanal cheese was not significantly associated with NA, additional population‐based studies and further assessments regarding dairy products as potential alternative routes of disease spread are necessary for guiding public health authorities in planning and implementation of preventive and control programs.…”

“…5,[48][49][50] Although the consumption of raw milk and artisanal cheese was not significantly associated with NA, additional Demographic characteristics and potential exposure factors related to the presence of anti-OPV neutralizing antibodies in unvaccinated individuals, Minas Gerais, Brazil, 2015-2018.…”

Educational Approach to Prevent the Burden of Vaccinia Virus Infections in a Bovine Vaccinia Endemic Area in Brazil

“…During a Buffalopox virus (a close variant of VACV) outbreak in Western Maharashtra, India, Gurav and colleagues suggested that individuals with oral lesions could have been infected due to the consumption of raw milk [ 33 ]. Additionally, some studies in Brazil have detected viable VACV particles in milk and dairy products [ 34 , 35 , 36 ]. However, there’s no evidence of oral infections caused by VACV directly associated with the consumption of raw milk, artisanal cheese, or other dairy products to date.…”