No Virological Evidence for an Influenza A ‐ like Virus in European Bats

New members of the influenza A virus genus have been detected recently in bats from South America. By molecular investigations, using a generic real‐time RT‐PCR (RT‐qPCR) that detects all previously known influenza A virus subtypes (H1‐H16) and a newly developed RT‐qPCR specific for the South American bat influenza‐like virus of subtype H17, a total of 1571 samples obtained from 1369 individual bats of 26 species from Central Europe were examined. No evidence for the occurrence of such influenza viruses was found. Further attempts towards a more comprehensive evaluation of the role of bats in the ecology and epidemiology of influenza viruses should be based on more intense monitoring efforts. However, given the protected status of bats, not only in Europe, such activities need to be embedded into existing pathogen‐monitoring programs.     

云南边境Asia 1型口蹄疫监测及病毒vp1基因序列比较

口蹄疫是由口蹄疫病毒引起的主要侵袭偶蹄动物的一种急性热性高度接触性传染病。口蹄疫病毒存在7个不同血清型,病毒VP1蛋白抗原性差异是病毒血清型划分依据,而其编码基因核苷酸序列差异是同型病毒Topotype型或基因型划分依据。采用RT-PCR及O／A／C／Asia1多重RT-PCR技术,对2006年期间自云南边境地区采集境外流动动物组织样品120份,进行口蹄疫病原监测,检出Asia1型口蹄疫病毒阳性样品7份。对阳性样品中病毒vp1基因全序列进行扩增、纯化后,克隆至pMD18-T载体测序,并与已知代表性毒株进行比对及系统发育分析。结果发现：云南边境Aisa1型口蹄疫病毒阳性样品vp1基因核苷酸序列同源性介于83．4％～99．5％,不同分离毒株以15％序列差异作为分型标准,存在1个新拓朴型或基因型V,且与已知的4个拓朴型或基因型不同。系统发育分析确定了1个新的遗传谱系Ⅶ。部分VP1蛋白表位关键性氨基酸位点存在变异。     

Syndromic survey and molecular analysis of influenza viruses at the human–swine interface in two West African cosmopolitan cities suggest the possibility of bidirectional interspecies transmission

Influenza viruses are frequently transmitted between pigs and their handlers, and among pig handlers. However, reports on socio‐environmental variables as potential risk factors associated with transmission of influenza in West African swine production facilities are very scarce. Syndromic survey for influenza was therefore conducted in Ibadan, Nigeria, and Kumasi, Ghana, in order to identify and elucidate selected socio‐environmental variables that may contribute to the occurrence and distribution of influenza‐like illness (ILI) among swine industry workers. In addition, molecular analyses were conducted to elucidate the nature of influenza viruses circulating at the human–swine interface in these cities and better understand the dynamics of their transmission. Influenza viruses were detected by type‐specific and subtype‐specific RT–PCR. Sequencing and phylogenetic analyses were carried out. Socio‐environmental variables were tested by both univariable and multivariable regression methods for significance at p < 0.05. Three risk factors for ILI were identified in each city. These included “frequency of visit of pig handler to pig pen or lairage” (Ibadan: risk ratio [RR] = 1.54, 95% confidence interval [CI] = 1.36–1.79, p = 0.02; Kumasi: RR = 1.28, 95% CI = 1.11–1.71, p = 0.01) and “pig handler's awareness about biosecurity measures” (Ibadan: RR = 7.09, 95% CI = 2.36–21.32, p < 0.001; Kumasi: RR = 4.84, 95% CI = 1.98–11.80, p < 0.001). Influenza A(H1N1)pdm09 viruses, with M genes closely related to those which circulated among pigs in the two cities during the same period, were detected among Nigerian and Ghanaian pig industry workers. These findings suggest the possibility of bidirectional transmission of influenza at the human–swine interface in these cities and underscore the need for more extensive molecular studies. Risk factors identified may assist in the control of human‐to‐human and human‐to‐swine transmission of influenza in the West African swine industry.     

Impacts of misclassification on Lyme disease surveillance

In Maryland, Lyme disease (LD) is the most widely reported tickborne disease. All laboratories and healthcare providers are required to report LD cases to the local health department. Given the large volume of LD reports, the nuances of diagnosing and reporting LD, and the effort required for investigations by local health department staff, surveillance for LD is burdensome and subject to underreporting. To determine the degree to which misclassification occurs in Maryland, we reviewed medical records for a sample of LD reports from 2009. We characterized what proportion of suspected and “not a case” reports could be reclassified as confirmed or probable once additional information was obtained from medical record review, explored the reasons for misclassification, and determined multipliers for a more accurate number of LD cases. We reviewed medical records for reports originally classified as suspected (n = 44) and “not a case” (n = 92). Of these 136 records, 31 (23%) suspected cases and “not a case” reports were reclassified. We calculated multipliers and applied them to the case counts from 2009, and estimate an additional 269 confirmed and probable cases, a 13.3% increase. Reasons for misclassification fell into three general categories: lack of clinical or diagnostic information from the provider; surveillance process errors; and incomplete information provided on laboratory reports. These multipliers can be used to calculate a better approximation of the true number of LD cases in Maryland, but these multipliers only account for underreporting due to misclassification, and do not account for cases that are not reported at all (e.g., LD diagnoses based on erythema migrans alone that are not reported) or for cases that are not investigated. Knowing that misclassification of cases occurs during the existing LD surveillance process underscores the complexities of LD surveillance, which further reinforces the need to find alternative approaches to LD surveillance.     

Control of cystic echinococcosis: Background and prospects

Cystic echinococcosis (CE), caused by Echinococcus granulosus, is a chronic and debilitating zoonotic larval cestode infection in humans, which is principally transmitted between dogs and domestic livestock, particularly sheep. Human CE occurs in almost all pastoral communities and rangeland areas of the underdeveloped and developed world. Control programmes against CE have been implemented in several endemic countries to reduce or eliminate the disease. New Zealand and Tasmania are examples of some of the first programmes to be undertaken (in insular territories) and which were very successful in the elimination of CE. The advent and proven effectiveness of praziquantel, plus the experience of insular models, produced high expectations for rapid advances in a second generation of control programmes undertaken in continental areas (Argentina, Uruguay and Chile). Nevertheless, only moderate gains in CE control have been made and the impact on prevalence among humans has been slight. A major impediment to the adoption of procedures that were successful in New Zealand and Tasmania has been the requirement to administer praziquantel to dogs in rural areas eight times per year over numerous years. In addition, there have been clear technological improvements made in the diagnosis of canine echinococcosis for surveillance, the genetic characterization of parasite strains and in vaccination against CE infection in livestock. In order to establish new paradigms and appropriate combinations of control strategies, we have carried out a review and discussion of the available control tools and control models. Control strategies must be suitable and sustainable to benefit the Echinococcosis–endemic areas primarily, which at the same time are the poorest regions of the world.     

Prevalence and antimicrobial resistance among Escherichia coli and Salmonella in Ontario smallholder chicken flocks

Surveillance is an important component of an overall strategy to address antimicrobial resistant bacteria in food animals and the food chain. The poultry market has many points of entry into the Canadian food chain, and some production practices are underrepresented in terms of surveillance. For example, pathogen carriage and antimicrobial resistance surveillance data are limited in smallholder chicken flocks raised for slaughter at provincially inspected abattoirs. In Canada, antimicrobial resistance in Escherichia coli and Salmonella isolated from commercial broiler chicken flocks, slaughtered at federally inspected abattoirs, is monitored by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS ). The objective of this study was to establish baseline information of antimicrobial resistance presence in E. coli and Salmonella isolated from smallholder flocks in Ontario, utilizing CIPARS collection and isolation methodologies, and to compare findings with CIPARS federally inspected abattoir data from Ontario, Canada. Five chickens per flock were sampled from 205 smallholder flocks. Of 1,025 samples, the E. coli prevalence was 99% (1,022/1,025), and 47% (483/1,022) of positive E. coli isolates were resistant to one or more of the 14 antimicrobials. Furthermore, as compared to results reported for the CIPARS commercial flocks, E. coli isolates from smallholder flocks had significantly lower resistance prevalence to six of 14 individual antimicrobials. Recovery of E. coli did not differ between federally inspected and provincially inspected flocks. Salmonella prevalence at the bird level in smallholder flocks was 0.3% (3/1,025), significantly lower (p  ? 0.0001, 95% CI 0.080%–0.86%) than federally inspected commercial flocks. The overall differences found between the commercial and smallholder flocks may be explained by differences in poultry husbandry practices and hatchery sources.     

Temporal trends in Giardia occurrence in the Grand River and surrounding tributaries,Waterloo, Ontario (2005–2013), a retrospective analysis of surveillance data

Giardia contamination in the Grand River Watershed (south‐western Ontario, Canada) was monitored from 2005 to 2013 as part of FoodNet Canada. Our study objectives were to describe the temporal pattern of Giardia occurrence and determine whether water quality parameters and bacterial indicators could act as effective markers for Giardia occurrence. Water samples were collected monthly from the Grand River near a drinking water intake point (2005–2013) and also collected intermittently from other areas in the watershed during the study period. Samples were tested for Giardia cysts using the US EPA method 1623. Samples were also tested for chemical and microbial water quality indicators. Univariable and multivariable linear regression models were built to examine whether temporal, water quality and bacterial indicators were associated with Giardia cyst concentration. Giardia cysts were identified in 89% of samples (n = 228), with highest measured concentrations downstream of a waste water treatment plant outfall. Year and season were found to be predictors for Giardia occurrence. Concentrations were significantly higher in the winter and fall compared to the summer, and significantly higher in 2007 compared to other study years. After controlling for season, year and sampling location, dissolved oxygen was the only variable significantly associated with Giardia cyst concentration. Seasonal peaks in Giardia cyst concentrations in samples collected near the intake for the drinking water plant did not align with the seasonal peak in human Giardiasis cases in this region that are reported annually by public health authorities. This suggests that the risk of contracting Giardiasis from treated drinking water in this community is possibly low when the treatment plant is functioning adequately. Instead, waterborne exposure is likely the result of seasonal behaviours surrounding recreational water use. Therefore, the collective findings of our study are important to help inform future risk management studies and guide public health protection policies.     

Epidemiological study of people living in rural North Carolina for novel respiratory viruses

During the last 10 years, scientists have grown increasingly aware that emerging respiratory viruses are often zoonotic in their origin. These infections can originate from or be amplified in livestock. Less commonly recognized are instances when humans have transmitted their respiratory pathogens to animals (reverse zoonoses). Even with this knowledge of viral exchange at the human–livestock interface, few studies have been conducted to understand this cross‐over. In this pilot study, we examined persons with influenza‐like illness at an outpatient clinic for evidence of infection with novel zoonotic respiratory pathogens in rural North Carolina where there are dense swine and poultry farming. Environmental air sampling was also conducted. From July 2016 to March 2017, a total of 14 human subjects were enrolled and sampled, and 192 bioaerosol samples were collected. Of the 14 human subject samples molecularly tested, three (21.4%) were positive for influenza A, one (7.1%) for influenza B and one (7.1%) for human enterovirus. Of the 192 bioaerosol samples collected and tested by real‐time RT‐PCR or PCR, three (1.6%) were positive for influenza A and two (1.0%) for adenovirus. No evidence was found for novel zoonotic respiratory viruses.     

完善我国动物卫生监测制度措施的若干建议——OIE标准视角下的动物卫生监测措施研究

动物疫病监测是防治动物疫病的关键。世界动物卫生组织(OIE)是动物卫生领域的权威国际组织,在动物疫病等卫生监测方面制定了科学的标准规则。本文拟在研究OIE标准规则的基础上,立足实际,提出进一步完善我国动物疫病监测制度措施的意见建议。