Daniele De Meneghi

Rickettsia Infection in Dogs and Rickettsia parkeri in Amblyomma tigrinum Ticks, Cochabamba Department, Bolivia

Only few published data are available on ticks and tick-borne zoonotic pathogens in Bolivia. To evaluate rickettsial seroprevalence and infection in dogs and ticks, during February-April 2007, we collected whole blood, sera, and ticks from dogs living in the rural, peri-urban, and urban areas of Cochabamba, Bolivia. Dog sera were subjected to enzyme-linked immunosorbent assay test to detect IgG antibodies against Rickettsia rickettsii and 68.2% of samples were found to be positive (n = 30; 95% confidence interval [CI]: 52.4-81.4). Blood samples and ticks were tested using polymerase chain reaction to detect spotted fever group (SFG) rickettsiae. One blood sample was positive for Rickettsia parkeri (2.3%; 95% CI: 0.06-12.3). Ticks were collected from 10 dogs and were identified as Amblyomma tigrinum (n = 44) and Rhipicephalus sanguineus (n = 1). All A. tigrinum ticks were collected from resident dogs from the rural areas of Cochabamba, whereas R. sanguineus was from a dog originating from Santa Cruz. Of 42 DNA samples extracted from ticks, 23 (54.8%; 95% CI: 38.7-70.1) were polymerase chain reaction positive for Rickettsia spp. Sequencing analysis identified 22 samples as R. parkeri and one as Rickettsia aeschlimannii. Positive ticks (all A. tigrinum) were collected from six dogs, all of which were seropositive. This is the first report of SFG rickettsiae in A. tigrinum, suggesting that this tick-like others species in the Amblyomma maculatum group--may play a role in the biological cycle of Ri. parkeri. The high infection prevalence of SFG rickettsiae in ticks and the even higher seroprevalence in dogs suggest an active circulation of agents of rickettsiosis in the study area, although there are no confirmed cases of infection in humans. Our study supports the use of canine serology as risk indicator for SF rickettsioses.

A Blueprint to Evaluate One Health

One Health (OH) positions health professionals as agents for change and provides a platform to manage determinants of health that are often not comprehensively captured in medicine or public health alone. However, due to the organization of societies and disciplines, and the sectoral allocation of resources, the development of transdisciplinary approaches requires effort and perseverance. Therefore, there is a need to provide evidence on the added value of OH for governments, researchers, funding bodies, and stakeholders. This paper outlines a conceptual framework of what OH approaches can encompass and the added values they can provide. The framework was developed during a workshop conducted by the “Network for Evaluation of One Health,” an Action funded by the European Cooperation in Science and Technology. By systematically describing the various aspects of OH, we provide the basis for measuring and monitoring the integration of disciplines, sectors, and stakeholders in health initiatives. The framework identifies the social, economic, and environmental drivers leading to integrated approaches to health and illustrates how these evoke characteristic OH operations, i.e., thinking, planning, and working, and require supporting infrastructures to allow learning, sharing, and systemic organization. It also describes the OH outcomes (i.e., sustainability, health and welfare, interspecies equity and stewardship, effectiveness, and efficiency), which are not possible to obtain through sectoral approaches alone, and their alignment with aspects of sustainable development based on society, environment, and economy.

Genome analysis of small-ruminant lentivirus genotype E: a caprine lentivirus with natural deletions of the dUTPase subunit, vpr-like accessory gene, and 70-base-pair repeat of the U3 region.

ABSTRACT The nucleotide sequence of the highly divergent small-ruminant lentivirus genotype E has been determined. The full genome consists of 8,418 nucleotides and lacks two large portions corresponding nearly to the entire dUTPase subunit of the pol and vpr-like accessory genes. Moreover, the 70-bp repeat of the U3 region of the long terminal repeat was observed to be deleted. Interestingly, this lentivirus genotype is able to persist in a local breed population, and retrospective analysis revealed its presence in milk samples collected in 1999. gag sequences obtained from a flock coinfected with the B1 and E genotypes revealed that the evolutionary rates of the two viruses were quite similar. Since a reduced viral load and/or disease progression was observed for viruses with artificially deleted dUTPase and vpr-like genes, it is proposed that this viral cluster be designated a low-pathogenicity caprine lentivirus.

Divergent environmental preferences and areas of sympatry of tick species in the Amblyomma cajennense complex (Ixodidae)

Four species of Neotropical ticks, Amblyomma mixtum, Amblyomma cajennense, Amblyomma tonelliae and Amblyomma sculptum (formerly included in the catch-all name A. cajennense), have an allopatric distribution in much of their range, with areas of parapatry for at least two of them. We inferred the abiotic niches of these organisms using coefficients of a harmonic regression of the temperature and the Normalized Difference Vegetation Index (NDVI, reflecting plant stress) from remotely sensed data from MODIS satellites with 0.05° spatial resolution. Combinations of coefficients describing the phenology of these two variables pointed to divergent niche preferences, compatible with previous events of vicariance among the species. Amblyomma cajennense has been recorded in areas with small variations in temperature and NDVI. The remaining species were recorded in areas with large variations. The maximum environmental niche overlap was ∼73.6% between A. mixtum and A. cajennense and 73.5% between A. tonelliae and A. sculptum. Projecting these inferences on the geographical space revealed probable areas of sympatry or parapatry between A. mixtum and A. cajennense or between A. tonelliae and A. sculptum, the latter of which was confirmed with field collections. The A. sculptum distribution overlaps with that of A. tonelliae in northern Argentina and Paraguay; parapatry occurs at one extreme of the conditions occupied by both species. Compared with areas of allopatry, sites with both species had consistently lower temperatures, except for 10-12weeks during the summer, and higher NDVI values throughout the year. We hypothesise that the overlap between A. tonelliae and A. sculptum resulted from secondary contact between populations, with A. sculptum adapting to sites with high water availability to balance high summer temperatures. Additional surveys of the areas of spatial overlap among these species are necessary to elucidate the forces driving their evolution and their adaptation to the environment.

Experiences in Tick Control by Acaricide in the Traditional Cattle Sector in Zambia and Burkina Faso: Possible Environmental and Public Health Implications.

Livestock, especially cattle, play a paramount role in agriculture production systems, particularly in poor countries throughout the world. Ticks and tick-borne diseases (TBDs) have an important impact on livestock and agriculture production in sub-Saharan Africa. The authors review the most common methods used for the control of ticks and TBDs. Special emphasis is given to the direct application of acaricides to the host animals. The possible environmental and public health adverse effects (i.e., risks for the workers, residues in the environment and in food products of animal origin) are mentioned. The authors present two case studies, describing different field experiences in controlling ticks in two African countries. In Zambia (Southern Africa), a strategic dipping regime was used to control Rhipicephalus appendiculatus ticks, vectors of theileriosis, a deadly disease affecting cattle in the traditional livestock sector in Southern Province. The dipping regime adopted allowed to reduce the tick challenge and cattle mortally rate and, at the same time, to employ less acaricide as compared to the intensive dipping used so far, without disrupting the building-up of enzootic stability. In Burkina Faso (West Africa), where dipping was never used for tick control, an acaricide footbath was employed as an alternative method to the traditional technique used locally (portable manual sprayers). This was developed from field observations on the invasion/attachment process of the Amblyomma variegatum ticks – vector of cowdriosis – on the animal hosts, leading to a control method aimed to kill ticks temporarily attached to the interdigital areas before their permanent attachment to the predilection sites. This innovative method has been overall accepted by the local farmers. It has the advantage of greatly reducing costs of treatments and has a minimal environmental impact, making footbath a sustainable and replicable method, adoptable also in other West African countries. Although the two methods described, developed in very different contexts, are not comparable – if public health and environmental implications are taken into account, if a balance among efficacy of the control method(s), cost-effectiveness and sustainability is reached – a way forward for the implementation of a One Health strategy can be set.

Colostrum and milk can transmit jaagsiekte retrovirus to lambs

Ovine pulmonary adenocarcinoma (OPA) is a contagious disease caused by jaagsiekte sheep retrovirus (JSRV). In the three studies performed, we have obtained data of the importance of colostrum/milk (C/M) in the transmission of JSRV. In the first study, a group of sheep from a flock with a long history of OPA, samples from colostrum and peripheral blood leucocytes (PBLs) were collected. Two specific PCRs (U3-LTR and env of the JSRV) were carried out. Using U3PCR 8/34 sheep were positive in colostrum whereas with envPCR 7/34 were positive. From these animals only one was positive with U3PCR in the PBLs. Evidence of the transmission of JSRV infection by C/M was obtained in two more separate studies. In the second study, PBLs from five lambs from JSRV+ ewes and two from JSRV-ewes were tested by the U3PCR. They were fed C/M by their mothers during 3 months and slaughtered 7 months after birth. Three out of five lambs from the JSRV+ sheep become PBL positive at 3-4 months old and the other two were also positive at 4-6 months of age. One lamb of the JSRV-sheep became also PBL positive at an age of 3 months. In the third study, a group of lambs from JSRV negative mothers were fed with C/M from JSRV+ sheep and housed in separate unit. For comparison, another group of the same origin and maintained in another different unit, were fed with C/M containing a JSRV virus preparation. All lambs were blood sampled monthly and JSRV infection was detected as early as 15 days and several times onwards in both groups. Control groups fed with C/M from JSRV free flock and JSRV blood test negative sheep were always negative. Together these results indicate that suckling is an important natural transmission route for JSRV.

Identification of Mycobacterium avium subsp. paratuberculosis in wild cervids ( Cervus elaphus hippelaphus and Capreolus capreolus ) from Northwestern Italy

Seventy-seven red deer (Cervus elaphus hippelaphus), 40 roe deer (Capreolus capreolus) from the Northwestern (NW) Alps (Turin Province, NW Italy) and 29 roe deer from the NW Apennines (Alessandria province, NW Italy) were examined for the presence of Mycobacterium avium subsp. paratuberculosis (MAP) by culture, IS900 nested polymerase chain reaction (PCR) and IS1311 PCR restriction endonuclease analysis for strain characterisation. MAP identification (nested PCR and/or culture) allowed us to detect 32.9% MAP-infected red deer and 22.5% infected roe deer in the NW Alps and 41.4% MAP infected roe deer in the NW Apennines. On the basis of the polymorphism present in the IS1311 sequence, all MAP isolates were characterised as cattle strains. Our results show that MAP circulates widely among populations of wild cervids in NW Italy.

Immunological parameters in goats experimentally infected with SRLV genotype E, strain Roccaverano

Genotype E of small ruminant lentivirus has been recently described in goats from different breeds in Italy. Genotype E infection may differ from known genotypes since deletions of dUTPase and VPR proteins have been confirmed in different independent areas and goat breed, and play a key role on virus replication and pathogenesis. In particular, genotype E Roccaverano strain has been described as low pathogenic since does not lead to clinical symptoms in goats. In contrast, classical CAEV infected goats of the same area and breed presented arthritis. In this study, we have used intratracheal and intra-bone marrow routes to establish genotype E persistent infections. Humoral and cellular immune responses elicited in the host against genotype E and genotype B derived antigens were evaluated until 200 days post-inoculation. Compared to genotype B antigen, seroconversion against genotype E GAG P16-25 antigen was detected at 2-3 weeks after inoculation, significantly earlier and at higher titres. Interestingly, antibody avidity did not increase in the course of the experiment neither against P16-25 nor against SU5, both derived from genotype E. T cell proliferation against P25-GST fusion protein antigens derived from genotype E was firstly detected at 15 days post-inoculation and was maintained throughout time until week 20 post-infection, while T cell proliferation against the genotype B P25 was not produced by the end of the experiment at 20 weeks post-inoculation. The strength of reaction was also higher when using P25 E as stimulator antigen. In contrast with antibody and T cell proliferation, cytotoxic-T-lymphocyte (CTL) activity in the circulating lymphocytes (effector cells) using blood-derived macrophages (BDM) as target cells, was not strain specific being surprisingly higher against genotype B infected antigen presenting cells (APCs). This is the first study reporting experimentally induced immunological changes in SRLV genotype E infection and indicates that CTL activity may be the adaptive immune response able to induce protection against heterologous infection.

Setting priorities for surveillance, prevention, and control of zoonoses in Bogotá, Colombia

OBJECTIVE To establish priorities for zoonoses surveillance, prevention, and control in Bogotá, Colombia. METHODS A Delphi panel of experts in veterinary and human medicine was conducted using a validated prioritization method to assess the importance of 32 selected zoonoses. This exercise was complemented by a questionnaire survey, using the knowledge, attitudes, and practices (KAP) methodology, administered in 19 districts of Bogotá from September 2009 to April 2010 to an at-risk population (workers at veterinary clinics; pet shops; butcher shops; and traditional food markets that sell poultry, meat, cheese, and eggs). A risk indicator based on level of knowledge about zoonoses was constructed using categorical principal component and logistic regression analyses. RESULTS Twelve experts participated in the Delphi panel. The diseases scored as highest priority were: influenza A(H1N1), salmonellosis, Escherichia coli infection, leptospirosis, and rabies. The diseases scored as lowest priority were: ancylostomiasis, scabies, ringworm, and trichinellosis. A total of 535 questionnaires were collected and analyzed. Respondents claimed to have had scabies (21%), fungi (8%), brucellosis (8%), and pulicosis (8%). Workers with the most limited knowledge on zoonoses and therefore the highest health risk were those who 1) did not have a professional education, 2) had limited or no zoonoses prevention training, and 3) worked in Usme, Bosa, or Ciudad Bolívar districts. CONCLUSIONS According to the experts, influenza A(H1N1) was the most important zoonoses. Rabies, leptospirosis, brucellosis, and toxoplasmosis were identified as priority diseases by both the experts and the exposed workers. This is the first prioritization exercise focused on zoonoses surveillance, prevention, and control in Colombia. These results could be used to guide decision-making for resource allocation in public health.

An integrated database on ticks and tick-borne zoonoses in the tropics and subtropics with special reference to developing and emerging countries

Tick-borne zoonoses (TBZ) are emerging diseases worldwide. A large amount of information (e.g. case reports, results of epidemiological surveillance, etc.) is dispersed through various reference sources (ISI and non-ISI journals, conference proceedings, technical reports, etc.). An integrated database—derived from the ICTTD-3 project (http://www.icttd.nl)—was developed in order to gather TBZ records in the (sub-)tropics, collected both by the authors and collaborators worldwide. A dedicated website (http://www.tickbornezoonoses.org) was created to promote collaboration and circulate information. Data collected are made freely available to researchers for analysis by spatial methods, integrating mapped ecological factors for predicting TBZ risk. The authors present the assembly process of the TBZ database: the compilation of an updated list of TBZ relevant for (sub-)tropics, the database design and its structure, the method of bibliographic search, the assessment of spatial precision of geo-referenced records. At the time of writing, 725 records extracted from 337 publications related to 59 countries in the (sub-)tropics, have been entered in the database. TBZ distribution maps were also produced. Imported cases have been also accounted for. The most important datasets with geo-referenced records were those on Spotted Fever Group rickettsiosis in Latin-America and Crimean-Congo Haemorrhagic Fever in Africa. The authors stress the need for international collaboration in data collection to update and improve the database. Supervision of data entered remains always necessary. Means to foster collaboration are discussed. The paper is also intended to describe the challenges encountered to assemble spatial data from various sources and to help develop similar data collections.