Rearing Management and Its Impact on Caseous Lymphadenitis in Sheep.

Two surveys were conducted to assess the prevalence and risk factors of ovine caseous lymphadenitis (CL) and explore the association between its superficial and visceral forms in Sardi sheep in Settat province, Morocco. A total of 1521 sheep, including 318 lambs < 6 months, 572 young sheep aged 6-24 months, and 631 adult sheep > 24 months, were examined from 57 flocks. Superficial CL prevalence levels were as follows: 69/318 in lambs, 292/572 in young sheep, and 114/631 in adult sheep. Additionally, 2124 sheep, including 1813 young and 311 adult sheep, were inspected in slaughterhouses ante- and post-mortem. Among all infected animals, the prevalence of visceral abscesses was notably higher in adult sheep (83%, OR = 9.8, 95% CI = 5.5-17.2) compared to young sheep (35%). Data on flock size, sex, age, body condition score, rearing methods, and hygienic measures were collected. Suspected CL cases were confirmed using quadruplex-PCR. Poor barn ventilation, lack of abscess control, and younger age were identified as key risk factors for CL. Additionally, a high percentage (89%) of animals with thoracic abscesses did not display superficial lesions. While age and abscess control have been reported in previous studies, barn ventilation appears to be a new, but important, risk factor. In conclusion, the identified risk factors in Settat province are linked to breeding management practices. Implementing regular abscess control measures and improving barn ventilation are essential for CL prevention.

Evaluation of dog vaccination schemes against rabies in Kinshasa, Democratic Republic of the Congo.

The traditional rabies control strategy based on annual mass vaccination of dogs appears to be costly and cumbersome. Given the existence of different risk zones for rabies transmission, the present study aimed at proposing risk-based vaccination schemes by considering canine population dynamics as well as vaccine efficacy and duration of immunity (DOI). The capital of the Democratic Republic of the Congo (RDC), Kinshasa, was chosen as study site. The turnover rate of dogs was used to assess their population dynamics in two low-roaming (<25 % of dogs are roaming) and in two high-roaming zones (>75 % of dogs are roaming). The sero-conversion rate was assessed in response to primo-vaccination in three age groups: 24 puppies (≤3months), 37 juveniles (4-12 months) and 22 adult dogs. The DOI was evaluated serologically by revaccinating dogs previously vaccinated since 1-2 years (n = 31), 2-3 years (n = 12) or 3-7.5 years (n = 4). Rapid Fluorescent Focus Inhibition Test was used to quantify antibodies. These data were used to implement vaccination outcome models.The turnover rate was twice as high in high-roaming zones (36 %) as that in lowroaming zones (17 %). Irrespective of roaming level, 75 % of dogs were less than 3 years old. The vaccine was equally effective in puppies (96 %), juvenile (97 %) and adult dogs (100 %, p = 0.24). The vaccine was effective in 93 % (11/12) of puppies without pre-vaccinal protective titers (≥0.5 IU/mL). The anamnestic response was strong within 5-8 days upon the booster vaccination, in 96 % (45/47) of dogs reported vaccinated 1-7.5 years before. This suggests that the vaccine provided a long-term protection (≥3 years) which is likely to occur in 75 % of dogs in Kinshasa.Hypothesizing a vaccination stop, the vaccination outcome model allowed to estimate the time point after which vaccination coverage would drop below 40 % in function of dog population turnover rate. The systematic vaccination of puppies as well as annual vaccination of dogs aged between 3 and 15 months or annual vaccination of all unvaccinated dogs aged more than 3 months of age appeared as valuable alternative to systematic annual mass vaccination.In conclusion, this study developed a vaccination outcome model pointing out the impact of dog population dynamics and of effective duration of immunity. It appears as a promising tool for designing cost-effective rabies vaccination campaigns.

Feasibility and acceptability of a new integrated approach to control cystic echinococcosis in Morocco: Vaccination of sheep and anthelmintic treatment of dogs.

Cystic echinococcosis (CE) or hydatidosis is a common parasitic disease worldwide, especially in poor and developing countries. In Morocco, CE is a major zoonosis, despite the implementation of a national control program since 2007. Therefore, in 2016, a field trial that associates the EG95 vaccine (lambs) and anthelmintic treatment (dogs) was started in the Mid Atlas, the most endemic region in Morocco, with preliminary positive results. Here, a qualitative approach was used to analyze the feasibility and social acceptability of this strategy. Fifteen focus group discussions were separately conducted with breeders and with their wives, and forty-two individual interviews were performed with private-sector veterinarians and officers from structures responsible for the CE control program. Recordings were transcribed and analyzed with the R software, using the RQDA package. This qualitative research was validated using the credibility, transferability, dependability and confirmability criteria. This study showed that the professionals' views on sheep vaccination and anthelmintic treatment were divided between acceptability and concerns. Conversely, breeders and their wives highlighted the issue of the costs of procedures the utility of which was not immediately clear to them. All participants proposed solutions to improve this strategy, and also stressed the lack of education on CE. By bringing together the views of the communities and the professionals, this study traced the main lines (targeting the different aspects of CE and taking into account the local socio-cultural beliefs) that must be taken into account to ensure the short- and long-term CE control in Morocco.

Control of cystic echinococcosis in the Middle Atlas, Morocco: Field evaluation of the EG95 vaccine in sheep and cesticide treatment in dogs.

BACKGROUND: Cystic echinococcosis (CE) is an important cause of human morbidity and mortality worldwide, particularly in Morocco and other North African countries. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the potential of three strategies to reduce Echinococcus granulosus transmission: (1) 4-monthly treatment of dogs with praziquantel, (2) vaccination of sheep with the EG95 vaccine and (3) a combination of both measures. These measures were implemented during four consecutive years in different areas of the Middle Atlas Mountains in Morocco. The outcome of the interventions was assessed through hydatid cyst (viable and non-viable) counts in liver and lungs using necropsy or in vivo ultrasound examination of the liver. A total of 402 lambs were recruited for annual vaccination with the EG95 anti-E. granulosus vaccine and 395 similar lambs were selected as non-vaccinated controls. At approximately four years of age the relative risk (estimated as odds ratio) for vaccinated sheep to have viable hydatid cysts compared with non-vaccinated controls was 3% (9.37% of the vaccinated sheep were found infected while 72.82% of the controls were infected; p = 0.002). The number of viable cysts in vaccinated animals was reduced by approximately 97% (mean counts were 0.28 and 9.18 respectively; p<0.001). An average of 595 owned dogs received 4-monthly treatment during the 44 months trial, corresponding to 91% of the owned dog population. Approximately, 5% of them were examined for E. granulosus adult worms by arecoline purge or eggs in feces (confirmed by PCR). The proportion of infected dogs significantly decreased after treatment (12% versus 35%; p<0.001). Post-treatment incidence of re-infestation corresponded to a monthly risk of 4% (95% CI: 3-6%). Treatment of owned dogs on a 4-monthly basis did not reduce the level of transmission of E. granulosus to sheep, nor did it enhance the level of control generated by vaccination of sheep with EG95, possibly because of unowned dogs and wild canids were not treated. CONCLUSIONS/SIGNIFICANCE: These data suggest that vaccination of sheep with EG95 has the potential to reduce the level of CE in Morocco and in other parts of the world with similar transmission dynamics. Under the epidemiological circumstances existing in the trial area, 4-monthly treatment of owned dogs with praziquantel was insufficient to have a major impact of E. granulosus transmission to sheep.

Brucellosis in wildlife in Africa: a systematic review and meta-analysis.

This study aimed to consolidate current knowledge of wildlife brucellosis in Africa and to analyse available predictors of infection. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Information on species, test used, test results, area, rainfall, livestock and wildlife contact and year of study were extracted. This systematic review revealed 42 prevalence studies, nine disease control articles and six articles on epidemiology. Brucella abortus, Brucella melitensis, Brucella inopinata and Brucella suis were reported in wildlife. The prevalence studies revealed serological evidence of brucellosis in buffalo, antelope (positive in 14/28 species), carnivores (4/12) and other species (7/20) over the last five decades. Buffalo populations were more likely to be infected and had a higher seroprevalence than other species; the pooled seroprevalence was 13.7% (95% CI 10.3-17.3%) in buffalo, 7.1% (95% CI 1.1-15.5%) in carnivores and 2.1% (95% CI 0.1-4.9%) in antelope. Wildlife in high rainfall areas (≥ 800 mm) were more likely to be infected, and infected populations showed higher seroprevalence in high rainfall areas and in studies published after 2000. Domestic animal contact was associated with increased seroprevalence in antelope and carnivore species, but not in buffalo, supporting the hypothesis that buffalo may be a reservoir species.

Using qualitative approaches to explore the challenges of integrated programmes for zoonosis control in developing countries: Example of hydatidosis control in Morocco.

Cystic echinococcosis, rabies and bovine tuberculosis are major neglected zoonoses in many developing countries, including Morocco. A common step in their control strategies is the management of slaughterhouses and/or the control of dog populations. This study used a qualitative approach to identify the barriers to the implementation of the cystic echinococcosis control programme in Morocco that focused on slaughterhouses and dog control. This approach could be used to understand the causes leading to the defective management of other zoonoses, and to go beyond the often-invoked 'lack of means' reason to explain failure in disease control in the Global South. Specifically, slaughterhouse observation and in-depth individual interviews with stakeholders involved in the cystic echinococcosis control programme were carried out in five Moroccan regions (Rabat-Sale-Kenitra, Mellal-Khenifra, Sous-Masaa, Laayoune-Sakia El Hamra and Guelmim-Oued Noun) for 3 years (from 2014 to 2016). Interviews (n = 81) were with agents responsible of the services managing slaughterhouses and dog population control, and also with slaughterers. Recordings were fully transcribed and narratives were analysed with the RQDA package and the R software. Triangulations and the criteria proposed by Guba and Lincon were used to assess the approach validity. This analysis revealed that in addition to 'lack of means', zoonosis control programmes can be hindered by overlapping authority/functions among the involved authorities, conflicts of interest, lack of proper training and professional practices. Zoonosis control requires the commitment of all structures, the establishment of a national and inter-regional strategy, and the updating of the legislative arsenal.

Stakeholder analysis to improve the national control program of cystic echinococcosis in Morocco.

Cystic echinococcosis (CE) is a major zoonosis in Morocco. Despite a national hydatidosis control programme (NHCP) established in 2005, CE burden is still high nationwide. The aim of this study was to carry out an NHCP stakeholders' analysis to identify weak points and propose improvement strategies. In total, 164 semi-structured interviews were carried out with national and local stakeholder representatives, and one stakeholders' workshop was organized. Classical categories of stakeholder analysis (i.e. involvement, interest, importance, influence, priority, and power) were semi-quantified. Based on these categories, an analytical framework was proposed, by selecting elements from the stakeholder analysis, to structure the assessment around three criteria: measure appropriation, political agency, and socio-technical agency. Besides specific weak points of the NHCP, the analysis highlighted the complexity of implementing a zoonotic disease control programme due to the involvement of many different stakeholders. Finally, this study provides a simplified stakeholder analysis method that could be used to assess other health programmes targeting zoonotic diseases, in Morocco and in similar countries.

An alternative cold chain for storing and transporting East Coast fever vaccine.

East Coast fever (ECF) is an often fatal, economically important cattle disease that predominantly affects eastern, central, and southern Africa. ECF is controlled through vaccination by means of simultaneous injection of oxytetracycline and cryogenically preserved stabilate containing live, disease-causing parasites. Storage and transportation of the stabilate requires liquid nitrogen, a commodity that is commonly unreliable in low-resource settings. Here we show that storage of conventionally prepared stabilate at -80 °C for up to 30 days does not significantly affect its ability to infect cultured peripheral blood mononucleated cells or live cattle, suggesting an alternative cold chain that maintains these temperatures could be used to effectively manage ECF.

The socio-economic burden of cystic echinococcosis in Morocco: A combination of estimation method.

Cystic echinococcosis (CE) is a major zoonosis in Morocco despite the launch of a national control programme in 2005. As its economic consequences have not been studied yet in Morocco, this study estimated CE impact in terms of monetary losses, disability-adjusted life years (DALY), and DALY for zoonotic diseases (zDALY) in the entire country and in specific regions for the 2011 to 2014 period. The direct monetary losses were related to organ seizure from infected animal in slaughterhouses, and to healthcare expenses as well as lost wages for infected humans. Animal production losses concerned milk yield, fertility, carcass weight, and wool production. Losses due to human infection were also composed of disability and productivity losses at work. Monte Carlo simulations were used to estimate monetary losses and zDALY values. Nationwide, the estimated DALY was 0.5 years per 100,000 persons per year, and the zDALY was 55 years per 100,000 persons per year. Total yearly losses were estimated at 73 million USD (54-92 million USD). However, losses differed significantly among regions. Most of the economic losses consisted of unperceived consequences, i.e. decreased animal production and reduced productivity of asymptomatic individuals. Future studies should determine the socioeconomic and epidemiological factors underlying the differences in economic losses among regions to develop better adapted control programmes.

Cystic Echinococcosis in Three Locations in the Middle Atlas, Morocco: Estimation of the Infection Rate in the Dog Reservoir.

A longitudinal study was carried out in Middle atlas, Morocco (locality of Had Oued Ifrane) in a population of 255 dogs from three localities, including two categories of dogs (owned and stray dogs). The dogs were investigated three times over a period ranging from 4 to 8 months between December and August. At each investigation, dogs were treated with arecoline, inducing defecation and allowing feces collection. Dogs were further treated with praziquantel to clear them from Echinococcus granulosus. Microscopic examination of feces was performed to assess the infection status of dogs at each investigation, and positive samples underwent copro-PCR to determine the circulating strain of E. granulosus. A high prevalence of infestation ranging from 23.5% to 38.8% and from 51.3% to 68.5% was, respectively, found in owned and in stray dogs. The PCR results revealed the presence of G1 strain in all positive samples. A logistic regression model was used to determine the incidence of infestation and showed that stray dogs underwent a significantly higher risk of infection (odds ratio = 14; 95% confidence interval: 6-30; p < 0.001) compared with owned dogs. Only anthelmintic treatment intervals of 2 months efficiently prevented egg shedding in owned and stray dogs. The seasonal effect was also significant, with the highest risk of reinfestation in winter and the lowest risk in summer. This study confirms that stray dogs undergo an increased risk of infestation by E. granulosus and indicate that infective pressure is influenced by season.

Genetic and antigenic variation of the bovine tick-borne pathogen Theileria parva in the Great Lakes region of Central Africa.

BACKGROUND: Theileria parva causes East Coast fever (ECF), one of the most economically important tick-borne diseases of cattle in sub-Saharan Africa. A live immunisation approach using the infection and treatment method (ITM) provides a strong long-term strain-restricted immunity. However, it typically induces a tick-transmissible carrier state in cattle and may lead to spread of antigenically distinct parasites. Thus, understanding the genetic composition of T. parva is needed prior to the use of the ITM vaccine in new areas. This study examined the sequence diversity and the evolutionary and biogeographical dynamics of T. parva within the African Great Lakes region to better understand the epidemiology of ECF and to assure vaccine safety. Genetic analyses were performed using sequences of two antigen-coding genes, Tp1 and Tp2, generated among 119 T. parva samples collected from cattle in four agro-ecological zones of DRC and Burundi. RESULTS: The results provided evidence of nucleotide and amino acid polymorphisms in both antigens, resulting in 11 and 10 distinct nucleotide alleles, that predicted 6 and 9 protein variants in Tp1 and Tp2, respectively. Theileria parva samples showed high variation within populations and a moderate biogeographical sub-structuring due to the widespread major genotypes. The diversity was greater in samples from lowlands and midlands areas compared to those from highlands and other African countries. The evolutionary dynamics modelling revealed a signal of selective evolution which was not preferentially detected within the epitope-coding regions, suggesting that the observed polymorphism could be more related to gene flow rather than recent host immune-based selection. Most alleles isolated in the Great Lakes region were closely related to the components of the trivalent Muguga vaccine. CONCLUSIONS: Our findings suggest that the extensive sequence diversity of T. parva and its biogeographical distribution mainly depend on host migration and agro-ecological conditions driving tick population dynamics. Such patterns are likely to contribute to the epidemic and unstable endemic situations of ECF in the region. However, the fact that ubiquitous alleles are genetically similar to the components of the Muguga vaccine together with the limited geographical clustering may justify testing the existing trivalent vaccine for cross-immunity in the region.

Community perception and knowledge of cystic echinococcosis in the High Atlas Mountains, Morocco.

BACKGROUND: Cystic echinococcosis (CE), a neglected zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus, remains a public health issue in many developing countries that practice extensive sheep breeding. Control of CE is difficult and requires a community-based integrated approach. We assessed the communities' knowledge and perception of CE, its animal hosts, and its control in a CE endemic area of the High Atlas Mountains, Morocco. METHODS: We conducted twenty focus group discussions (FGDs) stratified by gender with villagers, butchers and students in ten Berber villages that were purposefully selected for their CE prevalence. RESULTS: This community considers CE to be a severe and relatively common disease in humans and animals but has a poor understanding of the parasite's life cycle. Risk behaviour and disabling factors for disease control are mainly related to cultural practices in sheep breeding and home slaughtering, dog keeping, and offal disposal at home, as well as in slaughterhouses. Participants in our focus group discussions were supportive of control measures as management of canine populations, waste disposal, and monitoring of slaughterhouses. CONCLUSIONS: The uncontrolled stray dog population and dogs having access to offal (both at village dumps and slaughterhouses) suggest that authorities should be more closely involved in CE control. This study also highlights the need for improved knowledge about the transmission cycle of the parasite among communities and health professionals. Inter-sectoral collaboration between health staff, veterinarians, and social scientists appears to be crucial for sustainable control of this parasitic zoonosis.

Mitochondrial phylogeography and population structure of the cattle tick Rhipicephalus appendiculatus in the African Great Lakes region.

BACKGROUND: The ixodid tick Rhipicephalus appendiculatus is the main vector of Theileria parva, wich causes the highly fatal cattle disease East Coast fever (ECF) in sub-Saharan Africa. Rhipicephalus appendiculatus populations differ in their ecology, diapause behaviour and vector competence. Thus, their expansion in new areas may change the genetic structure and consequently affect the vector-pathogen system and disease outcomes. In this study we investigated the genetic distribution of R. appendiculatus across agro-ecological zones (AEZs) in the African Great Lakes region to better understand the epidemiology of ECF and elucidate R. appendiculatus evolutionary history and biogeographical colonization in Africa. METHODS: Sequencing was performed on two mitochondrial genes (cox1 and 12S rRNA) of 218 ticks collected from cattle across six AEZs along an altitudinal gradient in the Democratic Republic of Congo, Rwanda, Burundi and Tanzania. Phylogenetic relationships between tick populations were determined and evolutionary population dynamics models were assessed by mismach distribution. RESULTS: Population genetic analysis yielded 22 cox1 and 9 12S haplotypes in a total of 209 and 126 nucleotide sequences, respectively. Phylogenetic algorithms grouped these haplotypes for both genes into two major clades (lineages A and B). We observed significant genetic variation segregating the two lineages and low structure among populations with high degree of migration. The observed high gene flow indicates population admixture between AEZs. However, reduced number of migrants was observed between lowlands and highlands. Mismatch analysis detected a signature of rapid demographic and range expansion of lineage A. The star-like pattern of isolated and published haplotypes indicates that the two lineages evolve independently and have been subjected to expansion across Africa. CONCLUSIONS: Two sympatric R. appendiculatus lineages occur in the Great Lakes region. Lineage A, the most diverse and ubiquitous, has experienced rapid population growth and range expansion in all AEZs probably through cattle movement, whereas lineage B, the less abundant, has probably established a founder population from recent colonization events and its occurrence decreases with altitude. These two lineages are sympatric in central and eastern Africa and allopatric in southern Africa. The observed colonization pattern may strongly affect the transmission system and may explain ECF endemic instability in the tick distribution fringes.

Immunological response to Brucella abortus strain 19 vaccination of cattle in a communal area in South Africa.

Brucellosis is of worldwide economic and public health importance. Heifer vaccination with live attenuated Brucella abortus strain 19 (S19) is the cornerstone of control in low- and middle-income countries. Antibody persistence induced by S19 is directly correlated with the number of colony-forming units (CFU) per dose. There are two vaccination methods: a 'high' dose (5-8 × 1010 CFU) subcutaneously injected or one or two 'low' doses (5 × 109 CFU) through the conjunctival route. This study aimed to evaluate serological reactions to the 'high' dose and possible implications of the serological findings on disease control. This study included 58 female cases, vaccinated at Day 0, and 29 male controls. Serum was drawn repeatedly and tested for Brucella antibodies using the Rose Bengal Test (RBT) and an indirect enzyme-linked immunosorbent assay (iELISA). The cases showed a rapid antibody response with peak RBT positivity (98%) at 2 weeks and iELISA (95%) at 8 weeks, then decreased in an inverse logistic curve to 14% RBT and 32% iELISA positive at 59 weeks and at 4.5 years 57% (4/7 cases) demonstrated a persistent immune response (RBT, iELISA or Brucellin skin test) to Brucella spp. Our study is the first of its kind documenting the persistence of antibodies in an African communal farming setting for over a year to years after 'high' dose S19 vaccination, which can be difficult to differentiate from a response to infection with wild-type B. abortus. A recommendation could be using a 'low' dose or different route of vaccination.

Prevalence of Selected Zoonotic Diseases and Risk Factors at a Human-Wildlife-Livestock Interface in Mpumalanga Province, South Africa.

A lack of surveillance and diagnostics for zoonotic diseases in rural human clinics limits clinical awareness of these diseases. We assessed the prevalence of nine zoonotic pathogens in a pastoral, low-income, HIV-endemic community bordering wildlife reserves in South Africa. Two groups of participants were included: malaria-negative acute febrile illness (AFI) patients, called febrilers, at three clinics (n = 74) and second, farmers, herders, and veterinary staff found at five government cattle dip-tanks, called dip-tanksters (n = 64). Blood samples were tested using one PCR (Bartonella spp.) and eight antibody-ELISAs, and questionnaires were conducted to assess risk factors. Seventy-seven percent of febrilers and 98% of dip-tanksters had at least one positive test. Bartonella spp. (PCR 9.5%), spotted fever group (SFG) Rickettsia spp. (IgM 24.1%), Coxiella burnetii. (IgM 2.3%), and Leptospira spp. (IgM 6.8%) were present in febrilers and could have been the cause of their fever. Dip-tanksters and febrilers had evidence of past infection to Rickettsia spp. (IgG 92.2% and 63.4%, respectively) and C. burnetii (IgG 60.9% and 37.8%, respectively). No Brucella infection or current Bartonella infection was found in the dip-tanksters, although they had higher levels of recent exposure to Leptospira spp. (IgM 21.9%) compared to the febrilers. Low levels of West Nile and Sindbis, and no Rift Valley fever virus exposure were found in either groups. The only risk factor found to be significant was attending dip-tanks in febrilers for Q fever (p = 0.007). Amoxicillin is the local standard treatment for AFI, but would not be effective for Bartonella spp. infections, SFG rickettsiosis, Q fever infections, or the viral infections. There is a need to revise AFI treatment algorithms, educate medical and veterinary staff about these pathogens, especially SFG rickettsiosis and Q fever, support disease surveillance systems, and inform the population about reducing tick and surface water contact.

Documenting the absence of brucellosis in cattle, goats and dogs in a "One Health" interface in the Mnisi community, Limpopo, South Africa.

This study shows the absence of the world's most common bacterial zoonoses caused by Brucella abortus and Brucella melitensis in cattle, goats and dogs in an agro-pastoral community in South Africa, where heifer vaccination against brucellosis with the live Strain 19 vaccine is compulsory. The study site is bordering wildlife reserves with multiple wildlife species infected with brucellosis. The results showed a low seroprevalence (1.4%) in cattle. Seroprevalence in cattle decreased with age after 4 years in females, males were less positive than females and a tissue culture from a brucellin skin test-positive male was negative. The results indicate that Brucella seropositivity in cattle is due to S19 vaccination and not natural infections. This conclusion is reinforced by the absence of Brucella seropositivity in goats (1/593 positive result) and dogs (0/315), which can be seen as potential spillover hosts. Therefore, the close proximity of brucellosis-infected wildlife is not a threat to domestic animals in this controlled setting with vaccination, fencing and movement control.

Why pigs are free-roaming: Communities' perceptions, knowledge and practices regarding pig management and taeniosis/cysticercosis in a Taenia solium endemic rural area in Eastern Zambia.

Taenia solium cysticercosis is a neglected parasitic zoonosis in many developing countries including Zambia. Studies in Africa have shown that the underuse of sanitary facilities and the widespread occurrence of free-roaming pigs are the major risk factors for porcine cysticercosis. Socio-cultural determinants related to free range pig management and their implications for control of T. solium remain unclear. The study objective was to assess the communities' perceptions, reported practices and knowledge regarding management of pigs and taeniosis/cysticercosis (including neurocysticercosis) in an endemic rural area in Eastern Zambia, and to identify possible barriers to pig related control measures such as pig confinement. A total of 21 focus group discussions on pig husbandry practices were organized separately with men, women and children, in seven villages from Petauke district. The findings reveal that the perception of pigs and their role in society (financial, agricultural and traditional), the distribution of the management tasks among the family members owning pigs (feeding, building kraal, seeking care) and environmental aspects (feed supply, presence of bush, wood use priorities, rainy season) prevailing in the study area affect pig confinement. People have a fragmented knowledge of the pork tapeworm and its transmission. Even if negative aspects/health risks of free-range pigs keeping are perceived, people are ready to take the risk for socio-economic reasons. Finally, gender plays an important role because women, and also children, seem to have a higher perception of the risks but lack power in terms of economic decision-making compared to men. Currently pig confinement is not seen as an acceptable method to control porcine cysticercosis by many farmers in Eastern Zambia, vaccination and treatment seemed to be more appropriate. Embedded in a One Health approach, disease control programs should therefore ensure a complementary appropriate set of control strategies by engaging new sectors such as agronomy, spatial ecology and finally consider the socio-cultural context, which is likely to enhance the development of control methods that could be accepted by the communities.

Impact of habitat fragmentation on tsetse populations and trypanosomosis risk in Eastern Zambia.

BACKGROUND: Fragmentation of tsetse habitat in eastern Zambia is largely due to encroachments by subsistence farmers into new areas in search of new agricultural land. The impact of habitat fragmentation on tsetse populations is not clearly understood. This study was aimed at establishing the impact of habitat fragmentation on physiological and demographic parameters of tsetse flies in order to enhance the understanding of the relationship between fragmentation and African animal trypanosomosis (AAT) risk. METHODS: A longitudinal study was conducted to establish the age structure, abundance, proportion of females and trypanosome infection rate of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in areas of varying degrees of habitat fragmentation in Eastern Zambia. Black screen fly rounds were used to sample tsetse populations monthly for 1 year. Logistic regression was used to analyse age, proportion of females and infection rate data. RESULTS: Flies got significantly older as fragmentation increased (p < 0.004). The proportion of old flies, i.e. above ovarian category four, increased significantly (P < 0.001) from 25.9% (CI 21.4-31.1) at the least fragmented site (Lusandwa) to 74.2% (CI 56.8-86.3) at the highly fragmented site (Chisulo). In the most fragmented area (Kasamanda), tsetse flies had almost disappeared. In the highly fragmented area a significantly higher trypanosome infection rate in tsetse (P < 0.001) than in areas with lower fragmentation was observed. Consequently a comparatively high trypanosomosis incidence rate in livestock was observed there despite lower tsetse density (p < 0.001). The overall proportion of captured female flies increased significantly (P < 0.005) as fragmentation reduced. The proportion increased from 0.135 (CI 0.10-0.18) to 0.285 (CI 0.26-0.31) at the highly and least fragmented sites, respectively. CONCLUSIONS: Habitat fragmentation creates conditions to which tsetse populations respond physiologically and demographically thereby affecting tsetse-trypanosome interactions and hence influencing trypanosomosis risk. Temperature rise due to fragmentation coupled with dominance of old flies in populations increases infection rate in tsetse and hence creates high risk of trypanosomosis in fragmented areas. Possibilities of how correlations between biological characteristics of populations and the degree of fragmentation can be used to structure populations based on their well-being, using integrated GIS and remote sensing techniques are discussed.

Longevity of Mycobacterium bovis in Raw and Traditional Souring Milk as a Function of Storage Temperature and Dose.

BACKGROUND: Unpasteurised fresh and souring dairy products form an essential component of household diets throughout many rural communities in southern Africa. The presence of milk-borne zoonotic pathogens such as Mycobacterium bovis (M. bovis), the causative agent of bovine tuberculosis and zoonotic tuberculosis in humans, constitute a public health threat, especially in remote areas with poor disease surveillance in livestock and highly compromised human health due to HIV/AIDS. METHODS: In this study we used culture to determine the longevity of M. bovis in experimentally inoculated fresh and naturally souring milk obtained from communal cattle in the KwaZulu-Natal province of South Africa. The effect of bacterial load and storage temperature on the survival of M. bovis was evaluated by spiking mixtures of fresh milk and starter soured milk (aMasi) culture with three concentrations of bacteria (10(2), 10(4), 10(7) colony forming units/ml), followed by incubation under controlled laboratory conditions that mimicked ambient indoor (20°C) and outdoor (33°C) temperatures and periodic sampling and testing over time (0-56 days). RESULTS: M. bovis cultured from samples of the fresh and souring milk was identified by PCR analysis. At the highest spiking concentration (10(7) cfu/ml), M. bovis survived for at least 2 weeks at 20°C; but, at all concentrations in the 33°C treatment, M. bovis was absent by three days after inoculation. Logistic regression analysis was used to assess the effects of bacterial concentration and time since inoculation, as well as determine the potential half-life of M. bovis in raw souring milk. Given the most favourable tested conditions for bacterial survival (20°C), approximately 25% of mycobacteria were alive after one day of storage (95% CI: 9-53%), giving an estimated half-life of M. bovis in raw souring milk of approximately 12 hours (95% CI: 7-27 hours). CONCLUSIONS: This study demonstrates that M. bovis may survive in fresh and souring milk for periods of time that represent a risk of exposure to people consuming these products, as well as domestic or wild animal populations that have reported opportunities to consume homemade unpasteurised dairy products. The temperature at which the milk is soured and stored substantially affects the survival time of M. bovis.