Recent years have seen a change in the relative prevalence of environmental and contagious intramammary pathogens, as well as a change in the relative number of total mixed ration (TMR)-based and pasture (PAS)-based dairies in South Africa. The objectives of the study were to determine and compare the prevalence of mastitis pathogens in TMR and PAS dairies in South Africa during 2008 and 2013; furthermore, the within-herd prevalence of Streptococcus uberis in Str. uberis-positive herds was determined and compared. The prevalence of each pathogen, as well as the within-herd prevalence of Str. uberis, were compared between the two years and the two management systems using bacterial culture results from routinely collected composite cow milk samples submitted to the Onderstepoort Milk Laboratory, Faculty of Veterinary Science, University of Pretoria. Coagulase-negative staphylococci had the highest prevalence in both TMR and PAS dairies for both 2008 (29.60% &#91;95.00% CI: 28.80% - 30.40%&#93; and 26.90% &#91;95.00% CI: 25.50% - 28.30%&#93;, respectively) and 2013 (20.20% &#91;95.00% CI: 19.30% - 21.10%&#93; and 22.70% &#91;95.00% CI: 22.20% - 23.10%&#93;, respectively), which decreased significantly from 2008 to 2013 in both TMR and PAS dairies (p < 0.001). Streptococcus uberis showed an increase in prevalence in both TMR (p = 0.002) and PAS dairies (p = 0.001) from 2008 (2.36% &#91;95.00% CI: 2.10% - 2.65%&#93; and 2.63% &#91;95.00% CI: 2.16% - 3.16%&#93;, respectively) to 2013 (3.10% &#91;95.00% CI: 2.72% - 3.51%&#93; and 3.64% &#91;95.00% CI: 3.45% - 3.83%&#93;, respectively). Staphylococcus aureus showed a significant decrease in both TMR (p = 0.011) and PAS (p < 0.001) dairies from 2008 (4.71% &#91;95.00% CI: 4.34% - 5.10%&#93; and 5.62% &#91;95.00% CI: 4.94% - 6.36%&#93;, respectively) to 2013 (3.95% &#91;95.00% CI: 3.52% - 4.40%&#93; and 1.71% &#91;95.00% CI: 1.58% - 1.84%&#93;, respectively). The median within-herd prevalence of Str. uberis for the combined dairy systems showed a significant increase from 2008 (1.72% &#91;IQR: 0.88% - 5.00%&#93;) to 2013 (3.10% &#91;IQR: 1.72% - 4.70%&#93;) (p < 0.001). Statistically significant differences were found in the prevalence of most of the major contagious and environmental mastitis pathogens between 2008 and 2013 and between TMR and PAS dairies. The within-herd prevalence of Str. uberis increased from 2008 to 2013, with the highest within-herd prevalence in PAS dairies in 2013.

Recent years have seen a change in the relative prevalence of environmental and contagious intramammary pathogens, as well as a change in the relative number of total mixed ration (TMR)-based and pasture (PAS)-based dairies in South Africa. The objectives of the study were to determine and compare the prevalence of mastitis pathogens in TMR and PAS dairies in South Africa during 2008 and 2013; furthermore, the within-herd prevalence of Streptococcus uberis in Str. uberis-positive herds was determined and compared. The prevalence of each pathogen, as well as the within-herd prevalence of Str. uberis, were compared between the two years and the two management systems using bacterial culture results from routinely collected composite cow milk samples submitted to the Onderstepoort Milk Laboratory, Faculty of Veterinary Science, University of Pretoria. Coagulase-negative staphylococci had the highest prevalence in both TMR and PAS dairies for both 2008 (29.60% [95.00% CI: 28.80% – 30.40%] and 26.90% [95.00% CI: 25.50% – 28.30%], respectively) and 2013 (20.20% [95.00% CI: 19.30% – 21.10%] and 22.70% [95.00% CI: 22.20% – 23.10%], respectively), which decreased significantly from 2008 to 2013 in both TMR and PAS dairies (p < 0.001). Streptococcus uberis showed an increase in prevalence in both TMR (p = 0.002) and PAS dairies (p = 0.001) from 2008 (2.36% [95.00% CI: 2.10% – 2.65%] and 2.63% [95.00% CI: 2.16% – 3.16%], respectively) to 2013 (3.10% [95.00% CI: 2.72% – 3.51%] and 3.64% [95.00% CI: 3.45% – 3.83%], respectively). Staphylococcus aureusshowed a significant decrease in both TMR (p = 0.011) and PAS (p < 0.001) dairies from 2008 (4.71% [95.00% CI: 4.34% – 5.10%] and 5.62% [95.00% CI: 4.94% – 6.36%], respectively) to 2013 (3.95% [95.00% CI: 3.52% – 4.40%] and 1.71% [95.00% CI: 1.58% – 1.84%], respectively). The median within-herd prevalence of Str. uberis for the combined dairy systems showed a significant increase from 2008 (1.72% [IQR: 0.88% – 5.00%]) to 2013 (3.10% [IQR: 1.72% – 4.70%]) (p < 0.001). Statistically significant differences were found in the prevalence of most of the major contagious and environmental mastitis pathogens between 2008 and 2013 and between TMR and PAS dairies. The within-herd prevalence of Str. uberis increased from 2008 to 2013, with the highest within-herd prevalence in PAS dairies in 2013.

Enterococcus species have developed from being commensal bacteria to leading pathogens that cause infections in humans and animals. The gastrointestinal tract of mammals is the normal habitat of these species. Virulence factors are proteins that are produced by the bacterium which are used to enhance their pathogenicity. The objectives of this study were to isolate Enterococcus spp. from livestock and companion animals, differentiate between the different sub-species and detect the presence of important virulence genes. Rectal and saliva swabs were collected from dogs and cats, whereas only rectal swabs were collected from cattle and cloacal swabs from chickens. Presumptive Enterococcus was selected using Bile Esculin Azide (BEA) agar, and Enterococcus species were confirmed using the polymerase chain reaction (PCR) by amplifying the tuf gene. In order to differentiate between E. faecalis and E. faecium, a multiplex PCR was used to detect the SodA gene. The genes responsible for gelatinase production (gelE) and for conjugation (ccf) were also detected using PCR. Out of 211 animal swabs, 182 (86%) were positive for the tuf gene. Overall, there were 55 isolates of E. faecalis (30%) compared to 22 isolates of E. faecium (12%). The virulence genes had a prevalence of 52% and 36% for gelE and ccf, respectively, in all animal hosts. The results demonstrated that chicken cloacal samples had the highest prevalence for E. faecalis, gelE and ccf genes compared to all the other isolates detected from other animal hosts. The results also demonstrated a statistically significant (p < 0.05) association between the prevalence of virulence genes (gelE and ccf) and animal species from which Enterococcus spp. was isolated. We provided evidence that healthy livestock and companion animals can harbour pathogenic Enterococcusthat can be transferred via the food chain as well as through close association such as petting and licking of humans. This study partially demonstrated that Enterococcispp. are capable of evolving from being simple commensal bacteria to becoming pathogens that cause infection in humans and animals through the acquisition of virulence factors through mobile genetic elements.

Enterococcus species have developed from being commensal bacteria to leading pathogens that cause infections in humans and animals. The gastrointestinal tract of mammals is the normal habitat of these species. Virulence factors are proteins that are produced by the bacterium which are used to enhance their pathogenicity. The objectives of this study were to isolate Enterococcus spp. from livestock and companion animals, differentiate between the different sub-species and detect the presence of important virulence genes. Rectal and saliva swabs were collected from dogs and cats, whereas only rectal swabs were collected from cattle and cloacal swabs from chickens. Presumptive Enterococcus was selected using Bile Esculin Azide (BEA) agar, and Enterococcus species were confirmed using the polymerase chain reaction (PCR) by amplifying the tuf gene. In order to differentiate between E. faecalis and E. faecium, a multiplex PCR was used to detect the SodA gene. The genes responsible for gelatinase production (gelE) and for conjugation (ccf) were also detected using PCR. Out of 211 animal swabs, 182 (86%) were positive for the tuf gene. Overall, there were 55 isolates of E. faecalis (30%) compared to 22 isolates of E. faecium (12%). The virulence genes had a prevalence of 52% and 36% for gelE and ccf, respectively, in all animal hosts. The results demonstrated that chicken cloacal samples had the highest prevalence for E. faecalis, gelE and ccf genes compared to all the other isolates detected from other animal hosts. The results also demonstrated a statistically significant (p < 0.05) association between the prevalence of virulence genes (gelE and ccf) and animal species from which Enterococcus spp. was isolated. We provided evidence that healthy livestock and companion animals can harbour pathogenic Enterococcus that can be transferred via the food chain as well as through close association such as petting and licking of humans. This study partially demonstrated that Enterococci spp. are capable of evolving from being simple commensal bacteria to becoming pathogens that cause infection in humans and animals through the acquisition of virulence factors through mobile genetic elements.

African swine fever (ASF) is a contagious haemorrhagic disease associated with causing heavy economic losses to the swine industry in many African countries. In 2017, Zambia experienced ASF outbreaks in Mbala District (Northern province) and for the first time in Isoka and Chinsali districts (Muchinga province). Meanwhile, another outbreak was observed in Chipata District (Eastern province). Genetic analysis of part of the B646L gene, E183L gene, CP204L gene and the central variable region of the B602L gene of ASF virus (ASFV) associated with the outbreaks in Mbala and Chipata districts was conducted. The results revealed that the ASFV detected in Mbala District was highly similar to that of the Georgia 2007/1 isolate across all the genome regions analysed. In contrast, while showing close relationship with the Georgia 2007/1 virus in the B646L gene, the ASFV detected in Chipata District showed remarkable genetic variation in the rest of the genes analysed. These results suggest that the Georgia 2007/1-like virus could be more diverse than what was previously thought, underscoring the need of continued surveillance and monitoring of ASFVs within the south-eastern African region to better understand their epidemiology and the relationships between outbreaks and their possible origin.

African swine fever (ASF) is a contagious haemorrhagic disease associated with causing heavy economic losses to the swine industry in many African countries. In 2017, Zambia experienced ASF outbreaks in Mbala District (Northern province) and for the first time in Isoka and Chinsali districts (Muchinga province). Meanwhile, another outbreak was observed in Chipata District (Eastern province). Genetic analysis of part of the B646L gene, E183L gene, CP204L gene and the central variable region of the B602L gene of ASF virus (ASFV) associated with the outbreaks in Mbala and Chipata districts was conducted. The results revealed that the ASFV detected in Mbala District was highly similar to that of the Georgia 2007/1 isolate across all the genome regions analysed. In contrast, while showing close relationship with the Georgia 2007/1 virus in the B646L gene, the ASFV detected in Chipata District showed remarkable genetic variation in the rest of the genes analysed. These results suggest that the Georgia 2007/1-like virus could be more diverse than what was previously thought, underscoring the need of continued surveillance and monitoring of ASFVs within the south-eastern African region to better understand their epidemiology and the relationships between outbreaks and their possible origin.

Anthrax, a neglected zoonotic disease that is transmitted by a spore-forming, rod-shaped bacterium, Bacillus anthracis, has reached endemic proportions in the Western Province of Zambia. Transmission of anthrax from the environment as well as between cattle has been observed to be partly because of entrenched beliefs, perceptions and traditional practices among cattle farmers in the known outbreak areas. This study was aimed at exploring lay perceptions, beliefs and practices that influence anthrax transmission in cattle of the Western Province. A mixed-methods study was conducted from August to December 2015. Quantitative data were collected using a cross-sectional survey. Qualitative data were generated by interviewing professional staff and community members. Five focus group discussions and five key informant interviews were conducted. Thematic analysis of interview data was performed using NVivo software. The findings suggested that cattle anthrax was biologically as well as culturally maintained. Cattle farmers were reluctant to have their livestock vaccinated against anthrax because of perceived low efficacy of the vaccine. Also, the cattle farmers did not trust professional staff and their technical interventions. Popular cultural practices that involved exchange of animals between herds contributed to uncontrolled cattle movements between herds and subsequent transmission of anthrax. These findings imply the need for professional staff to be culturally competent in handling socio-cultural issues that are known to be barriers for disease control in animals. There is a need to develop a policy framework that will foster integrated control of anthrax across disciplines.

Anthrax, a neglected zoonotic disease that is transmitted by a spore-forming, rod-shaped bacterium, Bacillus anthracis, has reached endemic proportions in the Western Province of Zambia. Transmission of anthrax from the environment as well as between cattle has been observed to be partly because of entrenched beliefs, perceptions and traditional practices among cattle farmers in the known outbreak areas. This study was aimed at exploring lay perceptions, beliefs and practices that influence anthrax transmission in cattle of the Western Province. A mixed-methods study was conducted from August to December 2015. Quantitative data were collected using a cross-sectional survey. Qualitative data were generated by interviewing professional staff and community members. Five focus group discussions and five key informant interviews were conducted. Thematic analysis of interview data was performed using NVivo software. The findings suggested that cattle anthrax was biologically as well as culturally maintained. Cattle farmers were reluctant to have their livestock vaccinated against anthrax because of perceived low efficacy of the vaccine. Also, the cattle farmers did not trust professional staff and their technical interventions. Popular cultural practices that involved exchange of animals between herds contributed to uncontrolled cattle movements between herds and subsequent transmission of anthrax. These findings imply the need for professional staff to be culturally competent in handling socio-cultural issues that are known to be barriers for disease control in animals. There is a need to develop a policy framework that will foster integrated control of anthrax across disciplines.

Canine babesiosis and ehrlichiosis are important tick-borne infections in South Africa. Many South African general veterinary practitioners perceive co-infection with Ehrlichia spp. as a common occurrence in dogs with babesiosis. Studies about the prevalence of co-infection in South African dogs are lacking. This retrospective study aimed to determine the prevalence of Ehrlichia co-infection in dogs with babesiosis. Additionally, the predicative value of specific haematological variables for co-infection was evaluated. The study population consisted of 205 dogs diagnosed with canine babesiosis presented to the Onderstepoort Veterinary Academic Hospital (OVAH) in 2006 and between 2011 and 2013. The Babesia-infected dogs were grouped based on presence or absence of an Ehrlichia spp. co-infection. Ehrlichia spp. co-infection was confirmed using polymerase chain reaction. Positive and negative predictive values (PPVs and NPVs) of leukopenia or thrombocytopenia for co-infection were also calculated. The prevalence of Babesia spp. and Ehrlichia spp. co-infection in this cohort of dogs was 2%. In the babesiosis dogs, the PPV of leukopenia for co-infection with Ehrlichia spp. was 1.3%, and the NPV 97.4%. Similarly, the PPV and NPVs of thrombocytopenia for co-infection were 2.1% and 100%, respectively. Co-infection with Ehrlichia spp. was a rare occurrence in dogs with babesiosis presented to the OVAH. Normal leukocyte or platelet counts confidently ruled out the presence of concurrent ehrlichiosis in this cohort of dogs. However, the diagnosis of Ehrlichia co-infection based on the presence of thrombocytopenia or leukopenia would have been associated with false positive results in more than 97.4% of cases.

Canine babesiosis and ehrlichiosis are important tick-borne infections in South Africa. Many South African general veterinary practitioners perceive co-infection with Ehrlichia spp. as a common occurrence in dogs with babesiosis. Studies about the prevalence of co-infection in South African dogs are lacking. This retrospective study aimed to determine the prevalence of Ehrlichia co-infection in dogs with babesiosis. Additionally, the predicative value of specific haematological variables for co-infection was evaluated. The study population consisted of 205 dogs diagnosed with canine babesiosis presented to the Onderstepoort Veterinary Academic Hospital (OVAH) in 2006 and between 2011 and 2013. The Babesia-infected dogs were grouped based on presence or absence of an Ehrlichia spp. co-infection. Ehrlichia spp. co-infection was confirmed using polymerase chain reaction. Positive and negative predictive values (PPVs and NPVs) of leukopenia or thrombocytopenia for co-infection were also calculated. The prevalence of Babesiaspp. and Ehrlichia spp. co-infection in this cohort of dogs was 2%. In the babesiosis dogs, the PPV of leukopenia for co-infection with Ehrlichia spp. was 1.3%, and the NPV 97.4%. Similarly, the PPV and NPVs of thrombocytopenia for co-infection were 2.1% and 100%, respectively. Co-infection with Ehrlichia spp. was a rare occurrence in dogs with babesiosis presented to the OVAH. Normal leukocyte or platelet counts confidently ruled out the presence of concurrent ehrlichiosis in this cohort of dogs. However, the diagnosis of Ehrlichia co-infection based on the presence of thrombocytopenia or leukopenia would have been associated with false positive results in more than 97.4% of cases.

Ozobranchus spp. are leeches that feed solely on turtle blood. They are common ectoparasites found on a range of marine turtle species, with some species of the leech being implicated as vectors of fibropapilloma-associated turtle herpesvirus (FPTHV). Green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles are the two commonly occurring species in the inner granitic islands of the Seychelles. Routine monitoring of nesting turtles on Cousine Island, Seychelles, allowed for opportunistic sightings of leeches on two hawksbill females. In both cases infestation was low, with three leeches collected off one female turtle and five off the other. No obvious signs of papillomas secondary to infection of FPTHV were seen. All of the turtle leeches collected were determined to be Ozobranchus margoi as they had five pairs of lateral digiform branchiae. The specimens were deposited in the Seychelles Natural History Museum on Mahé. To the best of our knowledge this is the first record of Ozobranchus margoi recorded in the inner granitic Seychelles on hawksbill turtles.

Ozobranchus spp. are leeches that feed solely on turtle blood. They are common ectoparasites found on a range of marine turtle species, with some species of the leech being implicated as vectors of fibropapilloma-associated turtle herpesvirus (FPTHV). Green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles are the two commonly occurring species in the inner granitic islands of the Seychelles. Routine monitoring of nesting turtles on Cousine Island, Seychelles, allowed for opportunistic sightings of leeches on two hawksbill females. In both cases infestation was low, with three leeches collected off one female turtle and five off the other. No obvious signs of papillomas secondary to infection of FPTHV were seen. All of the turtle leeches collected were determined to be Ozobranchus margoi as they had five pairs of lateral digiform branchiae. The specimens were deposited in the Seychelles Natural History Museum on Mahé. To the best of our knowledge this is the first record of Ozobranchus margoi recorded in the inner granitic Seychelles on hawksbill turtles.

In Bangladesh, veterinarians often claim to reduce the mortality of natural peste des petits ruminants (PPR) outbreaks with the help of supportive fluid and electrolyte therapy. Information on haematological and biochemical parameters of PPR-infected goats, which is often altered because of associated tissue damages, is necessary to formulate the appropriate supportive therapy. This study determined the haematological and serum biochemical parameters of Black Bengal goats naturally infected with PPR virus. Blood and serum samples from 13 PPR-affected Black Bengal goats from 13 field outbreaks and 5 healthy goats were collected and analysed by routine haematological and biochemical examination. Haematological analysis of PRR-affected goats showed severe anaemia characterised by significant decrease in the values of haemoglobin, total erythrocyte counts (TECs) and packed cell volume (PCV). On the contrary, PPR-affected goats showed marked leucocytosis with absolute increase in lymphocytes and neutrophils counts compared to the healthy goats. Biochemical analysis revealed significant decrease in total protein and albumin level and increased creatine kinase, aspartate transaminase and alanine transaminase that mirrored the gross and histopathological changes in the PPR-affected goats. Significant increase in the values of sodium and chloride ions was found in the sera of PPR-infected goats. Peste des petits ruminants virus altered the haematological and serum biochemical parameters of the infected goats. Antidiarrheal agents with aqua solution together with other drugs to support liver and kidney function could help improve therapy of PPR-infected goats.

In Bangladesh, veterinarians often claim to reduce the mortality of natural peste des petits ruminants (PPR) outbreaks with the help of supportive fluid and electrolyte therapy. Information on haematological and biochemical parameters of PPR-infected goats, which is often altered because of associated tissue damages, is necessary to formulate the appropriate supportive therapy. This study determined the haematological and serum biochemical parameters of Black Bengal goats naturally infected with PPR virus. Blood and serum samples from 13 PPR-affected Black Bengal goats from 13 field outbreaks and 5 healthy goats were collected and analysed by routine haematological and biochemical examination. Haematological analysis of PRR-affected goats showed severe anaemia characterised by significant decrease in the values of haemoglobin, total erythrocyte counts (TECs) and packed cell volume (PCV). On the contrary, PPR-affected goats showed marked leucocytosis with absolute increase in lymphocytes and neutrophils counts compared to the healthy goats. Biochemical analysis revealed significant decrease in total protein and albumin level and increased creatine kinase, aspartate transaminase and alanine transaminase that mirrored the gross and histopathological changes in the PPR-affected goats. Significant increase in the values of sodium and chloride ions was found in the sera of PPR-infected goats. Peste des petits ruminants virus altered the haematological and serum biochemical parameters of the infected goats. Antidiarrheal agents with aqua solution together with other drugs to support liver and kidney function could help improve therapy of PPR-infected goats.

Shiga toxin-producing Escherichia coli (STEC) O157 and non-O157 are food-borne pathogens and contaminants of foods of animal origin. This study was conducted to investigate the presence of virulence and integrase genes in STEC isolates from diarrhoeic calves in Fars Province, Iran. Five hundred and forty diarrheic neonatal calves were randomly selected for sampling. Rectal swabs were collected and cultured for isolation and identification of E. coli following standard methods. The isolates were analysed for the presence of class 1 integrons and bacterial virulence factors using polymerase chain reaction (PCR). Antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Out of 540 diarrhoeic faecal samples, 312 (57.7%) harboured E. coli and 71 (22.7%) of them were identified as STEC: 41(69.5%) carried the stx2 gene, 21 (35.6%) carried the stx1 gene and 3 (5%) carried both. Twenty-six (44%) of the isolates showed the eae gene. Among the STEC isolates examined for susceptibility to eight antimicrobial agents, erythromycin and penicillin (96.8%) resistance were most commonly observed, followed by resistances to ampicillin (71.8%), tetracycline (62.5%) and trimethoprim/sulfamethoxazole (39%). Integrons were detected by PCR in 36% of the STEC tested isolates, 57 (89%) of which showed resistance to at least three antimicrobial agents. Our findings should raise awareness about antibiotic resistance in diarrhoeic calves in Fars Province, Iran. Class 1 integrons facilitate the emergence and dissemination of multidrug-resistance (MDR) among STEC strains recovered from food animals.

Shiga toxin-producing Escherichia coli (STEC) O157 and non-O157 are food-borne pathogens and contaminants of foods of animal origin. This study was conducted to investigate the presence of virulence and integrase genes in STEC isolates from diarrhoeic calves in Fars Province, Iran. Five hundred and forty diarrheic neonatal calves were randomly selected for sampling. Rectal swabs were collected and cultured for isolation and identification of E. coli following standard methods. The isolates were analysed for the presence of class 1 integrons and bacterial virulence factors using polymerase chain reaction (PCR). Antimicrobial susceptibility testing was performed using the Kirby–Bauer disc diffusion method. Out of 540 diarrhoeic faecal samples, 312 (57.7%) harboured E. coli and 71 (22.7%) of them were identified as STEC: 41(69.5%) carried the stx2 gene, 21 (35.6%) carried the stx1 gene and 3 (5%) carried both. Twenty-six (44%) of the isolates showed the eaegene. Among the STEC isolates examined for susceptibility to eight antimicrobial agents, erythromycin and penicillin (96.8%) resistance were most commonly observed, followed by resistances to ampicillin (71.8%), tetracycline (62.5%) and trimethoprim/sulfamethoxazole (39%). Integrons were detected by PCR in 36% of the STEC tested isolates, 57 (89%) of which showed resistance to at least three antimicrobial agents. Our findings should raise awareness about antibiotic resistance in diarrhoeic calves in Fars Province, Iran. Class 1 integrons facilitate the emergence and dissemination of multidrug-resistance (MDR) among STEC strains recovered from food animals.

In this article, the main amphistome species infecting domestic and wild ruminants in East and Southern Africa, their snail intermediate hosts and epidemiological features are reviewed and discussed. Twenty-six amphistome species belonging to nine genera from three families occur in domestic and wild ruminants in the region under review and over 70% of them belong to the genera Calicophoron, Carmyerius and Cotylophoron. Of the amphistome species, 76.9% are shared between domestic and wild ruminant hosts - an important observation when considering the different options for control. Seven freshwater snail species belonging to four genera from two families act as intermediate hosts of the identified amphistome species, with the genus Bulinus contributing 57% of the snail species. Some of the snails are intermediate hosts of amphistome species belonging to the same genus or to different genera; a phenomenon not yet fully elucidated as some snails are reported to be naturally infected with amphistome cercariae of unidentified species. Only nine (34.6%, 9/26) of the amphistome species have known snail intermediate hosts, while most (65.4%, 17/26) have unknown hosts. Species of intermediate hosts and the potential of the flukes to infect these hosts, the biological potential of the snail hosts, the definitive hosts management systems and their grazing habits are considered to be the main factors influencing the epidemiology of amphistomosis. Based on the epidemiological features of amphistome infections, various practical control options are discussed. Further research is necessary to determine amphistome-snail associations, develop diagnostic tests that can detect prepatent infections in the definitive host, determine the burden and economic importance of amphistomosis in domestic and wild ruminants and the efficacy of different anthelmintics in the treatment of patent infections.

In this article, the main amphistome species infecting domestic and wild ruminants in East and Southern Africa, their snail intermediate hosts and epidemiological features are reviewed and discussed. Twenty-six amphistome species belonging to nine genera from three families occur in domestic and wild ruminants in the region under review and over 70% of them belong to the genera Calicophoron, Carmyerius and Cotylophoron. Of the amphistome species, 76.9% are shared between domestic and wild ruminant hosts – an important observation when considering the different options for control. Seven freshwater snail species belonging to four genera from two families act as intermediate hosts of the identified amphistome species, with the genus Bulinus contributing 57% of the snail species. Some of the snails are intermediate hosts of amphistome species belonging to the same genus or to different genera; a phenomenon not yet fully elucidated as some snails are reported to be naturally infected with amphistome cercariae of unidentified species. Only nine (34.6%, 9/26) of the amphistome species have known snail intermediate hosts, while most (65.4%, 17/26) have unknown hosts. Species of intermediate hosts and the potential of the flukes to infect these hosts, the biological potential of the snail hosts, the definitive hosts management systems and their grazing habits are considered to be the main factors influencing the epidemiology of amphistomosis. Based on the epidemiological features of amphistome infections, various practical control options are discussed. Further research is necessary to determine amphistome–snail associations, develop diagnostic tests that can detect prepatent infections in the definitive host, determine the burden and economic importance of amphistomosis in domestic and wild ruminants and the efficacy of different anthelmintics in the treatment of patent infections.