Knowledge, attitudes and practices regarding porcine cysticercosis control among smallholder pig farmers in Kongwa and Songwe districts, Tanzania: A cross-sectional study.

Taenia solium taeniasis/cysticercosis (TSTC) is a parasitic zoonotic disease that is endemic in several developing countries, causing serious public health and economic impacts. A cross-sectional study was conducted to assess knowledge, attitudes and practices (KAP) related to porcine cysticercosis (PCC) transmission, prevention and control among smallholder pig farmers in Kongwa and Songwe Districts in Tanzania. A semi-structured questionnaire was administered to 692 smallholder pig farmers from randomly selected households. STATA software version 17 was used to analyse quantitative data, summarize farmers' KAP about PCC and calculate performance scores. Nearly half (42%) of the respondents had little knowledge regarding PCC, only 17% of the respondents had good practices towards prevention/control of PCC and 72% had a positive attitude towards PCC- prevention/control measures. The majority (73%) of smallholder pig farmers admitted deworming their pigs regularly, whereas 76% reported deworming themselves and their family members regularly. Albendazole and ivermectin are the most commonly used medications for deworming people and pigs, respectively. According to the findings, the majority of smallholder pig farmers in Kongwa and Songwe Districts showed a good attitude towards PCC prevention/control measures but had limited knowledge of the PCC life cycle and control. In addition, only one in five farmers was engaged in good practices. The findings revealed further that farmers are engaged in risky behaviours that aid the spread and perpetuation of the T. solium parasite in the study area. It is recommended that farmers should be given proper health education on the T. solium transmission cycle and preventive/control practices to limit PCC transmission.

Detection of African swine fever virus DNA in blood samples stored on FTA cards from asymptomatic pigs in Mbeya region, Tanzania.

The aim of the study was to assess whether blood samples collected onto FTA(®) cards could be used in combination with real-time PCR for the detection of African swine fever virus (ASFV) DNA in samples from resource-poor settings under the assumption that asymptomatically (sub-clinically) infected pigs may be present. Blood samples were collected from clinically healthy pigs from Mbeya Region, Tanzania. The blood samples were stored on FTA(®) cards and analysed by real-time PCR assays in duplicate; three pigs had high levels of viral DNA (Ct values of 27-29), and three pigs had a low level of viral DNA (Ct 36-45). Four pigs were positive in one of the duplicate samples only, but clear products of the expected size were obtained when the reactions were analysed by gel electrophoresis. For comparison, blood samples from pigs experimentally infected with either a pathogenic (OURT T88/1) or a non-pathogenic (OURT T88/3) isolate of ASFV were collected, stored on FTA(®) cards and analysed in the same way. The blood from pigs infected with the OURT T88/1 isolate showed high levels of viral DNA (Ct 22-33), whereas infection with non-pathogenic OURT T88/3 isolate resulted in only low levels of viral DNA (Ct 39) in samples collected at 10-14 days after inoculation.

Distribution and histopathological changes induced by cysts of Taenia solium in the brain of pigs from Tanzania.

Neurocysticercosis (NCC) caused by Taenia solium cysts is a frequent but neglected parasitic disease of the central nervous system (CNS) worldwide. The aim of this study was to describe anatomical locations of cysts in the CNS and the corresponding inflammation. A total of 17 naturally infected pigs were used to evaluate the distribution of cysts and, of these, seven were used to evaluate the corresponding inflammation further, through histopathology. Clinical signs in the pigs included dullness, sluggishness, somnolence, apathy and loss of consciousness. Cysts were distributed in all cerebral lobes, i.e. 39.7% in the frontal lobe, 20.3% in the parietal lobe, 20.0% in the occipital lobe and 19.7% in the temporal lobe, and only 0.4% in the cerebellum. No cysts were found in the spinal cord. Cysts were localized as follows: 47.9% in the dorsal subarachnoid, 46.9% in the parenchyma, 4.4% in the subarachnoid base and 0.9% in the ventricles. The results of the histopathology revealed lesions in an early inflammatory stage, i.e. stage I, in all anatomical locations except for two, which showed more of an inflammatory reaction, stage III, in one pig. It was concluded that clinical signs in pigs were neither pathognomonic nor consistent. These signs, therefore, cannot be used as a reliable indicator of porcine NCC. Furthermore, T. solium cysts were found to be in abundance in all cerebral lobes, and only a few were found in the cerebellum. Regarding the inflammatory response, no significant differences were found in the location and total number of cysts. Thus, further studies are needed to explain the determinants of cyst distribution in the CNS and assess in detail clinical signs associated with porcine NCC.

Distribution and histopathological changes induced by cysts of Taenia solium in the brain of pigs from Tanzania.

Neurocysticercosis (NCC) caused by Taenia solium cysts is a frequent but neglected parasitic disease of the central nervous system (CNS) worldwide. The aim of this study was to describe anatomical locations of cysts in the CNS and the corresponding inflammation. A total of 17 naturally infected pigs were used to evaluate the distribution of cysts and, of these, seven were used to evaluate the corresponding inflammation further, through histopathology. Clinical signs in the pigs included dullness, sluggishness, somnolence, apathy and loss of consciousness. Cysts were distributed in all cerebral lobes, i.e. 39.7% in the frontal lobe, 20.3% in the parietal lobe, 20.0% in the occipital lobe and 19.7% in the temporal lobe, and only 0.4% in the cerebellum. No cysts were found in the spinal cord. Cysts were localized as follows: 47.9% in the dorsal subarachnoid, 46.9% in the parenchyma, 4.4% in the subarachnoid base and 0.9% in the ventricles. The results of the histopathology revealed lesions in an early inflammatory stage, i.e. stage I, in all anatomical locations except for two, which showed more of an inflammatory reaction, stage III, in one pig. It was concluded that clinical signs in pigs were neither pathognomonic nor consistent. These signs, therefore, cannot be used as a reliable indicator of porcine NCC. Furthermore, T. solium cysts were found to be in abundance in all cerebral lobes, and only a few were found in the cerebellum. Regarding the inflammatory response, no significant differences were found in the location and total number of cysts. Thus, further studies are needed to explain the determinants of cyst distribution in the CNS and assess in detail clinical signs associated with porcine NCC.

ASFV in Tanzania: asymptomatic pigs harbor virus of molecular similarity to Georgia 2007.

In 2011 African swine fever virus (ASFV) genome was detected in asymptomatic pigs in field samples in Mbeya, Tanzania. The aim of this paper is to partly characterize the virus that was harbored in these pigs and furthermore to confirm, by a second sampling, the latest occurrence of ASFV in the study area. ASFV genome was detected in serum from 10 out of 127 healthy European/crossbreed pigs. ASFV DNA was polymerase chain reaction (PCR) amplified and sequenced from sera with high viral loads using primers targeting p54 or p72. Both p54 and p72 had total identity to ASFV Genotype II (Georgia 2007/1). The ASFV epidemiology in Mbeya was studied in a new collection of 804 pig sera obtained in 2012. The antibody prevalence in four age groups (3-6 months.; 7-12 months; 13-18 months or 19-36 months) was 3-5%; all antibody positive sera were analyzed by PCR with negative results. The presence of antibodies in 3-month-old pigs confirms the circulation of ASFV in Mbeya several months after our detection of ASFV in asymptomatic pigs. The initial blood samples were obtained on Whatman FTA filter papers as dried blood samples. The samples were stored under field conditions and ASFV could be sequenced in DNA eluted 10 months later, showing the use of FTA samples. Studies on the genetic breed of the pigs are needed as well as sequence studies including the variable region of ASFV to elucidate why asymptomatic pigs with high viral loads were detected.

Smallholder pig production: prevalence and risk factors of ectoparasites.

A cross-sectional study was carried out in the Mbeya Region, Tanzania, with the aim of describing the distribution and diversity of ectoparasites on pigs, within confinement and free-range production systems of smallholder farms. A total of 128 farms were surveyed, with 96 practising confinement and 32 practising free-range production systems. The prevalence of ectoparasites on pigs within confinement and free-range production systems was 24% and 84%, respectively. Logistic regression analyses revealed that keeping pigs in a free-range system and the presence of neighbouring pigs were risk factors for ectoparasites. Within the confinement system, contact with neighbouring pigs and the time interval (in months) since last ectoparasitic treatment were additionally identified as risk factors. The prevalence of Haematopinus suis was 20% in confined pigs and 63% among free-range pigs. Free-ranging of pigs and presence of neighbouring pigs were also identified as risk factors for the presence of lice. Three species of fleas were identified; Tunga penetrans, Echidnophaga gallinacea and Ctenocephalides canis. The prevalence of fleas was 5% and 13% within confined and free-range, respectively. Two pigs (2%) were found infested with Sarcoptes scabiei var. suis. Ticks found belonged to four genera; Amblyomma spp., Rhipicephalus spp., Haemaphysalis spp., and Boophilus spp. The prevalence of hard ticks among the free-range pigs was 50%. Ectoparasites were more prevalent in the free-range system although highly prevalent within both production systems. Keeping pigs in a free-range system and contact with neighbouring pigs were main risk factors for the presence of ectoparasites. Confinement was highly effective as a preventive tool against hard ticks.

A health-education intervention trial to reduce porcine cysticercosis in Mbulu District, Tanzania.

We conducted a randomised community controlled trial to estimate the effectiveness of health and pig-management education intervention in reducing the incidence rate of porcine cysticercosis caused by Taenia solium in Mbulu District, northern Tanzania, between April 2002 and July 2004. We included a random sample of 827 pig-keeping households from 42 randomly selected villages in our 27-month study. We collected baseline data on the prevalence of porcine cysticercosis based on lingual examination of live pigs, and pig-management and sanitation knowledge and practices based on questionnaire interviews and observations. We allocated 21 of the villages to the health-education intervention, developed with community participation; we used stratified randomisation to balance the village-level baseline prevalence of porcine cysticercosis. From July 2003 to March 2004 following the intervention, we gave each participant household a sentinel piglet to raise (the timing was balanced between the intervention groups). Knowledge about the transmission and prevention of porcine cysticercosis was improved >42% in both groups when measured 10-12 months post-intervention. There was no improvement in observed practices in either group throughout the study period. However, the intervention had a significant reduction in the reported cases of household consumption of infected pork (a reduction by 20%). The intervention was associated with a considerable decrease in the incidence rate of porcine cysticercosis (incidence rate ratio 0.57) as measured by antigen-ELISA in sentinel pigs. Public education could lead to a reduction of the risk of infection in humans.

Prevalence of thermophilic campylobacter infections in humans, chickens and crows in Morogoro, Tanzania.

Prevalence of thermophilic Campylobacter infections in humans, chickens and crows was determined in a cross-sectional study that was carried out in urban and rural areas of Morogoro region, Tanzania during the period of January 2003 to December 2004. A total of 632 human stool samples, 536 cloacal swabs from local and broiler chickens and 22 intestinal contents from crows were screened for presence of thermophilic campylobacters using Skirrow's protocol. Representative Campylobacter jejuni isolates from human and chicken samples were also analysed by polymerase chain reaction (PCR) as a definitive identification method. The overall prevalence of thermophilic campylobacters was 9.3% (95% CI: 7.2-11.9), 69.8% (95% CI: 65.7-73.6) and 72.7% (95% CI: 49.8-89.3) in humans, chickens and crows respectively. In humans, 59 thermophilic campylobacters were isolated of which 96.6% were C. jejuni and 3.4%Campylobacter coli. There was a significantly (P<0.001) higher prevalence in young individuals (16%) than in adults (7%). Of 341 isolates from chickens, 91.2% were C. jejuni and 8.8% were C. coli. A significantly (P<0.05) higher infection rate was observed in rural local chicken (76%) than in broilers (60%). In crows, of 16 isolates, 93.8% were C. jejuni and 6.2% were C. coli. Definitive identification of C. jejuni by PCR revealed positive results in 74.1% of 243 analysed isolates. Findings in this study indicate high prevalence of thermophilic campylobacters in humans, chickens and crows in Morogoro, and a higher infection rate of C. jejuni than that of C. coli in different animal species. Age of humans and location of chickens were identified as risk factors for thermophilic Campylobacter infections. Positive isolates to biochemical tests that indicated negative results on PCR indicates the additional value of PCR for definitive diagnosis of C. jejuni.

A slaughter slab survey for extra-intestinal porcine helminth infections in northern Tanzania.

A survey on extra-intestinal porcine helminths was conducted at three slaughter slabs that receive pigs from Mbulu, a district endemic for porcine cysticercosis in northern Tanzania. Seventy carcases of pigs between 1 and 2 years old were examined between December 1997 and March 1998. The examination involved ante-mortem lingual examination for Taenia solium cysticercosis followed by post-mortem inspection. In addition, a laboratory procedure was performed to determine whether any of these domestic pigs were infected with Trichinella species. Parasites detected were Ascaris suum (44.3%), Echinococcus granulosus (4.3%) and Taenia hydatigena (1.4%). The lack of cases of porcine cysticercosis in this study compared to previous studies suggests that pig traders are conducting their own ante-mortem lingual examinations before purchasing pigs in the rural communities where the parasite is still highly prevalent. It is concluded that improved meat inspection could prove useful in reducing the local population's risk of infection with these parasites. The results of this study have revealed the parasites of agricultral and public health importance in the targeted communities. Further epidemiological investigations are required to better determine parasite prevalence and impact in order to formulate appropriate and cost-effective strategies for control.

Risk factors for the prevalence of porcine cysticercosis in Mbulu District, Tanzania.

To estimate prevalence of and risk factors for the prevalence of porcine cysticercosis in Mbulu District, Tanzania, 770 live pigs were examined by lingual examination in 21 villages. Structured observations and questionnaire interviews were used to assess pig rearing practices and household use of latrines. Associations between factors were analyzed using a Bayesian hierarchical model to obtain prevalence odds ratio (OR) and 95% Bayesian Credible Intervals (95% BCI). Prevalence was 17.4% (village-specific range 3.2-46.7%). Prevalence of porcine cysticercosis was considerably higher in pigs reared in households lacking latrines than in those reared in households that were using latrines (OR = 2.04; 95% BCI = 1.25, 3.45). About 96% of the pigs were kept under free-range conditions. This study suggests the need for further studies in order to design and implement effective prevention and control measures for porcine cysticercosis in Mbulu District, Tanzania.