Sero-prevalence and associated risk factors of peste des petits ruminants and contagious caprine pleuro-pneumonia in goats and sheep in the Southern Zone of Tanzania.

A retrospective Sero-prevalence analysis was conducted in 2012 in order to find out whether contagious caprine pleuro-pneumonia (CCPP) and peste des petits ruminants (PPR) had already been introduced in Mtwara and Lindi regions of Southern Tanzania by 2007 and 2009. A total of 477 randomly selected sera from a bank of 3500 small ruminant samples that were collected as part of Rift Valley Fever surveillance of 2007 in Mtwara and Lindi regions were used in this study. Seroconversion was also evaluated in the 504 sera that were collected in 2009 as part of disease outbreak investigations in Tandahimba and Newala districts of Mtwara region. Seroconversions to CCPP and PPR were tested using competitive ELISA. In addition, information on different variables available in the existing surveillance forms gathered during sampling was used in the analysis of risk factors associated with seropositivity to the two diseases. The overall seroprevalence of CCPP for the sera of 2007 and 2009 in goats was 52.1% (n=447) and 35.5% (n=434) respectively; while in sheep the seroprevalence was 36.7% (n=30) and 22.9% (n=70) respectively. Seroconversion to PPR in goats and sheep was 28.7% (n=434) and 35.7% (n=70) respectively based on the sera of 2009. However, no antibodies were detected in the 2007 sera. Mixed infections were detected in 7.4% (n=434) of the goat and 12.9% (n=70) of sheep samples. Significant risk factors associated with seropositivity to CCPP in 2007 included introduction of new animals in flocks (OR=3.94; 95% CI 1.86-8.36; p<0.001) and raising animals in government farms (OR=4.92; 95% CI 1.57-15.76; p=0.02); whereas, seropositivity to CCPP in 2009 increased with introduction of new animals in flocks (OR=18.82; 95% CI 8.06-43.96; p<0.001), raising animals in government farms (OR=4.04; 95% CI 2.69-6.42; p<0.001) and raising animals in Newala district (OR=2.35; 95% CI 1.53-3.62; p<0.001). On the other hand, predictors for seropositivity to PPR in 2009 were introduction of new animals in flocks (OR=2.83; 95% CI 1.73-4.62; p<0.001) and communal grazing of animals (OR=7.60; 95% CI 1.77-32.58; p=0.01). Therefore, these results show that CCPP was already circulating in goats in the southern zone by 2007 and that PPR was probably introduced thereafter. Their presence in this emerging animal keeping area in Tanzania calls for improved surveillance and control systems.

The incursion, persistence and spread of peste des petits ruminants in Tanzania: epidemiological patterns and predictions.

Peste des petits ruminants virus, which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Tanzania. An epidemiological study was carried out between September 2008 and October 2010 to investigate the incursion, persistence and spread of the virus in Tanzania. The investigation involved serosurveillance, outbreak investigation and computation of epidemiological indices such as the effective reproductive number, persistence and the threshold level for vaccination. Field and molecular epidemiological techniques were applied to isolate, characterise and trace the origin of the virus in Tanzania. A total of 2182 serum samples from goats and 1296 from sheep from 79 villages across 12 districts were investigated. Village-level prevalence of infection was variable (0.00% ­ 88.00%) and was higher in pastoral than in agro-pastoral villages. The overall antibody response to the virus was 22.10% (CI95% = 20.72% ­ 23.48%). About 68.00% and 73.00% of seropositive goats and sheep, respectively, did not show clinical signs. The proportion of seropositive animals differed significantly (p ≤ 0.001) between age groups, sex and farming practices. Real-time polymerase chain reaction results showed that the isolated strains belong to lineage III, whose origin is in East Africa and the Middle East. This indicates that one of the northern neighbouring countries is most likely the source of infection. The computed overall effective reproductive number, the threshold level of vaccination necessary to eradicate the disease and persistence were 4.75% and 98.00%, respectively. These estimates indicate that achieving elimination of the peste des petits ruminants virus from pastoral flocks will require significant effort and development of highly effective intervention tools.

Sanitary practices and occurrence of zoonotic conditions in cattle at slaughter in Morogoro Municipality, Tanzania: implications for public health.

As meat consumption is increasing worldwide to cover for protein demands, also raise concerns and challenges regarding meat hygiene and safety. The current one year follow up study aimed at investigating on sanitary practices and occurrence of zoonotic conditions, during post-mortem examination, in cattle at slaughter in Morogoro Municipality abattoir. Sanitary practices were assessed through direct observation where as routine post-mortem inspection procedures were employed to detect zoonotic conditions in cattle at slaughter. During the study period a total of 30,713 cattle were slaughtered and inspected at the abattoir. Results revealed poor hygienic practices at the level of abattoir surrounding, the slaughter operation area, personnel as well as meat vans. Whole carcasses, lungs, livers, hearts and heads were condemned due to zoonotic conditions at rates of 0.026%, 1.96%, 1.61%, 0.02% and 0.21% respectively. Bovine tuberculosis, Cysticercus bovis cysts, fasciolosis and hydatidosis were the responsible zoonotic conditions for the condemnations. Bovine tuberculosis was a leading zoonotic cause of condemnations accounting for 95.7% of lungs and 100% of all head and carcass condemnations. Cysticercus bovis cysts were ranking the second in serving as causes of condemnations closely followed by fasciolosis and lastly hydatidosis. Occurrence of disease conditions with zoonotic implication in cattle at slaughter, meant for human consumption, may pose significant economic and public health risks to especially disaster-prone marginalized communities. Thus, there is a need to introduce appropriate control measures of livestock diseases to minimize the rate of infection; and eventually reduce economic losses and safeguard public health.

Sanitary Practices and Occurrence of Zoonotic Conditions in Cattle at Slaughter in Morogoro Municipality; Tanzania: Implications for Public Health

Abstract:As meat consumption is increasing worldwide to cover for protein demands; also raise concerns and challenges regarding meat hygiene and safety. The current one year follow up study aimed at investigating on sanitary practices and occurrence of zoonotic conditions; during postmortem examination; in cattle at slaughter in Morogoro Municipality abattoir. Sanitary practices were assessed through direct observation where as routine post-mortem inspection procedures were employed to detect zoonotic conditions in cattle at slaughter. During the study period a total of 30;713 cattle were slaughtered and inspected at the abattoir. Results revealed poor hygienic practices at the level of abattoir surrounding; the slaughter operation area; personnel as well as meat vans. Whole carcasses; lungs; livers; hearts and heads were condemned due to zoonotic conditions at rates of 0.026; 1.96; 1.61; 0.02 and 0.21 respectively. Bovine tuberculosis; Cysticercus bovis check for this species in other resources cysts; fasciolosis and hydatidosis were the responsible zoonotic conditions for the condemnations. Bovine tuberculosis was a leading zoonotic cause of condemnations accounting for 95.7 of lungs and 100 of all head and carcass condemnations. Cysticercus bovis cysts were ranking the second in serving as causes of condemnations closely followed by fasciolosis and lastly hydatidosis. Occurrence of disease conditions with zoonotic implication in cattle at slaughter; meant for human consumption; may pose significant economic and public health risks to especially disaster-prone marginalized communities. Thus; there is a need to introduce appropriate control measures of livestock diseases to minimize the rate of infection; and eventually reduce economic losses and safeguard public health