Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. In Uganda, FMD outbreaks are mainly controlled by ring vaccination and restriction of animal movements. Vaccination stimulates immunity and prevents animals from developing clinical signs which include lameness, inappetence, and decreased production. Ring vaccination and restriction of animal movements have, however, not successfully controlled FMD in Uganda and outbreaks reoccur annually. The objective of this study was to review the use of FMD virus (FMDV) vaccines and assess the effectiveness of vaccination programs for controlling FMD in Uganda (2001-2010), using retrospective data. FMD vaccine distribution patterns in Uganda (2001-2010) matched occurrence of outbreaks with districts reporting the highest number of outbreaks also receiving the largest quantity of vaccines. This was possibly due to "fire brigade" response of vaccinating animals after outbreaks have been reported. On average, only 10.3 % of cattle within districts that reported outbreaks during the study period were vaccinated. The average minimum time between onset of outbreaks and vaccination was 7.5 weeks, while the annual cost of FMDV vaccines used ranged from US $58,000 to 1,088,820. Between 2001 and 2010, serotyping of FMD virus was done in only 9/121 FMD outbreaks, and there is no evidence that vaccine matching or vaccine potency tests have been done in Uganda. The probability of FMDV vaccine and outbreak mismatch, the delayed response to outbreaks through vaccination, and the high costs associated with importation of FMDV vaccines could be reduced if virus serotyping and subtyping as well as vaccine matching were regularly done, and the results were considered for vaccine manufacture.

dAlthough many studies have reported the indirect immunofluorescence assay (IFA) to be more sensitive in detection of antibodies to Coxiella burnetii than the complement fixation test (CFT), the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the assay have not been previously established for use in ruminants. This study aimed to validate the IFA by describing the optimization, selection of cutoff titers, repeatability, and reliability as well as the DSe and DSp of the assay. Bayesian latent class analysis was used to estimate diagnostic specifications in comparison with the CFT and the enzyme-linked immunosorbent assay (ELISA). The optimal cutoff dilution for screening for IgG and IgM antibodies in goat serum using the IFA was estimated to be 1:160. The IFA had good repeatability (>96.9% for IgG, >78. Coxiella burnetii causes Q fever in humans as well as abortions, stillbirths, and infertility in ruminants (1-5). The organism replicates in the placenta of infected ruminants, reaching a level of up to 10 9 bacteria per gram of placenta tissue (4-6). C. burnetii organisms are shed in an extremely high concentration in birth fluids, placental tissues, and membranes of aborted fetuses as well as in milk, urine, and feces of infected ruminant animals around the parturition period (4, 5). The high concentration of C. burnetii organisms shed in tissues, fluids, and excreta of infected ruminants is the primary source of human infections (7).Caprine and ovine infections have been reported to result in severe placentitis and consequently in shedding of higher numbers of C. burnetii organisms than infections of cattle (8). Studies have also revealed that goats and sheep shed higher quantities of C. burnetii in feces, vaginal mucus, and birth tissues than other livestock (9). Thus, the risk of human transmission is higher when infections occur in herds of small ruminants than when they occur with other livestock. Unsurprisingly, the majority of reported large outbreaks of Q fever have been associated with infected sheep and goat flocks, including a major outbreak of more than 4,000 human Q fever cases in the Netherlands that was linked to sheep and goat farms with over 50 animals (9)(10)(11)(12)(13)(14). Infection with C. burnetii can be asymptomatic in many animals and may be detected in ruminants only when infection causes abortions and reproductive abnormalities in pregnant animals (1). Delay in diagnosis in livestock slows the implementation of appropriate control strategies, thus increasing the risk of human infection.Coxiellosis in animals can be diagnosed through microscopic examination of stained tissues, culture, detection of C. burnetii DNA using PCR, and detection of antibodies to C. burnetii in blood and milk (15,16). The microscopic diagnosis of coxiellosis is mainly undertaken on placental tissues using Stamp-Macchiavello coloration or Giemsa stain. The organism can be cultured in cells, embryonated hen eggs, or cell-free media (15,17). However, microscopy and culture are expensive and requi...

BackgroundThis was a panel study of the prevalence of C. burnetii infection in does in an endemic dairy goat enterprise in Victoria, Australia. Our first objective was to determine the prevalence of does shedding C. burnetii at the time of parturition and to quantify the concentration of genome equivalents (GE) present in each C. burnetii positive sample. Our second objective was to determine the proportion of positive does that were persistent shedders. Our final objective was to quantify the association between C. burnetii qPCR status at the time of kidding and daily milk volumes produced during the subsequent lactation.ResultsVaginal swabs (n= 490) were collected from does at the time of kidding and analysed using a quantitative polymerase chain reaction (qPCR) assay. Shedding of C. burnetii was detected in 15% (95% CI: 12% to 18%) of the sampled does. Does were classified as qPCR-negative, qPCR-positive low and qPCR-positive high based on the estimated concentration of GE from the qPCR. Persistent shedding at relatively low concentrations was detected in 20% (95% CI: 10% to35%) of shedding does sampled again at their subsequent parturition. After controlling for possible confounders and adjusting for variation in daily milk yields at the individual doe level, daily milk yields for qPCR-positive high does were reduced by 17% (95% CI: 3% to 32%) compared to qPCR-negative does (p= 0.02).ConclusionsShedding concentrations of C. burnetii were highly skewed, with a relatively small group of does shedding relatively high quantities of C. burnetii. Further, high shedding does had reduced milk yields compared to qPCR-negative does. Early detection and culling of high shedding does would result in increased farm profitability and reduce the risk of Q fever transmission.

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