Exploratory field study on the effects of porcine circovirus 2 (PCV-2) sow vaccination at different physiological stages mimicking blanket vaccination.

BACKGROUND: The objective of the present study was to explore the benefits of Porcine circovirus 2 (PCV-2) blanket vaccination in a sow herd on productive parameters, PCV-2 infection and immune status in sows and their progeny. For this purpose, 288 sows were distributed among four balanced experimental groups. One group remained as negative control group and the other three received 1 mL of PCV-2 Ingelvac Circoflex® intramuscularly at different productive cycle moments: before mating, mid gestation (42-49 days post-insemination) or late gestation (86-93 days post-insemination); phosphate buffered saline (PBS) was used as negative control item. Reproductive parameters from sows during gestation and body weight of their progeny from birth to weaning were recorded. Additionally, blood was collected from sows at each vaccination time and piglets at 3 weeks of age. Moreover, up to 4 placental umbilical cords (PUC) per sow were taken at peri-partum. Sera from sows and piglets were analysed for PCV-2 antibody detection using an enzyme-linked immunosorbent assay (ELISA). Sera from sows and PUC were tested to quantify viraemia using a real time quantitative polymerase chain reaction (qPCR) assay. RESULTS: Globally, results indicated that vaccinated sows showed heavier piglets at birth and at weaning, less cross-fostered piglets, lower viral load at farrowing as well as in PUC, and higher antibody levels at farrowing, compared to non-vaccinated ones. When all groups were compared among them, sows vaccinated at mid or late gestation had heavier piglets at birth than non-vaccinated sows, and lower proportion of PCV-2 positive PUC. Also, cross-fostering was less frequently practiced in sows vaccinated at pre-mating or mid gestation compared to non-vaccinated ones. CONCLUSIONS: In conclusion, the present study points out that PCV-2 sow vaccination at different time points of their physiological status (mimicking blanket vaccination) offers benefits at production and serological and virological levels.

Fecal microbiota transplantation from warthog to pig confirms the influence of the gut microbiota on African swine fever susceptibility.

African swine fever virus (ASFV) is the causative agent of a devastating hemorrhagic disease (ASF) that affects both domestic pigs and wild boars. Conversely, ASFV circulates in a subclinical manner in African wild pigs, including warthogs, the natural reservoir for ASFV. Together with genetic differences, other factors might be involved in the differential susceptibility to ASF observed among Eurasian suids (Sus scrofa) and African warthogs (Phacochoerus africanus). Preliminary evidence obtained in our laboratory and others, seems to confirm the effect that environmental factors might have on ASF infection. Thus, domestic pigs raised in specific pathogen-free (SPF) facilities were extremely susceptible to highly attenuated ASFV strains that were innocuous to genetically identical domestic pigs grown on conventional farms. Since gut microbiota plays important roles in maintaining intestinal homeostasis, regulating immune system maturation and the functionality of the innate/adaptive immune responses, we decided to examine whether warthog fecal microbiota transplantation (FMT) to domestic pigs affects host susceptibility to ASFV. The present work demonstrates that warthog FMT is not harmful for domestic weaned piglets, while it modifies their gut microbiota; and that FMT from warthogs to pigs confers partial protection against attenuated ASFV strains. Future work is needed to elucidate the protective mechanisms exerted by warthog FMT.

HIV prevalence in a gold mining camp in the Amazon region, Guyana.

The prevalence of HIV infection among men in a gold mining camp in the Amazon region of Guyana was 6.5%. This high percentage of HIV infection provides a reservoir for the virus in this region, warranting immediate public health intervention to curb its spread. As malaria is endemic in the Amazon Basin (>30,000 cases/year), the impact of coinfection may be substantial.

Intestinal parasites among young children in the interior of Guyana

Intestinal parasites contribute greately to morbidity in developing countries. While there have been several studies of the problem in the Caribbean, including the implementation of control programmes, this has not been done for Guyana. The aim of this study was to determine the prevalence of intestinal parasites among young children in a town located in the interior of Guyana. Eighty-five children under the age of 12 years were studied prospectively for intestinal parasites in Mahdia, Guyana. Stool samples were transported in formalin to the Department of microbiology, the University of the West Indies, Jamaica, for analysis using the formalin-ether concentration and Ziehl-Neelsen techniques. Data on age and gender of the children were recorded on field sheets. At least one intestinal parasite was detacted in 43.5 percent (37/85) of the children studied and multiple parasitic infections were recorded in 21.2 percent (18/85). The most common intestinal helminth parasite was hookworm (28.2 percent; 24/85), followed by Ascaris lumbricoides (18.8 percent; 16/85) and then Trichuris trichuria (14.1 percent; 12/85). Among the protozoan infections Giardia lamblia was detected in 10.5 percent (9/85) of the study population while Entamoeba histolytica appeared rarely. All stool samples were negative for Cryptosporidium and other intestinal Coccidia. There was no predilection for gender with any of the parasites. The pattern of distribution of worms in this area of Guyana was unlike that seen in other studies. Hookworm infection was the most common among the children and a large proportion had multiple infections. The study established the occurrence and prevalence of a number of intestinal parasites in the population of Guyana. This sets the stage for the design and implementation of more detailed epidemiological studies. (AU)

Report of a serological survey of the southern half of Eleuthera Island, Bahamas

A serum survey on a 10 percent sample of the population of the south of Eleuthera Island, Bahamas, is described. The survey was intended to give a general picture of the distributions of certain antibodies, blood components, blood pressure and tuberculosis among the islanders. Its purpose has been to help in instituting both clinical facilities and public health measures. The following observations were made: 1. V.D.R.L. test showed an overall rate of 12.8 percent positive. The more accurate FTA-200 test for treponemes showed an overall rate of 10.1 percent positive. Although no serologic evidence was found for congenital treponematosis, the authors believe that, because of the high treponemal infection rate in the persons of reproductive age, some small rate of congenital infection exists. 2. Antibodies to all three types of poliovirus were almost universally present in persons over the age of five years. At the time of the survey, no vaccination progamme had been in force in the island. 3. Of the survey population 17.4 percent, 2.2 percent and 0.0 percent had antibodies to Entamoeba histolytica, Trichinella spirallis, and Schistosoma mansoni, respectively. 4. The result of tuberculin tests on children aged 5-19 showed an increasing positive rate with age, reaching 42.3 percent in the 15-19 year group. There was no active tuberculosis detected in a mass X-Ray survey. 5. Hemoglobin levels in both sexes were low when compared with those with U.S. whites. It would appear that there is generalized anemia, particularly apparent in women of child-bearing age. 6. Serum cholesterol levels were low in the range considered normal in the U.S. population. 7. The blood pressure of both sexes was similar to that found in other Negro populations in the Bahamas, the Caribbean and the southern U.S., but higher than in comparable white populations (AU)