Transmission of West Nile virus in the Niagara Region among a population at risk for exposure

Background. West Nile Virus (WNV), a mosquito-borne flavivirus, is one of an increasing number of infectious diseases that have been emerging or re-emerging in the last two decades. Since the arrival ofWNV to Canada to present date, the Niagara Region has only reported 30 clinical cases, a small number compared to the hundreds reported in other regions of similar conditions. Moreover, the last reported human case in Niagara was in 2006. As it has been demonstrated that the majority of WNV infections are asymptomatic, the question remains whether the lack of clinical cases in Niagara truly reflects the lack of transmission to humans or if infections are still occurring but are mostly asymptomatic. Objectives. The general objective of this study was to establish whether or not active WNV transmission could be detected in a human population residing in Niagara for the 2007 transmission season. To fullfil this objective, a cross-sectional seroprevalence study was designed to investigate for the presence of anti-WNV antibodies in a sample of Mexican migrant agricultural workers employed in farms registered with the Seasonal Agricultural Workers Program (SAWP). Due to the Mexican origin of the study participants, three specific research objectives were proposed: a) determine the seroprevalence ofanti-WNV antibodies as well as anti-Dengue virus antibodies (a closely related virus prevalent in Mexico and likely to confound WNV serology); b) analyze risk factors associated with WNV and Dengue virus seropositivity; and c) assess the awareness of study participants about WNV infection as well as their understanding of the mode of transmission and clinical importance of the infection. Methodology: After obtaining ethics clearance from Brock University, farms were visited and workers invited to participate. Due to time constraints, only a small number of farms were enrolled with a resulting convenience and non-randomized study sample. Workers' demographic and epidemiological data were collected using a standardized questionnaire and blood samples were drawn to determine serum anti-WNV and anti- Dengue antibodies with a commercial ELISA. All positive samples were sent to the National Microbiology Laboratory in Winnipeg, Manitoba for confirmation with the Plaque Reduction Neutralization Test (PRNT). Data was analyzed with Stata 10.0. Antibody determinations were reported as seroprevalence proportions for both WNV and Dengue. Logistic regression was used to analyze risk factors that may be associated with seropositivity and awareness was reported as a proportion of the number of individuals possessing awareness over the total number of participants. Results and Discussion. In total 92 participants working in 5 farms completed the study. Using the commercial ELISA, seropositivity was as follows: 2.2% for WNV IgM, 20.7% for WNV IgG, and 17.1 % for Dengue IgG. Possible cross-reactivity was demonstrated in 15/20 (75.0%) samples that were positive for both WNV IgG and Dengue IgG. Confirmatory testing with the PRNT demonstrated that none of the WNV ELISA positive samples had antibodies to WNV but 13 samples tested positive for anti-Dengue antibodies (14.1 % Dengue sereoprevalence). The findings showed that the ELISA performance was very poor for assessing anti-WNV antibodies in individuals previously exposed to Dengue virus. However, the ELISA had better sensitivity and specificity for assessing anti-Dengue antibodies. Whereas statistical analysis could not be done for WNV seropositivity, as all samples were PRNT negative, logistic regression demonstrated several risk factors for Dengue exposure_ The first year coming to Canada appeared to be significantly associated with increased exposure to Dengue while lower socio-economic housing and the presence of a water basin in the yard in Mexico appeared to be significantly associated with a decreased exposure to Dengue_ These seemingly contradictory results illustrate that in mobile populations such as migrant workers, risk factors for exposure to Dengue are not easily identified and more research is needed. Assessing the awareness of WNV and its clinical importance showed that only 23% of participants had some knowledge of WNV, of which 76% knew that the infection was mosquito-borne and 47% recognized fever as a symptom. The identified lack of understanding and awareness was not surprising since WNV is not a visible disease in Mexico. Since WNV persists in an enzootic cycle in Niagara and the occurrence of future outbreaks is unpredictable, the agricultural workers remain at risk for transmission. Therefore it important they receive sufficient health education regarding WNV before leaving Mexico and during their stay in Canada. Conclusions. Human transmission of WNV could not be proven among the study participants even when due to their occupation they are at high risk for mosquito bites. The limitations of the study sample do not permit generalizable conclusions, however, the study findings are consistent with the absence of clinical cases in the Niagara Region, so it is likely that human transmission is indeed neglible or absent. As evidenced by our WNV serology results, PRNT must be utilized as a confirmatory test since false positivity occurs frequently. This is especially true when previous exposure to Dengue virus is likely.

Benjamin Woodruff Price Papers, 1851, 1853-1860, 1862-1863, 1874, n.d.

The fonds includes sixty two items of correspondence between Benjamin Woodruff Price, aka Woodruff, Ben or Uncle, and various family members, both immediate and distant cousins. Also included is business correspondence related to Price’s activities as a watchmaker and/or jeweler. Benjamin Woodruff Price was born in Thorold Township ca. 1831, the son of Joseph Price and Mary Smith. B.W. Price married Ella or Ellen McGlashan (1851-1906) ca. 1868. Price died between 1891 and 1901, his burial location is unknown at present. A watchmaker and jeweler, Price lived most of his life in Fonthill, Ont. He also included auctioneer, undertaker and photographer as some of his other professional activities. His siblings included David Smith Price (wife Isabella Ann), John Smith Price (wife Elizabeth Jane), and sisters Susan Page (husband Edward Rice Page), Jerusha Price, Mary Price and Martha W. Stone (husband Dudley Ward Stone). John Smith Price died 18 April 1860, leaving no descendents. It is likely that G.W. Stone was a nephew to B.W. Price, the son of his sister Martha W. Stone and her husband Dudley Ward Stone. Susan Page was a sister of Benjamin Woodruff Price. She was married to Edward Rice Page and they had at least two children, Joseph and Clayton. At the time of this correspondence they lived in Suspension Bridge, NY, now part of Niagara Falls, New York. Edward Rice Page’s occupation was listed as saloon keeper. The Price family appears to have had a very large extended family. This information was gleaned from the contents of letters of Maggie Tisdale, daughter of Ephraim and Hannah (Price) Tisdale, P.A. or Ann Morgan, [may also be Phebe Ann] of Newark, NY? and Marietta House of Bayham Township. DeWitt Higgins of Suspension Bridge, NY aka Niagara Falls, NY was an auctioneer, specialized in buying jewellery, watches, clocks, from individuals and reselling his product to others like B.W. Price.

Letter Regarding an Affidavit discussing the Half Pay of Daniel Shannon, Ensign- June 13, 1820

A letter regarding an affidavit discussing the half pay of Daniel Shannon from the 25th June to the 21st of December 1819.

Oath of Employment History by Daniel Shannon- 1820

An oath by Daniel Shannon concerning his employment from the 25th of June to the 24th of December 1820.

Letter from the Adjutant General's Office in York. March 10th, 1820

This letter discusses an Order in Council put out in January of the same year concerning the First Flank Company. It discusses those that served in June to December of 1812 and those who joined afterward. It is addressed to Col. Clark of the 2nd Regiment of the Lincoln Militia

B.N. Peach letter, 1918.

Ben N. Peach (1842-1926) was a well-known geologist whose work focused on the geological structure of Scotland, and in particular the Northwest Scottish Highlands and Southern Uplands. He formed a close working relationship with John Horne and the two colloborated on many works, most notably two memoirs of the Geological Survey of Great Britain, The Silurian Rocks of Britain (1899) and The Geological Structure of the North-West Highlands of Scotland (1907).

DEFORMATION OF INTERIOR LAYERED DEPOSITS (ILD) AND THEIR ASSOCIATED LANDFORMS IN WEST CANDOR CHASMA, MARS: IMPLICATIONS FOR THE TIMING OF ILD DEPOSITION

On Mars, interior layered deposits (ILD) provide evidence that water was once stable at the surface of the planet and present in large quantities. In West Candor Chasma, the ILD and their associated landforms record the depositional history of the chasma, and the deformation of those deposits provide insight into the stresses acting on them and the chasma as a whole. The post ILD structural history of West Candor is interpreted by analyzing the spatial relationships and orientation trends of structural features within the ILD. Therecording of stresses through brittle deformation of ILDs implies that the ILD had been lithified before the stress was imposed. Based on the prominent orientation trends of deformation features, the orientation of the stress regime acting upon the ILD appears to be linked to the regime that initially created the chasma-forming faults. An additional minor stress orientation was also revealed and may be related to large structures outside west Candor Chasma. The late depositional history of Ceti Mensa is herein investigated by examining the attributes and spatial relationship between unique corrugated, linear formations (CLF). The CLFs appear to be aeolian in origin but display clear indications of brittle deformation, indicating they have been Iithified. Evidence of lithification and the mineral composition of the surrounding material support the interpretation of circulating water in the area.

Letter to Mr. Walsh, Registrar Office, 1836

The man to whom the letter is addressed is Francis Leigh Walsh who was a land surveyor and registrar. Mr. Walsh was born on March 12, 1789 in Harford County, Maryland to Thomas Welsh, a United Empire Loyalist. In 1793, his family moved to Norfolk County and in 1810, Francis succeeded his father as registrar for Norfolk County. During the War of 1812 he served in the local militia and became a captain in 1824. He was the representative for Norfolk in the legislative assembly of Upper Canada from 1820 to 1828 and 1834 to 1836. He became justice of the peace in the London district in 1821 and 1838 in the Talbot district. He died in Simcoe on Oct. 14th, 1884. His son, Aquila Walsh served in the Legislative Assembly of the Province of Canada and in the Canadian House of Commons. Benjamin Hardison was born in Berwick in the Thirteen Colonies (British colonies on the Atlantic Coast of North America) on April 2, 1757 to Thomas Hardison and Mary Chadbourne. He was a farmer, miller and political figure. He was the representative for 4th Lincoln and Norfolk in the Legislative Assembly of Upper Canada from 1797-1800. On January 21, 1800 he married Jane Warren. He served with the American forces during the American Revolution at which time he was taken prisoner and sent to Canada. Later, he settled in Fort Erie where he was a captain in the militia and a justice of the peace for the Niagara district. He operated mills and a distillery in Fort Erie and died there on July 26, 1823. Source: http://en.vionto.com/show/me/Francis+Leigh+Walsh http://en.wikipedia.org/wiki/Benjamin_Hardison

Genealogical notes of Elizabeth Pettit and Benjamin Bell

Genealogical notes of Elizabeth Pettit and Benjamin Bell. Lists dates of birth for Benjamin Bell and Elizabeth and includes birth dates for ten children. Also included is the date of the death of Benjamin and Elizabeth and four of their children.

Letter addressed by Benjamin Bates (bearer of the memorial) to a Member of the Legislature, ca. 1812.

Benjamin Bates was a member of the Religious Society of Friends, and served as Clerk of the Society at the time that the Memorial and Petition was written.

Letter addressed by Benjamin Bates (bearer of the memorial) to a Member of the Legislature, ca. 1812.

Benjamin Bates was a member of the Religious Society of Friends, and served as Clerk of the Society at the time that the Memorial and Petition was written.

Map - Plan of Attack of a Iagdkommaudo west of Cantigny, 27 May 1918

A map titled "Plan of Attack of a Iagdkommaudo west of Cantigny on 27 May 1918. There are two sketches and the legend indicates that sketch no. 1 is "Firing until 7A.M." and sketch no. 2 is "Firing after 7A.M."

Indenture of Land Sold by Benjamin Middough to William Woodruff

Indenture stating that Benjamin Middough of Stamford sold a tract of land in the County of Oxford, district of London to William Woodruff of Niagara. The land consisted of 200 acres on lot 34 of the 2nd Concession. This transaction was registered on August 4, 1834 - instrument no. 2413. The date of sale was January 17, 1823.

Indenture between Benjamin Middough and William Woodruff

Indenture between Benjamin Middough of the town of Pendleton in Niagara County, New York and William Woodruff of Niagara Township regarding the sale of Lot no. 36 in the 9th Concession in the Township of Nottawasaga. This is accompanied by a memorial of the Deed of Bargain which is dated June 10, 1837. Memorial no. 4060, May 20, 1837.

Indenture between Barnet Ulman, Benjamin Ulman, Peter Ulman and Philophilus Carpenter

Indenture between Barnet Ulman and Peter Ulman of Niagara Township to Asa Philophilus Carpenter of Niagara Township regarding 300 acres in Lot no. 15 in the 1st Concession and the north half of Lot no. 11 in the 2nd Concession of the Township of Southwood - instrument no. 680. This was listed in folio 287, November 9, 1852.