The seroprevalence of Rocky Mountain spotted fever in shelter dogs in Harris County

Rocky Mountain spotted fever (RMSF) is a tick-borne illness caused by the bacteria Rickettsia rickettsii, with infections occurring in humans and dogs. The prominent tick vector of RMSF, Dermacantor variabilis, and another potential vector, Rhipacephalus sanguineus, are prevalent in Texas. The goal of this study was to determine the prevalence of past infections by testing for IgG antibodies to R. rickettsii in dogs in an animal shelter in Harris County using an immunofluorescence assay (IFA) test. We found that 12.6% (24) of 191 dogs tested had a positive IFA test at 1:64 serum dilution, indicating infection at some time in the past. We also sampled the ticks present on dogs in the animal shelter to understand the prevalence of potential vector species. Of a total of 58 ticks, 86% were D. variabilis and the remaining 14% were R. sanguineus. The results of this study demonstrate that RMSF has the potential to be, and may already be, endemic to the Harris County area. Public health actions such as heightened surveillance and education that RMSF is present would be appropriate in the Harris County area.^

Syndromic surveillance at a long term shelter for persons displaced by hurricanes Katrina and Rita conducted by the San Antonio Metropolitan Health District

Background. Beginning September 2, 2005, San Antonio area shelters received approximately 12,700 evacuees from Hurricane Katrina. Two weeks later, another 12,000 evacuees from Hurricane Rita arrived. By mid-October, 2005, the in-shelter population was 1,000 people. There was concern regarding the potential for spread of infectious diseases in the shelter. San Antonio Metropolitan Health District (SAMHD) established a syndromic surveillance system with Comprehensive Health Services (CHS) who provided on-site health care. CHS was in daily contact with SAMHD to report symptoms of concern until the shelter closed December 23, 2005. ^ Study type. The objective of this study was to assess the methods used and describe the practical considerations involved in establishing and managing a syndromic surveillance system, as established by the SAMHD in the long-term shelter clinic maintained by CHS for the hurricane evacuees. ^ Methods. Information and descriptive data used in this study was collected from multiple sources, primarily from the San Antonio Metropolitan Health District’s 2006 Report on Syndromic Surveillance of a Long-Term Shelter by Hausler & Rohr-Allegrini. SAMHD and CHS staff ensured that each clinic visit was recorded by date, demographic information, chief complaint and medical disposition. Logs were obtained daily and subsequently entered into a Microsoft Access database and analyzed in Excel. ^ Results. During a nine week period, 4,913 clinic visits were recorded, reviewed and later analyzed. Repeat visits comprised 93.0% of encounters. Chronic illnesses contributed to 21.7% of the visits. Approximately 54.0% were acute care encounters. Of all encounters, 17.3% had infectious disease potential as primarily gastrointestinal and respiratory syndromes. Evacuees accounted for 86% and staff 14% of all visits to the shelter clinic. There were 782 unduplicated individuals who sought services at the clinic, comprised of 63% (496) evacuees and 36% (278) staff members. Staff were more likely to frequent the clinic but for fewer visits each. ^ Conclusion. The presence of health care services and syndromic surveillance provided the opportunity to recognize, document and intervene in any disease outbreak at this long-term shelter. Constant vigilance allowed SAMHD to inform and reassure concerned people living and working in the shelter and living outside the shelter.^

THE EVALUATION OF PUBLIC HEALTH COMPONENTS OF INTERNATIONAL DISASTER RELIEF OPERATIONS: INDOCHINESE REFUGEES IN THAILAND, 1979-1982

Refugee populations suffer poor health status and yet the activities of refugee relief agencies in the public health sector have not been subjected previously to comprehensive evaluation. The purpose of this study was to examine the effectiveness and cost of the major public health service inputs of the international relief operation for Indochinese refugees in Thailand coordinated by the United Nations High Commissioner for Refugees (UNHCR). The investigator collected data from surveillance reports and agency records pertaining to 11 old refugee camps administered by the Government of Thailand Ministry of Interior (MOI) since an earlier refugee influx, and five new Khmer holding centers administered directly by UNHCR, from November, 1979, to March, 1982.^ Generous international funding permitted UNHCR to maintain a higher level of public health service inputs than refugees usually enjoyed in their countries of origin or than Thais around them enjoyed. Annual per capita expenditure for public health inputs averaged approximately US$151. Indochinese refugees in Thailand, for the most part, had access to adequate general food rations, to supplementary feeding programs, and to preventive health measures, and enjoyed high-quality medical services. Old refugee camps administered by MOI consistently received public health inputs of lower quantity and quality compared with new UNHCR-administered holding centers, despite comparable per capita expenditure after both types of camps had stabilized (static phase).^ Mortality and morbidity rates among new Khmer refugees were catastrophic during the emergency and transition phases of camp development. Health status in the refugee population during the static phase, however, was similar to, or better than, health status in the refugees' countries of origin or the Thai communities surrounding the camps. During the static phase, mortality and morbidity generally remained stable at roughly the same low levels in both types of camps.^ Furthermore, the results of multiple regression analyses demonstrated that combined public health inputs accounted for from one to 23 per cent of the variation in refugee mortality and morbidity. The direction of associations between some public health inputs and specific health outcome variables demonstrated no clear pattern. ^

Seroprevalence of Chagas' disease in Texas among shelter dogs in Houston and the Rio Grande Valley region and its implication for human infection

Chagas’ disease, also called American Trypanosomiasis, is a vector-borne disease caused by the protozoan parasite Trypanosoma cruzi. T. cruzi is spread by triatomine insects, commonly referred to as ‘kissing bugs.’ After the insect takes a blood meal from its animal or human host, it usually defecates near the bite wound. The parasite is present in the feces, and when rubbed into the bite wound or mucous membranes by the host, infection ensues. Chagas’ disease is highly endemic in Central and South America where it originated. Many people in these endemic areas live in poor conditions surrounded by animals, mainly dogs, that can serve as a possible link to human infection. In Chagas’ endemic countries, dogs can be used as a sentinel to infer risk for human infection. In Texas, the prevalence of Chagas’ and risk for human infection is largely unknown. This study aimed to determine the prevalence of Chagas’ disease in shelter dogs in Houston, Texas and the Rio Grande Valley region by using an immunochromatographic assay (Chagas’ Stat-Pak) to test for the presence of T. cruzi antibodies. Of the 822 samples tested, 26 were found to be positive (3.2%). In both locations, Chagas’ prevalence increased over time. This study found that dogs, especially strays, can serve as sentinels for disease activity. Public health authorities can implement this strategy to understand the level of Chagas’ activity in a defined geographic area and prevent human infection.^