Robert E. Klein

Epidemiologic studies of Cyclospora cayetanensis in Guatemala.

In 1996 and 1997, cyclosporiasis outbreaks in North America were linked to eating Guatemalan raspberries. We conducted a study in health-care facilities and among raspberry farm workers, as well as a case-control study, to assess risk factors for the disease in Guatemala. From April 6, 1997, to March 19, 1998, 126 (2.3%) of 5,552 surveillance specimens tested positive for Cyclospora; prevalence peaked in June (6.7%). Infection was most common among children 1.5 to 9 years old and among persons with gastroenteritis. Among 182 raspberry farm workers and family members monitored from April 6 to May 29, six had Cyclospora infection. In the case-control analysis, 62 (91%) of 68 persons with Cyclospora infection reported drinking untreated water in the 2 weeks before illness, compared with 88 (73%) of 120 controls (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.4, 10.8 by univariate analysis). Other risk factors included water source, type of sewage drainage, ownership of chickens or other fowl, and contact with soil (among children younger than 2 years).

Variation in Asthma Beliefs and Practices Among Mainland Puerto Ricans, Mexican-Americans, Mexicans, and Guatemalans

This study reports on community surveys of 160 representative Latino adults in Hartford, CT; Edinburg, TX; Guadalajara, Mexico; and in rural Guatemala. A 142-item questionnaire covered asthma beliefs and practices (e.g., causes, symptoms, and treatments). The cultural consensus model was used to analyze the agreement among respondents within each sample and to describe beliefs. Beliefs were then compared across the four samples. Analysis of the questionnaire data shows that there was overall consistency or consensus regarding beliefs and practices among individuals at each site (intraculturally) and to a lesser extent across respondents of all four different Latino cultural groups (i.e., interculturally). This pattern of response is indicative of a shared belief system among the four groups with regard to asthma. Within this shared belief system though, there is systematic variation between groups in causes, symptoms, and treatments for asthma. The most widely recognized and shared beliefs concerned causes of asthma. Notable differences were present between samples in terms of differences in beliefs about symptoms and treatments. The biomedical model is shown to be a part of the explanatory model at all sites; in addition to the biomedical model, ethnocultural beliefs such as the humoral (“hot/cold”) aspects and the importance of balance are also evident. The Connecticut Puerto Ricans had a greater degree of shared beliefs about asthma than did the other three samples (p<0.00005). It was concluded that the four Latino groups studied share an overall belief system regarding asthma, including many aspects of the biomedical model of asthma. In addition, traditional Latino ethnomedical beliefs are present, especially concerning the importance of balance in health and illness. Many beliefs and practices are site-specific, and caution should be used when using inclusive terms such as “Hispanic” or “Latino,” since there is variation as well as commonality among different ethnic groups with regard to health beliefs and practices.

A Cross-Cultural Approach to the Study of the Folk Illness Nervios

To systematically study and document regional variations in descriptions of nervios, we undertook a multisite comparative study of the illness among Puerto Ricans, Mexicans, Mexican Americans, and Guatemalans. We also conducted a parallel study on susto (Weller et al. 2002, Culture, Medicine and Psychiatry 26(4): 449– 472), which allows for a systematic comparison of these illnesses across sites. The focus of this paper is inter- and intracultural variations in descriptions in four Latino populations of the causes, symptoms, and treatments of nervios, as well as similarities and differences between nervios and susto in these same communities. We found agreement among all four samples on a core description of nervios, as well as some overlap in aspects of nervios and susto. However, nervios is a much broader illness, related more to continual stresses. In contrast, susto seems to be related to a single stressful event.

Regional variation in Latino descriptions of susto.

Susto, a folk illness notrecognized by biomedical practitioners as adisease, is now formally part of the diagnosticclassification system in psychiatry as a“culture-bound syndrome.” Susto has beenreported among diverse groups of LatinAmericans, but most of those reports areseveral decades old and many were conducted inIndian communities. This study focuses oncontemporary descriptions of susto anduses a cross-cultural, comparative design todescribe susto in three diverse Latinopopulations. Mestizo/ladino populations wereinterviewed in Guatemala, Mexico, and southTexas. An initial set of open-ended interviewswas conducted with a sample of “key” informantsat each site to obtain descriptive informationabout susto. A structured interviewprotocol was developed for use at all threesites, incorporating information from thoseinitial interviews. A second set of structuredinterviews was then conducted with arepresentative sample at each site. Resultsindicate a good deal of consistency in reportsof what susto is: what causes it, itssymptoms, and how to treat it. There appear tobe, however, some notable regional variationsin treatments and a difference between pastdescriptions and contemporary reports ofetiology.

The onchocerciasis elimination program for the Americas: a history of partnership

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center. OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US

Pneumonia case-finding in the RESPIRE Guatemala indoor air pollution trial: standardizing methods for resource-poor settings

2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela, so as to take full advantage of the Merck donation. Now halfway into a five-year, US

West Nile virus in horses, Guatemala

4 million grant provided through the Inter-American Development Bank, the OEPAs capacity to support the regional initiative is assured through 1999.

An epidemiological description of a folk illness: A study of empacho in Guatemala

OBJECTIVE Trials of environmental risk factors and acute lower respiratory infections (ALRI) face a double challenge: implementing sufficiently sensitive and specific outcome assessments, and blinding. We evaluate methods used in the first randomized exposure study of pollution indoors and respiratory effects (RESPIRE): a controlled trial testing the impact of reduced indoor air pollution on ALRI, conducted among children <or= 18 months in rural Guatemala. METHODS Case-finding used weekly home visits by fieldworkers trained in integrated management of childhood illness methods to detect ALRI signs such as fast breathing. Blindness was maintained by referring cases to study physicians working from community centres. Investigations included oxygen saturation (SaO2), respiratory syncytial virus (RSV) antigen test and chest X-ray (CXR). FINDINGS Fieldworkers referred > 90% of children meeting ALRI criteria, of whom about 70% attended a physician. Referrals for cough without respiratory signs and self-referrals contributed 19.0% and 17.9% of physician-diagnosed ALRI cases respectively. Intervention group attendance following ALRI referral was 7% higher than controls, a trend also seen in compliance with RSV tests and CXR. There was no evidence of bias by intervention status in fieldworker classification or physician diagnosis. Incidence of fieldworker ALRI (1.12 episodes/child/year) is consistent with high sensitivity and low specificity; incidence of physician-diagnosed ALRI (0.44 episodes/child/year) is consistent with comparable studies. CONCLUSION The combination of case-finding methods achieved good sensitivity and specificity, but intervention cases had greater likelihood of reaching the physician and being investigated. There was no evidence of bias in fieldworkers classifications despite lack of concealment at home visits. Pulse oximetry offers practical, objective severity assessment for field studies of ALRI.

Beliefs about AIDS in five Latin and Anglo‐American populations: The role of the biomedical model

To the Editor: West Nile virus (WNV, Flaviviridae: Flavivirus) is emerging as a public health and veterinary concern. Since its introduction into North America in 1999, it has spread rapidly, reaching the Caribbean Basin in 2001, Mexico in 2002, El Salvador in 2003, and Colombia in 2004 (1). However, reports of equine illness and deaths in Latin America are inconclusive. With the exception of viral isolates from a dead bird, a human, and a mosquito pool in Mexico (2,3), all reports of WNV presence in Latin America have relied on serologic evidence. WNV is a member of the Japanese encephalitis serocomplex, which in the Western Hemisphere includes St. Louis encephalitis virus (SLEV) (4). Serologic investigations for WNV in Latin America must use highly specific assays to differentiate WNV infection from potentially cross-reactive viruses such as SLEV or possibly additional unknown viruses. In particular, SLEV is of concern since it was previously isolated from Guatemalan mosquitoes (5). Alerted by the findings of WNV transmission in the region (1), we collected serum samples from horses from 19 departments of Guatemala from September 2003 to March 2004, to initially estimate the extent of WNV spread and its potential public health risk. Because no animals exhibited signs of neurologic illness at the time of the survey, only healthy horses were sampled. Before 2005, equine WNV vaccines were prohibited and unavailable in Guatemala (Unidad de Normas y Regulaciones, Ministerio de Agricultura Ganaderia y Alimentacion, Guatemala, pers. comm.); as such, cross-reactivity due to prior vaccination is highly unlikely. Samples were initially tested for WNV-reactive antibodies by using an epitope-blocking enzyme-linked immunosorbent assay (blocking ELISA) (6). The ability of the test sera to block the binding of the monoclonal antibodies to WNV antigen was compared to the blocking ability of control horse serum without antibody to WNV. Data were expressed as relative percentages and inhibition values >30% were considered to indicate the presence of viral antibodies. A subset of positive samples was further confirmed by plaque-reduction neutralization test (7). Of 352 samples, 149 (42.3%) tested positive with the 3.1112G WNV-specific monoclonal antibody. Of 70 blocking ELISA–positive samples, the neutralization tests indicated the infecting agent was WNV, SLEV, and undifferentiated flavivirus in 9, 33, and 21 samples, respectively. Titers were expressed as the reciprocal of serum dilutions yielding >90% reduction in the number of plaques in a plaque-reduction neutralization test (PRNT90). PRNT90 titers of horses seropositive for WNV ranged from 80 to 320. PRNT90 titers of horses seropositive for SLEV ranged from 40 to 2,560. For the differential diagnosis of samples with neutralizing antibody titers against both WNV and SLEV in this test, a >4-fold titer difference was used to identify the etiologic agent. The undifferentiated flavivirus-reactive specimens had <4-fold difference in cross-neutralization titers. Likely possibilities for the inability to distinguish the infecting virus include previous infection with these or other flaviviruses (previously described or unknown) resulting in elevated cross-reactive titers. The remaining 10% of specimens that tested negative by PRNT probably represent nonneutralizing antibodies in the serum or false positivity in the blocking ELISA. Our serologic results provide indirect evidence of past transmission of WNV, SLEV, and possibly other flaviviruses to horses in Guatemala. Although no confirmed cases of WNV-attributed disease have been reported in Central America to date, flavivirus transmission appears to be widely distributed in Guatemala (Figure). Efforts are under way to confirm WNV transmission by viral isolation and to evaluate the impact of WNV on human, horse, and wildlife populations. More information is needed to establish the public health threat of WNV and other zoonotic flaviviruses in the region. Figure Geographic distribution in Guatemala of horses showing previous infections with West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), or undifferentiated flavivirus as confirmed by plaque reduction neutralization test. Each location may have multiple ...

Use of illiterate volunteer workers for malaria case detection and treatment.

Although anthropologists have provided descriptions of many folk illnesses, few have systematically evaluated their prevalence and determined who is at greatest risk for acquiring them. This report attempts to provide a systematic description of the folk illness empacho including the symptoms that define it. Illness prevalence was estimated and subpopulations at greatest risk were identified from illness histories collected from a random sample of households in rural Guatemala. Empacho was found to constitute a distinct cluster of symptoms: diarrhea, vomiting, headache, and lack of appetite. It differed from other gastrointestinal illnesses in that headaches were more likely and stomachaches were less likely to be reported. Empacho was highly prevalent and occurred in adults and children. Further, results showed that although empacho was frequently diagnosed by residents, folk healers were rarely consulted for any illness. Nevertheless, a strong association exists between a household diagnosis of empacho and the use of folk healers by those households (p less than .001).