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J L Sanchez

Publications and source records attributed to J L Sanchez.

At least 55 records · Page 3Linked to original sources
PubMed1995

Immunogenicity in Peruvian volunteers of a booster dose of oral cholera vaccine consisting of whole cells plus recombinant B subunit.

Forty-nine subjects received two doses of oral cholera vaccine consisting of whole cells plus recombinant B subunit; this was followed by a booster dose one year later. After the primary series, a significant (greater than twofold) increase in the levels of vibriocidal, anti-cholera toxin immunoglobulin G and anti-cholera toxin immunoglobulin A antibodies occurred in 54, 88, and 81% of the subjects, respectively. Within one year, titers decreased to levels close to baseline. A booster dose then induced rises to those which occurred after the initial vaccination. The results suggest that 1-year booster doses may be necessary to maintain immunity against cholera in Latin America.

Administration, Oral↗
PubMed1995

Diarrheal disease among military personnel during Operation Restore Hope, Somalia, 1992-1993.

The potential for widespread diarrheal disease was regarded as a substantial threat to U.S. troops participating in the early phases of Operation Restore Hope in Somalia. Outpatient surveillance of 20,859 U.S. troops deployed during the first eight weeks, however, indicated that a mean of only 0.8% (range 0.5-1.2%) of personnel sought care for diarrhea each week, and in three epidemiologic surveys, < 3% of troops reported experiencing a diarrheal illness per week. Despite these low overall attack rates, diarrhea accounted for 16% of 381 hospital admissions and 20% of 245 patients admitted with a temperature > or = 38.5 degrees C. Sixty-one specimens were obtained from inpatients and 52 were obtained from outpatients. Shigella sp. were isolated from 33%, enterotoxigenic Escherichia coli from 16%, Giardia lamblia from 4%, and rotavirus from 1% of 113 stool samples obtained from inpatient (61) and outpatient (52) troops with diarrhea. Bacterial isolates obtained in Somalia were resistant to doxycycline (78%), ampicillin (54%), and sulfamethoxazole (49%), but uniformly sensitive to ciprofloxacin. With the exception of 10 Shigella sonnei isolates that were linked epidemiologically to one eating facility, bacterial pathogens occurred sporadically and demonstrated a wide variation of serotypes and antibiotic sensitivity patterns. Additionally, three of 11 paired sera collected from persons with nausea, vomiting, and watery diarrhea demonstrated a four-fold or greater increase in titer to Norwalk virus antibody. These data indicate that large outbreaks of diarrheal disease did not occur; however, highly drug-resistant enteric bacteria, and to a lesser extent viral and parasitic pathogens, were important causes of morbidity among U.S. troops in Somalia.

Acute Disease↗
PubMed1995

Dengue fever in U.S. troops during Operation Restore Hope, Somalia, 1992-1993.

Dengue fever (DF) was considered to be a potential cause of febrile illness in U.S. troops deployed to Somalia during Operation Restore Hope in 1992-1993. A prospective study of hospitalized troops with fever and a seroepidemiologic survey of 530 troops were conducted. Among 289 febrile troops hospitalized, 129 (45%) did not have an identified cause of their fever. Dengue (DEN) virus was recovered from 41 (43%) of 96 of these patients by inoculation of admission sera into C6/36 cell cultures. Thirty-nine (41%) of the isolates were identified as DEN-2 and two (2%) as DEN-3 by an indirect immunofluorescent antibody assay. An additional 18 (49%) of 37 culture-negative cases were shown by immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay to have anti-DEN virus antibody. All identified DF cases recovered within 1-2 weeks; no case of dengue hemorrhagic fever or shock syndrome was observed. A seroepidemiologic survey of a unit (n = 494) with 17 culture or serologically identified DF cases and a 13% attack rate of unidentified febrile illness revealed a 7.7% prevalence of anti-DEN virus IgM antibody. Failure to use bed nets was the only identified risk factor for DEN infection (adjusted odds ratio = 2.2, 95% confidence interval = 1.4-3.0). These data indicate that DF was an important cause of febrile illness among US troops in Somalia, and demonstrate the difficulties in preventing DEN infection in troops operating in field conditions.

Adult↗
PubMed1994

Protective efficacy of oral whole-cell/recombinant-B-subunit cholera vaccine in Peruvian military recruits.

The cholera epidemic in South America has reinforced the need for safe and effective oral vaccines. In a randomised, double-blind, placebo-controlled efficacy trial among 1563 Peruvian military recruits we have investigated the protective efficacy of an oral inactivated whole-cell/recombinant-B-subunit (WC/rBS) cholera vaccine. Participants were given two oral doses of cholera vaccine or Escherichia coli K12 placebo, with an interval of 7-14 days. 1426 (91%) subjects received the two prescribed doses and were followed up for a mean of 18 weeks (median 21 weeks). After vaccination, Vibrio cholerae O1 El Tor Ogawa was isolated from 17 subjects with diarrhoea. 16 of the cholera cases occurred 2 weeks or longer after the second dose of vaccine (14 placebo recipients, 2 vaccinees). We also detected 14 symptomless infections (11 [7 placebo recipients, 4 vaccinees]) 2 weeks or longer after the second dose. The vaccine had significant protective efficacy against cholera (86% [95% CI 37-97], p < 0.01) but not against symptomless infection (42% [-96 to 85]). All cholera cases were in people of blood group O, who made up 76% of the study population (p < 0.01). Two doses of WC/rBS vaccine, given 1 to 2 weeks apart, provide rapid, short-term protection against symptomatic cholera in adult South Americans, who are predominantly of blood group O. Long-term efficacy studies in Peruvian adults and children are under way.

ABO Blood-Group System↗
PubMed1994

Diarrheal disease in Peru after the introduction of cholera.

Surveillance was conducted one day each week from December 1992 through May 1993 to determine the clinical features and etiology of diarrhea among a population in a suburban community of Lima, Peru. Patients who had had three or more loose stools during the previous 24 hr were enrolled at a clinic located in the community or at a nearby regional hospital. A total of 143 cases of diarrhea were detected for an overall rate of 7.1 cases per 1,000 population. The enteropathogens isolated were Vibrio cholerae 01 (31%), enterotoxigenic Escherichia coli (22%), and Salmonella, Shigella, Campylobacter, and Aeromonas species (10%). Specimens from the remaining cases were negative for enteropathogens. All isolates of V. cholerae were susceptible to tetracycline, doxycycline, nalidixic acid, norfloxacin, trimethoprim-sulfamethoxazole, trimethoprim, gentamicin, chloramphenicol, and cephalothin. Cases of diarrhea associated with V. cholerae were more common among adults, and more likely to experience severe dehydration and require hospitalization than the non-cholera cases. Data indicated that among the cases diagnosed, V. cholerae and enterotoxigenic E. coli were the more common causes of diarrhea in a suburban community of Lima during the summer season.

Adolescent↗
PubMed1993

Safety and immunogenicity of the oral, whole cell/recombinant B subunit cholera vaccine in North American volunteers.

A newly formulated, oral, inactivated whole cell plus recombinant B subunit (WC/rBS) cholera vaccine was evaluated in US military personnel. In the first study, 74 subjects were given two doses 14 days apart. In the second study, 186 subjects were randomized into four groups; two groups received vaccine with either full (4 g) or half (2 g) strength bicarbonate buffer, and two groups received either full or half strength buffer without vaccine. Mild gastrointestinal symptoms were associated with full buffer (P = .02) but not with the vaccine. In the first study, 36% of all subjects and 55% with low prevaccination titers (< 1:40) had a > or = 2-fold rise in vibriocidal antibody level; > 80% of subjects developed a 4-fold rise in anti-cholera toxin (CT) titers. Post-vaccination IgA and IgG anti-CT titers were approximately 1.5-fold higher among persons receiving full strength buffer (P = .05). The WC/rBS vaccine is safe and immunogenic in North Americans, although some mild gastrointestinal symptoms occur with the high concentration of buffer necessary to protect the B subunit from gastric acid denaturation. Prior immunity to cholera conferred by parenteral vaccine decreased vibriocidal antibody response.

Administration, Oral↗
PubMed1993

Risk factors associated with inguinal hernias: a case control study.

OBJECTIVES: To assess reported risk factors for the development of inguinal hernias, to develop a method of quantifying physical effort, and to correlate them. DESIGN: Case control study. SETTING: District hospital, Valencia, Spain. SUBJECTS: 290 selected patients who had undergone inguinal hernia repair, and 290 age and sex matched controls. INTERVENTIONS: Each patient was interviewed and data collected on a specially designed questionnaire, and an "effort score" calculated. MAIN OUTCOME MEASURES: Incidence of specified risk factors. RESULTS: The only significant risk factor was physical effort (lifting heavy objects repeatedly over long periods of time), relative risk 2.92, 95% confidence interval 2.11 to 4.04. In addition, there were significant differences between index cases and controls in standard of education (p < 0.001), consumption of alcohol (p = 0.02), chronic cough (p < 0.001), net monthly income (p = 0.04), and amount of physical effort expended (p < 0.001). Patients with indirect hernias expended significantly more physical effort and were both heavier and taller, and patients with femoral hernias waited significantly longer than the others before having their hernias repaired. CONCLUSION: Inguinal hernias are associated with the expenditure of a considerable amount of physical effort, and are commoner among younger, poorly educated manual workers.

Adult↗
PubMed1992

Treatment of traveler's diarrhea with ciprofloxacin and loperamide.

To determine the efficacy of loperamide given with long- and short-course quinolone therapy for treating traveler's diarrhea, 142 US military personnel were randomized to receive a single 750-mg dose of ciprofloxacin with placebo, 750 mg of ciprofloxacin with loperamide, or a 3-day course of 500 mg of ciprofloxacin twice daily with loperamide. Culture of pretreatment stool specimens revealed campylobacters (41%), salmonellae (18%), enterotoxigenic Escherichia coli (ETEC, 6%), and shigellae (4%). Of the participants, 87% completely recovered within 72 h of entry. Total duration of illness did not differ significantly among the three treatment groups, but patients in the 3-day ciprofloxacin plus loperamide group reported a lower cumulative number of liquid bowel movements at 48 and 72 h after enrollment compared with patients in the single-dose ciprofloxacin plus placebo group (1.8 vs. 3.6, P = .01; 2.0 vs. 3.9, P = .01). While not delivering a remarkable therapeutic advantage, loperamide appears to be safe for treatment of non-ETEC causes of traveler's diarrhea. Two of 54 patients with Campylobacter enteritis had a clinical relapse after treatment that was associated with development of ciprofloxacin resistance.

Campylobacter Infections↗
PubMed1992

Cluster of tick-borne infections at Fort Chaffee, Arkansas: Rickettsiae and Borrelia burgdorferi in ixodid ticks.

Human intrusion into pristine habitats increases the likelihood of acquiring infectious agents from potentially infective ticks. As part of a larger human serological investigation into tick-borne illnesses, 3,000 ixodid ticks were collected during May, August, and November 1990 at Fort Chaffee, Arkansas. Ticks were examined to determine whether they harbor rickettsiae, ehrlichiae, and Borrelia burgdorferi, and to assess relationship to human exposure to tick-borne infections at Fort Chaffee, Ark. The overall tick infection rates with SFG rickettsiae, B. burgdorferi, and ehrlichiae were 4.8, 0.1, and 0.3%, respectively.

Animals↗
PubMed1992

Epidemiologic investigation of an outbreak of cutaneous leishmaniasis in a defined geographic focus of transmission.

An outbreak of cutaneous leishmaniasis occurred in a unit of 608 Puerto Rican national guardsmen conducting jungle warfare training in the Panama Canal Area in July 1984. An epidemiologic investigation of reported nonhealing, ulcerating skin lesions was conducted among 540 (89%) unit members in November and December 1984. Fifteen (88%) of 17 individuals with chronic, ulcerating skin lesions were confirmed as cases of cutaneous leishmaniasis by culture or histopathology. Twelve cases yielded positive Leishmania cultures, identified as L. braziliensis panamensis by cellulose acetate electrophoresis. Evaluation of different diagnostic techniques revealed that direct examination of tissues by Giemsa-stained histological examination was the most sensitive test (87% sensitivity), with an indirect immunofluorescent antibody test being rather insensitive (67%). All but one of the confirmed cases operated in small units that trained and slept overnight at a mortar firing site for a period of three days, yielding a site-specific attack rate of 22% (14 of 64). This contrasted with a much lower attack rate of 0.2% (1 of 476), experienced by unit members who trained at other locations during the same time frame (P less than 0.001). The median incubation period calculated from day of arrival at the mortar firing site was 17 days (range 2-78) for the 15 confirmed cases. Available personal protection methods, such as the use of insect repellents, were not appropriately implemented by unit personnel and thus, were not found to effectively protect against Leishmania infection. This is the largest reported outbreak of cutaneous leishmaniasis in military personnel associated with a single geographic focus of infection and contrasts with the usual sporadic disease experience in Panama.

Adult↗
PubMed1991

Treatment of travelers' diarrhea: ciprofloxacin plus loperamide compared with ciprofloxacin alone. A placebo-controlled, randomized trial.

OBJECTIVE: To compare the safety and efficacy of loperamide used in combination with ciprofloxacin or ciprofloxacin alone for the treatment of travelers' diarrhea. DESIGN: Double-blind, placebo-controlled, randomized clinical trial. SETTING: United States Army hospital in Egypt. PARTICIPANTS: United States military personnel with travelers' diarrhea (n = 104) during a military exercise in November 1989. Persons who were noncompliant, had bloody diarrhea, or had received antidiarrheal medications before entry into the study were excluded. INTERVENTIONS: All participants with travelers' diarrhea were treated with ciprofloxacin, 500 mg twice daily for 3 days. Fifty of these patients were randomly assigned to receive loperamide, a 4-mg first dose and 2 mg for every loose stool (as much as 16 mg/d), and 54 were randomly assigned to receive placebo. MEASUREMENTS: Enterotoxigenic Escherichia coli was isolated from 57% of patients; Shigella and Salmonella, seen in 4% and 2% of patients, respectively, were not common. MAIN RESULTS: After 24 hours, the symptoms of 82% of patients in the ciprofloxacin and loperamide group compared with 67% in the ciprofloxacin and placebo group had improved or fully recovered (odds ratio, 2.3; 95% CI, 0.8 to 6.3; P = 0.08). After 48 hours, the symptoms of 90% of both groups had improved or fully recovered. The mean number of stools for those receiving loperamide was not much lower than those who did not receive loperamide after 24 hours (1.9 +/- 0.2 [SE] compared with 2.6 +/- 0.2) or 48 hours (3.1 +/- 0.3 compared with 4.0 +/- 0.3) of treatment (P = 0.19). CONCLUSIONS: In a region where enterotoxigenic E. coli was the predominant cause of travelers' diarrhea, loperamide combined with ciprofloxacin was not better than treatment with ciprofloxacin alone. Loperamide appeared to have some benefit in the first 24 hours of treatment in patients infected with enterotoxigenic E. coli. Both regimens were safe.

Ciprofloxacin↗
PubMed1991

Isolation and characterization of an Ehrlichia sp. from a patient diagnosed with human ehrlichiosis.

A new disease was recognized in the United States in 1986. The etiologic agent, although not previously isolated from a human, appeared to be serologically related to Ehrlichia canis, a canine leukotropic rickettsia. We obtained blood specimens from 27 febrile patients with a history of tick exposure. Leukocytes from 24 patients not treated with tetracycline were placed onto a monolayer of DH82 cells. We performed indirect immunofluorescence on sera from all 27 febrile patients as well as sera from 12 patients with previously diagnosed ehrlichiosis. Intractoplasmic inclusions were first observed in culture 35 days after the addition of infected blood from one patient. Partial sequencing of the rRNAs from the human isolate and E. canis indicated that they are 98.7% related. Positive indirect immunofluorescence reactions to the human isolate were obtained for all 12 previously diagnosed patients and for 33% of the 27 febrile patients. Two patients were seropositive for the human isolate but not for E. canis. No sera were positive for E. canis and negative for the human isolate. We report the isolation of a previously unrecognized Ehrlichia sp. that appears to be the etiologic agent of human ehrlichiosis. Serologic data (range of antibody titers, 256 to 32,768) in combination with rRNA sequencing indicated that the newly isolated Ehrlichia sp. is similar, but not identical, to E. canis.

Adult↗
PubMed1990

Parasitological evaluation of a foodhandler population cohort in Panama: risk factors for intestinal parasitism.

A nonconcurrent, prospective intestinal parasitic disease study in a group of 200 foodhandlers employed in the Panama Canal Area was conducted in mid-1985 as part of an established occupational health medical surveillance program. The study included a review of laboratory testing (i.e., coprological exam), preexisting medical record data, and patient interview information to calculate estimates of incidence and risk factors associated with acquisition of Giardia lamblia and other protozoan/helminthic intestinal parasites. Significant increases in risk of infection were detected for specific native Indian and West Indian employee groups when compared with their Hispanic Panamanian (i.e., Latinos) or North American (i.e., U.S. born) counterparts. A three- to fourfold higher rate of infection was also documented during a one-year period when semiannual rather than annual examinations were conducted. No difference in the therapeutic efficacy of parasitological cure of Metronidazole versus Quinacrine was found when used in the treatment of individuals with asymptomatic G. lamblia infections (85% in both groups). The appropriateness of mass therapy of asymptomatically infected foodhandlers is discussed.

Adult↗
PubMed1988

Isolation of a newly recognized Bunyamwera serogroup virus from a febrile human in Panama.

A virus, strain 86MSP18, was isolated from the acute phase serum of a U.S. soldier with a febrile illness. He was stationed at Fort Sherman in the Republic of Panama when the onset of his illness occurred. A rise in neutralizing antibody to the viral isolate was observed between the patient's acute and convalescent-phase serum samples. Virus strain 86MSP18 has been shown by plaque reduction neutralization to be closely related to but distinct from Cache Valley virus and known subtypes. It appears to be a newly recognized subtype of Cache Valley virus and is believed to be the second isolation of a Cache Valley virus subtype from a human with a febrile illness. The name "Fort Sherman" virus for strain 86MSP18 is proposed.

Animals↗
PubMed1987

Bowenoid papulosis: clinical and histological study of eight cases.

Eight cases of bowenoid papulosis are reported. The clinical diagnoses were confirmed by histology. In one case an immunoperoxidase method showed the presence of papillomavirus antigen in the nucleus of the most superficial epidermal cells. We consider bowenoid papulosis to be a condition with specific features that distinguish it clinically and histologically from carcinoma in situ and condylomata acuminata.

Adult↗
PubMed1986

Erythema nodosum leprosum: nature and extent of the cutaneous microvascular alterations.

Skin biopsy specimens from four patients with erythema nodosum leprosum, when examined as Epon-embedded, 1-micron sections, exhibited a necrotizing vasculitis involving capillaries, venules, and small-to-medium arteries and veins. In the superficial dermis, affected venules and capillaries showed endothelial cell enlargement and focal necrosis associated with perivascular infiltrates of lymphocytes. In the deep dermis and subcutaneous tissue, affected venules, arterioles, and arteries exhibited endothelial cell necrosis and matted fibrin in the vessel walls associated with perivascular infiltrates of neutrophils. Throughout the dermis, mononuclear phagocytes with vacuoles containing numerous fragmented organisms were observed. By electron microscopy, electron-dense material resembling immune complexes was observed in the walls of these vessels. These observations support the concept that erythema nodosum leprosum is an immune complex-mediated necrotizing vasculitis involving capillaries, arterioles, arteries, venules, and veins.

Adult↗
PubMed1985

Histopathologic evaluation of melanocytic nervi in oculocutaneous albinism.

This is a report of the histopathologic findings of melanocytic nevi in patients with oculocutaneous albinism. Seven albino patients, four tyrosinase positive and three tyrosinase negative, with a total of 34 melanocytic lesions were available for examination. The specimens were examined histopathologically for the presence of intranuclear pseudoinclusions, giant melanocytic cells, eosinophilic globules, features of congenital nevi, and atypical changes. A statistically significant increased number of giant melanocytic cells were found in intradermal nevi (p less than 0.0025), compound nevi (p less than 0.01), and junctional nevi of the patients with albinism compared with controls. Eosinophilic globules were found in 17% of the 34 nevi, and congenital features in 8.8%. All lesions showed adequate maturation of cells with no atypical changes. Marked solar elastosis was found in the dermis around and beneath the nevi, even though most lesions were in covered areas.

Adult↗