Leptospirosis among patients presenting with dengue-like illness in Puerto Rico.

Leptospirosis is difficult to distinguish from dengue fever without laboratory confirmation. Sporadic cases/clusters of leptospirosis occur in Puerto Rico, but surveillance is passive and laboratory confirmation is rare. We tested for leptospirosis using an IgM ELISA on sera testing negative for dengue virus IgM antibody and conducted a case-control study assessing risk factors for leptospirosis, comparing clinical/laboratory findings between leptospirosis (case-patients) and dengue patients (controls). Among 730 dengue-negative sera, 36 (5%) were positive for leptospirosis. We performed post mortem testing for leptospirosis on 12 available specimens from suspected dengue-related fatalities; 10 (83%) tested positive. Among these 10 fatal cases, pulmonary hemorrhage and renal failure were the most common causes of death. We enrolled 42 case-patients and 84 controls. Jaundice, elevated BUN, hyperbilirubinemia, anemia, and leukocytosis were associated with leptospirosis (p < .01 for all). Male sex, walking in puddles, rural habitation, and owning horses were independently associated with leptospirosis. Epidemiological, clinical, and laboratory criteria may help distinguish leptospirosis from dengue and identify patients who would benefit from early antibiotic treatment.

Asymptomatic infection and risk factors for leptospirosis in Nicaragua.

As part of an investigation of a 1995 outbreak of leptospirosis in Nicaragua, a cross-sectional serologic survey was conducted in the town of El Sauce. Of 566 persons, 85 (15%) were positive for IgM anti-Leptospira antibodies, indicating recent leptospirosis infection. Asymptomatic leptospirosis infection was common, with only 25 (29.4%) of the 85 seropositive inhabitants reporting a febrile illness in the 2 months before the survey. Multivariable analysis revealed that having an indoor water source remained independently protective against leptospirosis. Gathering wood was independently associated with infection. These findings suggest that asymptomatic infection with Leptospira is common in endemic areas of Leptospira transmission. Improvement in water sanitation and behavioral modifications to reduce environmental exposure may reduce the risk of leptospirosis in endemic regions.

Increase of leptospirosis in dengue-negative patients after a hurricane in Puerto Rico in 1996 [correction of 1966].

Leptospirosis has rarely been reported in Puerto Rico, although in the period from 1948 to 1952, 208 cases of leptospirosis and an island-wide seroprevalence of antibody to Leptospira of 14% were documented. In Puerto Rico in October 1996, following rainfall and a period of flooding generated by Hurricane Hortense, serum specimens of 4 patients with suspected dengue fever that were negative for dengue tested positive for Leptospira-specific IgM antibodies in a dipstick assay. Subsequently, we used an island-wide dengue laboratory-based surveillance system to determine the increase in leptospirosis after hurricane-generated floods. All anti-dengue IgM-negative patients (n = 142) with disease onset from August 8 to October 6, 1996 from prehurricane and posthurricane groups were investigated for leptospirosis. Laboratory-confirmed leptospirosis cases were defined as microscopic agglutination test titers > or = 1 :400 to 1 or more serovars, or positive immunohistochemistry in autopsy tissues. Four (6%) of 72 prehurricane and 17 (24%) of 70 posthurricane patients had laboratory-confirmed cases of leptospirosis (relative risk [RR] = 4.4, 95% confidence interval [CI] = 1.6-12.4). The mean age of case-patients was 34 years (range = 13-64). Eighteen (86%) of 21 confirmed case-patients were males, including one patient who died (31 years old). Patients were located in 18 (38%) of 48 municipalities that submitted serum samples. Clinical features significantly associated with leptospirosis were eye pain (RR = 1.5, 95% CI = 1.3-1.9), joint pain (RR = 1.4, 95% CI = 1.1-1.6), diarrhea (RR = 1.7, 95% CI = 1.2-2.5), and jaundice (RR = 3.3, 95% CI = 1.5-7.2). This study demonstrates the utility of a dengue laboratory-based surveillance system for the detection of an increase of leptospirosis, which most likely would have gone unrecognized. Leptospirosis is treatable with antibacterial agents; knowledge of this diagnosis may significantly reduce morbidity and mortality.

Epidemic leptospirosis associated with pulmonary hemorrhage-Nicaragua, 1995.

In October 1995, epidemic "hemorrhagic fever," without jaundice or renal manifestations, was reported in rural Nicaragua following heavy flooding; 2259 residents were evaluated for nonmalarial febrile illnesses (cumulative incidence, 6.1%) and 15 (0.7%) died with pulmonary hemorrhage. A case-control study found that case-patients were more likely than controls to have ever walked in creeks (matched odds ratio [MOR], 15.0; 95% confidence interval [CI], 1.7-132.3), have household rodents (MOR, 10.4; 95% CI, 1.1-97.1), or own dogs with titers >/=400 to Leptospira species (MOR, 23.4; 95% CI, 3.6-infinity). Twenty-six of 51 case-patients had serologic or postmortem evidence of acute leptospirosis. Leptospira species were isolated from case-patients and potential animal reservoirs. This leptospirosis epidemic likely resulted from exposure to flood waters contaminated by urine from infected animals, particularly dogs. Leptospirosis should be included in the differential diagnosis for nonmalarial febrile illness, particularly during periods of flooding or when pulmonary hemorrhage occurs.

Prospective study of histoplasmosis in patients infected with human immunodeficiency virus: incidence, risk factors, and pathophysiology.

Histoplasmosis is a common opportunistic infection in patients with human immunodeficiency virus (HIV) infection who reside in areas where Histoplasma capsulatum is endemic. We undertook a prospective study of a cohort of 304 HIV-Infected patients in Kansas City from October 1990 through March 1993 to define the incidence-specific risk factors, and pathophysiology of histoplasmosis. The annual incidence of histoplasmosis was 4.7%; 74% of the patients with histoplasmosis were symptomatic (all of whom had disseminated disease). A history of exposure to chicken coops, a positive baseline serology for complement-fixing antibodies to Histoplasma mycelium antigen, and a baseline CD4+ lymphocyte count of < 150/microL were associated with an increased risk for histoplasmosis. Histoplasmin reactivity and the presence of pulmonary calcifications were not useful markers for patients at high risk. Symptomatic infection occurred in 9.9% of patients with evidence of prior exposure to H. capsulatum, in 4.0% of patients without documented prior exposure, and in 3.0% of patients who were anergic; these findings suggest that the pathophysiology of histoplasmosis in patients with AIDS involves reactivation of latent infection in some cases and dissemination of exogenously acquired infection in other cases.

A coccidioidomycosis outbreak following the Northridge, Calif, earthquake.

OBJECTIVE: To describe a coccidioidomycosis outbreak in Ventura County following the January 1994 earthquake, centered in Northridge, Calif, and to identify factors that increased the risk for acquiring acute coccidioidomycosis infection. DESIGN: Epidemic investigation, population-based skin test survey, and case-control study. SETTING: Ventura County, California. RESULTS: In Ventura County, between January 24 and March 15, 1994, 203 outbreak-associated coccidioidomycosis cases, including 3 fatalities, were identified (attack rate [AR], 30 cases per 100,000 population). The majority of cases (56%) and the highest AR (114 per 100,000 population) occurred in the town of Simi Valley, a community located at the base of a mountain range that experienced numerous landslides associated with the earthquake. Disease onset for cases peaked 2 weeks after the earthquake. The AR was 2.8 times greater for persons 40 years of age and older than for younger persons (relative risk, 2.8; 95% confidence interval [CI], 2.1-3.7; P<.001). Environmental data indicated that large dust clouds, generated by landslides following the earthquake and strong aftershocks in the Santa Susana Mountains north of Simi Valley, were dispersed into nearby valleys by northeast winds. Simi Valley case-control study data indicated that physically being in a dust cloud (odds ratio, 3.0; 95% CI, 1.6-5.4; P<.001) and time spent in a dust cloud (P<.001) significantly increased the risk for being diagnosed with acute coccidioidomycosis. CONCLUSIONS: Both the location and timing of cases strongly suggest that the coccidioidomycosis outbreak in Ventura County was caused when arthrospores were spread in dust clouds generated by the earthquake. This is the first report of a coccidioidomycosis outbreak following an earthquake. Public and physician awareness, especially in endemic areas following similar dust cloud-generating events, may result in prevention and early recognition of acute coccidioidomycosis.

Preventing disseminated Mycobacterium avium complex disease in patients infected with human immunodeficiency virus.

Disseminated Mycobacterium avium complex (MAC) infection is an important late-stage complication of infection with the human immunodeficiency virus. Since MAC is widely dispersed in the environment, the source of infection for patients with disseminated MAC generally cannot be determined. Therefore, specific recommendations for avoiding exposure are not supported at this time. Routine screening of stools and sputum to detect MAC colonization as a means of targeting prophylaxis for disseminated disease is also not recommended at present. Two randomized, placebo-controlled trials have demonstrated that prophylactic use of rifabutin in persons with low CD4 lymphocyte counts results in a 50% decrease in MAC bacteremia as well as a reduction in some signs, symptoms, and laboratory abnormalities associated with MAC disease. Thus a prophylactic daily dose of rifabutin (300 mg) should be considered for adults who have had a previous AIDS-defining opportunistic illness and who have a CD4 lymphocyte count of < 75/microL. Many experts would consider prophylaxis appropriate only when the CD4 lymphocyte count is < 50/microL, particularly when there has not been a previous AIDS-defining opportunistic infection. Clinicians should be aware of drug interactions and potential adverse effects associated with the use of rifabutin. Preliminary reports of randomized, placebo-controlled trials suggest that chemoprophylaxis with clarithromycin is also effective in the prevention of disseminated MAC disease, and evaluation of other agents is under way. Prophylaxis for disseminated MAC infection in children has not been evaluated but is presumed to be as effective as that in adults. Decisions regarding initiation of MAC chemoprophylaxis should be individualized.

Immunization, oral rehydration therapy and malaria chemotherapy among children under 5 in Bomi and Grand Cape Mount counties, Liberia, 1984 and 1988.

As part of an evaluation of child survival programmes in 13 African countries, cluster surveys were carried out in two Liberian counties in 1984 and 1988 to measure use of three primary health care services: immunization of infants, antimalarial treatment of children with fever, and oral rehydration of childhood diarrhoea. Immunization rates increased (30-53% for DPT-1 and 13-33% for measles), treatment of malaria with drugs available in the home increased from 5 to 35%, and home use of sugar-salt solution to prevent dehydration remained essentially unchanged, 5.9% in 1984 and 3.8% in 1988.

Indigenous cases of Lyme disease diagnosed in North Carolina.

Between January 1984 and December 1989, 102 indigenous cases of Lyme disease were reported in North Carolina. Lyme disease was reported in each of the three major geographic regions of the state: mountain, piedmont, and coastal plain. One or more diagnoses were made in 42 of 100 counties. Patients ranged in age from 5 months to 78 years (median, 27 years); 58 patients (57%) reported a history of tick exposure within 1 month of the onset of symptoms. Erythema migrans was reported by 93 patients (91%). Arthritis (30%), neurologic symptoms (10%), and cardiac abnormalities (7%) were observed. Thirty of the 102 cases were confirmed serologically by indirect fluorescence microscopy or enzyme-linked immunosorbent assay.

A large outbreak of antibiotic-resistant shigellosis at a mass gathering.

In July 1987, a large outbreak of shigellosis occurred among attendees at a mass gathering in a national forest, the annual Rainbow Family Gathering. Sanitation in the campsite was poor, allowing widespread transmission of disease, probably by food, water, and person-to-person spread. The attack rate may have been greater than 50% among the estimated 12,700 attendees. The outbreak was caused by Shigella sonnei, resistant to ampicillin, tetracycline, and trimethoprim-sulfamethoxazole; the organism was of colicin type 9 and contained a 90-kilobase plasmid not found in non-outbreak-related strains. The dispersal of the group resulted in nationwide dissemination of the organism, and outbreaks in three states were linked to transmission from attendees at the Gathering. This outbreak demonstrates the potential for rapid dissemination of disease in such a setting and the necessity for careful planning of mass gatherings.

Seroprevalence of human T-lymphotropic virus type I or II in sexually transmitted disease clinic patients in the USA.

Serum specimens from patients attending sexually transmitted disease (STD) clinics in Denver and several southeastern US cities were tested for antibody to human T-lymphotropic virus type I or II (HTLV-I/II). In Denver, 8 (2.1%) of 384 patients with a history of intravenous (IV) drug use, versus none of 201 non-IV-drug users, were HTLV-I/II seropositive. Only 2 (0.18%) of 1095 STD clinic patients from the southeastern USA had antibodies to HTLV-I/II. These data document a low prevalence of HTLV-I/II in STD clinic patients from the southeastern USA and confirm that IV drug use is an important risk factor for HTLV-I/II in the USA.

Human T-cell lymphotropic virus I and adult T-cell leukemia: report of a cluster in North Carolina.

PURPOSE: Human adult T-cell leukemia-lymphoma is a malignant, proliferative disease of CD4+ lymphocytes associated with infection with human T-cell lymphotropic virus type I (HTLV-I). Following the presentation of a patient who was infected with the virus, we undertook a study of his family members and sexual contacts to see if a cluster of infected persons could be identified. CASE REPORT: A black heterosexual North Carolina native with a history of drug abuse presented with jaundice, and pancytopenia subsequently developed. He then became hypercalcemic and leukemic, with high numbers of circulating, morphologically abnormal CD4+ lymphocytes. RESULTS: As determined by radioimmunoassay and immunoblot analyses, the serum of the index case contained antibodies against core proteins (p19 and p24) of HTLV-I. When cultured in vitro with interleukin-2, the lymphocytes expressed HTLV-I specific core proteins. The virus recovered from these T cells was transmitted to cord blood T cells, which became immortalized for continuous growth in vitro, expressed HTLV-I p19 protein, and displayed characteristic C-type particles by electron microscopy. Studies of family members and sexual contacts, all of whom were black, heterosexual central North Carolina natives, revealed five of 28 whose serum had anti-HTLV-I antibodies as determined by radioimmunoassay and immunoblot. Neither the patient nor the seropositive family/contacts had antibodies against human immunodeficiency virus proteins. Four of the six people with HTLV-I infection had no history of intravenous drug abuse. Three of the five seropositive family/contacts had circulating, morphologically abnormal lymphocytes suggestive of "preleukemic" or "smoldering" human adult T-cell leukemia-lymphoma.

Diazepam and succinylcholine chloride for restraint of the American alligator.

Diazepam followed by succinylcholine chloride was administered intramuscularly to 26 healthy mature female alligators on 2 occasions. The mean diazepam dosage was 0.37 mg/kg (range, 0.22 mg/kg to 0.62 mg/kg) and the mean succinylcholine chloride dosage was 0.24 mg/kg (range, 0.14 mg/kg to 0.37 mg/kg). This drug combination reduced stress and allowed adequate immobilization for restraint and handling. The reduced drug volume, low dosage of succinylcholine chloride required, short induction period, maintenance of respiration, and adequate degree of immobilization make this drug combination a good alternative to the use of muscle relaxants alone in chemical restraint of alligators.