Early Bactericidal Activity Trial of Nitazoxanide for Pulmonary Tuberculosis.

This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 µg/ml; the mean NTZ maximum concentration (Cmax) in plasma was 10.2 µg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.).

CD4 deficit and tuberculosis risk persist with delayed antiretroviral therapy: 5-year data from CIPRA HT-001.

SETTING: Port-au-Prince, Haiti. OBJECTIVE: To determine long-term effects of early vs. delayed initiation of antiretroviral therapy (ART) on immune recovery and tuberculosis (TB) risk in human immunodeficiency virus (HIV) infected individuals. DESIGN: Open-label randomized controlled trial of immediate ART in HIV-infected adults with CD4 counts between 200 and 350 cells/mm(3) vs. deferring ART until the CD4 count was <200 cells/mm(3). The primary comparisons were CD4 counts over time and risk for incident TB, with 5 years of follow-up. RESULTS: A total of 816 participants were enrolled, with 408 in each treatment arm. The early treatment group started ART within 2 weeks, while the deferred treatment group started ART a median of 1.3 years after enrollment. After 5 years, the mean CD4 count in the early treatment group was significantly higher than in the deferred treatment group (496 cells/mm(3), 95% confidence interval [CI] 477-515 vs. 373 cells/mm(3), 95%CI 357-389; P < 0.0001). TB risk was higher in the deferred treatment group (unadjusted HR 2.41, 95%CI 1.56-3.74; P < 0.0001) and strongly correlated with lower CD4 counts in time-dependent multivariate analysis. CONCLUSION: Delays in ART initiation for HIV-infected adults with CD4 counts of 200-350 cells/mm(3) can result in long-term immune dysfunction and persistent increased risk for TB.

Integration of tuberculosis screening at an HIV voluntary counselling and testing centre in Haiti.

OBJECTIVE: To describe the integration of tuberculosis screening into the activities of an HIV voluntary counselling and testing (VCT) centre in a country with endemic tuberculosis. SETTING: An HIV VCT centre in Port au Prince, Haiti. DESIGN: All patients presenting for HIV VCT who reported cough received same-day evaluation for active tuberculosis. Of the 1327 adults presenting to the centre for the first time between January and April 1997, 263 (20%) reported cough and of these 241 (92%) were evaluated. RESULTS: Of the 241 patients evaluated for cough, 76 (32%) were diagnosed with pulmonary tuberculosis. Of the 76 patients diagnosed with pulmonary tuberculosis, 28 (37%) had a positive smear for acid-fast bacilli (AFB), 14 (18%) had a negative AFB smear but a positive sputum culture for Mycobacterium tuberculosis, and 34 (45%) had culture-negative tuberculosis. Also, 31 out of 241 (13%) VCT clients evaluated for cough were diagnosed with bacterial pneumonia. CONCLUSION: This report confirms that in areas with a high HIV and tuberculosis prevalence, a high proportion of VCT clients have active pulmonary tuberculosis. The integration of tuberculosis screening offers several benefits, including the diagnosis and treatment of large numbers of individuals with tuberculosis, a decreased risk of nosocomial tuberculosis transmission, and the opportunity to provide tuberculosis prophylaxis to HIV-positive patients in whom tuberculosis has been excluded. Future studies are needed to determine the cost-effectiveness of integrated tuberculosis and HIV VCT services, and whether integration should be recommended in all countries with high HIV and tuberculosis rates.

A novel approach to directly observed therapy for tuberculosis in an HIV-endemic area.

OBJECTIVES: This study evaluated a novel approach to the delivery of directly observed therapy (DOT) for tuberculosis in Haiti. METHODS: A total of 194 patients (152 HIV seropositive, 42 HIV seronegative) received daily unsupervised triple-drug therapy for 4 to 8 weeks, followed by twice-weekly 2-drug therapy for the remainder of the 6-month period. DOT was deferred until initiation of the twice-weekly phase. RESULTS: A total of 169 of 194 patients (87.1%) completed the 6-month course. The program of deferred DOT had an effectiveness of 85%. Overall cost was reduced by approximately 40%. CONCLUSIONS: Flexible approaches to DOT, integrating behavioral knowledge, cost considerations, and practicality may improve completion rates and program effectiveness.

Effect of post-treatment isoniazid on prevention of recurrent tuberculosis in HIV-1-infected individuals: a randomised trial.

BACKGROUND: Patients with HIV-1 infection respond well to treatment for active tuberculosis, but whether such patients are at increased risk of disease recurrence after complete cure is uncertain. We did a randomised trial in Port au Prince, Haiti, to determine whether recurrent tuberculosis after curative tuberculosis treatment is more common in HIV-1-infected individuals than HIV-1-uninfected individuals, and to determine whether post-treatment isoniazid prophylaxis decreases the risk of recurrent tuberculosis. METHODS: Patients older than 18 years who were diagnosed with a first episode of tuberculosis at the national HIV testing centre in Haiti, and who successfully completed a 6-month rifampicin-containing regimen for active pulmonary tuberculosis, were randomly assigned 1 year of post-treatment isoniazid prophylaxis or placebo. The primary outcome measure was rate of recurrent tuberculosis after at least 24 months. An intention-to-treat analysis was used. FINDINGS: Of 354 patients with active pulmonary tuberculosis, 274 successfully completed treatment, and 233 were randomised. Of 142 HIV-1-positive patients, 68 were assigned isoniazid and 74 placebo. Of 91 HIV-1-negative individuals, 51 were assigned isoniazid and 40 placebo. The rate of recurrent tuberculosis was 4.8 per 100 person-years in HIV-1-infected individuals and 0.4 per 100 person-years in uninfected individuals (relative risk 10.7 [95% CI 1.4-81.6]). Among HIV-1-positive patients receiving isoniazid, the tuberculosis recurrence rate was 1.4 per 100 person-years, and among HIV-1-positive patients receiving placebo, it was 7.8 per 100 person-years (0.18 [0.04-0.83]). Among HIV-1-positive individuals, all cases of recurrent tuberculosis occurred in individuals with a history of HIV-1-related symptoms before initial tuberculosis diagnosis. INTERPRETATION: The rate of recurrent tuberculosis is higher in HIV-1-positive individuals than in HIV-1-negative individuals, and is strongly associated with a history of symptomatic HIV-1 disease before initial tuberculosis diagnosis. Post-treatment isoniazid prophylaxis decreases the risk of recurrence in HIV-1-positive individuals, and should be considered for HIV-1-positive individuals with a history of HIV-1-related symptoms at the time of tuberculosis diagnosis.

Active tuberculosis in individuals infected with human immunodeficiency virus after isoniazid prophylaxis.

A review was conducted in Haiti to determine the timing and outcome of active tuberculosis (TB) in human immunodeficiency virus (HIV)-positive patients who had previously received isoniazid (INH) prophylaxis. Of 1005 HIV-seropositive patients who completed INH prophylaxis, 14 (1.4%) subsequently had active TB diagnosed. The median interval between discontinuation of INH prophylaxis and TB diagnosis was 8 months for 6 patients receiving 6 months of INH, 22 months for 5 patients receiving 12-24 months of INH, and 40 months for 3 patients receiving 24-36 months of INH (P = .026). There is a postprophylaxis effect on INH that is dependent upon the duration of therapy.

Clonally related penicillin-nonsusceptible Streptococcus pneumoniae serotype 14 from cases of meningitis in Salvador, Brazil.

Active hospital-based surveillance in the city of Salvador, Brazil, from December 1995 through October 1998, identified 221 patients with confirmed pneumococcal meningitis. Of these 221 patients, 29 (13%) had isolates with intermediate-level resistance to penicillin. Infection with these penicillin-nonsusceptible isolates was significantly associated with age of <2 years (P<.0019), previous antibiotic use (P<.0006), and coresistance to trimethoprim-sulfamethoxazole (P<.0000). Serotype 14 was the most prevalent serotype (55.2%) of penicillin-nonsusceptible isolates. Strain typing by repetitive element BOX polymerase chain reaction (PCR) analysis showed that penicillin-nonsusceptible serotype 14 isolates had closely related BOX PCR patterns, whereas penicillin-susceptible serotype 14 isolates each had distinct, unrelated patterns. Penicillin-nonsusceptible serotype 14 isolates from Salvador and other Brazilian cities had similar BOX PCR patterns. These observations indicate that in Brazil a large proportion of cases of penicillin-nonsusceptible pneumococcal meningitis appear to be caused by a closely related group of serotype 14 strains that may have disseminated to widely separate geographic areas.

HIV infection in Haiti: natural history and disease progression.

OBJECTIVE: A study was conducted to define the natural history and disease progression of HIV infection in a developing country. DESIGN: A prospective longitudinal cohort study. METHODS: Forty-two patients with documented dates of HIV seroconversion were followed in Port-au-Prince, Haiti. Patients were seen at 3 month intervals or when ill. Patients were treated for bacterial, mycobacterial, parasitic, and fungal infections, but antiretroviral therapy was not available. Patients were followed until death or until 1 January 2000; median follow-up was 66 months. RESULTS: By Kaplan-Meier analyses, the median time to symptomatic HIV disease (CDC category B or C) was 3.0 years [95% confidence interval (CI) 2.3-5.0 years]. The median time to AIDS (CDC category C) was 5.2 years (95% CI 4.7-6.5 years), and the median time to death was 7.4 years (95% CI 6.2-10.2 years). Community-acquired infections, including respiratory tract infections, acute diarrhea, and skin infections were common in the pre-AIDS period. AIDS-defining illnesses included tuberculosis, wasting syndrome, cryptosporidiosis, cyclosporiasis, candida esophagitis, toxoplasmosis, and cryptococcal meningitis. Rapid progression to death was associated with anemia at the time of seroconversion hazards ratio (HR) 4.1 (95% CI 1.1-15.0), age greater than 35 years at seroconversion HR 4.4 (95% CI 1.1-16.6), and lymphopenia at seroconversion HR 11.0 (95% CI 2.3-53.0). CONCLUSION: This report documents rapid disease progression from HIV seroconversion until death among patients living in a developing country. Interventions, including nutritional support and prophylaxis of common community-acquired infections during the pre-AIDS period may slow disease progression and prolong life for HIV-infected individuals in less-developed countries.

IS1245 genotypic analysis of Mycobacterium avium isolates from patients in Brazil.

OBJECTIVE: Disseminated Mycobacterium avium infection is an emerging opportunistic disease among patients with acquired immunodeficiency syndrome (AIDS) in Brazil. The mode of transmission of M. avium in a developing country setting needs to be better characterized. METHODS: Mycobacterium avium strain collections in São Paulo and Rio de Janeiro were analyzed according to the strains' IS1245 DNA gel electrophoretic migration patterns. Medical records of the patients from whom M. avium isolates were available were reviewed, and their demographic characteristics were stratified according to the isolates' IS1245 DNA fingerprint patterns. RESULTS: Of 105 patients, 33 (31%) with M. avium isolated between 1990 and 1994 had strains having IS1245 patterns identical in patterns seen in isolates from two or more patients (designated as cluster pattern strains). Cluster pattern strains were isolated from 21 (39%) of 54 patients with disseminated infection (defined as infection due to M. avium isolated from a sterile site in an adult patient). Six of the cluster pattern strains were isolated only from sterile sites. In São Paulo, cluster pattern strains were significantly more likely to be isolated from patients with disseminated disease. CONCLUSIONS: These preliminary observations suggest that in large cities of Brazil, a high proportion (at least 39%) of disseminated M. avium infections in patients with AIDS results from a recent transmission. Some strains of M. avium may be more likely to cause disseminated disease than others after an infection.

Urban epidemic of severe leptospirosis in Brazil. Salvador Leptospirosis Study Group.

BACKGROUND: Leptospirosis has, traditionally, been considered a sporadic rural disease. We describe a large urban outbreak of leptospirosis. METHODS: Active surveillance for leptospirosis was established in an infectious-disease referral hospital in Salvador, Brazil, between March 10 and Nov 2, 1996. Patients meeting case criteria for severe manifestations of leptospirosis were recruited into the study. The diagnosis was confirmed in the laboratory with the microagglutination test and identification of leptospires in blood or urine. Risk factors for death were examined by multivariate analyses. FINDINGS: Surveillance identified 326 cases of which 193 (59%) were laboratory-confirmed (133) or probable (60) cases. Leptospira interrogans serovar copenhageni was isolated from 87% of the cases with positive blood cultures. Most of the cases were adult (mean age 35.9 years [SD 15.9]), and 80% were male. Complications included jaundice (91%), oliguria (35%), and severe anaemia (26%). 50 cases died (case-fatality rate 15%) despite aggressive supportive care including dialysis (in 23%). Altered mental status was the strongest independent predictor of death (odds ratio 9.12 [95% CI 4.28-20.3]), age over 37 years, renal insufficiency, and respiratory insufficiency were also significant predictors of death. Before admission to hospital, 42% were misdiagnosed as having dengue fever in the outpatient clinic; an outbreak of dengue fever was taking place concurrently. INTERPRETATION: An epidemic of leptospirosis has become a major urban health problem, associated with high mortality. Diagnostic confusion with dengue fever, another emerging infectious disease with a similar geographic distribution, prevents timely intervention that could minimise mortality.

The natural history of human immunodeficiency virus 1 infection in Haitian infants.

OBJECTIVES: The current study followed HIV-infected women through pregnancy and their infants through the first 2 years of life to determine the rate of vertical transmission of HIV infection from Haitian women, factors in maternal health and obstetrical history that might influence such transmission and the natural history of HIV infection in their affected offspring. STUDY DESIGN: The medical histories of 81 infants born of HIV-infected women and of a control group of 88 infants born to uninfected women were documented with close clinical and serologic follow-up. In addition to standard tests for persistence of HIV antibodies, the use of acid-dissociated p24 assays enabled us to assign some additional infants to the HIV-infected cohort. RESULTS: Transmission could be documented in 27% of infants born to HIV-infected women. Excess early deaths occurred in infants of HIV-infected women in Port-au-Prince with 60% of infected infants dead by 6 months of age. This is a more accelerated mortality than that in a group of 42 HIV-infected infants born of Haitian mothers living in Miami where 10% were dead at 6 months. Clinically, in 6 of 19 deaths in HIV-infected children in Haiti, failure to thrive and gastroenteritis lead to a systemic infection manifested as meningitis, sepsis or pneumonia as the immediate cause of death. CONCLUSIONS: Early mortality attributable to perinatally acquired AIDS was identified in Haiti. The comparison of data from Miami and Port-au-Prince suggests that environmental exposures in developing countries may be more operative in this early mortality than viral strain or maternal host factors, both of which might be expected to be similar between the two groups of Haitian ethnicity.

Clinical manifestations of human immunodeficiency virus infection in Haitian children.

OBJECTIVE: This study was designed to describe the characteristics of HIV-1 infection in children in Haiti and to assess its impact on morbidity and mortality. BACKGROUND: Throughout the developing world the female-to-male ratio of HIV-1 infection approaches 1:1, leading to a tremendous burden of vertically transmitted HIV-1 infection. The frequency of transmission, progression of disease and AIDS-defining clinical illnesses are not as well-described in this setting as in the industrial world. METHODS: Children were identified as being HIV-1-seropositive from case findings among family members of individuals presenting for screening at the GHESKIO Centers in Port-au-Prince, Haiti. Children who were seronegative from the same population were also enrolled and both groups were followed at regular intervals. The clinical course and illnesses associated with HIV infection were documented. RESULTS: Rapid progression to symptomatic disease and death was seen and a battery of physical findings enabled a clinician over time to assign with high sensitivity and specificity the diagnosis of AIDS to a child. Although many findings are similar, the presentation of HIV-1 infection in Haiti differed in significant ways from observations in the industrial world. In particular signs of malnutrition, failure to thrive and tuberculosis were more common in the Haitian population. CONCLUSION: Pediatric HIV-1 infection in Haiti differs significantly from the illness in the industrial world. Early mortality poses a particular difficulty in diagnosing and ascribing mortality to HIV-1 infection.

Tuberculosis and HIV infection among female inmates in São Paulo, Brazil: a prospective cohort study.

Prison populations are at increased risk of both human immunodeficiency virus (HIV) and Mycobacterium tuberculosis infections, but among female inmates information on such risks remains scarce, especially in developing countries. Between October 1992 and November 1993, 350 women incarcerated at a prison in São Paulo, Brazil, were prospectively evaluated for HIV and M. tuberculosis infection and disease. Among them, 87 (25%) were HIV seropositive, and 20 (5.7%) had tuberculosis (TB). During the incarceration period, the purified protein derivative test conversion rate was 29% for HIV-positive and 32% for HIV-negative women. However, the incidence of TB was 9.9 per 100 person-years for HIV-positive and 0.7 per 100 person-years of incarceration for HIV-negative women (p < 0.0001). A multivariate analysis indicated that HIV infection (p < 0.0001) and incarceration time < 12 months (p < 0.05) were each associated with TB. These findings indicate that new transmissions of M. tuberculosis infection are common among female inmates and that HIV-infected women are more likely to acquire active disease during the first 12 months of incarceration. Because of their role in childbearing and care female inmates are an important potential source of transmission of M. tuberculosis, and new strategies to control the spread of TB in prisons need to be developed.

Heterosexual transmission of HIV in Haiti.

BACKGROUND: Despite the importance of human immunodeficiency virus (HIV) transmission through heterosexual contact, the incidence of HIV infection in heterosexual cohorts has not been well studied, particularly in the developing world. OBJECTIVE: To 1) determine the incidence of HIV infection in discordant heterosexual couples (couples in which one partner had HIV infection and the other did not) in Haiti and 2) assess risk factors for and methods of preventing HIV infection. DESIGN: Prospective study. SETTING: National Institute for Laboratory Research, Portau-Prince, Haiti. PARTICIPANTS: 475 HIV-infected patients and their noninfected regular sex partners. MEASUREMENTS: Patients and their partners were evaluated at 3- to 6-month intervals for HIV infection, sexually transmitted diseases, and sexual practices. The efficacy of counseling and provision of free condoms was also evaluated. RESULTS: Among the 177 couples who remained sexually active during the prospective study period, 20 seroconversions to HIV positivity occurred, for an incidence rate of 5.4 per 100 person-years (95% CI, 5.16 to 5.64 per 100 person-years). Thirty-eight couples (21.5%) discontinued sexual activity during the study. Only 1 seroconversion occurred among the 42 sexually active couples (23.7% of the 177 sexually active couples) who always used condoms. In contrast, the incidence in sexually active couples who infrequently used or did not use condoms was 6.8 per 100 person-years (CI, 6.49 to 7.14 per 100 person-years). Transmission of HIV was associated with genital ulcer disease, syphilis, and vaginal or penile discharge in the HIV-negative partner and with syphilis in the HIV-infected partner. CONCLUSION: Counseling and the provision of free condoms contributed to the institution of safe sex practices or abstinence in 45% of discordant heterosexual couples. However, 55% of couples reported that they continued to have unprotected sex, resulting in an incidence of HIV infection of 6.8 per 100 person-years.

PIP: A prospective study of 475 individuals infected with human immunodeficiency virus (HIV) and their non-infected regular sex partners indicated that discordant heterosexual couples comprise a major source of acquired immunodeficiency syndrome (AIDS) spread in Haiti. Participants were recruited from the National Institute for Laboratory Research in Port-au-Prince. Of the 2687 HIV-positive individuals who returned to the Institute during 1988-92 to obtain their HIV test result, 1201 brought in a regular sexual partner for testing; 583 (49%) of these partners were HIV-negative. Discordant couples received free condoms and counseling and were evaluated at 3-month intervals. Sexual activity was discontinued by 298 (63%) of couples within 6 months of study entry, largely because of advanced AIDS. Overall, 20 sex partners seroconverted after a median follow-up of 27 months. Seroconversion was associated with non-use of condoms (relative risk, 6.8/100 person-years), the presence of genital ulcer disease in the initially HIV-negative partner (6.55), and syphilis in the HIV-infected index patient (2.9). Counseling increased condom use from none at study entry to 24%. The rate of seroconversion in those who always used condoms was only 1/100 person-years.

Interleukin-12 restores interferon-gamma production and cytotoxic responses in visceral leishmaniasis.

American visceral leishmaniasis (AVL) is associated with the absence of lymphocyte proliferative responses and interleukin (IL)-2 and interferon-gamma (IFN-gamma) production upon stimulation with Leishmania antigen. In contrast, cure of AVL is associated with restoration of these T cell functions. In the present study, the ability of IL-12, a cytokine that acts on NK and T cells to restore cellular immune responses in AVL, was evaluated. Participants of the study included 12 patients with AVL and 7 subjects cured of AVL. The [3H]thymidine uptake and IFN-gamma production in cultures of peripheral blood mononuclear cells (from AVL patients) stimulated with Leishmania chagasi antigen were 882 +/- 1393 cpm and zero, respectively. Addition of IL-12 enhanced the proliferative response to 5097 +/- 6429 cpm (P < .001) and IFN-gamma production to 305 +/- 325 pg/mL (P < .01). IL-12 also restored cytotoxic activity against the K562 cell line. These results indicate that IL-12 has an important role in the regulation of the cellular immune response in human leishmaniasis.

The influence of CD4+ T cells, HIV disease stage and zidovudine on HIV isolation in Bahia, Brazil.

HIV-1 isolation was attempted on 72 individuals, including persons with known HIV infection and five without proven HIV infection but with indeterminate Western blot patterns, as well as on low-risk HIV seronegative persons. The ability to detect HIV-1 from culture supernatant by p24 antigen capture assay was evaluated by segregating patients by absolute CD4+ cell counts, clinical stage of disease, p24 antigenemia and zidovudine use. The likelihood of a p24 positive HIV culture was highest among patients with CD4+ T-cell counts below 200/ul and patients with advanced clinical disease. Use of zidovudine did not affect the rate of HIV positivity in cultures.

Visceral leishmaniasis in a new ecological niche near a major metropolitan area of Brazil.

In 1991, a community cross-sectional study was conducted in a village situated near the beach and close to Salvador, the capital city of Bahia, in Brazil, to determine the prevalence of visceral leishmaniasis since 1989. A serological survey was made of human and canine reservoirs and an intradermal skin test for leishmaniasis was used to assess cellular immune responses. Nearly 30% of the 243 individuals in the study area had positive skin tests and 14% had positive serology, the latter being compatible with recent infection; 29 of 460 dogs examined were seropositive. A possible association was observed between human infection and the presence of dogs in or near residences, but not between human infection and malnutrition. This report describes the evolution of a new focus of visceral leishmaniasis, its expansion toward a metropolitan area, and current measures taken to control the epidemic.

Cyclospora infection in adults infected with HIV. Clinical manifestations, treatment, and prophylaxis.

OBJECTIVE: To determine the prevalence and clinical manifestations of Cyclospora in Haitians infected with human immunodeficiency virus (HIV) who have diarrhea and to evaluate therapy and prophylaxis. DESIGN: Cohort study. From 1990 to 1993, stool samples were collected from adults seropositive for HIV who had had diarrhea for at least 3 weeks. SETTING: A clinic in Haiti. INTERVENTIONS: Stool samples were examined for enteric protozoa after acid-fast staining. Patients with Cyclospora infection were treated with trimethoprimsulfamethoxazole (160 mg and 800 mg, respectively) given orally four times a day for 10 days. After completion of therapy, patients were evaluated weekly and re-treated if clinical and parasitologic recurrences occurred, followed by trimethoprim-sulfamethoxazole prophylaxis three times a week. RESULTS: 804 of 2400 patients (33%) seropositive for HIV had a history of chronic or intermittent diarrhea; 502 of these 804 patients (62%) currently had diarrhea, and 450 patients each provided two stool specimens for examination. Enteric protozoa identified included Cryptosporidium (30%), Isospora belli (12%), Cyclospora species (11%), Giardia lamblia (3%), and Entamoeba histolytica (1%). Forty-three patients with diarrhea and Cyclospora infection were studied; their symptoms were indistinguishable from those seen in patients with isosporiasis or cryptosporidiosis. In all patients, diarrhea ceased and results from stool examinations were negative within 2.5 days after beginning oral trimethoprim-sulfamethoxazole therapy. Recurrent symptomatic cyclosporiasis developed in 12 of 28 patients (43%) followed for 1 month or more, but it also responded promptly to trimethoprim-sulfamethoxazole therapy. These 12 patients received trimethoprim-sulfamethoxazole three times a week as secondary prophylaxis, with only a single recurrence after 7 months. CONCLUSION: Cyclospora infection is common in Haitian patients with HIV infection, responds to trimethoprim-sulfamethoxazole therapy, and has a high recurrence rate that can be largely prevented with long-term trimethoprim-sulfamethoxazole prophylaxis.