CUBAN MEDICAL LITERATURE - ABSTRACTS

Factors Associated with Tuberculosis in Patients with
Acquired Immunodeficiency Syndrome in Cuba

Reyes Corcho A(1); Díaz Jidy M(2); Pérez Rodríguez A(2); Bouza Jiménez Y(3); Bouza Jiménez Y(1)

OBJECTIVES: To determine the factors associated with the development of tuberculosis in patients with acquired immunodeficiency syndrome (AIDS) and to identify the most frequent signs and symptoms of tuberculosis in this group of patients.

METHODS: This retrospective observational case-control study was carried out with 143 patients diagnosed with AIDS who were discharged from the Pedro Kourí Institute of Tropical Medicine, Havana, Cuba, between January 1997 and March 2001. The cases were 72 patients with AIDS and some clinical form of tuberculosis, while the control group was made up of the first 71 AIDS patients without tuberculosis who were discharged. The following variables were evaluated: AIDS stage before the study, serious opportunistic infections suffered before the diagnosis of tuberculosis (pulmonary pneumocystosis, cerebral toxoplasmosis, systemic candidiasis, isosporiasis, and recurrent pneumonia), concentration of CD4+ T lymphocytes, and clinical signs and symptoms of tuberculosis. The primary data were taken from the clinical files of the patients. We calculated the frequency of the nominal qualitative variables and the crude odd ratios (ORs) and their 95% confidence intervals (CIs). The statistical association among the variables was determined with the chi-square test with Yates correction. The individual effect of each variable was assessed through multivariate logistic regression analysis. The level of statistical significance was 0.05.

RESULTS: Tuberculosis in this group of patients showed a statistically significant association with: being ill with AIDS before the study (OR = 3.57; 95% CI: 1.78 to 7.17); a history of pulmonary pneumocystosis (OR = 4.73; 95% CI: 1.51 to 15.76); cerebral toxoplasmosis (OR = 6.22; 95% CI: 1.21 to 42.99), or systemic candidiasis (OR = 11.29; 95% CI: 1.40 to 246.5); and having CD4+ T lymphocyte concentrations lower than 200 cells/mm 3 . However, the logistic regression showed a significant association only with the history of systemic candidiasis (OR = 10.47; 95% CI: 1.06 to 103.5; P = 0.0446). The symptoms associated with the clinical diagnosis of tuberculosis were hemoptysis (OR = 7.54; 95% CI: 1.88 to 170.34); fever of unknown origin (OR = 13.38; 95% CI: 5.55 to 32.96); night sweats (OR = 21.95; 95% CI: 4.66 to 142.43); and weight loss (OR = 3.52; 95% CI: 1.65 to 7.55). The associated signs were regional lymphadenopathies (OR = 10.00; 95% CI: 1.22 to 220.3); hepatomegaly (OR = 5.44; 95% CI: 1.76 to 17.95); and splenomegaly (OR = 5.08; 95% CI: 1.63 to 16.83).

CONCLUSIONS: The signs and symptoms seen most frequently in patients with AIDS and tuberculosis are characteristic of tuberculosis in patients without AIDS. In patients with AIDS, tuberculosis can be associated with other diseases whose symptoms are similar to those of tuberculosis. Nevertheless, these results indicate that the traditional symptoms of tuberculosis can help diagnose tuberculosis in this group of patients.

Keywords:TUBERCULOSIS; HUMAN IMMUNODEFICIENCY VIRUS; CUBA

1. Clinical Surgical Teaching Hospital Dr. Gustavo Aldereguía Lima, Cienfuegos, Cuba
2. Pedro Kourí Institute of Tropical Medicine, Ciudad de La Habana, Cuba
3. Pediatric Teaching Hospital Paquito González Cueto, Cienfuegos, Cuba

Source : Revista Panamericana de Salud Publica , Volume 15, no.5, May 2004. Available at: http://publications.paho.org/english/backissues/backissues.cfm?Product_ID=764

Tuberculin Reactivity Among Ninth-Graders in Havana City

Borroto Gutiérrez SM(1); González Ochoa E(1); Armas Pérez L(1); Urbino López-Chávez A(1); Martínez AM(1); Llanes MJ(2); Sevy Court J(3); Carreras Corzo L(3)

OBJECTIVES: To determine the proportion of 14-year-old schoolchildren in the city of Havana, Cuba, with a positive tuberculin skin test, as an indicator of the prevalence of tuberculosis infection among them.

METHODS: Using single-stage cluster sampling, 1936 Mantoux (tuberculin) tests were carried out with ninth-grade students (cohort born in 1985) during the 1999–2000 school year in 20 junior high schools randomly selected in Havana. The tests were performed according to the standard technique recommended by the World Health Organization, and they were read after 72 hours.

The percentage of skin tests that were positive and the average diameter of the indurations were calculated for the cohort overall and by gender. The means and the percentages were compared using the chi-square test, with 95% confidence intervals. The computer software used was Epi Info version 6.0.

RESULTS: Of the tests read, 96% of them were negative (0–4 mm), 2.5% were doubtful (5–9 mm), and 1.5% were positive (> 10 mm). The percentage of reactivity was 0.1% when a cutoff value of 15 mm was used. The mean diameter of the indurations was 0.41 mm. No statistically significant difference was found between the genders.

CONCLUSIONS: In this study the proportion of schoolchildren with tuberculin reactivity, using an induration-diameter cutoff point of 10 mm, was very low (1.5%), and it was much lower (0.1%) when a cutoff point of 15 mm was used.

The skin reactions with an induration diameter of > 10 mm could be the expression of a natural infection if one takes into account the low frequency of bacillary tuberculosis in Cuba and that there is an inverse relationship between the time elapsed from the BCG vaccination and the intensity of the response to tuberculin. Therefore, that would mean that in this case the point prevalence of tuberculosis infection in this group of schoolchildren would be 1.5%.

Keywords : TUBERCULOSIS; TUBERCULIN TEST; CUBA

1. Pedro Kourí Institute of Tropical Medicine, Vice Direction of Epidemiological Surveillance, City of Havana, Cuba
2. Ministry of Public Health, National Direction of Epidemiology, City of Havana, Cuba
3. Benéfico Jurídico Pneumonology Hospital, Pulmonary Services, City of Havana, Cuba

Source: Pan American Journal of Public Health, Volume 14, no. 3, September 2003 pp. 209-214(6) . Available at: http://publications.paho.org/english/backissues/backissues.cfm?Product_ID=719#8e

Construction and Characterization
of a Non-proliferative El Tor Cholera Vaccine Candidate
from Strain 638

Valle E(1); Ledón T(1); Cedré B(2); Campos J(1); Valmaseda T(2); Rodríguez B(1); García L(2); Marrero K(1); Benítez J(1); Rodríguez S(1); Fando S(1)

Abstract: In recent clinical assays, our cholera vaccine candidate strain, Vibrio cholerae 638 El Tor Ogawa, was well tolerated and immunogenic in Cuban volunteers. In this article we describe the construction of 638T, a thymidine auxotrophic version of improved environmental biosafety. In so doing, the thyA gene from V. cholerae was cloned, sequenced, mutated in vitro, and used to replace the wild-type allele. Except for its dependence on thymidine for growth in minimal medium, 638T is essentially indistinguishable from 638 in the rate of growth and morphology in complete medium.

The two strains showed equivalent phenotypes with regard to motility, expression of the celA marker, colonization capacity in the infant mouse cholera model, and immunogenicity in the adult rabbit cholera model. However, the ability of this new strain to survive environmental starvation was limited with respect to that of 638. 

Taken together, these results suggest that this live, attenuated, but non-proliferative strain is a new, promising cholera vaccine candidate.

1. Genetic Group, National Center for Scientific Research (CENIC)
2. Finlay Institute, Vaccines and Serums, Havana, Cuba

Source: Infection and Immunity, November 2000, p. 6411-6418, Vol. 68, No. 11 . Available at: http://iai.asm.org/cgi/content/abstract/68/11/6411

The Epidemiology of Dengue and
Dengue Hemorrhagic Fever in Santiago de Cuba, 1997

Valdés L; Guzmán MG; Kourí G; Delgado J; Carbonell I; Cabrera MV; Rosario D; Vázquez S

Abstract: A dengue epidemic that Cuba reported in 1997 registered more than 500,000 cases of dengue fever produced by viral serotype 1. In 1981, there was an epidemic of dengue hemorrhagic fever produced by serotype 2 of the virus. This time, 344,203 clinical cases were reported, 10,312 of which were severe cases of hemorrhagic fever that led to 158 fatalities (101 of them children).

The reintroduction of dengue, and specifically of dengue viral serotype 2 ( Jamaica genotype), was quickly detected in January 1997 through an active surveillance system with laboratory confirmation of cases in the municipality of Santiago de Cuba, in the province of the same name.

The main epidemiological features of this outbreak are reported in this paper. A total of 3,012 cases were reported and serologically confirmed. These included 205 cases classified as dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), 12 of which were fatalities (all among adults). Secondary infection with dengue virus was one of the most important risk factors for DHF/DSS. Ninety eight percent of the DHF/DSS cases and 92% of the fatal cases had contracted a secondary infection.

It was the first time dengue hemorrhagic fever was documented as a secondary infection 16 to 20 years after initial infection. Whites were more at risk for DHF/DSS, as had been observed during the 1981 epidemic.

During the most recent epidemic it was demonstrated that the so called “fever alert” is not useful for early detection of an epidemic. Measures taken by the country’s public health officials prevented spread of the epidemic to other municipalities plagued by Aedes aegypti.

Source: Pan American Journal of Public Health, July 1999. Available at: http://publications.paho.org/spanish/backissues/backissues.cfm?Product_ID=396#3e