Tuberculosis in the Republic of Cuba: its possible elimination

[Response capacity and challenges of the Cuban health system against communicable diseasesCapacidade de resposta e desafios do sistema de saúde cubano contra doenças transmissíveis]

En el presente artículo se identifican rasgos distintivos y esenciales en las transformaciones del sistema de salud cubano que han permitido la erradicación y disminución de las tasas de incidencia de algunas enfermedades transmisibles a niveles inferiores a 0,1 por 100 000 habitantes. Los resultados obtenidos son consecuencia de la importancia otorgada a la prevención y control de estas enfermedades, así como a los riesgos y daños potenciales. La estructura y funcionamiento del subsistema de higiene y epidemiología y sus interrelaciones con el resto del sistema a partir de los diferentes modelos de prestación de servicios han constituido escenarios de integración permanentes para la toma de decisiones. Se eliminaron enfermedades como la poliomielitis, paludismo, difteria, tosferina, rubéola, parotiditis, meningitis posparotiditis, sarampión, fiebre amarilla, cólera, formas graves de la tuberculosis, rabia humana transmitida por caninos, leishmaniasis, enfermedad de Chagas, la transmisión vertical del virus de inmunodeficiencia humana, sífilis congénita y formas clínicas como el tétanos neonatal y el síndrome de rubéola congénita. Se hace énfasis en algunas enfermedades transmisibles y, en especial, en la respuesta social desarrollada contra la tuberculosis, la lepra, el sida y las enfermedades transmitidas por vectores. Se demuestra que el contexto sanitario actual revela aún desafíos para la sostenibilidad de los logros alcanzados en el país. Garantizar el mantenimiento de la cobertura universal con acceso de la población cubana a los servicios de salud será siempre un principio de la salud pública cubana.

Tuberculosis en niños de 0-14 años: Cuba, 1994-2003

INTRODUCTION

Tuberculosis in infants and children is a sign of continuous transmission. The present article describes the distribution and the trend in incidence rates of new tuberculosis cases in 0-15-year-olds in Cuba.

METHODS

Incidence rates and their trend were estimated by provinces and age groups for the 1994-2003 period. Distribution and overall variation percentages, annual average rates, and rates and percentages according to classification were determined.

RESULTS

The incidence rate decreased from 0.76 x 10(5) in 1994 to 0.31 in 2003 (59.2% of the overall reduction and 6.6% of the annual average reduction). The highest rate (1.06 x 10(5)) was found in 1995 (26 cases). In almost all provinces, the incidence trend decreased, except in the City of Havana, Sancti Spíritus, Santiago de Cuba, and the Isle of Youth. Childhood tuberculosis was mainly pulmonary (69.6%). Among the affected population, the highest percentages were found in the groups aged 10-14 years (35.6%) and 1-4 years (35.2%).

CONCLUSIONS

Tuberculosis is infrequent and is extremely uncommon in infants. Notification is low throughout the country and the overall trend shows a steady decrease.

The DOTS strategy for controlling the global tuberculosis epidemic

This article reviews the principles, scientific basis, and experience with implementation of the directly observed treatment strategy, short course (DOTS) for tuberculosis. The relevance of DOTS in the context of multidrug-resistant tuberculosis and the HIV epidemic also is discussed.

Molecular epidemiological study on transmission of tuberculosis in a hospital for mentally handicapped patients in Havana, Cuba

The IS 6110 restriction fragment length polymorphism (RFLP) analysis of Mycobacterium tuberculosis isolates has revolutionized the description of the epidemiology of tuberculosis. This technique has been used to confirm suspected cases of transmission in several institutional settings. In this study, we analysed by conventional and molecular epidemiological methods the unexpectedly high number of tuberculosis cases which occurred among 14 mentally handicapped patients and a healthcare worker in Havana's Psychiatric Hospital in the period from 1995 to 1998. Twelve M. tuberculosis isolates of the respective patients showed the same DNA fingerprint, consisting of nine bands. Three other different IS 6110 RFLP patterns with 10, eight, and 10 bands were observed. The results of RFLP analysis and of an additional epidemiological investigation allowed the identification of the probable source of this chain of transmission in the healthcare facility. This would not have been possible without the aid of DNA fingerprinting. Delays in diagnosis of the source patient and of the secondary cases, a tardy and deficient tuberculin skin test and the difficulties of management of mentally handicapped patients probably contributed to spread the M. tuberculosis strain in Havana's Psychiatric Hospital.

[Economic and social impact of the National Tuberculosis Control Program (NTCP) on the Cuban population]

Tuberculosis (TB) control strategies provide one of the greatest cost/effectiveness results. To assess the impact of the national TB control program on the Cuban population, the time series of new TB cases and death reports, potential years of life lost, and the numbers of beds for TB case hospitalization in the entire country during 1964-91 and 1992-96 were described by common simple calculation on the basis of estimated expected values. The reduction in new TB cases and deaths, potential years of life saved, and savings in expenditures for treatment, hospitalization, and unemployment compensation were estimated. From 1965 to 1991 new case reports were reduced by 94.6% (4% per year); 86,500 cases were avoided; 166,439 potential years of life were saved; 2,831,625 million pesos were saved on tuberculostatic drugs; 82.7 million pesos were saved on unemployment compensation under the social security system for workers with active TB. Estimated savings totaled 494,919,631.3 pesos. Nationwide intervention for TB control produced an important impact on the basis of the sociopolitical status making it possible to approach complete elimination of the disease in the future.

Encompassing treatment with prevention: the path for a lasting control of tuberculosis

Tuberculosis is an important cause of death, mainly in the less developed countries. Thus far the strategy for its control had relied on the diagnosis of sick individuals and provision of chemotherapy. However, this strategy is problematic for several reasons: poor education about the disease and the low income of people with tuberculosis are important barriers for them to have access to early diagnosis and to keep adherence to treatment; provision of 'preventive therapy' to the enormous pool of people infected with tuberculosis is not feasible in less developed countries; and finally, long-term political commitment with the strategy is unlikely. Several facts indicate that tuberculosis patterns in different populations are shaped by biological, behavioral and socio-economic factors. This paper argues that a lasting control of tuberculosis requires a strategy based on a broader model of causality, which takes account of all these three causal factors.