zoonoses and communicable diseases common to ... - PAHO/WHO

CRYPTOCOCCOSIS 327has grown worldwide as the number of AIDS patients has increased. In Argentina,the annual number of cases ranged from four to eight until 1987, began to increasein 1988, and reached 35 cases in 1990. The age group most affected was 20- to 39-year-olds. More men were affected than women, particularly when the underlyingdisease was AIDS (Bava and Negroni, 1992). It is estimated that the male-femaleratio was 3:1. The percentage of AIDS patients who contracted cryptococcosis inArgentina increased from 12.5% in 1990 to 25.9% in 1991. This percentage is similarto the incidence of cryptococcosis in AIDS patients in central Africa and southeastAsia (20% to 35%), but greater than that in Europe and the United States (6%to 10%). In greater Buenos Aires, cryptococcosis is second among the tracer diseasesof AIDS, after esophageal candidiasis (Bava et al., 1992). In Malaysia, on theother hand, only 14% of the patients studied had AIDS.Epidemiologic studies based on the intradermal test indicate that many individualsexposed to the agent show no symptoms of the disease.Occurrence in Animals: Rare, sporadic cases. Some epizootic outbreaks of mastitisand cryptococcal pneumonia have been described in cattle. The disease has beendescribed in goats, horses, and cats.The Disease in Man: The large majority of cases are meningitis or meningoencephalitis.This form is preceded by a pulmonary infection, which is often asymptomaticor, if symptomatic, may resolve spontaneously. In most cases of localizationin the CNS, pulmonary invasion is not evident (Diamond, 1990). The initial pulmonaryinfection can resolve spontaneously, give rise to a granulomatous mass(“cryptococcoma”), or disseminate via the bloodstream. The pulmonary form manifestswith fever, cough, chest pain, and hemoptysis. Radiography shows single ormultiple nodules or large cryptococcomas. The course is usually chronic. When disseminationfrom the original pulmonary focus occurs, the infection localizes primarilyin the meninges, spreading to the brain. The most obvious symptoms of themeningeal form of the disease are headache and visual disturbances. Other symptomsmay include confusion, personality changes, agitation, and lethargy.Cryptococcal meningoencephalitis can follow a course lasting for weeks or monthsand is almost always fatal if not properly treated. The characteristic lesion in thebrain is comprised of groups of fungal cysts without inflammation. This lesion canalso be found in other sites (Diamond, 1990). Asymptomatic meningitis sometimesoccurs when there are other locations and the disease is discovered through lumbarpuncture and culture of the cerebrospinal fluid (Liss and Rimland, 1981). The lesioncan affect the skin, the mucosa, and the bones, as well as various other organs.Cutaneous infection is characterized by the formation of papules and abscesses andsubsequent ulceration.Man is resistant to C. neoformans. There are cryptococcosis patients who show noobvious predisposing factors. However, the fungus is to a large extent an opportunisticpathogenic agent. The number of cases increased significantly with the HIVepidemic. In the United States, cryptococcosis is the fourth potential leading case ofdeath in AIDS patients, after Pneumocystis carinii, cytomegaloviruses, andmycobacteria. A retrospective study of AIDS patients was conducted in a hospital inPorto Alegre, Brazil to determine the diseases that could affect the CNS. Between1985 and 1990, 138 autopsies were performed and all the brains were examinedmacro- and microscopically. According to the results, 29 (21%) suffered from