[Cryptococcosis caused by Cryptococcus neoformans var. Gattii. A case associated with acquired immunodeficiency syndrome (AIDS) in Kinshasa, Zaire]

Abstract

Since the introduction of AIDS, the biovar neoformans of Cryptococcus neoformans has replaced the biovar gattii as the predominant agent of cryptococcal meningitis in Kinshasa and in other tropical areas. That this is not an absolute rule is demonstrated by the present case of a HIV-positive patient, observed at the Kinshasa University Hospital, with cryptococcal meningitis due to the biovar gattii. Only four cases of this association have been published before. The authors conclude that both biovars are capable of infecting HIV-positive patients but that the apparent decline of the biovar gattii is related to the rarity of its natural reservoir in the urban environment, where the AIDS epidemic is concentrated.

PIP: In July 1990 in Zaire, a 36-year-old man was admitted to the University Clinic in Kinshasa for intense headaches, fever, vertigo, vision troubles, hallucinations, and irregular speech. He exhibited moderate wasting, left facial paralysis, and prurigo spots on the legs. Laboratory examinations revealed HIV seropositivity, antibodies to cryptococci, protein in the cerebrospinal fluid, and glucose in the cerebrospinal fluid. He was placed on 400 mg/d fluconazole. He died on August 4, two days after slipping into a coma. Cryptococcus neoformans var. gattii was isolated. The man had lived in a free union with two women. One died in 1989 of an illness characterized by persistent fever, considerable wasting, and pulmonary tuberculosis. The other woman is still alive although often having febrile episodes. She is HIV seropositive. Before AIDS arrived, cryptococcosis was rare in Zaire and Cryptococcus neoformans var. gattii was the most common etiologic agent. With AIDS, cryptococcosis has become an opportunistic infection. Since 1983, all cryptococcosis cases at the university clinics were a complication of AIDS. Cryptococcus neoformans var. neoformans was the etiologic agent in all these cases. It is possible that exposure to neoformans variety is more common than exposure to gattii variety. It is therefore an epidemiologic problem intimately associated with the geographic topography specific to ecological niches of these two varieties. Neoformans variety is found in pigeon droppings, while gattii variety has never been found in bird droppings. Gattii's natural host is the eucalyptus tree, found in Zaire. The case lived 400 m from a eucalyptus plantation. He was the only gattii variety cryptococcosis case in 1990-1991 among the 49 cryptococcosis cases at the Kinshasa University Clinics. In conclusion, gattii variety rarely causes cryptococcosis among AIDS patients because its natural reservoir is rare in urban areas where the AIDS epidemic is centered.