Cryptoccocal meningitis in Yaoundé (Cameroon) HIV infected patients: Diagnosis, frequency and Cryptococcus neoformans isolates susceptibility study to fluconazole.

Cryptococcal meningitis is a mycosis encountered especially in patients with Acquired Immunodeficiency Syndrome and is fatal in the absence of treatment. Information on epidemiology, diagnosis and susceptibility profile to antifungal drugs, are scarce in Cameroon. Authors evaluated the diagnosis possibilities of the cryptococcal meningitis in Cameroon, and studied the antifungal susceptibility of isolated strains to fluconazole, used as first line treatment of the disease in Cameroon. Between December 2009 and July 2011, 146 cerebrospinal fluids obtained from HIV patients with suspicion of meningitis were analysed. The diagnosis procedure involved macroscopic and cyto-chemical analysis, India ink test, culture on Sabouraud chloramphenicol medium and antigen latex agglutination test. Antifungal susceptibility testing of isolated strains to fluconazole was done by the E-test(®) method. The diagnosis of cryptococcal meningitis gave 28.08% positive cases. Among these patients, 80% were at stages III and IV and 20% at stage I of the HIV infection, according to the WHO previous classification. Cyto-chemical analysis showed current findings in the case of cryptococcal meningitis. India ink test and latex agglutination test exhibited very high sensitivity and specificity (>94%). Fluconazole antifungal susceptibility testing gave MICs lower than 32µg/mL to 92.7% of isolated strains and MICs greater than this value to 7.3% of isolates. These results showed that cryptococcal meningitis remains a real problem among HIV infected patients in Yaoundé. The emergence of fluconazole reduced susceptibility strains is worrying. Nevertheless, efficacy of rapid detection tests is interesting because this will help in rapid diagnosis and treatment of patients.

Genotyping and antifungal susceptibility testing of Cryptococcus neoformans isolates from Cameroonian HIV-positive adult patients.

Cryptococcus neoformans is the most common cause of meningitis amongst adult Africans with HIV/AIDS. The widespread use of fluconazole may lead to the emergence of isolates with reduced susceptibility. We studied C. neoformans isolates from HIV-infected patients with cryptococcal meningitis. Genotyping and antifungal testing were performed to assess the genetic diversity, occurrence of mixed infections and in vitro activity of antifungal agents. Isolates were recovered from cerebrospinal fluid prior to systemic antifungal treatment. Six isolates were studied for each sample (a total of 114 isolates from 19 patients). Serotyping was performed via LAC 1 and CAP 64 gene amplification and genotyping was performed using phage M13 core, (GACA)4 and (GTG)5 primers and restriction polymorphism analysis of the URA5 gene. Susceptibilities for amphotericin B, flucytosine, fluconazole, voriconazole and posaconazole were tested by the Sensititre YeastOne® method. All strains were identified as C. neoformans var. grubii serotype A. We identified nine major genotypes. Up to two genotypes were identified in the same sample. None of the isolates were resistant to the studied drugs. However, 13 of 114 strains exhibited a reduced susceptibility to fluconazole and 13 of 114 strains exhibited a reduced susceptibility to flucytosine. No correlation was found between the genotype and susceptibility. This study confirms the prevalence of C. neoformans serotype A in Cameroon. Two genotypes may be responsible for a single episode of cryptococcosis. The possibility of mixed infection and diminished susceptibility to fluconazole or flucytosine must be considered for the management of cryptococcosis.