Background: Emerging fungus pathogens pose serious global public health threats. The World Health Organization has developed a Fungal Priority Pathogens List (FPPL) in response to the growing threat of historically neglected fungal illnesses. The highest-ranking fungal pathogen in the FPPL is Cryptococcus. Cryptococcus neoformans and Cryptococcus gatti are the most common species in the genus Cryptococcus to cause disease in humans and mainly targets the lungs and the central nervous system, subsequently leading to cryptococcus meningitis. Cryptococcus-related deaths are most frequent in immune compromised individuals in sub-Saharan Africa. The National Institute for Communicable Diseases (NICD) reported that 35000 patients were found positive for cryptococcal antigen in South Africa in a survey between 2017-2019. However, laboratory data for the occurrence of cryptococcal infections post COVID-19 is lacking in KwaZulu-Natal (KZN) region with known high HIV-TB incidence. We therefore investigated the occurrence of cryptococci positive incidences in patient samples either by culture or LFA and observe the hotspot for the infections among hospitals in the KwaZulu-Natal region.
Methods: We retrospectively analyzed data from 8703 samples tested in the KwaZulu-Natal province between January 2022 and June 2023. The results of phenotypic culture or cryptococcal antigen lateral flow assay (CrAg® LFA, IMMY) were collected from the laboratory information system and statistically analyzed.
Results: One hundred and fifty-six samples (156/8703) were positive during the study period. These positives were mostly detected from cerebrospinal fluid samples (70%; 109/156) using culture or LFA. C. neoformans (88%; 138/156) was more prevalent when compared to C. gatti (12%; 18/156). Males accounted for 60% (94/156) of the positive cases while females accounted for 40% (62/156). In the first quarter of 2022, King Edward III hospital (28%) detected the highest number of positive samples in their acute medical and out-patient departments, followed by Edendale (7%) and Benedictine (5%) Hospital.
Conclusion: The study provides valuable epidemiological data and highlights the importance of LFA in screening of patients for early detection of cryptococcal infection. However, as previously published data LFA negative results need to be correlated with gold standard culture. Identification of cryptococcal infection hotspot adds value in planning programmatic interventions and surveillance.
Keywords: Emerging fungal infections, Fungal priority pathogens list, Surveillance, C. neoformans, KwaZulu-Natal