Infant-juvenile paracoccidioidomycosis. Two Argentine endemic zones with different epidemiological and clinical aspects? What influences this situation

GIUSIANO G; CHACON Y; VALDEZ R

New Delhi

Congreso; 21st Congress of the International Society for Human and Animal Mycology; 2022

International Society for Human and Animal Mycology

Argentina has two endemic areas of paracoccidioidomycosis (PCM). It is noteworthy that epidemiological characteristics differ in both areas, especially in frequency, and clinical aspects of infant-juvenile PCM form (I-JF). In this work, we have reviewed and analyzed 10 years of juvenile PCM form (JF) in both areas emphasizing in acute/subacute I-JF cases.From January 2012 to December 2021 data of epidemiological characteristics, clinical history and laboratory results of I-JF cases were recorded on standardized protocols and entered into a database that helped consolidate the information.Although the more extensive area of PCM historically with the highest incidence is located in Northeast Argentina (NEA), the major number of I-JF was observed in the smaller PCM endemic area, located in the Northwest of the country (NWA).In NWA, 32 JF were recorded including 20 cases of I-JF form in children from 1-13 years old. No outbreak was registered. Cases were equally distributed over the 10 years.In NEA, 28 JF were recorded including 8 cases of I-JF form in children from 7-14 years old. Of these cases, 6/8 (75%) presented as an outbreak in 2012. The rest were only registered in 2018-2020.More frequent clinical manifestation of I-JF:NWA: 70% hepatosplenomegaly with peritonitis and ascites, 33% gastrointestinal symptoms including diarrhea. Adenomegaly (70% cervical, 15% mediastinal).Serology (ID) non-reactive: 32%NEA: 62% cutaneous, 37% hepatosplenomegaly, 25% osteolytic lesions, 25% pulmonary nodules, 25% pericardial effusion, 25% mucocutaneous. Adenomegaly (75% cervical, 62% mediastinal-retroperitoneal).Serology (ID) non-reactive: 12.5%NWA records most cases of I-JF with a constant frequency and with a lower median age. NEA seems to only occur in outbreaks.Are striking the different epidemiological characteristics observed? Predominantly hepatosplenomegaly and intestinal forms in NWA, being with fecal material the first sample where Paracoccidioides is detected in many cases. In contrast, more diverse clinical manifestations are observed in NEA. Most cases with cutaneous/mucocutaneous lesions and the presence of pulmonary and pericardial forms characterized I-JF in this zone.Considering serological tests are important in the PCM diagnosis and to follow up the treatment success, no-reactive tests obtained (32% in NWA, 12.5% in NEA) show a serious diagnostic problem emphasize the need to work on more sensitive tools to reduce the high mortality of this clinical form. The variable expression of gp43 among isolates of Paracoccidioides species may suggest not to use a single antigen preparation for serological tests and include autochthonous isolates.Our group reported climatic and anthropogenic changes influencing the appearance of I-JF outbreaks in the NEA, a region where the observation of these cases was historically very rare. Probably, NWA provides a different ecological niche for Paracoccidioides, which favors its constant appearance over time. We have already started a multicenter molecular epidemiological, probably include soil studies of NWA would be important to try to better understand this situation.