Penicillium Marneffei (PM) is one of the few Penicillium species found so far to cause human disease, is a conditional pathogen, can be parasitic intracellular, is the only temperature biphasic fungus in Penicillium; mainly infects immunocompromised people, especially AIDS patients, causing Penicillium Marneffei ( PSM is less commonly reported in immunocompetent people, and infection is even rarer in immunocompetent children, which often results in a lack of awareness of PSM in children, leading to delayed diagnosis and a relatively higher mortality rate in children. In this paper, we report a rare case of non-HIV children with Penicillium marneffei pneumonia and review the clinical data and literature on the characteristics of pulmonary infections in order to improve the early diagnosis and differential diagnosis of Penicillium marneffei pneumonia. Clinical data The child, female, 8 years old, from Wenzhou. She was admitted to the hospital with “recurrent cough and sputum for 1 year, aggravated by fever for 3 weeks”. The initial presentation was fever, cough and sputum, with yellow mucous sputum in large amount. The fever was intermittent, with a body temperature of about 37.5℃, with no obvious regularity. The local hospital investigated the lung shadows and proposed “lung infection”, and gave various antibiotics (penicillin, amoxicillin, ceftriaxone, etc.) repeated anti-infection treatment for nearly 10 months, but no improvement. Physical examination: T: 37.5℃, P: 144 times/min, R: 20 times/min, BP: 100/72mmHg. anemic appearance, no yellowish staining of skin and mucous membrane, no petechiae, no rash. Superficial lymph nodes of the whole body were not enlarged. The respiratory sounds in both lungs were slightly coarse, and no dry or wet woven Pmu 144 times/min, and no pathological murmur was heard in rhythm. The abdomen was flat and soft, with no pressure pain and rebound pain throughout the abdomen. The liver was 1 cm below the ribs and 2 cm below the sword, with soft texture and no tenderness; the spleen was 1 cm below the ribs, with medium texture and mobile turbid sounds (±). Auxiliary examination: liver function ALT 108U/L,AST 141U/L,A 30.8g/L; blood routine: Hb 83.7g/L, N7 3.9%, PLT 122.0×109/L, RBC 4.11×1012/L, WBC 7.19×109/L; coagulation index: PT 15.8s; HIV negative; blood sedimentation, tuberculosis smear Tuberculosis antibody, cellular immunity, and blood cryptococcal culture did not show any significant abnormalities. Abdominal CT: hepatosplenomegaly, enlarged peritoneal and retroperitoneal lymph nodes, and small amount of ascites. Cranial MR: abnormal signals in the left basal ganglia region and the left frontal falx pars compacta. The child was admitted to the hospital with a chest CT: large lamellar solid shadow in the right hilum, multiple small lamellar high-density shadows in both lungs, and small cavities in both upper lung lesions; with pleural effusion and pulmonary atelectasis (see Figure 1). Considered “severe pneumonia, possible invasive fungal disease”, voriconazole was given for 5 days, and the condition deteriorated rapidly with accelerated respiration; chest CT showed an increase in lesions, hepatomegaly and splenomegaly, abnormal liver function, and a rapid decrease in the level of hematocrit, and a large number of phagocytes were seen on bone puncture. The PT was prolonged from 38.7s to 58.4s (only 1d); the child was transferred to ICU for treatment, but his condition progressed rapidly and soon developed into MODS, and he died 3 days after transfer to ICU. The child died after 3 days of transfer to ICU. The sputum culture and bone marrow culture results were reported as PM on the second day after death (Figure 2, 3). Figure 1 Chest CT showed multiple small patchy high-density shadows with small cavities in both lungs Figure 2 Fungal culture: biphasic growth, mycobacterial growth at 25°C, with characteristic burgundy pigmentation Figure 3 Fungal culture: microscopic examination showed broomstick mycelium Discussion The incidence of disseminated PSM has been increasing year by year in recent years, and PM has spread from the AIDS population to the general population. In China, the first case was reported in Guangxi in 1985, and then the number of cases increased gradually, especially in Guangxi and Guangdong provinces in southern China; with the increase of cases, there is a trend of expansion from south to north, and according to statistics, there are nearly 200 publicly reported cases in China, which is only the tip of the iceberg, and there are many unpublished cases and undiagnosed cases. One case of HIV infection with PM has been reported in Shanghai, but there are no reports of PM infection in children with non-HIV. The transmission route of the disease is not clear, Hamilton et al. found that inhalation of conidia of Penicillium marneffei may be the most important transmission route. The mode of transmission through direct contact with the excrement of the bamboo rat or the bamboo rat, the consumption of the bamboo rat or the sugarcane contaminated with Penicillium marneffei is yet to be further demonstrated [3]. PM usually invades the body through the lungs, and after entering the body, the fungus changes to the yeast type and spreads through the reticuloendothelial system. The clinical manifestation of PM pulmonary infection lacks obvious characteristics, and most cases are diagnosed by lavage fluid culture or lung biopsy through fibrinoscopy, and the sputum culture positivity rate is not high. The chest imaging abnormalities are common, and the lungs are mostly characterized by coarse breath sounds without obvious dry and moist woven P. The abrupt X-rays show interstitial changes in both lungs, with diffuse, corn-like fungal pneumonia; lamellar exudative changes; small pleural effusions; and enlarged mediastinal lymph nodes, which are easily misdiagnosed as pulmonary tuberculosis and other opportunistic infections. The patient is a rare case of tuberculosis and other opportunistic infections. The first symptoms were fever, cough, and chest X-ray suggesting lung shadow. The child came to our hospital and was considered to have “severe pneumonia” with possible invasive fungal disease, and died of MODS after 5 days of antifungal treatment with voriconazole, and PM was found in the sputum culture and bone marrow culture after death, which confirmed the diagnosis of disseminated PSM. In the case of recurrent refractory pulmonary infections in children, the possibility of fungal infection should be considered and the pathogen should be searched for early, because once disseminated PSM occurs, the morbidity and mortality rate is extremely high. It is extremely important to find the pathogen and identify the cause of early unexplained pulmonary infection. The CT chest of this child showed the following: (1) lung lamellar solid shadow; (2) diffuse small patchy high-density shadow in both lungs with corn-like nodular shadow of different sizes; (3) enlarged mediastinal and hilar lymph nodes; (4) pleural effusion and pulmonary atelectasis; (5) small cavity shadow in the lesion. The CT changes in the chest of this child were basically consistent with the literature reports and were more typical. The lack of familiarity with the imaging changes of early pulmonary infections is also the reason why this child was not diagnosed early. PSM has a rapid progression and a high mortality rate, but if early diagnosis is made and effective antifungal drugs are applied, a better outcome can usually be achieved. The E-test method has been used to do antifungal drug sensitivity test for PM, and it was confirmed that amphotericin B and itraconazole are more sensitive drugs, which can control the symptoms and clinical cure. The initial treatment with amphotericin B at a dose of 0.6 mg/(kg?d) for 2 weeks followed by itraconazole 400 mg/d for 10 weeks was reported to be effective in most cases. Although fungal infection was considered in this child with voriconazole antifungal treatment, the disease progressed rapidly and he died of MODS; therefore, early diagnosis and early identification of the etiology of pulmonary infection are especially important to reduce the death of patients.