Clinical and epidemiological analyses of human pythiosis in Thailand.
BACKGROUND
Pythiosis is an emerging and life-threatening infectious disease in humans and animals that is caused by the pathogenic oomycete Pythium insidiosum. Human pythiosis is found mostly in Thailand, although disease in animals has been increasingly reported worldwide. Clinical information on human pythiosis is limited, and health care professionals are unfamiliar with the disease, leading to underdiagnosis, delayed treatment, and poor prognosis.


METHODS
To retrospectively study the clinical and epidemiological features of human pythiosis, we analyzed clinical data from patients with pythiosis diagnosed during the period of January 1985 through June 2003 at 9 tertiary care hospitals throughout Thailand.


RESULTS
A total of 102 cases of human pythiosis were documented nationwide. A substantial proportion (40%) of cases occurred in the last 4 years of the 18-year study interval. Clinical presentations fell into 4 groups: cutaneous/subcutaneous cases (5% of cases), vascular cases (59%), ocular cases (33%), and disseminated cases (3%). Almost all patients with cutaneous/subcutaneous, vascular, and disseminated pythiosis (85%) had underlying thalassemia-hemoglobinopathy syndrome. Most ocular cases (84%) were associated with no underlying disease. A majority of the patients were male (71%), were aged 20-60 years (86%), and reported an agricultural occupation (75%). Regarding treatment outcomes, all patients with disseminated infection died; 78% of patients with vascular disease required limb amputation, and 40% of these patients died; and 79% of patients with ocular pythiosis required enucleation/evisceration.


CONCLUSIONS
Here, we report, to our knowledge, the largest case study of human pythiosis. The disease has high rates of morbidity and mortality. Early diagnosis and effective treatment are urgently needed to improve clinical outcomes. Because P. insidiosum is distributed worldwide and can infect healthy individuals, an awareness of human pythiosis should be promoted in Thailand and in other countries.
Krajaejun
Theerapong
T
Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. mr_en@hotmail.com
Sathapatayavongs
Boonmee
B
Pracharktam
Roongnapa
R
Nitiyanant
Prawat
P
Leelachaikul
Paisan
P
Wanachiwanawin
Wanchai
W
Chaiprasert
Angkana
A
Assanasen
Paraya
P
Saipetch
Marisa
M
Mootsikapun
Piroon
P
Chetchotisakd
Ploenchan
P
Lekhakula
Arnuparp
A
Mitarnun
Winyou
W
Kalnauwakul
Sineenart
S
Supparatpinyo
Khuanchai
K
Chaiwarith
Romanee
R
Chiewchanvit
Siri
S
Tananuvat
Napaporn
N
Srisiri
Sawet
S
Suankratay
Chusana
C
Kulwichit
Wanla
W
Wongsaisuwan
Mawin
M
Somkaew
Shawarash
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000453:epidemiology* / Q000382:microbiology*; D011775:Pythium / Q000302:isolation & purification*; D013785:Thailand / Q000453:epidemiology