Resolution of eosinophilia after treatment of cutaneous gnathostomiasis.

The present study was to investigate the dynamics of eosinophil in peripheral blood of patients with cutaneous gnathostomiasis before and after worm removal. The total of 28 proven cases of cutaneous gnathostomiasis treated by albendazole were included in the present study. The absolute eosinophil count (AEC) was higher than 500/ul during infestation in almost all the patients, the positive rate was 89%, and significantly decreased to normal level after receiving albendazole and worm removal within 3 months in 96%. In conclusion, an increas of AEC is another important hallmarks of cutaneous gnathostomiasis and this parameter could be the earlier indicator for responsiveness to treatment.

Decrease of mosquito salivary gland proteins after a blood meal: an implication for pathogenesis of mosquito bite allergy.

Salivary gland protein profiles ofAedes aegypti (L.) and Culex quinquefasciatus (Say) pre- and post-blood feeding were analyzed. SDS-PAGE studies before blood feeding of Ae. aegypti demonstrated 8 major polypeptide bands of 20, 35, 37, 42, 45, 47, 70 kDa and a high molecular weight band >118 kDa, whereas those of Cx. quinquefasciatus demonstrated 9 major polypeptide bands of 20, 26, 36, 38, 45, 47, 49 kDa and 2 high molecular weight bands >118 kDa. After a blood feeding, salivary gland polypeptides of Ae. aegypti at 35, 37, 45, 47, 70 kDa and high molecular weight band >118 kDa were depleted, while the polypeptide bands of 20, 26, 36, 38 kDa were depleted in Cx. quinquefasciatus. The presented study suggests that these major polypeptides were introduced into vertebrate hosts when a mosquito took a blood meal. Further investigation in molecular, biochemical and immunological aspects of these salivary gland polypeptides may provide information for better understanding in the role of these proteins in mosquito bite allergy.

Prevalence of parasitic infections among Thai patients at the King Chulalongkorn Memorial Hospital, Bangkok, Thailand.

Parasitic diseases are still considered to be a major public health problem. Most patients with parasitic infections are asymptomatic and therefore remain undetected. Asymptomatic parasitic infections are usually discovered by routine parasite examination. To determine the result of parasite examination at the Parasitology Unit, Out Patient Department, King Chulalongkorn Memorial Hospital, Bangkok, Thailand, the authors collected the data of individuals examined for parasite infections from June to December 1997. A total of 6,231 Thais provided the data for analysis. Evidence of parasitic infections was found in 557 (8.94%) cases. The disease was most prevalent in males (57.3%), and in the age group >15-30 years old (11.13%). The population from the Northeast of Thailand was found to harbor parasites with the highest prevalence rate (17.03%), while it was 11.90 per cent in the northern group. The parasitic prevalence rates in the West, East, South and Central regions were 10.60 per cent, 8.90 per cent, 7.74 per cent, and 4.92 per cent, respectively. The parasite most commonly identified was Strongyloides stercoralis (33.39%), while giardiasis was the most common protozoan infection (14.36%). The highest infection rates of S. stercoralis, hookworms, Opisthorchis viverrini, and Gnathostoma spinigerum were found in northeasterners. People from the North of Thailand were infected mostly with G. lamblia. People of working-age from northeastern as well as northern regions harbored pathogenic parasites with high prevalence rates. To prevent parasitic infections, health education for these high risk groups should be provided.

Prevalence and intensity of third stage Gnathostoma spinigerum larvae in swamp eels sold in three large markets in Bangkok, Thailand.

Gnathostoma spinigerum is a common human tissue parasite in Thailand. The swamp eel is the major intermediate or paratenic host for this parasite. The high prevalence of the infective third stage larvae (L3) of this parasite in the rainy season has been noted in previous studies. During June 1999 (rainy season), we performed a cross-sectional survey of the prevalence and the intensity of G. spinigerum L3s in the livers of swamp eels that were obtained from three large Bangkok markets (Klong Toey, Pran Nok, and Tevej). Of a total of 785 livers, G. spinigerum L3s were found in 97: an infection rate of 12%. The prevalence rates in Klong Toey, Pran Nok, and Tevej markets were 13%, 10% and 14% respectively. There was no significant difference in the proportion of infected eels between the markets (p > 0.05). The intensity of L3 burden in the livers ranged from 1-17 larvae, with an average of 2.60 +/- 0.24 larvae (mean +/- SE). In this study a high prevalence of G. spinigerum L3s was found; there was no significant difference in the intensity of larvae in swamp eels between markets. These findings emphasize the importance of public health education: people need to be aware of the dangers of consuming raw or undercooked food.