Brugia malayi in a naturally infected cat from Narathiwat Province, southern Thailand.

Brugia malayi-like from an infected cat from Narathiwat Province, southern Thailand was identified intensively by microfilarial morphometry, acid phosphatase activity, and adult morphology. The results indicated that both microfilarial and adult characteristics conformed to the topotypic B. malayi.

Autogenous Aedes togoi sub-colony (Chanthaburi, Thailand strain), an efficient laboratory vector in study of filariasis.

Comparative filarial susceptibility and biology between stock colony and selectively autogenous Aedes. togoi sub-colony were carried out to determine the laboratorial vector-capacity and viability of autogenous sub-colony. The results of susceptibility revealed that the selectively autogenous Ae. togoi sub-colony yielded higher susceptibility than the stock colony, ie Dirofilaria immitis: susceptibility rates=80.00% [Exp1(F8)] and 76.19% [Exp2(F17)] (autogenous sub-colony), 53.33% (Exp1) and 71.43% (Exp2) (stock colony); Brugia malayi: susceptibility rates=83.33% [Exp1(F17)] and 84.38% [Exp2(F19)] (autogenous sub-colony), 81.25% (Exp1) and 75.00% (Exp2) (stock colony), but not at the level of statistically significant differences except the Exp1 of D. immitis, which was significant difference. In addition, the average No. L3 per infected mosquito in the selective autogenous sub-colony (D. immitis: Exp1=3.37, Exp2=3.19; B. mallayi: Exp1=8.80, Exp2=3.37) was also higher than in stock colony (D. immitis: Exp1=2.44, Exp2=2.73; B. malayi: Exp1=7.85, Exp2=3.02), but not at the level of statistically significant difference. The results of comparisons on some biological aspects demonstrated that most of the cases they have similar biology except the average egg deposition per gravid female of stock colony (130.17+/-43.33) was significantly more than selectively autogenous sub-colony(F9) (94.33+/-13.69), egg length x width 575.62+/-18.06 microm x 186.15+/-9.35 microm of stock colony was significantly larger than selectively autogenous sub-colony(F9) 560.49+/-18.96 microm x 177.99+/-8.40 microm, and mean longevity of adult female of stock colony [41.60(6-61)] was significantly longer than selectively autogenous sub-colony(F9) [35.00(5-39)]. The selectively autogenous sub-colony was established and twenty-two successive generations have been colonized.

Field trial of the ICT filariasis for diagnosis of Wuchereria bancrofti infections in an endemic population of Thailand.

The ICT Filariasis, a rapid card test format, which is based on qualitative detection by monoclonal antibody of the circulating antigen of Wuchereria bancrofti adult worm, is a new diagnostic test of choice for determining the infections under field conditions. By using clinical and recall techniques and microscopy (thick smear and capillary tube technique) as reference, we assessed the efficiency of the ICT card test in sera from 225 subjects living in W. bancrofti-endemic villages of Tak Province, Thailand, who were recruited during a cross-sectional community survey. The ICT card test gave a 20% antigen positive rate, while other tests gave lower positive rates of the same 5.8% by clinical and recall techniques and thick smear, and 5.3% by capillary tube technique, respectively. The ICT card test had a specificity of 100% when sera from microfilaremic subjects were positive, as when sera from W. bancrofti non-endemic subjects either with Brugia malayi microfilaremia or with other parasites, and those from normal controls were all negative by the test. When done in W. bancrofti microfilaremia sera, the ICT card test had a sensitivity of 100% using a microscopy as reference, and 84.6% when using clinical and recall techniques. However, the ICT card test was more sensitive than the others when done in endemic normal sera (14% positive). Such findings compared well with findings in endemic area of South America, suggested its usefulness to detect W. bancrofti infections in endemic area, especially on the Thai-Myanmar border.