Causes of fever in adults on the Thai-Myanmar border.

A hospital-based study was conducted along the Thai-Myanmar border to provide greater knowledge of the causes of febrile illness and to determine what zoonotic and vector-borne emerging infectious diseases might be present. A total of 613 adults were enrolled from June 1999 to March 2002. Cases were classified based on clinical findings and laboratory results.

Safety, immunogenicity and limited efficacy study of a recombinant Plasmodium falciparum circumsporozoite vaccine in Thai soldiers.

Thai soldiers were vaccinated with a recombinant protein derived from the central repeat region of the circumsporozoite (CS) protein of Plasmodium falciparum conjugated to Toxin A (detoxified) of Pseudomonas aeruginosa (R32Tox-A) to evaluate its safety, immunogenicity and efficacy. In a randomized, double-blind manner, 199 volunteers received either R32Tox-A or a control vaccine at 0, 8 and 16 weeks. Immunization was performed in a malaria non-transmission area, after completion of which volunteers were deployed to an endemic border area and monitored closely to allow early detection and treatment of infection.

Feeding nymphs of Hyalomma truncatum (Acari: Ixodidae) on guinea pigs previously exposed to nymphs.

The ability of nymphal Hyalomma truncatum Koch to feed on guinea pigs previously exposed to nymphal ticks was studied by measuring the percentage of ticks engorging and molting, their engorged weight, and hemoglobin content. Four guinea pigs were infested with 20, 40, 80, and 200 nymphs, respectively, on three occasions at 21-d intervals, followed by a fourth infestation after another 21-d interval with 100 nymphs. Guinea pigs originally infested with 20 and 80 nymphs were infested a fifth time with 100 nymphs 3 mo after the fourth infestation.