Cysticercosis in Cambodia, Lao PDR and Vietnam

Abstract

Data in the international literature on Taenia solium taeniasis/cysticercosis in the former Indochina (Cambodia, Lao PDR, and Vietnam) are rather limited. Slaughterhouse reports and hospital records in urban centers indicate the presence of the parasite in the region. The prevalence of porcine cysticercosis in abattoirs is reported to be low. Sero-epidemiological studies in pigs are hampered by the presence of metacestodes of Taenia hydatigena, a common cestode in Vietnam that interferes with most serological tests for T solium cysticercosis. Human cysticercosis is well known in northern Vietnam where between 100 and 150 patients are referred to specialized hospitals each year. Sporadic cases of cysticercosis are reported from central and southern Vietnam and from Lao PDR and Cambodia. Preliminary surveys in northern Vietnam have indicated that the seroprevalence of cysticercosis may be between 2% and 5%. In northern and central Vietnam, the occurrence of tapeworm carriers was found to be between 0.2 - 7.2%; however, these results are inconclusive, since they were based on various imperfect techniques and it is unknown with which species of tapeworm the people were infected. In addition to T solium, which causes human cysticercosis, T saginata and T asiatica are also known to be present in Vietnam. In some areas typical risk factors are present for taeniasis/cysticercosis, such as traditional pig husbandry systems, inadequate meat inspection, and poor sanitation. Of particular interest are local practices that may facilitate transmission of T solium, such as eating raw pork dishes, eating raw vegetables, and using human stools to fertilizing vegetable gardens and paddy fields. The availability of serological and neuroimaging techniques in referral hospitals has increased the diagnostic capacity of this zoonotic disease. Clinical manifestations of cysticercosis in humans include subcutaneous nodules, epileptic seizures, severe headache, impaired vision and memory loss. In contrast to endemic regions in Latin America and Africa, the majority of neurocysticercosis (NCC) patients also have subcutaneous cysts. Neuroimaging in NCC patients typically shows the presence of multiple cysts that are either viable or in different degenerative stages, or both. Albendazole has been found to be the best drug for treating cysticercosis though it is not totally effective in curing cerebral cysts. Until now, no measures for controlling this helminth zoonosis in the region have been taken.