A method for genotyping hepatitis B virus by partial HBsAg gene sequencing with primers common to all known genotypes was developed. Mutations related to anti-HBs resistance are also detected with this method. Samples from 103 Brazilian patients were analyzed. Precore and core region of these viruses were also sequenced in 101 patients. Genotypes A, B, C, D, and F were found with frequencies of 49.5, 2.9, 13.6, 24.3, and 9.7%, respectively. Genotypes B and C were found only in Asian patients, whereas genotypes A, D, and F were more common in patients without an Asian background. Precore mutants were found in 32 ( Hepatitis B virus (HBV) infection is very common worldwide, and more than 350 million people are chronic carriers (22). HBV infection is associated with different clinical pic-tures and leads to chronic carrier state in 5 to 10% patients infected in adult life and 85 to 90% of those infected in infancy (13).HBV was formerly classified into four different subtypes that were afterward subdivided according to the antigenic determinants of HBsAg in adw (adw2 and adw4), ayw (ayw1, ayw2, ayw3, and ayw4), adr (adrqϩ adrqϪ), and ayr (33). Subtype a is common to the majority of viruses and is related to a neutralizing epitope. Divergence of the complete genome in a same subtype is ca. 8%, similar to the one found between different subtypes (38).Another classification reflecting the phylogenetic origin of the virus isolates was later proposed dividing HBV into six genotypes (36-38), designated A to F. These genotypes were differentiated by a sequence divergence in the entire genome exceeding 8%. Norder et al. (35) demonstrated that HBV genotyping could also be performed by sequencing the S gene.

In heavily infected young patients, there is a "non-congestive" phase of the disease with splenomegaly which can improve after chemotherapy. A strong correlation between hepatosplenic form and worm burden in young patients has been repeatedly shown. The pattern of vascular intrahepatic lesions, seems to depend on two mechanisms: (a) egg embolization, with a partial blocking of the portal vasculature; (b) the appearance of small portal collaterals along the intrahepatic portal system. The role played by hepatitis B virus (HBV) and C virus infections in the pathogenesis of liver lesions is variably considered. Selective arteriography shows a reduced diameter of hepatic artery with thin and arched branches outlining vascular gaps. A rich arterial network, as described in autopsy cases, is usually not seen in vivo, except after splenectomy or shunt surgery. An augmented hepatic arterial flow was demonstrated in infected animals. These facts suggest that the poor intrahepatic arterial vascularization demonstrated by selective arteriography in humans is due to a "functional deviation" of arterial blood to the splenic territory. The best results obtained in treatment of portal hypertension were: esophagogastric devascularization and splenectomy (EGDS), although risk of rebleeding persists; classical (proximal) splenorenal shunt (SRS) should be abandoned; distal splenorenal shunt may complicate with hepatic encephalopathy, although later and in a lower percentage than in SRS. Propranolol is currently under investigation. In our Department, schistosomatic patients with esophageal varices bleeding are treated by EGDS and, if rebleeding occurs, by sclerosis of the varices.

The long-term follow-up of patients with the severe form of Manson's schistosomiasis who had had elective surgical treatment for portal hypertension, in a randomized trial, was clinically evaluated. Of 94 patients, proximal splenorenal shunting was performed in 32, esophagogastric devascularization with splenectomy in 32 and distal splenorenal shunting in 30. Patients were observed during a mean of 85.7 +/- 33.1 mo, excluding nine patients (9.6%) who were lost to follow-up. Recurrence of upper gastrointestinal tract bleeding occurred in 24.1% of the patients, without statistical differences among the three groups, but rebleeding because of varices was more frequent after esophagogastric devascularization with splenectomy. Hepatic encephalopathy was significantly higher after proximal splenorenal shunting (39.3%) when compared with distal splenorenal shunting (14.8%) and with esophagogastric devascularization with splenectomy (0%). Lethality was also significantly higher after proximal splenorenal shunting (42.9%) when compared with distal splenorenal shunting (14.8%) and with esophagogastric devascularization with splenectomy (7.1%). Indirect hyperbilirubinemia was absent after esophagogastric devascularization with splenectomy and more frequent after distal splenorenal shunting (52%) although also present after proximal splenorenal shunting (29.6%). Esophagogastric devascularization with splenectomy was demonstrated to be the best option because of the absence of encephalopathy and because of low mortality rates. Hepatic encephalopathy occurred after distal splenorenal shunting but in a lesser percentage than after proximal splenorenal shunting. The higher incidence of encephalopathy and lethality proscribes proximal splenorenal shunting in Manson'schistosomiasis.

BackgroundClinical studies for testing new drugs against hepatitis B ought to be carried out in low prevalence areas despite difficulties on patient recruitment. In such areas, relatives of chronic hepatitis B patients are considered to be at risk of acquiring the hepatitis B virus (HBV). The aim of this study was to evaluate the prevalence of HBV markers (anti-HBc, HBsAg and anti-HBs) in familial members of chronic hepatitis B (CHB) patients according to their origin (Asian or Western) in a low prevalence area, the city of São Paulo, Brazil.MethodsTwenty three Asian CHB probands and their 313 relatives plus 31 CHB probands of Western origin and their 211 relatives were screened for HBV serological markers; the study was carried out in the outpatient clinic of the University of São Paulo School of Medicine.ResultsMother to child transmission was greater in the Asian group whereas sexual transmission was more frequent in the Western group (p < 0.0001). Anti-HBc was positive in 90% and 57% of the Asian and Western parents (p = 0.0432) and in 97% and 33% of the Asian and Western brothers (p = 0.0001), respectively. HBsAg was more frequent among the Asian (66%) than the Western (15%) mothers (p = 0.0260) as well as among the Asian (81%) than the Western (19%) brothers (p = 0.0001). We could detect 110 new HBsAg-positive subjects related to the 54 index patients, being the majority (81%) of Asian origin.ConclusionIn low prevalence area of hepatitis B, family members and household contacts of chronic HBV carriers are at high risk for acquiring hepatitis B.