Serum Antigen and Antibody Detection in Echinococcosis: Application in Serodiagnosis of Human Hydatidosis

Diagnosis of hydatidosis is based on immunodiagnostic methods along with radiological and ultrasound examinations. The objectives of the present study were to develop a specific and simple antigen-based ELISA method for diagnosis of hydatidosis and compare it with antibody detection method. The subjects in this study included 89 patients in the following groups: surgically confirmed hydatidosis patients (35 cases), control with other parasitic diseases (29 cases), and healthy controls (25 cases). Hyperimmune serum was raised against hydatid cyst fluid in rabbits. Anti-hydatid cyst IgG was purified by affinity chromatography using protein A column and labeled with horseradish peroxidase. Collected sera were assessed for hydatid cyst antigens and antibody by ELISA. Circulating hydatid antigen was found in 9 out of 35 patients with surgically confirmed hydatidosis. A sensitivity of 25.7% and a specificity of 98.0% were calculated for the antigen detection assay. Antibody detection by indirect ELISA, using antigen B, showed that 94.2% of patients (33 cases) have anti-hydatid cyst antibodies in their serum while cross reaction was noted in a few of non-hydatidosis patients. A sensitivity of 94.2% and specificity of 81.6% were found for the antibody detection assay. Findings of this study indicated that antibody detection assay is a sensitive approach for diagnosis of hydatid cyst while antigen detection assay might be a useful approach for assessment of the efficacy of treatment especially after removal of the cyst.     

Epidemiology of Echinococcus granulosus in Arbil province, northern Iraq, 1990-1998

During the period 1990-1998, 99 cases of human cystic hydatidosis (12.4 cases per year) were surgically treated at the two main hospitals in Arbil province, northern Iraq, and from this the human occurence for the province was estimated to be 2 per 100,000 inhabitants. In the same area, 1270 sheep, 550 goats and 320 cattle were examined at slaughter for hydatid cysts and prevalence rates were found to be 15.0%, 6.2% and 10.9%, respectively. A decreasing tendency in livestock prevalences was found towards the end of the study period. As in humans, most of the hydatid cysts in livestock were located in the liver. Fertility of sheep cysts, i.e. those containing protoscoleces, was found to be significantly higher (64%) than that of goats (35.7%) and cattle (29.8%). The percentage of fertile cysts containing viable protoscoleces varied between 63 and 82% in the livers and between 72 and 79% in the lungs of the different animal species. A total of 97 stray dogs were examined post-mortem in the years 1991, 1992 and 1998, and Echinococcus granulosus worms were found in the intestines of 48 dogs (49.5%). High worm burdens (> 1000) were observed in 37% of the dogs, medium worm burdens (200-1000) in 41%, and low worm burdens (< 200) in 22%. In 1998, the prevalence of canine echinococcosis (24.3%) was found to be significantly lower than in 1991 (70.4%) and 1992 (60.6%). The prevalence of human hydatidosis did not differ significantly over the years, but the study confirmed that hydatidosis is endemic in northern Iraq, and that housewives, labourers and farmers appear to be at the greatest risk of infection.     

National epidemiologic study on hydatidosis

The results of an epidemiological survey on surgical cases of human hydatidosis in 9 italian regions (Central, Southern and Insular Italy) with the highest incidence of disease and a population of 27,054,000 inhabitants are reported. The period considered was from 1980 through 1984. 2,592 cases have been collected and related to sex, age, occupation, residence of surgically treated patients and cyst localization. Comparison of results from the present and a previous survey was carried out.     

Prevalence and characterization of hydatidosis in Najdi sheep slaughtered in Riyadh city,Saudi Arabia

Hydatidosis is considered to be one of the important zoonotic diseases and has a significant public health importance due to the difficulties of the diagnosis. Domestic animals act as intermediate hosts and the main reservoir for the disease in humans. The main purpose of this work therefore was to determine the prevalence of hydatidosis in Najdi sheep slaughtered in Riyadh city, Saudi Arabia. Cyst location and cyst fertility and viability were also estimated, together with effect of seasons, age and sex on the prevalence of the infection. The prevalence of hydatidosis was evaluated by post-mortem examination, with intensive inspection of the visceral organs of 2785 Najdi sheep. The infection was found to prevail throughout the year in both sex, with an overall prevalence of 2.33%. The highest prevalence was recorded in winter (6.48%) while the lowest was encountered in summer (1.36%). Females were proved to be more prone to infection (70.7%) than males (29.3%). In the present study, younger sheep tended to have a higher prevalence of infection than older ones. The most commonly infected organ was the liver, with a prevalence of 81.5%. The recorded cysts showed a fertility rate of 75.4%, and a high viability rate of 61.2%. Hepatic cysts were the most fertile and viable ones (46%), while calcified cysts were not recorded during the study. Measurements of recorded cysts in all organs ranged from 2 to 6?cm in diameter.In conclusion, the high fertility and viability rate of the recorded cysts suggest that sheep are a potential source of hydatidosis transmission to dogs and the continuation of its life cycle in this region. Consequently, authorities are recommended to instigate stricter regulation of the slaughtering process, including the secure disposal of infected offal so as to minimise the transmission of cysts from slaughter houses, along with treatment of stray dogs.     

Human cystic hydatidosis in Italy: a public health emergency? Past to present

Starting from 1991 the Central Office of Statistics ISTAT, according to changed regulations on notification of infective diseases, stopped reporting official national data on human hydatidosis. On the other hand until then notified data, concerning only about a hundred cases per year in mean during the last decades and just 36 in 1991, appeared unreliable, suggesting a diffusion far from the actual. Owing to specific studies on different research groups it is possible to try to describe a not exhaustive but indicative pattern of trend of human hydatidosis in Italy. More recent publications regarding different regions report an annual mean incidence rate of surgical cases of 9.77/100,000 inhabitants in Sardinia, of 1.57 in Emilia Romagna, of 2.30 in Sicily and of 2.33 in Apulia, the latter encompassing only hepatic cysts treated in the region, irrespective of residence of subjects. A comparison with previous studies regarding the period between 1948-1952 and 1980-84 respectively, indicates an increase in the more recent surveys. However, as even underlined by Authors, former surveys were not all-embracing (for example not including patients from private Clinics etc). On the other hand during time, improvements in surgical as well in anaesthesiological skills have made surgery possible in patients previously inoperable, and particularly in old subjects. Conversely, at present, availability of alternative therapies such as chemotherapy, PAIR or modified PAIR-based techniques may allow cases to avoide surgical surveys. However, actual parasite burden in humans may be estimated by assessing the trend of likely young cysts, as due to recent infections. Rate of pulmonary cysts, that are sure to be young, was of 48.6%/100,000 inhab. in 1952 in Italy, then falling to 18.2 in 1980-84 in the 9 considered regions, to 12.7 in Sicily (1989-91), 6.5 in Emilia-Romagna (1989-93) and 15.7 in Sardinia (1990-95). Another "class" of surely young cysts regards all cysts in young age group that necessarily have been recently infected. Ratio of infection rates in the old/young people was around 1 in 1941-52 but was exceeding 3 in 1980-84. In addition available data from more recent surveys indicate that ratio is at present still relatively low in Sardinia (3.9), where sheep-breeding is widespread, and dog-livestock-man interaction is most likely to exist, and conversely is very high in Emilia-Romagna (5.75) where pastoral economy is not prevalent (just 92,000 sheep). Actual trend both parasitological and in terms of public health would ameliorate if studies were provided with long temporary series. In Sardinia all hydatid cases surgically treated from 1969 to 1995 have been registered and analysed with a standardized methodology. During the considered period incidence appears nearly unvaried (16.9 in 1969 vs 15.8 in 1985), with a fall only for the last 5 years (9.1 in 1995), and with an increase regarding 1984-88 period. Analysis according to cyst localization strongly suggests that fall in the last period is only weakly related to hepatic cysts, that conversely are near completely responsible of rise in 1984-88. On the contrary for pulmonary cysts, i.e. young cysts, a slow but continuous and significant decrease (from 6.5 in 1969 to 1.4 in 1995) is evident. In the same way the above- mentioned old/young ratio rises from 1.7 (1969-79) to 3.9 (1990-95). On the whole analysed data suggest that although parasitic burden, strong in central-south Italy for decades, is now slow lowering due to structural changes and improvements in general conditions of life rather to specific preventive actions, human hydatidosis still represents a public health problem that will continue in the future as, because of latency, incidence rates will stay long relevant.     

Perioperative Challenges and Surgical Treatment of Large Simple,and Infectious Liver Cyst - A 12-Year Experience

Background

Cystic lesions of the liver consist of a heterogeneous group of disorders that can present diagnostic and therapeutic challenges.

Methods

A retrospective review of all medical records of adult patients diagnosed with large (>7 cm) cystic lesions of the liver between January 2000 and December 2011, at Kurume University Hospital. Cases with polycystic disease were excluded.

Results

Twenty three patients were identified. The mean size was 13.9 cm (range, 7-22cm). The majority of simple cysts were found in women (females: males, 2: 21). In 19 patients, the cyst was removed surgically by wide deroofing (laparoscopically in 16 cases, combined with ethanol sclerotherapy in 13 cases). Infection of the liver cyst occurred in one patient, who later underwent central bi-segmentectomy.

Conclusion

Simple large cysts of the liver can be successfully treated by laparoscopic deroofing and alcohol sclerotherapy. Large hepatic cyst considered to need drainage should be removed surgically to avoid possible infection.     

New cases of human diphyllobothriasis in Panguipulli, Chile

A retrospective laboratory survey on 10758 patients at the Hospital of Panguipulli showed the existence of 11 cases of diphyllobothriasis during a ten year (1979-1988) period. Age and sex as well as data of biannual prevalence of diphyllobothriasis are given. Some factors that determine the existence of diphyllobothriasis focus at lakes from Valdivia River Basin are briefly reviewed.     

Common bile duct obstruction caused by the hydatid daughter cysts

Echinococcosis is a human parasitary disease. In 2002, 29 new cases of liver echinococcosis were recorded in Croatia. Liver is the most common site of hydatid cysts. Nine patients with echinoccocal liver disease were operated in our department in 2002. Here we present a case where a patient with verified hydatid cyst in the left liver lobe developed high fever, jaundice, nausea, vomiting and pain in the upper abdomen. The symptoms were initially ascribed to the acute cholangitis. After unsuccessful antibiotic treatment, computerized tomography and endoscopic retrograde cholangiopancreatography (ERCP) were performed, demonstrating daughter cysts in the common bile duct. During ERCP, papilotomy was made and daughter cysts were extracted. Hydatid cyst was surgically removed, and a communication between the cyst and left hepatic duct was noted during surgery. Pericystectomy, choledochotomy, removal of remaining daughter cysts from the common bile duct, and sutures of left hepatic duct were performed. The patient recovered fully after the surgery. One of the possible complications of the liver hydatid cysts is the communication between cyst and the biliary tree. Such communications are usually asymptomatic, but symptoms can also mimic acute cholangitis and jaundice, which may lead to the misdiagnosis of the patient's condition.     

Human hydatidosis in Sardinia. Epidemiologic study of the cases operated on from 1974 to 1981

A retrospective survey of surgical cases to obtain baseline data on hydatid disease in Sardinia from 1974 to 1981 revealed an annual mean rate of 11.1/100.000 population. However, real prevalence is obviously higher, since infection is not always synonymous with disease and surgical incidence should be regarded as the figure that counts. Information on sex, age, residence, occupation, cyst location, number of re-operations was collected to assess the public health impact to hydatidosis within the island. The obtained results indicate that not all population is at equal risk, being hydatid disease most prevalent in rural areas and particularly in the districts where sheep-breeding is highly diffused (annual mean rate greater than 20/100.000 population). The highest rate was observed in farmers and shepherds (34.2/100.000) respect to retired (14.1/100.000), housewives (10.9/100.000), employed in services (8.9/100.000) and students (8.3/100.000). Over 55% of the cysts were found in the liver, about 30% in the lung and 15% in other sites. A correlation between age and cyst location and between profession and cyst location was shown. Pulmonary cysts were prevalent in children and young people, hepatic in grown-up people, whereas nearly the same hepatic and pulmonary frequency was observed in shepherds. Comparisons between previous surveyed periods were done and results were discussed, suggesting the need of a continuous and well-planned control programme.     

Assessment of prevalence of hydatidosis in slaughtered Sawakny sheep in Riyadh city,Saudi Arabia

Hydatidosis, or echincoccosis, is a serious medical and veterinary problem in many countries, particularly those with rural communities where there is a greater contact between dogs and domestic animals. Domestic livestock act as intermediate hosts which are the main reservoir for the disease in humans. It is therefore very important to estimate the prevalence of hydatid cysts in slaughtered animals since it can be transmitted to humans through dogs, which act as the final host for the disease. From this point of view, the present study was suggested to determine the prevalence of hydatidosis in Sawakny sheep slaughtered in Riyadh city, Saudi Arabia. During the course of the study 12,569 Sawakny sheep were inspected for hydatidosis infection. An overall prevalence of 1.06% was detected among the examined sheep, with the highest prevalence occurring in winter (1.38%) and lowest prevalence in summer (0.67%). Sheep aged 6–12 months had a higher rate of infection than older animals, and males were the predominant carriers of infection (97.7%) compared to females (2.3%). The liver was the most infected organ (79.1%), followed by the lungs (14.6%), while concurrent infections of both the liver and the lungs occurred in 6% of cases. The fertility and viability rates of hydatid cysts in the liver (70.1% and 85.1% respectively) were higher than that in any other organs. In conclusion, it is evident that fertile cysts in slaughtered sheep could have an important role in the continuation of hydatid cyst transmission to humans through dogs. Considerable effort should be devoted to controlling the transmission of cysts from abattoirs by the secure disposal of infected offal. In addition, plans are required for further epidemiological studies and control programs.     

Ultrasonic diagnosis of liver hydatidosis

The paper is concerned with a study of an ultrasound picture of verified hydatidosis in 62 patients. The symptoms of hydatid cysts are the presence of daughter cysts and "hydatid sand", cuticular membrane desquamation, local cyst wall thickening and parietal layers, a necrotic zone in a preparasitic space and cyst calcification. The detection of these symptoms helps to estimate not only the type of a hydatid cyst but also the state and character of parasite activity permitting a choice of therapeutic tactics.     

The diagnostic value of Western blot method in patients with cystic echinococcosis

Cystic echinococcosis (CE) is the larval cystic stage (called echinococcal cysts) of a small taeniid-type tapeworm (Echinococcus granulosus). Carnivores such as dogs are usually definitive hosts. Intermediate hosts are typically herbivores such as sheep and cattle. CE can be detected using various imaging techniques such as ultrasonography or radiology. Moreover the primary diagnosis has to be confirmed by serological tests since the clinical signs of the disease are non-specific. This study examined the antigenic band patterns useful for serologic diagnosis of hydatidosis. We also report on the post-operative evolution of patients treated for this disease and also determined the diagnostic performance of Western blot IgG kit. Twenty-five (16 females and 9 males) non-operated patients with hydatid cysts (NOP) and 33 (21 females and 12 males) operated patients with hydatid cysts (OP) were included as study group and 22 healthy individuals (14 females and 8 males) with no known chronic diseases were included as a control group. The ages of the patients and control group individuals were between 16-83 years. Patient and control groups were matched for age and sex. Cyst hydatid IgG antibodies were detected in the sera from all patient groups but no antibodies were found in the sera from the control group using ELISA IgG method. Twenty-three (92%) non-operated patients and 18 (54.5%) operated patients exhibited positive results when Western blot IgG kit was used. The P7 band pattern was detected in the sera from all operated and non-operated patients. Twenty-seven of these positive cases had p7 and (p7+p16/18), (p7+p24/26) or (p7+p16/18+p24/26). No antibodies against p7, p16/18 ve p24/26 band patterns were seen in sera from the control group A statistically significant difference was detected between operated and nonoperated patients for Western blot positivity.(p<0.01). p: 0.018- X2=5,604- OR: 0.176- 95% CI: 0.037- 0.841. The sensitivity, specificity, positive prediction and negative prediction values of Echinococcus granulosus Western blot kit for 25 cases with CE and 22 healthy controls were calculated as 92%, 100%, 100% and 91.7%, respectively. In conclusion, we suggest that monitoring p7 in all non-operated patients may be useful to determine the efficiacy of medical treatment and that monitoring p7 antibodies using serological and Western blot methods in operated patients may be useful for the screening of post-operative evolution in patients with hydatid cyst.     

Midline (dermoid) cysts of the floor of the mouth: report of 16 cases and review of surgical techniques

A retrospective review of 16 cases of midline (dermoid) cysts of the floor of the mouth is presented, evaluating the different surgical approaches. Sixteen cases of patients with a diagnosis of midline cyst of the floor of the mouth, treated at the Maxillofacial Surgery Department of the School of Medicine and Surgery of the "Federico II" University of Naples (Naples, Italy), were observed over a 10-year period, between 1988 and 1998; age, sex, localization, diagnostic technique, and type of treatment were evaluated. Male patients were more frequently affected, with a male-to-female ratio of 3:1 (12:4 cases). Patients ranged in age from 5 to 51 years (average age, 27.8 years). The preoperative assessment was made using ultrasonography in all cases but one, computed tomography in eight cases, and magnetic resonance imaging in three cases. Regarding surgical techniques used, a transcutaneous approach was adopted for median geniohyoid cysts, an extended median glossotomy technique was used for very large median genioglossal cysts, a median glossotomy technique was used for median genioglossal cysts, and a midline incision of the oral mucosa along the lingual frenulum was used for sublingual cysts. During the postoperative course, there were no complications except for modest edema in three cases. Follow-up ranged between 24 months and 12 years; no relapses or malignant changes were observed. In the authors' experience, the intraoral approach was also effective for the treatment of large lesions and led to very good cosmetic and functional results, whereas the extraoral incision was necessary only when the cysts were under the geniohyoid muscle.     

Treatment of hepatic hydatid disease with mebedazole: preliminary results in four cases.

Mebendazole was given to four patients with hepatic hydatid disease. In three patients hydatidosis had remained after surgery, and in the fourth it could not be treated surgically. Mebendazole was given orally in maximum doses of 400-600 mg three times a day during courses lasting 21 to 30 days. Ultrasonic echotomography showed a complete regression of the intrahepatic cysts after four to 13 months in all four cases. In three patients the course of treatment had to be repeated. Mebendazole also induced clinical improvement and a progressive lowering of the concentration of specific IgE of Echinococcus granulosus. During treatment circulating blood levels of specific immune complexes of antigen 5 were increased. These observations indicate that mebendazole has a lethal effect on E granulosus cysts in primary hydatid disease in man and that the efficacy of chemotherapy can be assessed with ultrasonography and by measuring changes in the concentration of specific IgE of E granulosus and circulating immune complexes.     

Artemia monica cyst production and recruitment in Mono Lake,California, USA

Annual egg production was determined for Artemia monica in Mono Lake, California, from 1983 to 1987. Annual oviparous (overwintering cyst) production was 3 and 7 million cysts m^–2 yr^–1 in 1986 and 1987, respectively, as measured by in situ sediment traps. Cyst production for the entire five year period was calculated using Artemia census data and inter-brood duration derived from mixolimnetic temperature. These estimates ranged from 2 to 5 million cysts m^–2 yr^–1. This method underestimated annual production by 30%, when compared to estimates using sediment traps. Cyst production was similar during 1983–1986 and showed a significant increase in 1987, which was due primarily to a larger reproductive population later in the year. Recruitment into the adult populations of the following spring ranged between 1.4 to 3.2%. Overall abundance of this generation reflected the patterns in annual cyst production. Compensatory effects must operate on the second generation of each year, since summer populations were similar in all years despite differences in cyst production.     

Treatment of hepatic hydatid cysts by percutaneous aspiration and hypertonic saline injection: results of a cooperative work

Percutaneous puncture-aspiration-injection-reaspiration (PAIR) of hydatid liver cysts, was performed in 38 patients 14-80 years old, with a total of 60 liver hydatid cysts. After aspiration under computed tomography guidance, hypertonic saline was injected into the cystic cavities of patients as a scolecidal agent. No major complications were associated with the procedures. In the follow-up period of 18 months, control CT scans of 35 cysts revealed a gradual decrease in cyst size with a mean volume reduction of 66%. Complications included two cases of urticaria, one case of anaphylaxis and one subcapsular hematoma. No mortality occurred. It is concluded that percutaneous aspiration and hypertonic saline injection for liver hydatid cysts appears to be an effective form of treatment and may eventually prove to be an alternative to surgical intervention.     

Risk factors for postpartum ovarian cysts and their spontaneous recovery or persistence in lactating dairy cows

Cystic ovarian disease is a major cause of reproductive failure and economic loss for the dairy industry. Many cysts that develop during the early postpartum period regress spontaneously. However, it is difficult to decide at what point it would be more cost effective to treat ovarian cysts than to wait for spontaneous recovery. The objective of this study was to analyze risk factors for the development of the ovarian cystic condition during early and late postpartum, and for its persistence or recovery during the pre-service period in lactating dairy cows. Using multiple logistic regression, we analyzed data derived from 873 lactating dairy cows from a single herd. An ovarian cyst was diagnosed if it was possible to observe a single follicular structure with an antrum diameter > or = 25 mm in the absence of a corpus luteum in three sonograms performed at 7-day intervals. The cystic condition was denoted as early if the cyst was diagnosed 43-49 days postpartum, and late if detected 57-63-day postpartum. Spontaneous cyst regression before 60-day postpartum was regarded as early cystic recovery. For the early cystic group, there were no significant effects of lactation number, body condition score on prepartum Day 60, at parturition or on postpartum Day 30, or of body condition loss from parturition to 30-day postpartum. Cows calving in summer were 2.6 times more likely to develop ovarian cysts than those giving birth in winter. The risk of having a cyst was 1.9 times higher in cows with an abnormal puerperium. A 1-kg increase in milk yield raised the risk of cysts by a factor of 1.05. A 1-unit increase in body condition score (scale from 1 to 5) from prepartum Day 60 to parturition increased the risk of cyst development 8.4 times. Milk production and lactation number were negatively correlated with spontaneous early cyst recovery. A 1-kg decrease in milk production increased the probability of cyst recovery by a factor of 1.06, and a 1-unit drop in lactation number was associated with a 1.4-fold increased probability of cyst recovery. For the late cystic group, there were no significant effects of abnormal puerperium and body score data, except for a prepartum change in body score. Calving season (Odds ratio: 2.3), lactation number (Odds ratio: 1.36), increased milk production (Odds ratio: 1.05) and increased body condition score during the prepartum period (Odds ratio: 4.3) were all related to an increased risk of ovarian cysts. The probability of having a late cyst was 36.6 times greater in cows with early cysts. These findings suggest that it would be profitable to treat multiparous cows having cysts very early in the postpartum period, while treatment of primiparous cows should be delayed, at least until the end of the pre-service period, to provide the opportunity for spontaneous recovery.     

An abattoir-based study on the prevalence of hydatidosis in livestock in Mashhad, Iran

A 6-year (2004-2010) retrospective study was carried out to determine the prevalence of hydatidosis in livestock slaughtered in Mashhad abattoir, Mashhad, in north-eastern Iran and the capital of Khorasan province. Between 20 March 2004 and 19 March 2010, 5,131,485 animals (411,163 cattle; 4,547,618 sheep; 172,704 goats) were slaughtered in the study area and 388,399 (7.5%) livers and 1,139,529 (22.2%) lungs were discarded. Hydatidosis was responsible for 4% and 6.5% of total livers and lungs inspected, respectively. Of the cattle livers and lungs inspected over the survey period, 5.5% and 7.9% were condemned, respectively, because they held hydatid cysts. The corresponding values for livers and lungs of sheep (2%, 4%) and of goats (4.5%, 7.8%), respectively, were also condemned due to hydatidosis. Data showed a prominent seasonal pattern for hydatidosis. Liver condemnations due to hydatidosis were higher in winter and autumn for cattle and sheep, respectively, whereas lung condemnations were higher in summer for sheep and cattle. In goats, liver and lung condemnations were higher in winter. This could be attributed to various factors, such as sources of slaughtered animals, changes in management practice and ecological factors. The present survey provides baseline data for the future monitoring of this potentially important parasitic disease in the region.     

Control of hydatidosis in the Province of Rio Negro, Argentina: epidemiology]

In this paper we attempt to present a general view of the situation of hydatidosis in the Province of Rio Negro, Argentina, considering the magnitude of infection in man and dog. Because of its seriousness a 10 year program for the control of hydatidosis has been carried out, which included veterinary and medical care. The number of human cases with hydatidosis in the period 1981-1988 was determined by a retrospective study of the registers of Public Health. From 1188 cases registered in the period, the annual numbers varied between 152 in 1981 and 104 in 1988. This implies an incidence rate of 40 x 100,000. The most frequent localization observed was in the liver. The average days of hospitalization has decreased to 15.8 per patient. Screening seroepidemiological surveys using DD5 allowed us to determine that the prevalence rate was in some departments of 2330 x 100,000. Also included are the results, up to now, of 10 years of field work done in the program area.