Pleuropulmonary paragonimiasis due to Paragonimus heterotremus: molecular diagnosis, prevalence of infection and clinicoradiological features in an endemic area of northeastern India

In the northeastern region of India, paragonimiasis is emerging as an important public health problem. However, until now the identity of the species causing human infection has been uncertain and there has been little information on the prevalence and clinicoradiological features of infection in the community. Parasitological and immunological surveys revealed that paragonimiasis was hyperendemic in parts of Arunachal Pradesh. Egg positivity in the sputum was 20.9% and 4.1% in children (age 15 years), respectively. Antibody positivity against excretory-secretory antigen of the adult worm in children and adults was 51.7% and 18.7%, respectively. Chronic cough (97.2%) and haemoptysis (83.3%) were common respiratory symptoms among egg-positive cases. Chest radiography (n=68) images from egg-positive cases showed that air space consolidation (75%), cavitary lesions (14.7%) and mediastinal adenopathy (11.8%) were very frequent. Less frequent findings were nodular lesions, bronchiectasis, mediastinal adenopathy, pleural thickening and pleural effusion. DNA extracted from eggs from the sputum of patients from Arunachal Pradesh was sequenced. Analyses of the second internal transcribed spacer (ITS2) of nuclear rDNA revealed that the species responsible is Paragonimus heterotremus.     

The effect of eight half-yearly single-dose treatments with DEC on Wuchereria bancrofti circulating antigenaemia

The effect of eight half-yearly treatment rounds with diethylcarbamazine (DEC; 6mg/kg bodyweight) on Wuchereria bancrofti-specific circulating filarial antigen (CFA), a marker of adult worm infection, was followed in 79 individuals who were CFA-positive before start of treatment. Half of these were also microfilariae (mf)-positive. Microfilaraemia decreased rapidly after onset of treatment and became undetectable after four treatments. Circulating antigenaemia also decreased progressively, but at a much slower rate. After two, four and eight treatment rounds, the mean CFA intensity was reduced by 81, 94 and 98%, and the prevalence of CFA positivity was 85, 66 and 57%, compared with pre-treatment, respectively. CFA clearance rates were negatively related to pre-treatment CFA intensities, and were higher among pre-treatment mf-negative individuals than among pre-treatment mf-positive individuals. Even among patients who had pre-treatment CFA intensities above the upper measuring level (32000antigen units), and who continued to have intensities above this level after treatment, a decrease in post-treatment CFA intensities was obvious from a continuous decrease in ELISA optical density values. Repeated DEC therapy thus appears to have a slow but profound and persistent macrofilaricidal effect, which in the long run may be beneficial to populations undergoing DEC-based control interventions by reducing the probability of future morbidity development.     

Predictive value of the eosinophil counts in the biological diagnosis of lymphatic filariasis in French Polynesia

Settings

Lymphatic filariasis is common in many tropical and subtropical areas and is a major public health issue in south Pacific islands. In endemic areas, most infected individuals are asymptomatic but may harbor microfilariae or filarial antigens in their peripheral blood. Microscopy remains the reference diagnostic tool for the identification of microfilariae but is weakly sensitive. The diagnosis of Wuchereria bancrofti infection was dramatically altered by the development of filarial antigen tests, which are easy to perform but expensive for routine use. Lymphatic filariasis is responsible for acquired eosinophilia and blood eosinophil count is commonly used as a screening tool in endemic areas.

Method

We retrospectively analyzed all the results of eosinophil counts, antigen and microfilariae detection performed in our laboratory over a 24-month period. We calculated the prevalence of antigenemia for various eosinophilic cut offs.

Results

The prevalence of antigenemia was estimated at 25.78% with eosinophilia defined as a count eosinophilic PMN above 500 per mm³.

Discussion

Our prevention strategy against lymphatic filariasis is based on annual mass drug administration, vector control, and systematic treatment of antigenemic and microfilaremic patients. Antigenemic and microfilaremic detection cannot be routinely performed because of their cost. Current treatments used for lymphatic filariasis are safe and cheaper than antigenic detection. A possible additional strategy to decrease the prevalence of antigenemia would be the systematic treatment of patients with hypereosinophilia.     

Persistent hepatitis B virus infection and hepatoma in The Gambia, west Africa. A case-control study of 140 adults and their 603 family contacts.

To determine the incidence of persistent hepatitis B virus infection and its etiologic role as a cause of hepatoma, the authors carried out a case-control investigation of 70 persons with hepatoma, 70 controls, and their families in 1981-1982 in The Gambia, West Africa. The risk of developing hepatoma after the age of 39 years was 1.4% in men and 0.3% in women. Hepatoma occurred more than twice as frequently among persons who had four or more older siblings as among persons who had less than two older siblings. The attributable risk between persistent infection with hepatitis B virus and hepatoma was 78% for individuals aged less than 50 years and 37% for persons aged 50 years or more, with an overall risk of 53%. The high prevalence of hepatitis B surface antigen and hepatitis B e antigen antigenemia in children under 15 years of age (14% of 341 children) and the positive correlation between late birth order and risk of developing hepatoma suggest that postnatal early childhood exposure to hepatitis B virus is an important risk factor. The use of a hepatitis B virus vaccine which provides durable immunity in very young children will probably prevent most cases of hepatoma.     

The effect of single dose ivermectin alone or in combination with albendazole on Wuchereria bancrofti infection in primary school children in Tanzania

Examination of 1829 children from 6 primary schools in coastal Tanzania revealed overall Wuchereria bancrofti microfilaria (mf) and circulating filarial antigen (CFA) prevalences of 17.3% and 43.7%, respectively. A randomized double-blind field trial with a single dose of ivermectin (150-200 microg/kg body weight) alone or in combination with albendazole (400 mg) was subsequently carried out among these children. Both treatment regimens resulted in a considerable decrease in mean mf intensities, with overall reductions being slightly but statistically significantly higher for the combination than for ivermectin alone. The difference in effect between the two treatment regimens was most pronounced at 6 months, whereas it was minor at 12 months after treatment. The relative effect of treatment on mean CFA units was less pronounced than on mf. For both treatment regimens, reductions in CFA intensity appeared to be higher in children who were both CFA and mf positive before treatment, which may suggest that treatment mainly affected the survival and/or production of mf, rather than the survival of adult worms. New cases of infection appeared after treatment with both regimens among the pre-treatment mf and CFA negative children. Adverse reactions were few and mild in both groups, and mainly reported from pre-treatment mf and CFA positive children. The alarmingly high prevalence of W. bancrofti infection in primary school children highlights the importance of also determining the reversibility of already acquired early lesions, and the development of new measures and strategies to specifically protect children from later developing clinical disease.     

Prevalence and intensity of Wuchereria bancrofti antigenaemia in Sri Lanka by Og4C3 ELISA using filter paper-absorbed whole blood

In Sri Lanka 2741 people from Matara, an endemic area for Wuchereria bancrofti, were examined in 1996/97 for microfilariae by 60-microL blood smear and for circulating filarial antigens by Og4C3 ELISA using filter paper-absorbed whole blood. The overall prevalence of microfilaraemia was 3.4%, and that of antigenaemia 14.4%. The prevalence of antigen-positive and microfilaria-negative people was 11.3%. Analysed by age-group, antigenaemia prevalence was similar in all groups, and the average number of antigen units was already very high in the age-group < 10 years, indicating that the infection started in early childhood. Among those who were antigen positive, the microfilaria prevalence was lower in females than in males. Diethylcarbamazine treatment eliminated microfilariae in 78% of the positives. However, 17 months after the treatment, antigenaemia was still positive in 76% of those who were parasitologically cured.     

Mansonella perstans filariasis in Uganda: patterns of microfilaraemia and clinical manifestations in two endemic communities

Surveys for Mansonella perstans infection and potentially related clinical manifestations were undertaken in two endemic communities in Mukono and Luwero districts of Uganda where no other human filarial infections are transmitted. A sensitive and accurate counting chamber method was used for quantifying microfilaraemia in 100microl of finger-prick blood. Among 575 and 991 examined individuals aged >or=1 year in the two communities, the overall microfilariae (mf) prevalence was significantly higher in Mukono (76.5%) than in Luwero (57.7%). As early as age 1-4 years, 40.6% and 20.5% of the children were mf-positive. Prevalences increased rapidly with increasing age to reach 89.2% and 81.4% in the 15-19 years age group and then remained high in subsequent age groups. The geometric mean mf intensity among mf-positive individuals was slightly higher in the Mukono community (32.4mf/100microl) than in the Luwero community (29.9mf/100microl), and this parameter increased with age in both communities. No obvious associations were observed between various clinical parameters and M. perstans microfilaraemia in any of the study communities. The observed patterns of microfilaraemia and the lack of obvious visible clinical manifestations suggest that the host's regulatory responses are downregulated in M. perstans infections. [ClinicalTrials.gov identifier: NCT00215280].     

Changing pattern of age-specific prevalence of hepatitis B surface antigen and corresponding antibody in Japan

During the period 1978-1984 in Japan, the prevalence of hepatitis B surface antigen (HBsAg) in age groups below age 15 years was 18/2,550 (0.7%), and it was particularly low in the group below age 5 years (2/706 (0.3%)). The low prevalence of HBsAg in children under 15 years of age contrasted sharply with the much higher prevalence in persons age 15 years and older (36/2,050 (1.8%)). In accord with this, the prevalence of antibody to hepatitis B surface antigen (anti-HBs) was much lower in children below age 15 years than that in persons 15 years of age and older (29/2,550 (1.1%) vs. 242/2,050 (11.8%)). Furthermore, the prevalence of hepatitis B viral markers in 1978-1984 was lower than that during the period from 1972-1977 in every age group. A total of 13 (81%) of 16 mothers of carrier children, identified in 1978-1984, were positive both for HBsAg and hepatitis B e antigen in their sera. Now that mother-to-baby transmission appears to be the main route for establishing the persistent carrier state, its interruption should reduce the reservoir of hepatitis B virus, toward its eventual eradication, in Japan.     

Environmental and demographic risk factors associated with the prevalence of Cryptosporidium infection in the Alice rural settlements of the Eastern Cape Province of South Africa: a pilot study

We undertook this study to identify the risk factors and prevalence of Cryptosporidium spp. in HIV-positive and HIV-negative diarrhea patients in the Alice rural settlement in the Eastern Cape Province of South Africa. A total of 180 stool specimens (35 HIV-positive diarrhea, 125 HIV-negative diarrhea patients, and 20 apparently healthy subjects) were screened for cryptosporidiosis using an ELISA-based approach. Sociodemographic information, water supply, and animal contact were recorded for diarrhea-positive patients. The data were analyzed using Pearson's chi2-test and Fisher's exact test. Cryptosporidium antigen was detected in 122 of 180 specimens (overall prevalence=67.8%). In HIV-positive diarrhea patients, the age groups 31-43 years (mean age 36.5 years) and 70-82 years (mean age 75.8 years) had a higher prevalence (100%) of the antigen than age groups 18-30 years (mean age 23.2 years) and 83-95 years (mean age 88.8 years) (50.0%). In HIV-negative diarrhea patients, the prevalence was highest (87.5%) at ages 18-30 years (mean age 23.2 years) and lowest (35.7%) at ages 83-95 years (mean age 88.8 years). Cryptosporidium antigenemia was slightly higher in females (78.2%, mean age 46.7 years) than in males (71.1%, mean age 42.6 years), but the difference was not significant (p>0.05). No apparently healthy control subject was infected with Cryptosporidium. HIV-negative patients had a significantly higher prevalence of antigen than HIV-positive patients, with farm animals considered a possible risk factor. In HIV-positive diarrhea patients, the prevalence peak was detected in more low income patients (85.7%) than in high income patients (32%). The high infection rate of specific groups was associated with exposure to a contaminated water supply. The results indicate that Cryptosporidium infection is highly prevalent in adult fecal specimens from the Nkonkobe Municipality, an indication of active infection that is likely to emerge as a major human pathogen in this locality owing to socioeconomic changes that favor transmission.     

Filariasis due to Loa loa and Mansonella perstans: distribution in the region of Okondja, Haut-Ogooué Province, Gabon, with parasitological and serological follow-up over one year

The prevalence of Loa loa and Mansonella perstans filariasis has been determined in 6 rural villages in eastern Gabon. Between 18.9 and 27.2% of people carry L. loa microfilariae with an overall microfilarial rate of 25.1%. The microfilarial rate for M. perstans was more variable, between 33.3 and 62.2% (average 49.1%). No significant difference was seen in the microfilarial rate with age over 15 years for either parasite, but men were infected more frequently than women. Anti-L. loa antibody titres were measured, using a homologous microfilarial antigen in ELISA. Taking the parasitological and immunological evaluations together, only 10% of the sample population appear to be free of these filarial infections. L. loa and M. perstans microfilaraemia and corresponding serology were also investigated twice in 150 people at a one-year interval. 99.1% of the cases who had no circulating L. loa microfilaria in March 1984 still did not show any 12 months later. Similarly, 97.1% of the untreated, microfilaraemic cases still harboured this parasite a year later. The same was not observed for M. perstans, since microfilariae appeared or disappeared in 26.7% of the cases. This suggests different dynamics for the two filarial infections. Variation in individual anti-L. loa antibody titres was low. The possibility of a genetic influence on the expression of loiasis is discussed.     

Epidemiology of hepatitis B virus infection in South African Chinese

The authors determined the age-specific prevalence of hepatitis B virus markers in 1,408 Chinese who resided in South Africa in 1983-1985. The small South African Chinese community consists of original Chinese settlers, almost all of whom migrated from the hepatitis B virus endemic mainland China province of Guangdong, and their South African-born descendants. The Chinese live among the white South African community, which has a very low hepatitis B virus carrier rate. The overall hepatitis B virus carrier rate was 5.3%, and the carrier rate was highest in age group 30-39 years (11.9%) and significantly lower in children aged 1-9 and 10-19 years (2.4% and 2.0%, respectively). Overall infection rates increased progressively with increasing age, starting at about 10% in the children aged 1-19 years and reaching 50% in adults aged 60-69 years. Among carrier children, 89% had carrier mothers, and all of the latter were also hepatitis e antigen (HBeAg)-positive. The prevalence of hepatitis B virus carriers in South African Chinese women of child-bearing age was 6.1%, and 41.9% of these carriers were HBeAg-positive. The age-specific prevalence of hepatitis B virus markers among South African Chinese is appreciably lower than that of Chinese in southeastern China, who have carrier rates of 15-20% with a peak in childhood. The prevalence of hepatitis B virus infection appears to be decreasing in South African Chinese, probably because improved hygienic and socioeconomic circumstances, in comparison with those in Guangdong, have resulted in less horizontal transmission of the virus. A diminishing pool of carriers is maintained by perinatal maternal-infant infection.     

Asymptomatic HBsAg antigenemia in children referred to hospital treatment for various reasons

HBsAg antigenemia still constitutes a serious clinical problem. In 852 children at the age of 3 months to 17 years (54.2% boys and 45.8 girls) referred in 2001 to J. Korczak hospital in ?ód?, antigen HBsAg was determined with the Axsym (V2) test, MEIA (Abbott) method. Asymptomatic HBsAg antigenemia was recognized in 2.35% (20/852) children. The children were from 9 to 17 years old (0 girls and 10 boys); they came mainly from ?ód?. Among HBsAg antigenemic children, 95% (19/20) had not been vaccinated against Hepatitis B. The Children were hospitalized mainly on the surgical wards (because of accidents and injuries) as well as the neurological ward. Hospitalization was shown to be the mainly cause of HBV infection.     

Prevalence and trends in overweight and obesity among children and adolescents in Denmark

AIM: To study the current prevalence and trends in overweight and obesity among children and adolescents in Denmark from 1995 to 2000-2002. METHODS: Cross-sectional national dietary surveys were conducted in 1995 and 2000-2002. The analysis was based on two random population samples from the Danish civil registration system. Body mass index (BMI) was calculated from self-reported height and weight for 1,026 and 1,152 children and adolescents (4-18 years), who participated in 1995 and 2000-2002, respectively. The prevalence of overweight and obesity was defined according to the international age and gender-specific child BMI cut-off points. In the statistical analysis, overweight and obesity were included in the prevalence of overweight. RESULTS: Mean BMI increased significantly between 1995 and 2000-2002 for all combinations of age groups (4-6, 7-10, 11-14 and 15-18 years) and genders. Prevalence of overweight increased between survey years for boys and girls for all age groups (4-6, 7-10, 11-14 and 15-18 years), although formal statistical significance was not reached (p>0.05). When all children and adolescents (4-18 years) were analysed, the prevalence of overweight rose significantly from 10.9% (95% confidence interval (CI) 9.0-12.8) to 14.4% (95% CI 12.5-16.3) between 1995 and 2000- 2002 (p=0.01), whereas the increase in the prevalence of obesity did not reach significance (1995, 2.3% (95% CI 1.3-3.3) vs. 2000-2002, 2.4% (95% CI 1.6-3.3); p=0.74). CONCLUSIONS: The present study revealed a significant increase from 1995 to 2000-2002 in mean BMI for boys and girls for all age groups and a significant increase in the prevalence of overweight when all Danish children and adolescents (4-18 years) were analysed.     

Cartography of trachoma in Mali: results of a national survey

Prior to a campaign to eliminate blinding trachoma, a survey of the prevalence of the disease was conducted in the seven administrative regions of Mali between March 1996 and June 1997. In each region (with the exception of Bamako District) a random sample of thirty clusters was taken from the general population, in accordance with the principle of probability proportionate to the size of the communities. All children under 10 years of age and all women over 14 years were examined. The simplified coding proposed by WHO was used for data gathering. A total of 15,310 children and 11,530 women were examined. The prevalence of active trachoma, follicular (TF) or intense (TI), was estimated to be 34.9% among children under 10 years of age (95% CI: 32.3-37.6). The prevalence of TI showing the intensity of trachoma was 4.2% (95% CI: 3.5-5.0) among the same children. The prevalence increased up to the age of 3 years, when it reached 49.2%. The prevalence of TF/TI was 35.7% among boys and 34.3% among girls. The prevalence of entropion trichiasis among women over 14 years of age was 2.5% (95% CI: 2.1-2.9), and 1% had central corneal opacity (95% CI: 0.8-1.3). These prevalences increased with age, such that 10% of women over 70 years of age had trichiasis. By region of the country, the prevalence ranged from 23.1% of active trachoma among children in Ségou, to 46.2% in Gao. The prevalence of entropion trichiasis was 0.65% in Gao region and 3.9% in Koulikoro region. This survey allows the trachoma treatment needs of Mali to be quantified. We estimate that 1.09 million children under 10 years are carriers of active trachoma and require local or general antibiotic treatment. If all the under-10-year-olds from all villages where TF/TI exceeded 20% were to be treated, a total of 2.436 million children would be involved. A total of 85,000 adults should have surgery to correct trichiasis and avoid the onset of blindness.     

Hepatitis-B virus infection in children and adults in Northern Nigeria: a preliminary survey

Hepatitis-B surface antigen (HBsAg) and its corresponding antibody (anti-HBs) have been detected by radio-immunoassay in children and adults and in adult expatriates in Zaria, Northern Nigeria. The exposure rate to hepatitis-B virus (frequency of HBsAg and anti-Hbs) was found to vary from 59% in children under five years to 72·5% in adults over 30 years of age, while the frequency of HBsAg alone was 40% and 10% respectively. The anti-HBs prevalence rates rose progressively with age and reached a peak at 62·5% in adults. Five of 32 adult expatriates (15·6%) were positive for anti-HBs. The factors contributing to the high exposure rate in the indigenous population in this region require further study to enable judicious use to be made of preventive measures.     

Infectious states of human T lymphotropic virus type I and hepatitis B virus among Japanese immigrants in the Republic of Bolivia

Serologic tests for human T lymphotropic virus type I (HTLV-I) and hepatitis B virus infections were conducted in 1986 in two Japanese immigrant colonies located in Santa Cruz, Bolivia. A total of 322 adults (283 Japanese and 39 Bolivians) over age 35 years and 305 children (166 Japanese, 124 Bolivians, and 15 of mixed blood) aged 8-17 years were sampled at the time of a routine health checkup. The prevalence of antibody to HTLV-I was 17% in first-generation Japanese immigrants and 6% in second- or third-generation Japanese children. Prevalences among native Bolivians were 3% and 5% in adults and children, respectively. Seropositive Japanese immigrants and mothers showed clustering according to birthplace in endemic areas of Japan. The prevalence of either hepatitis B virus surface antigen (HBsAg) or antibody to HBsAg was 48% in Japanese adults, 21% in Japanese children, 13% in Bolivian adults, and 1% in Bolivian children. Seropositive adults did not show clustering according to birthplace, but children in one colony showed clustering and a narrow age range. A correlation of seropositivity between husbands and wives was found only for HTLV-I. The seropositivity was independent of whether an HTLV-I or a hepatitis B virus infection marker was present.     

Hepatitis-B surface antigen and antibody: prevalence and persistence in institutionalized and noninstitutionalized persons.

A total of 426 persons were studied in an attempt to more clearly define the high prevalence of hepatitis-B surface antigen (HBsAg) seen among institutionalized persons. HBsAg was found in 63.4 percent of the children and young adults with Down's syndrome (DS) at the Central Wisconsin Center (CWC) and in 45.5 percent of those at the Northern Wisconsin Center (NWC). Significantly more subjects with DS had hepatitis-B antigenemia than age- and sex-matched non-DS institutionalized subjects. Antibody (anti-HBs) to HBsAg was found in 19.5 percent of the DS subjects at CWC and in 38.6 percent of those at NWC. The prevalence of anti-HBs was similar among DS and non-DS institutionalized subjects. None of the noninstitutionalized subjects had HBsAg in their serums and their anti-HBs prevalence was low (2.1 percent). HBsAg was found to persist for at least 10 years in both DS and non-DS institutionalized subjects. However, persistence occurred more frequently among DS subjects. Anti-HBs persisted at least 10 years among non-DS subjects, but DS subjects tended to lose antibody sooner. The study findings indicated that the high prevalence of HBsAg seen in institutionalized DS subjects at CWC and NWC were not related to the age of the subject at admission nor to the duration of institutionalization.     

Reduced lymphocyte response to mitogens in patients with Bancroftian filariasis

Peripheral blood lymphocytes from patients with acute and chronic Wuchereria bancrofti infections responded poorly to concanavalin A, phytohaemagglutinin and pokeweed mitogen when cultured in heat-inactivated pooled normal serum. The lymphocyte response to mitogens in carriers of microfilariae (mff) were normal. The suppression of transformation to mitogens was not reversible by the removal of plastic adherent cells. Incubation with mitogens and the adult filarial worm antigen (BmA) did not alter the mitogen response either in control subjects or in filarial patients. The possible mechanism of immunosuppression is discussed.     

河南省3~15岁儿童青少年肥胖流行状况及与生活饮食行为关联

目的 研究河南省3~15岁儿童青少年肥胖流行现状,并分析其与生活饮食方式的关联。方法 采用分层整群随机抽样方法抽取河南省10市的3~15岁儿童青少年,采用描述性分析方法分析不同年龄、性别儿童青少年肥胖率,通过单、多因素方法分析儿童青少年肥胖与相关生活饮食行为的关系。结果 本研究共纳入12 481名3~15岁儿童青少年参与调查,平均年龄为（7.92±3.15）岁,肥胖1 407例,发生率为11.3%,其中男生12.9%,女生9.5%。9岁~<12岁年龄段男生肥胖率高于女生,差异有统计学意义（P<0.05或P<0.01）。早餐就餐地点为家（OR=0.745）、经常参加体育锻炼（OR=0.522）为儿童青少年肥胖的保护性因素。结论 河南省3~15岁儿童青少年肥胖率较高,防控应在青春期前进行,鼓励在家进餐早餐及经常体育锻炼的生活方式。     

Lymphatic filariasis in Lower Shire,southern Malawi

Surveys for lymphatic filariasis were carried out for the first time in Lower Shire (Nsanje and Chikawawa Districts) of southern Malawi, in April-June 2000. There were 3 phases. In phase I, questionnaire surveys in 48 randomly selected villages indicated that chronic manifestations of lymphatic filariasis ('swollen scrotum' and 'swollen legs') were common and widespread in the area. In phase II, volunteers from 10 of the villages reporting frequent manifestations of filariasis in phase I were examined with the ICT whole-blood test for Wuchereria bancrofti-specific circulating filarial antigen (CFA). The observed prevalence of CFA positivity was very high (range, 38.8-79.1% for the villages). In phase III, a more detailed parasitological, CFA and clinical investigation was carried out in 2 of the high CFA prevalence villages identified in phase II (1 in each district). Overall, 18.1% and 22.2% were positive for microfilariae, and 62.3% and 64.6% were positive for CFA in the 2 villages. Among those aged > or = 15 years, 3.7% and 1.3% had leg elephantiasis, and 17.9% and 13.0% (of males only) had hydrocoele. In both phase II and III, CFA prevalences were unexpectedly high, especially in children. This was probably related to a recent increase in transmission of filariasis as a result of extensive flooding in the area prior to the study. The study indicated that lymphatic filariasis is highly endemic in the Lower Shire area of Malawi, and calls for action towards its control.