High prevalence of Brugia timori infection in the highland of Alor Island, Indonesia.
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To identify areas endemic for Brugia timori infection, a field survey was carried out in 2001 on Alor, East Nusa Tenggara Timor, Indonesia. Elephantiasis was reported on this island by villagers as a major health problem. Bancroftian filariasis was detected in four villages in the coastal area, whereas B. timori was identified in four rice-farming villages. No mixed infections with both species were found. In the highland village Mainang (elevation = 880 m), 586 individuals were examined for B. timori infection and 157 (27%) microfilaria carriers were detected. The prevalence of microfilaremic individuals standardized by sex and age was 25%. The geometric mean microfilarial density of microfilaremic individuals was 138 microfilariae/ml. Among teenagers and adults, males tended to have a higher microfilarial prevalence than females. Microfilaria prevalence increased with age and a maximum was observed in the fifth decade of life. In infected individuals, the microfilarial density increased rapidly and high levels were observed in those individuals 11-20 years old. The highest microfilaria density was found in a 27-year-old woman (6,028 microfilariae/ml). Brugia timori on Alor was nocturnally periodic, but in patients with high parasite loads, a small number of microfilariae was also detected in the day blood. The disease rate was high and many persons reported a history of acute filarial attacks. Seventy-seven (13%) individuals showed lymphedema of the leg that occasionally presented severe elephantiasis. No hydrocele or genital lymphedema were observed. This study showed that B. timori infection is not restricted to the lowland and indicated that it might have a wider distribution in the lesser Sunda archipelago than previously assumed. (+info)
Efficacy and sustainability of a footcare programme in preventing acute attacks of adenolymphangitis in Brugian filariasis.
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Lymphatic filariasis is associated with considerable disability related to the intensity and frequency of acute adenolymphangitis (ADL) attacks. The global programme for elimination of lymphatic filariasis emphasizes the need to combine transmission control with alleviation of disability. Footcare aimed at the prevention of secondary bacterial infections is the mainstay of disability alleviation programmes. We evaluated the efficacy and sustainability of an unsupervised, personal footcare programme by examining and interviewing 127 patients who had previously participated in a trial that assessed the efficacy of diethylcarbamazine, penicillin and footcare in the prevention of ADL. During the trial period these patients had been educated in footcare and were supervised. During the unsupervised period, which lasted 1 year or longer, 47 patients developed no ADL, and ADL occurred less frequently in 72.5%. Most patients were practising footcare as originally advised, unsupervised and without cost, which proves that such a programme is sustainable and effective. (+info)
The effect of six rounds of single dose mass treatment with diethylcarbamazine or ivermectin on Wuchereria bancrofti infection and its implications for lymphatic filariasis elimination.
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Annual mass treatment with single-dose diethylcarbamazine (DEC) or ivermectin (IVM) in combination with albendazole (ALB) for 4-6 years is the principal tool of lymphatic filariasis (LF) elimination strategy. This placebo-controlled study examined the potential of six rounds of mass treatment with DEC or IVM to eliminate Wuchereria bancrofti infection in humans in rural areas in south India. A percentage of 54-75 of the eligible population (> or =15 kg body weight) received treatment during different rounds of treatment - 27.4% in the DEC arm and 30.7% in the IVM arm received all six treatments, 4.8% and 5.6% received none, and the remainder received one to five treatments. After six cycles of treatment, the microfilaria (Mf) prevalence in treated communities dropped by 86% in the DEC arm (P < 0.01) (n = 5 villages) and by 72% in the IVM arm (P < 0.01) (n = 5 villages), compared with 37% in the placebo arm (P < 0.05) (n = 5 villages). The geometric mean intensity of Mf fell by 91% (t = 8.11, P < 0.05), 84% (t = 6.91, P < 0.05) and 46% (t = 2.98, P < 0.05) in the DEC, IVM and placebo arms, respectively. The proportion of high-count Mf (>50 Mf per 60 mm(3) of blood) carriers was reduced by 94% (P < 0.01) in the DEC arm and by 90% (P < 0.01) in the IVM arm. Among those who received all six treatments, 1.4% in the DEC arm and 2.4% in the IVM arm remained positive for Mf. Two of five villages in the DEC arm and one of five in the IVM arm showed zero Mf prevalence, but continued to have low levels of transmission of infection. The results also indicate that DEC is as effective as or slightly better than IVM against microfilaraemia. Results from this and other recent operational studies proved that single-dose treatment with antifilarials is very effective at community level, feasible, logistically easier and cheap and hence a highly appropriate strategy to control or eliminate LF. Higher treatment coverage than that observed in this study and a few more than six cycles of treatment and more effective treatment tools/strategies may be necessary to reduce microfilaraemia to zero level in all communities, which may lead to elimination of LF. (+info)
Treatment of Brugia timori and Wuchereria bancrofti infections in Indonesia using DEC or a combination of DEC and albendazole: adverse reactions and short-term effects on microfilariae.
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Filariasis caused by Brugia timori and Wuchereria bancrofti is an important public health problem on Alor island, East Nusa Tenggara, Indonesia. To implement a control programme, adverse reactions and short-term effects on the microfilaria (mf) density were studied following a divided dose of diethylcarbamazine (DEC, 6 mg/kg body weight - 100 mg on day 1 and the rest on day 3) or a single dose of DEC (6 mg/kg body weight on day 3) and albendazole (Alb, 400 mg). In order to define the most appropriate regimen, 30 persons infected with B. timori were treated in the hospital and results were compared with those obtained from the treatment of 27 persons infected with W. bancrofti. Adverse reactions consisted of systemic reactions such as fever, headache, myalgia, itching and local reactions such as adenolymphangitis. Fever experienced by a number of patients in both treatment groups generally occurred 12-24 h after drug administration and lasted up to 2 days. Adenolymphangitis tended to occur later and was resolved within 4 days. The number of W. bancrofti patients suffering from adverse reactions was lower and the reactions were milder than those of the B. timori patients. There was no difference in adverse reactions between DEC alone and DEC-Alb treatment for either infection. The geometric mean mf count decreased on day 7 in the B. timori infected patients from 234 mf/ml in the DEC group and from 257 mf/ml in the DEC-Alb group to 7 and 8 mf/ml, respectively. The mf densities of the W. bancrofti infected patients decreased on day 7 from 214 mf/ml in the DEC group and from 559 mf/ml in the DEC-Alb group to 15 and 14 mf/ml, respectively. Our data indicate that the microfilaricidal effect of the drugs is achieved more rapidly for B. timori, which is associated with more adverse reactions than W. bancrofti. In addition, 111 B. timori infected persons were treated in the community with DEC-Alb in one selected village. The adverse reactions and the reduction of mf density was similar to the findings of the hospital-based study. In this group, there was a strong correlation of mf density with the frequency and severity of adverse reactions. The addition of Alb resulted in no additional adverse reactions compared with DEC treatment alone and can also be used for the treatment of B. timori infection. In Indonesia, where the prevalence of intestinal helminths is high, the use of a combination of DEC and Alb to control lymphatic filariasis may also have impact on the control of intestinal helminths. (+info)
The impact of single-dose diethylcarbamazine treatment of bancroftian filariasis in a low-endemicity setting in Egypt.
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This study was designed to evaluate the effect of a single dose of diethylcarbamazine (DEC, 6 mg/kg) on Wuchereria bancrofti infections in a low-endemicity setting in Egypt (microfilaremia, or MF, 3.7%, median MF 34/mL). Subjects with MF or filarial antigenemia were treated and restudied 1 year later. Treatment with DEC dramatically reduced blood MF counts, with clearance in 69% of subjects. Treatment also reduced filarial antigen levels, but low clearance rates suggest that some adult worms survived treatment in most patients. Mass treatment was administered in one village; 27 months later, MF prevalence had decreased 84% (from 4.9% to 0.8%). These results show that single-dose DEC treatment can have a major effect on MF prevalence rates and levels in low-endemicity settings. Although the World Health Organization advocates repeated multidrug regimens for filariasis elimination, mass treatment with DEC alone may be sufficient to interrupt transmission in areas with low infection intensities and prevalence rates. (+info)
Prevalence of diurnally subperiodic bancroftian filariasis among the Nicobarese in Andaman and Nicobar Islands, India: effect of age and gender.
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We conducted a cross-sectional survey to assess the prevalence of disease and microfilaraemia caused by diurnally subperiodic strain of Wuchereria bancrofti transmitted by day biting Aedes niveus in Teressa Island, remotely located in the Nicobar district of Andaman and Nicobar Islands. Lymphatic filariasis is a considerable public health problem on this island with an overall endemicity rate of 16.2%. There was a gradual increase in microfilaraemia prevalence with age, reaching a plateau above 30 years. Both the microfilaraemia and disease rates were significantly higher in males (14.7% and 5.2%) than females (8.6% and 1.5%, P < 0.001). The age and gender specific distribution of chronic manifestations show a gradual increase with age, whereas acute disease started to occur from age 40 in males. Hydrocele (84.6%) was the commonest disease manifestation among males, whereas lymphoedema was the only manifestation encountered among females. As vector control measures are not practicable in this setting, chemotherapy using diethylcarbamazine (DEC) is the only potential option to control this disease. (+info)
Lymphatic filariasis elimination and schistosomiasis control in combination with onchocerciasis control in Nigeria.
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This paper describes a pilot initiative to incorporate lymphatic filariasis (LF) elimination and urinary schistosomiasis (SH) control into a mature onchocerciasis control program based on community-directed ivermectin treatment in central Nigeria. In the same districts having onchocerciasis we found LF (as determined by blood antigen testing in adult males) in 90% of 149 villages with a mean prevalence of 22.4% (range 0-67%). Similarly, SH, as determined by dipstick reagent testing for blood in urine from school children, was found in 91% of 176 villages with a mean orevalence in school age children of 24.4% (range 0-87%). Health education and treatment interventions for SH resulted in 52,480 cumulative praziquantel treatments, and 159,555 combined onchocerciasis and LF treatments (with ivermectin and albendazole) as of the end of 2000. Treatments for onchocerciasis and LF were separated by at least 1 week from treatments for SH. There was no negative impact on the coverage of the onchocerciasis program by the addition of LF and SH activities. (+info)
Mass treatment to eliminate filariasis in Papua New Guinea.
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BACKGROUND: The global initiative to eradicate bancroftian filariasis currently relies on mass treatment with four to six annual doses of antifilarial drugs. The goal is to reduce the reservoir of microfilariae in the blood to a level that is insufficient to maintain transmission by the mosquito vector. METHODS: In nearly 2500 residents of Papua New Guinea, we prospectively assessed the effects of four annual treatments with a single dose of diethylcarbamazine plus ivermectin or diethylcarbamazine alone on the incidence of microfilariae-positive infections, the severity of lymphatic disease, and the rate of transmission of Wuchereria bancrofti by mosquitoes. Random assignment to treatment regimens was carried out according to the village of residence, and villages were categorized as having moderate or high rates of transmission. RESULTS: The four annual treatments with either drug regimen were taken by 77 to 86 percent of the members of the population who were at least five years old; treatments were well tolerated. The proportion with microfilariae-positive infections decreased by 86 to 98 percent, with a greater reduction in areas with a moderate rate of transmission than in those with a high rate. The respective aggregate frequencies of hydrocele and leg lymphedema were 15 percent and 5 percent before the trial began, and 5 percent (P<0.001) and 4 percent (P=0.04) after five years. Hydrocele and leg lymphedema were eliminated in 87 percent and 69 percent, respectively, of those who had these conditions at the outset. The rate of transmission by mosquitoes decreased substantially, and new microfilariae-positive infections in children were almost completely prevented over the five-year study period. CONCLUSIONS: Annual mass treatment with drugs such as diethylcarbamazine can virtually eliminate the reservoir of microfilariae and greatly reduce the frequency of clinical lymphatic abnormalities due to bancroftian filariasis. Eradication may be possible in areas with moderate rates of transmission, but longer periods of treatment or additional control measures may be necessary in areas with high rates of transmission. (+info)