Short-term malaria reduction by single-dose azithromycin during mass drug administration for trachoma, Tanzania

This drug might be beneficial in areas to which malaria and trachoma are endemic.

Single-dose mass drug administration of azithromycin (AZT) is underway to eliminate trachoma worldwide. Studies in Ethiopia showed a reduction in all-cause childhood deaths after administration. To examine the effect of single-dose AZ MDA on prevalent malaria infections in a large prospective cohort of children and parents in Dodoma Province, Tanzania, we quantified the temporal prevalence of malaria parasitemia by real-time PCR for 6 months after single-dose AZT. In the first month after treatment but not in subsequent months, Plasmodium falciparum infections were reduced by 73% (95% CI 43%–89%) in treatment versus control villages and differences remained significant (p = 0.00497) in multivariate models with village-level random effects. Genetic sequencing of P. falciparum ribosomal L4 protein showed no mutations associated with AZT resistance. AZT mass drug administration caused a transient, 1-month antimalarial effect without selecting for P. falciparum ribosomal L4 resistance mutations in a region with a 10-year history of treating trachoma with this drug.

Lymphatic filariasis in Peninsular Malaysia: a cross-sectional survey of the knowledge, attitudes, and practices of residents

BACKGROUND

Lymphatic filariasis (LF) is a major cause of permanent disability in many tropical and sub-tropical countries of the world. Malaysia is one of the countries in which LF is an endemic disease. Five rounds of the mass drug administration (MDA) program have been conducted in Malaysia as part of the Global Program to Eliminate Lymphatic Filariasis (GPELF) by year 2020. This study investigated the level of awareness of LF and the MDA program in a population living in an endemic area of the country.

METHODS

A descriptive cross-sectional survey that involved 230 respondents (≥15 years old) living in the LF endemic communities of Terengganu state in Peninsular Malaysia was performed. Demographic, socioeconomic, and knowledge, attitudes and practices (KAP) data of the respondents were obtained using pre-tested questionnaires and were analyzed using SPSS software version 13.0.

RESULTS

More than 80% of the respondents were aware of LF and the common symptoms of the disease. Moreover, about 70% of the respondents that were aware of LF indicated that it is a problematic disease. Approximately 77% of the respondents indicated that filariasis is transmitted by mosquitoes. Two-thirds of respondents preferred hospital treatment for illness; however, only 12% had participated and/or received treatment for LF during an MDA program. Only 35% of the respondents that participated in this research were aware of the MDA program that had taken place in the area. None of the respondents had knowledge of the drug used in the treatment of LF. The findings from this research indicated that there was no significant association between LF awareness and with gender, age group, educational status, occupation, or socio-economic status of the respondents (P >0.05).

CONCLUSION

A good proportion of the respondents are aware of LF, its mode of transmission and symptoms, however they demonstrated a poor knowledge of MDA which took place in the study area. For greater understanding of LF in the Malaysian population, there is a need for an enhancement in the delivery of health education and information programs and mass mobilization campaigns in endemic communities.

Chemotherapy in the treatment, control, and elimination of human onchocerciasis

Onchocerciasis treatment is one of the most positive stories in tropical medicine although major challenges remain to reaching the ultimate goal of disease elimination. Such challenges are to be expected when the therapeutic goal is to kill and safely remove a large multistage, efficient, metazoan infectious agent such as Onchocerca volvulus that has an exceptionally complicated relationship with its host. Successful control of onchocerciasis has often been hampered by host reactions following chemotherapy, that can sometimes cause significant tissue pathology. Presence of other filariae, particularly Loa loa, in endemic onchocerciasis-treatment areas also poses severe problems due to adverse reactions caused by drug-induced death of the coincident microfilariae of this usually clinically benign species. Although ivermectin has been very successful, there is a need to enhance the progress toward elimination of onchocerciasis; new drugs and their efficient use are keys to this. The permanent absence of Onchocerca microfilaridermia, defined as the lack of resurgence of skin microfilarial loads after treatment, is the ultimate characteristic of a useful new chemotherapeutic agent. Several drugs are under investigation to achieve this, including the reassessment of currently available and previously tested agents, such as the antibiotic, doxycycline, which targets the adult parasites through its anti-Wolbachia endosymbiont activity. Flubendazole, a benzimidazole derivative approved for treatment of human gastrointestinal nematodes, is also being considered for repurposing as a macrofilaricide to aid in the achievement of eradication. The managerial challenges existing at the population level also need to be addressed; these include drug-distribution fatigue, the need to include noncompliant people, civil unrest in endemic areas, political cross-border issues, restrictions of age and pregnancy, and complications due to integration with other treatment programs. It is likely that a panel of chemotherapeutic options, new and old, supported by strong and effective distribution systems will be the best way to address challenges of treatment and elimination of this infection. Future research should also address management of treatment and control, and consider how new treatment paradigms can be incorporated to meet time lines set for global elimination by 2025.

Prevention and control of schistosomiasis: a current perspective

Schistosomiasis is a neglected tropical disease that ranks second only to malaria in terms of human suffering in the tropics and subtropics. Five species are known to infect man and there are currently over 240 million people infected worldwide. The cornerstone of control to date has been mass drug administration with 40 mg/kg of praziquantel but there are problems with this approach. Human and bovine vaccines are in various stages of development. Integrated control, targeting the life cycle, is the only approach that will lead to sustainability and future elimination.

Multidimensional complexities of filariasis control in an era of large-scale mass drug administration programmes: a can of worms

The impact of control and elimination programmes by mass drug administration (MDA) targeting onchocerciasis and lymphatic filariasis (LF) in sub-Saharan Africa over the last two decades has resulted in significantly reduced prevalence and intensity of infection, with some areas interrupting transmission. However, given that these infections are often co-endemic and the drugs (either ivermectin alone or combined with albendazole) also impact on soil transmitted helminths (STH), the importance of this, in terms of reaching the global goals has not been assessed. The additional problem posed by Loa loa, where ivermectin cannot be safely administered due to the risk of serious adverse events compounds this situation and has left populations drug naïve and an alternative strategy to eliminate LF is yet to be initiated at scale. Here, we present a series of operational research questions, which must be addressed if the effectiveness of integrated control of filarial and helminth infections is to be understood for the endgame. This is particularly important in the diverse and dynamic epidemiological landscape, which has emerged as a result of the long-term large-scale mass drug administration (or not). There is a need for a more holistic approach to address these questions. Different programmes should examine this increased complexity, given that MDA has multiple impacts, drugs are given over different periods, and programmes have different individual targets.

Gender and performance of community treatment assistants in Tanzania

OBJECTIVE

To examine the effects of gender and demographics of community treatment assistants (CTAs) on their performance of assigned tasks and quantity of speech during mass drug administration of azithromycin for trachoma in rural Tanzania.

DESIGN

Surveys of CTAs and audio recordings of interactions between CTAs and villagers during drug distribution.

SETTING

Mass drug administration program in rural Kongwa district.

PARTICIPANTS

Fifty-seven randomly selected CTAs, and 3122 residents of villages receiving azithromycin as part of the Kongwa Trachoma Project.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Speech quantity graded by Roter interaction analysis system, presence of culturally appropriate greeting and education on facial hygiene for trachoma prevention from coded analysis of audio-recorded interactions.

RESULTS

At sites with all female CTAs, each CTA spent more time and spoke more in each interaction in comparison with CTAs at sites with only male CTAs and CTAs at 'mixed gender' sites (sites with both male and female CTAs). At 'mixed gender' sites, males spoke significantly more than females. Female CTAs mentioned trachoma prevention with facial cleanliness more than twice as often as male CTAs; however, both genders mentioned hygiene in <10% of interactions. Both genders had culturally appropriate greetings in <25% of interactions.

CONCLUSIONS

Gender dynamics affect the amount of time that CTAs spend with villagers during drug distribution, and the relative amount of speech when both genders work together. Both genders are not meeting expectations for trachoma prevention education and greeting villagers, and novel training methods are necessary.

The potential impact of adding ivermectin to a mass treatment intervention to reduce malaria transmission: a modelling study

BACKGROUND

Ivermectin (IVM), used alongside mass treatment strategies with an artemisinin combination therapy, has been suggested as a possible tool for reducing malaria transmission. Mosquitoes ingesting a bloodmeal containing IVM have increased mortality, reducing the probability that the parasite completes sporogony.

METHODS

Human pharmacokinetic data and mortality data for mosquitoes taking bloodmeals containing IVM are used to quantify the mosquitocidal effect of IVM. These are incorporated into a transmission model to estimate the impact of IVM in combination with mass treatment strategies with artemether-lumefantrine on transmission metrics.

RESULTS

Adding IVM increases the reductions in parasite prevalence achieved and delays the reemergence of parasites compared to mass treatment alone. This transmission effect is obtained through its effect on vector mortality. IVM effectiveness depends on coverage with the highest impact achieved if given to the whole population rather than only those with existing detectable parasites. Our results suggest that including IVM in a mass treatment strategy can reduce the time taken to interrupt transmission as well as help to achieve transmission interruption in transmission settings in which mass treatment strategies alone would be insufficient.

CONCLUSIONS

Including IVM in mass treatment strategies could be a useful adjunct to reduce and interrupt malaria transmission.

Persistence of lymphatic filarial infection in the paediatric population of rural community, after six rounds of annual mass drug administrations

Under the Global Programme to Eliminate Lymphatic Filariasis (LF), mass drug administration (MDA) is being implemented in Tamil Nadu, south India, by the State health machinery. The impact of six annual rounds of MDA using diethylcarbamazine (DEC) with and without albendazole (ALB) on filarial infection (microfilaraemia prevalence-MFP; antigenaemia prevalence-AGP) in paediatric population of 2-9 years was determined in two revenue blocks, with a population of 321 000. After each MDA, 300-400 children were screened for filarial infection. After six MDAs, an overall MFP reduction of 84.67% and 57.95% was observed in DEC+ALB and DEC alone arms, respectively. Corresponding AGP reductions were 72.88% (p < 0.001) and 41.51% (p = 0.023). Observation of microfilaraemic children after six MDAs (0.32% in DEC+ALB; 0.75% in DEC alone), necessitates the need for supplementary control strategies (viz., vector control), in order to achieve the goal of LF elimination.

The contribution of mass drug administration to global health: past, present and future

Mass drug administration (MDA) is a means of delivering safe and inexpensive essential medicines based on the principles of preventive chemotherapy, where populations or sub-populations are offered treatment without individual diagnosis. High-coverage MDA in endemic areas aims to prevent and alleviate symptoms and morbidity on the one hand and can reduce transmission on the other, together improving global health. MDA is the recommended strategy of the World Health Organisation to control or eliminate several neglected tropical diseases (NTDs). More than 700 million people now receive these essential NTD medicines annually. The combined cost of integrated NTD MDA has been calculated to be in the order of $0.50 per person per year. Activities have recently been expanded due, in part, to the proposed attempt to eliminate certain NTDs in the coming two decades. More than 1.9 billion people need to receive MDA annually across several years if these targets are to be met. Such extensive coverage will require additional avenues of financial support, expanded monitoring and evaluation focusing on impact and drug efficacy, as well as new diagnostic tools and social science strategies to encourage adherence. MDA is a means to help reduce the burden of disease, and hence poverty, among the poorest sector of populations. It has already made significant improvements to global health and productivity and has the potential for further successes, particularly where incorporated into sanitation and education programmes. However logistical, financial and biological challenges remain.

Mass primaquine treatment to eliminate vivax malaria: lessons from the past

Recent successes in malaria control have put malaria eradication back on the public health agenda. A significant obstacle to malaria elimination in Asia is the large burden of Plasmodium vivax, which is more difficult to eliminate than Plasmodium falciparum. Persistent P. vivax liver stages can be eliminated only by radical treatment with a ≥ seven-day course of an 8-aminoquinoline, with the attendant risk of acute haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Primaquine is the only generally available 8-aminoquinoline. Testing for G6PD deficiency is not widely available, and so whilst it is widely recommended, primaquine is often not prescribed. In the past, some countries aiming for vivax malaria eradication deployed mass treatments with primaquine on a massive scale, without G6PD testing. In Azerbaijan, Tajikistan (formerly USSR), North Afghanistan and DPR Korea 8,270,185 people received either a 14-day "standard" or a 17-day "interrupted" primaquine treatment to control post-eradication malaria epidemics. These mass primaquine preventive treatment campaigns were conducted by dedicated teams who administered the drugs under supervision and then monitored the population for adverse events. Despite estimated G6PD prevalences up to 38.7%, the reported frequency of severe adverse events related to primaquine was very low. This experience shows that with careful planning and implementation of mass treatment strategies using primaquine and adequate medical support to manage haemolytic toxicity, it is possible to achieve high population coverage, substantially reduce malaria transmission, and manage the risk of severe acute haemolytic anaemia in communities with a relatively high prevalence of G6PD deficiency safely.

Mass drug administration for elimination of lymphatic filariasis: Recent experiences from a district of West Bengal, India

Background:

Annual mass drug administration (MDA) with diethyl carbamazine (DEC) and Albendazole is the most cost-effective strategy to control lymphatic filariasis (LF).

Materials and Methods:

The aim of the present study was to assess the coverage and the compliance of MDA, to elicit factors that influenced compliance, to document side-effects reported and to assess the awareness of the community regarding the disease and MDA program in Bankura district, West Bengal after 2012 round of MDA. Multistage cluster sampling method was adopted. Total four clusters; three villages and one urban municipality ward were selected. In each cluster, minimum 30 families were randomly selected and the head or any responsible family member was interviewed using a pre-designed, pre-tested schedule after taking written informed consent. Data were compiled and analyzed using SPSS 19.0.

Results:

Total eligible population was 683 among which 98.8% received both the drugs. About 5% of the recipients took none of the drugs. More than two-thirds of the families took unsupervised dose. Drug compliance rate was significantly lower in urban (90.7%) than in the rural clusters (95.7%) (z = 2.46, P < 0.05). Effective coverage rate was significantly lower in urban than in the rural clusters (87.4% vs. 95.3%; z = 3.57, P < 0.01). Coverage compliance gap was higher in urban (5.7%) than in rural cluster (3.9%). Fear of side-effects was the main reason for non-compliance. Reported side-effects were few, mild, and transient. Around 60% of the surveyed families were aware about the MDA program whereas, 67% of them heard about LF. Only 41% families were provided information, education, and communication in last 15 days before MDA. Major sources of information for the surveyed families were leaflets (20.3%) and poster (9.8%).

Conclusions:

Widespread rural urban variation in performance status, poor social mobilization activities, lack of supervised dosing, and lack of knowledge of the community about the disease and the program are the major areas of concern.

Factors determining noncompliance to mass drug administration for lymphatic filariasis elimination

Mass Drug Administration (MDA) for Lymphatic Filariasis (LF) elimination has been implemented worldwide and in India with a goal of eliminating the disease by 2020 and 2015 respectively. Compliance to MDA is less than adequate to achieve the goal in the desired time. This study aims to identify the factors related to awareness, acceptability and attitude and the role of certain theoretical constructs of health belief model in determining the compliant behavior to MDA. Within a cross-sectional study done in Thiruvananthapuram district of Kerala, India, undertaken to determine coverage, a comparison was done between compliant and noncompliant individuals. 300 households were selected using cluster sampling technique, for estimation of coverage of MDA. From these households, 99 noncompliant and 70 compliant individuals were selected as cases and controls. The independent factors determining noncompliance were client attitude of not perceiving the need with an adjusted odds ratio (OR) of 2.52 (1.29-4.92), an unfavorable provider attitude with an adjusted OR of 2.14 (1.05-4.35) and low drug administrator acceptability with an adjusted OR of 2.01 (1.01-3.99). In MDA, the person giving the drug to the beneficiary is the most important person, whose attitude and acceptability determines compliance. More rigorous selection and training for capacity building of drug administrators are essential to enhance the compliance level. Alternate drug delivery strategies, besides house to house campaign by voluntary drug administers also needs to be implemented.

Exploring network theory for mass drug administration

Network theory is a well-established discipline that uses mathematical graphs to describe biological, physical, and social systems. The topologies across empirical networks display strikingly similar organizational properties. In particular, the characteristics of these networks allow computational analysis to contribute data unattainable from examining individual components in isolation. However, the interdisciplinary and quantitative nature of network analysis has yet to be exploited by public health initiatives to distribute preventive chemotherapies. One notable application is the 2012 World Health Organization (WHO) Roadmap for Neglected Tropical Diseases (NTDs) where there is a need to upscale distribution capacity and to target systematic noncompliers. An understanding of local networks for analysing the distributional properties of community-directed treatment may facilitate sustainable expansion of mass drug-administration (MDA) programs.

Coverage and awareness of and compliance with mass drug administration for elimination of lymphatic filariasis in Burdwan District, West Bengal, India

India adopted WHO's strategy of repeated rounds of mass drug administration (MDA) with diethylcarbamazine to eliminate lymphatic filariasis. The present study attempted to assess the coverage and awareness of and compliance with MDA for elimination of lymphatic filariasis in Burdwan district of India, following MDA round in July 2010. A cross-sectional study was conducted among the four randomly-selected clusters in the district of Burdwan, West Bengal, India, covering 603 individuals from 154 households, using a predesigned pretested schedule. The drug distribution coverage, compliance, and effective coverage were 48.76%, 70.07%, and 34.16% respectively. Only 41.4% of the study population was aware of the MDA activity. This evaluation study noted that MDA is restricted to tablet distribution only. There is an urgent need to improve compliance with drug intake through strengthening of the awareness programme involving both government health workers and community volunteers.

Sentinel surveillance of soil-transmitted helminthiasis in preschool-aged and school-aged children in selected local government units in the Philippines: follow-up assessment

This study was a follow-up to the baseline nationwide survey of soil-transmitted helminth (STH) infections in preschool-aged children in the Philippines and in school-aged children in selected sentinel sites to assess the Integrated Helminth Control Program of the Department of Health. The objective of the study was to describe the current prevalence and intensity of STH infections in preschool-aged and school-aged children in 6 sentinel provinces and to compare these data with baseline findings. A cross-sectional study design was used to determine the prevalence and intensity of STH infections. Parasitological assessment involved the examination of stool samples by the Kato-Katz method. Although parasitological parameters in the 2 age groups at follow-up showed significant reductions from the baseline, these parameters remained high despite 3 years of mass drug administration (MDA). Efforts toward achieving high MDA coverage rates, provision of clean water, environmental sanitation, and promotion of hygiene practices must be prioritized.

Lymphatic filariasis in Papua New Guinea: distribution at district level and impact of mass drug administration, 1980 to 2011

BACKGROUND

Lymphatic filariasis (LF) caused by Wuchereria bancrofti is present at high prevalence in some parts of Papua New Guinea. However, there has been no rigorous data-based representative assessment of nationwide prevalence of LF. The LF programme has been daunted by the scope of the problem, and progress on mass drug administration (MDA) has been slow and lacking in resources.

METHODS

A systematic literature review identified LF surveys in Papua New Guinea between 1980 and 2011. Results were extracted by location, time period and test used (blood slide, immunochromatographic test (ICT) or Og4C3 ELISA) and combined by district. Three criteria schemes based on the Global Programme to Eliminate Lymphatic Filariasis guidelines, with modifications, were developed to classify and prioritize districts by prevalence level. Results of repeated surveys in the same sites were used to investigate the impact of MDA on LF prevalence over the time period.

RESULTS

There were 312 distinct survey sites identified in 80 of the 89 districts over the 31-year period. The overall LF prevalence in the sites tested was estimated at 18.5 to 27.5% by blood slide for microfilariae (Mf), 10.1% to 12.9% by ICT and 45.4% to 48.8% by Og4C3. Biases in site selection towards areas with LF, and change in type of assay used, affected the prevalence estimates, but overall decline in prevalence over the time period was observed. Depending on the criteria used, 34 to 36 districts (population 2.7 to 2.9 million) were classed as high endemic (≥5% prevalence), 15 to 25 districts (1.7 to 1.9 million) as low endemic (<5%) and 20 to 31 (1.3 to 2.2 million) as non-endemic. Nine districts (0.7 million) had no information. The strong impact of MDA, especially on microfilaria (Mf) prevalence, was noted in sites with repeat surveys.

CONCLUSIONS

This analytical review of past surveys of LF in Papua New Guinea enables better estimation of the national burden, identifies gaps in knowledge, quantifies and locates the population at risk, and can be used to predict the likely impact of MDA and/or vector control. Better targeting of districts by level of prevalence will strengthen the control programme, facilitate monitoring of the disease trend and increase the likelihood of reaching the target of LF elimination by 2020.

Elimination of lymphatic filariasis: mass drug administration in endemic areas of (bidar district) karnataka-2008

Background:

Lymphatic Filariasis is a mosquito transmitted disease, caused by parasitic worm Wuchereria bancrofti. Global Programme for Elimination of Lymphatic Filariasis was established in early 2000. The strategy recommended by the World Health Organization is annual Mass Drug Administration (MDA) of single-dose of Diethylcarbamazine 6 mg/kg (DEC), distributed to inhabitants of Filariasis endemic areas, excluding children below 2 years of age, pregnant women, and seriously ill persons, and Morbidity Management. The health system distributes the drugs by a door-to-door strategy.

Objective:

To assess the coverage and compliance of MDA in Bidar district during the campaign in November 2008.

Materials and Methods:

Cross-sectional population-based house-to-house visit. Outcome is assessed as actual coverage and compliance, in Percentage and proportions.

Results:

Eight clusters, total eligible population of 1 131 individuals were interviewed. The coverage rate was 78% with variation across different areas. The compliance with drug ingestion was 68%.

Conclusion:

The effective coverage was below the target (85%). Side effects of DEC were minimum, the overall coverage was better in rural areas compared with urban areas.

Greater Adherence to Mass Drug Administration Against Lymphatic Filariasis through Traditional Village Forums in Fiji

Objective: The aim of this study was to elucidate the roles of knowledge related to lymphatic filariasis (LF), contributions of taking roles in community activities to eradicate LF and participation in traditional village forums in adherence to mass drug administration (MDA) in a preventive chemotherapy program targeted at the community residents.

Materials and Methods: A survey on ingestion of diethylcarbamazine (DEC) and albendazole (ALB), knowledge related to LF, taking roles in community activities and participation in traditional village forums was carried out for 400 adult subjects randomly selected from the Central Division of Fiji within three months after the MDA campaign in 2010 in the respective communities. Multilevel logistic regression analysis and multilevel linear regression analysis were performed to examine relationships between knowledge, community activities, traditional village forums and ingestion of anti-filarial drugs. The LF knowledge score was defined as a factor score of five knowledge variables.

Results: Among 324 respondents, 40.4% of them ingested both DEC and ALB. Participation in traditional village forums was independently and significantly related to ingestion of DEC and ALB (OR=1.78, 95% CI=1.04–3.05) and taking roles in community activities for MDA (OR=1.87, 95% CI=1.18–2.94), regardless of the subject’s gender, education, knowledge and taking roles in community activities. Taking roles in community activities for MDA was independently related to the LF knowledge score (β=0.24, 95% CI=0.15–0.33).

Conclusion: Participation in traditional village forums in Fiji was related to taking roles in community activities for MDA and associated with adherence to MDA regimen regardless of the educational attainment of the individual residents.

Mass drug administration coverage evaluation survey for lymphatic filariasis in bagalkot and gulbarga districts

Background:

Lymphatic filariasis (LF) is endemic in 83 countries and territories, with more than a billion people at risk of infection. In view with the global elimination, mass drug administration (MDA) with single dose of diethylcarbamazine and albendazole tablets was carried out for the eligible population in Bagalkot and Gulbarga districts.

Objective:

Assess coverage of MDA against LF in Bagalkot and Gulbarga districts.

Materials and Methods:

In this cross-sectional coverage evaluation survey, one urban and three rural clusters were selected randomly in each district. The data were collected in a pretested performa, computed and analyzed using SPSS-10 to calculate frequencies and proportions.

Results:

A total of eight clusters in two districts resulted in a total study population of 1,228 individuals. The overall compliance rate in Bagalkot district was 78.6% and in Gulbarga district it was only 38.8%. The prime reason for noncompliance was fear of side effects and not received tablets.

Conclusion:

There is an urgent need for more effective drug delivery strategies to improve the compliance in both the districts.

An evaluation of coverage and compliance of mass drug administration 2006 for elimination of lymphatic filariasis in endemic areas of gujarat

Background:

Mass drug administration (MDA) means once-in-a-year administration of diethyl carbamazine (DEC) tablet to all people (excluding children under 2 years, pregnant women and severely ill persons) in identified endemic areas. It aims at cessation of transmission of lymphatic filariasis.

Objective:

What has been the coverage and compliance of MDA in Gujarat during the campaign in December 2006?

Study Design:

Cross-sectional population based house-to-house visit.

Setting:

Urban and rural areas in Gujarat identified as endemic for filariasis where MDA 2006 was undertaken.

Study Variables:

Exploratory - Rural and urban districts; Outcome - coverage, compliance, actual coverage, side effects.

Analysis:

Percentage and proportions.

Results:

Twenty-six clusters, each comprising 32 households from six endemic districts, yielded an eligible population of 4164. The coverage rate was 85.2% with variation across different areas. The compliance with drug ingestion was 89% with a gap of 11% to be targeted by intensive IEC. The effective coverage (75.8%) was much below the target (85%). Side effects of DEC were minimum, transient and drug-specific. Overall coverage was marginally better in rural areas. The causes of poor coverage and compliance have been discussed and relevant suggestions have been made.

The Global Programme to Eliminate Lymphatic Filariasis: History and achievements with special reference to annual single-dose treatment with diethylcarbamazine in Samoa and Fiji

Diethylcarbamazine (DEC), first introduced in 1947, was shown to have strong efficacy and safety for treatment of human lymphatic filariasis, which is caused mostly by a species Wuchereria bancrofti. Many studies to optimize the dosage and treatment schedule of DEC followed, and, based on the results, control programs with various regimens were implemented in different endemic areas/countries. By the mid 1970s, with endorsement by the WHO Expert Committee on Filariasis (3rd report, 1974), the standard DEC regimen for W. bancrofti infection in mass treatment had been established in principle: a total dose of 72 mg/kg of body weight given in 12 divided doses, once weekly or monthly, at 6 mg/kg each. Not long after the committee report, the efficacy of annual single-dose treatment at 6 mg/kg, which is only one twelfth of the WHO-recommended dose in a year, was reported effective in French Polynesia (study period: 1973-78), and later in Samoa (study period: 1979-81). These results were published between 1978 and 1985 in the Bulletin of WHO but received little attention. In the mid 1980s, the efficacy of ivermectin, the first-choice drug for onchocerciasis, against lymphatic filariae came to light. Since the effect at a single dose was remarkable, and often better than DEC, it was predicted that the newly introduced drug would replace DEC. Treatment experiments with ivermectin increased quickly in number. Meanwhile, annual single-dose mass drug administration (MDA) with DEC at 6 mg/kg was under scrutiny in Samoa and Fiji. In the early 1990s, the Samoan study, which covered the entire population of 160,000 with 3 annual MDAs, reported a significant reduction in microfilaria (mf) prevalence and mean mf density, while in Fiji, the efficacy of 5 rounds of annual MDA (total dose, 30 mg/kg) was shown to be as effective as 28 multi-dose MDA spread over 2 years (6 weekly plus 22 monthly treatments at 5 mg/kg; total dose, 140 mg/kg). Several additional studies carried out in Samoa in relation to the annual single-dose MDAs revealed that low density mf carriers, who have a very low mf count of 1-20/ml of venous blood, could not play a significant role in filariasis transmission.From around 1990, studies on spaced low-dose DEC treatments and various types of combination chemotherapy with DEC and ivermectin increased. Albendazole, a well-known anti-intestinal helminths agent, was later added to the combination. The main findings of these studies with W. bancrofti are: (i) a single dose of DEC at 6 mg/kg reduced mean mf density by ca. 90% 1 year after treatment; (ii) the same dose could damage/kill adult worms; (iii) a single dose of ivermectin at ca. 400 µg/kg was more effective than DEC in reducing mf density during the first year and was similarly or less effective in the second year; (iv) ivermectin probably could not kill adult worms; (v) a single combined dose of albendazole (400 mg) and DEC (6 mg/kg) was effective to reduce mf density by 85 to nearly 100% 12-24 months after treatment; and (vi) ivermectin or albendazole included in the combination chemotherapy produced "beyond-filariasis" benefits: clearance/reduction of intestinal helminths, and, additionally, in the case of ivermectin, skin-dwelling ectoparasites.The Global Programme to Eliminate Lymphatic Filariasis (GPELF) started its worldwide activities in 2000, with the target of elimination by 2020. The basic strategy is to conduct annual single-dose MDAs for 4-6 years. In 2000-2007, a minimum of 570 million individuals were treated in 48 of 83 endemic countries. The drugs used are DEC 6 mg/kg plus albendazole 400 mg in most countries, or ivermectin 200-400 µg/kg plus albendazole 400 mg particularly in onchocerciasis endemic countries in Africa. (MDAs with DEC alone had been used in India.)The GPELF achieved impressive results in terms of parasitological cure/improvement, clinical benefits, social and economic impacts, etc. However, the most impressive result of all was the programme's success in mobilizing hundreds of millions of local people, who not only took drugs but many of them actively supported MDAs as drug distributors and volunteers. Beyond filariasis, the role people can play in supplementing rural health services is now a topic of discussion and a source of hope for a new sustainable system.

The effect of oral anthelmintics on the survivorship and re-feeding frequency of anthropophilic mosquito disease vectors

In the Tropics, there is substantial temporal and spatial overlap of diseases propagated by anthropophilic mosquito vectors (such as malaria and dengue) and human helminth diseases (such as onchocerciasis and lymphatic filariasis) that are treated though mass drug administrations (MDA). This overlap will result in mosquito vectors imbibing significant quantities of these drugs when they blood feed on humans. Since many anthelmintic drugs have broad anti-invertebrate effects, the possibility of combined helminth control and mosquito-borne disease control through MDA is apparent. It has been previously shown that ivermectin can reduce mosquito survivorship when administered in a blood meal, but more detailed examinations are needed if MDA is to ever be developed into a tool for malaria or dengue control. We examined concentrations of drugs that follow human pharmacokinetics after MDA and that matched with mosquito feeding times, for effects against the anthropophilic mosquito vectors Anopheles gambiae s.s. and Aedes aegypti. Ivermectin was the only human-approved MDA drug we tested that affected mosquito survivorship, and only An. gambiae s.s. were affected at concentrations respecting human pharmacokinetics at indicated doses. Ivermectin also delayed An. gambiae s.s. re-feeding frequency and defecation rates, and two successive ivermectin-spiked blood meals following human pharmacokinetic concentrations compounded mortality effects compared to controls. These findings suggest that ivermectin MDA in Africa may be used to decrease malaria transmission if MDAs were administered more frequently. Such a strategy would broaden the current scope of polyparasitism control already afforded by MDAs, and which is needed in many African villages simultaneously burdened by many parasitic diseases.

Epidemiology and control of human gastrointestinal parasites in children

Parasites found in the human gastrointestinal tract can be largely categorized into two groups, protozoa and helminths. The soil-transmitted helminths (Ascaris lumbricoides, hookworm and Trichuris trichiura) are the most prevalent, infecting an estimated one-sixth of the global population. Infection rates are highest in children living in sub-Saharan Africa, followed by Asia and then Latin America and the Caribbean. The current momentum towards global drug delivery for their control is at a historical high through the efforts of numerous initiatives increasingly acting in coordination with donors, governments and local communities. Together, they have delivered enormous quantities of drugs, especially anthelmintics to children through nationwide annual or biannual mass drug administration largely coordinated through schools. However, a much larger and rapidly growing childhood population in these regions remains untreated and suffering from more than one parasite. Mass drug administration has profound potential for control but is not without considerable challenges and concerns. A principal barrier is funding. Stimulating a research and development pipeline, supporting the necessary clinical trials to refine treatment, in addition to procuring and deploying drugs (and sustaining these supply chains), requires substantial funding and resources that do not presently exist. Limited options for chemotherapy raise concerns about drug resistance developing through overuse, however, satisfactory pharmaco-epidemiology and monitoring for drug resistance requires more developed health infrastructures than are generally available. Further, the limited pharmacopeia does not include any effective second-line options if resistance emerges, and the research and development pipeline is severely depressed. Herein, we discuss the major gastrointestinal protozoa and helminths reviewing their impact on child health, changing epidemiology and how this relates to their control.