Search

Abstract Background A dramatic decline in the incidence of malaria due to Plasmodium falciparum infection in coastal East Africa has recently been reported to be paralleled (or even preceded) by an equally dramatic decline in malaria vector density, despite absence of organized vector control. As part of investigations into possible causes for the change in vector population density, the present study analysed the Anopheles gambiae s.l. sibling species composition in north-eastern Tanzania. Methods The study was in two parts. The first compared current species complex composition in freshly caught An. gambiae s.l. complex from three villages to the composition reported from previous studies carried out 2–4 decades ago in the same villages. The second took advantage of a sample of archived dried An. gambiae s.l. complex specimens collected regularly from a fourth study village since 2005. Both fresh and archived dried specimens were identified to sibling species of the An. gambiae s.l. complex by PCR. The same specimens were moreover examined for Plasmodium falciparum and Wuchereria bancrofti infection by PCR. Results As in earlier studies, An. gambiae s.s., Anopheles merus and Anopheles arabiensis were identified as sibling species found in the area. However, both study parts indicated a marked change in sibling species composition over time. From being by far the most abundant in the past An. gambiae s.s. was now the most rare, whereas An. arabiensis had changed from being the most rare to the most common. P. falciparum infection was rarely detected in the examined specimens (and only in An. arabiensis) whereas W. bancrofti infection was prevalent and detected in all three sibling species. Conclusion The study indicates that a major shift in An. gambiae s.l. sibling species composition has taken place in the study area in recent years. Combined with the earlier reported decline in overall malaria vector density, the study suggests that this decline has been most marked for An. gambiae s.s., and least for An. arabiensis, leading to current predominance of the latter. Due to differences in biology and vectorial capacity of the An. gambiae s.l. complex the change in sibling species composition will have important implications for the epidemiology and control of malaria and lymphatic filariasis in the study area.

Background: Reliable supply of laboratory supportive services contributes significantly to the quality of HIV diagnostic services. This study assessed the status of supply chain management of laboratory supportive services and its potential implications on the quality of HIV diagnostic services in selected districts of Tanzania. Methods: The study was conducted in 39 health facilities (HFs) from eight districts in four regions of Tanzania, namely Iringa, Mtwara, Tabora and Tanga. Facilities with care and treatment centres for HIV/AIDS patients were purposively selected for the study. The study utilized a quantitative method of data collection. A questionnaire was administered to heads of laboratories to obtain information on laboratory supply chain management. Results: A total of 39 health facilities (HF) were included in the study. This included 23 public and 16 private facilities. In 82% of the HFs, ordering of supplies was performed by the laboratory departments. The information commonly used to forecast requirements of the laboratories included the number of tests done (74.4%; n=29), current stock levels (69.2%; n=27), average monthly consumption (64.1%, n=25) and minimum and maximum stock levels (10.2%, n=4). Emergency orders were significantly common in public than private facilities (73.9% vs. 56.3%, p=0.004). Delivery of ordered supplies took 1 to 180 days with a significantly longer mean period for public than private facilities (32.5 vs. 13.1 days, p=0.044). Most of the public HFs ordered supplies from diverse sources compared to private facilities (68.2% vs. 31.8%). Conclusion: There was a weak inventory management system and delays in delivery of supplies in the majority of HFs, which are likely to impede quality of HIV care and treatment. Strengthening capacity for data management and ensure constant supply will potentially improve the quality of HIV diagnostic services. [ABSTRACT FROM AUTHOR]

Background: While donor funding is instrumental in initiation and implementation of malaria control efforts, national government contributions are key to local ownership and sustainability. This study explored in-kind contributions of local government and households towards the cost of indoor residual spraying (IRS) interventions in Tanzania. Methods: Data were collected through interviews with local government officials and technical teams in the IRS project. Household contribution was based on provision of water for IRS. Government contributions included government- provided warehouse and office space, vehicles, and staff labour. In-kind contributions were aggregated at the district, regional and national level. Calculations were based on proportion of total costs of IRS from 2010 to 2012. Results: The mainland government provided larger amounts of in-kind contribution in absolute value (mean of US$454 200) compared to Zanzibar (US$89 163). On average, in-kind contribution was 5.5% of total costs in Zanzibar and 2.9% in mainland. The proportion of government in-kind contribution was higher in Zanzibar versus the mainland (86% vs 50%) while household contribution was higher in mainland compared to Zanzibar (50% vs 14%). Conclusion: Government involvement, particularly through budgetary allocations and increased in-kind contribution, needs to be encouraged for malaria control efforts to be locally owned, managed and sustained. [ABSTRACT FROM AUTHOR]

Background: Strong health laboratory systems and networks capable of providing high quality services are critical components of the health system and play a key role in routine diagnosis, care, treatment and disease surveillance. This study aimed to assess the readiness of the national health laboratory system (NHLS) and its capacity to support care and treatment of HIV/AIDS in Tanzania. Methods: A documentary review was performed to assess the structure of the health system with reference to the status and capacity of the NHLS to support HIV diagnosis. Key informant interviews were also held with laboratory staff in all levels of the health care delivery system in four regions with different levels of HIV prevalence. Information sought included availability and utilization of laboratory guidelines, quality and the capacity of laboratories for diagnosis of HIV. Results: The findings indicate that a well-established NHLS was in place. However, the coordination of HIV laboratory services was found to be weak. Forty six respondents were interviewed. In most laboratories, guidelines for HIV diagnosis were available but health care providers were not aware of their availability. Utilization of the guidelines for HIV diagnosis was higher at national level than at the lower levels. The low level of awareness and utilization of guidelines was associated with inadequate training and supervision. There was a shortage of human resource, mostly affecting the primary health care level of the system and this was associated with inequity in employment and training opportunities. Laboratories in public health facilities were better staffed and had more qualified personnel than private-owned laboratories. Conclusion: Tanzania has a well established national health laboratory network sufficient to support HIV care and treatment services. However, laboratories at the primary health care level are constrained by inadequate resources and operate within a limited capacity. Improving the laboratory capacity in terms of number of qualified personnel, staff training on the national guidelines, laboratory diagnostic tools and coordination should be given a higher priority. [ABSTRACT FROM AUTHOR]

Background: Studies on the East African coast have shown a recent dramatic decline in malaria vector density and change in composition of sibling species of the Anopheles gambiae complex, paralleled by a major decline in malaria incidence. In order to better understand the ongoing changes in vector-parasite dynamics in the area, and to allow for appropriate adjustment of control activities, the present study examined the composition, and malaria and lymphatic filarial infection, of sibling species of the Anopheles funestus group. Similar to the An. gambiae complex, the An. funestus group contains important vectors of both malaria and lymphatic filariasis. Methods: Archived (from 2005-2012) and newly collected (from 2014) specimens of the An. funestus group collected indoors using CDC light traps in villages in northeastern Tanzania were analysed. They were identified to sibling species by PCR based on amplification of species-specific nucleotide sequence in the ITS2 region on rDNA genes. The specimens were furthermore examined for infection with Plasmodium falciparum and Wuchereria bancrofti by PCR. Results: The identified sibling species were An. funestus s.s., Anopheles parensis, Anopheles rivulorum, and Anopheles leesoni, with the first being by far the most common (overall 94.4%). When comparing archived specimens from 2005-2007 to those from 2008-2012, a small but statistically significant decrease in proportion of An. funestus s.s. was noted, but otherwise observed temporal changes in sibling species composition were minor. No P. falciparum was detected in archived specimens, while 8.3% of the newly collected An. funestus s.s. were positive for this parasite. The overall W. bancrofti infection rate decreased from 14.8% in the 2005-2007 archived specimens to only 0.5% in the newly collected specimens, and with overall 93.3% of infections being in An. funestus s.s. Conclusion: The study indicated that the composition of the An. funestus group had remained rather stable during the study period, with An. funestus s.s. being the most predominant. The study also showed increasing P. falciparum infection and decreasing W. bancrofti infection in An. funestus s.s. in the study period, most likely reflecting infection levels with these parasites in the human population in the area. [ABSTRACT FROM AUTHOR]

Background: Lymphatic filariasis (LF) control started in Tanga Region of Tanzania in 2004, with annual ivermectin/ albendazole mass drug administration (MDA). Since then, the current project has monitored the effect in communities and schools in rural areas of Tanga District. In 2013, after 8 rounds of MDA, spot check surveys were added in the other 7 districts of Tanga Region, to assess the regional LF status. Methods: LF vector and transmission surveillance, and human cross sectional surveys in communities and schools, continued in Tanga District as previously reported. In each of the other 7 districts, 2–3 spot check sites were selected and about 200 schoolchildren were examined for circulating filarial antigens (CFA). At 1–2 of the sites in each district, additional about 200 community volunteers were examined for CFA and chronic LF disease, and the CFA positives were re-examined for microfilariae (mf). Results: The downward trend in LF transmission and human infection previously reported for Tanga District continued, with prevalences after MDA 8 reaching 15.5% and 3.5% for CFA and mf in communities (decrease by 75.5% and 89.6% from baseline) and 2.3% for CFA in schoolchildren (decrease by 90.9% from baseline). Surprisingly, the prevalence of chronic LF morbidity after MDA 8 was less than half of baseline records. No infective vector mosquitoes were detected after MDA 7. Spot checks in the other districts after MDA 8 showed relatively high LF burdens in the coastal districts. LF burdens gradually decreased when moving to districts further inland and with higher altitudes. Conclusion: LF was still widespread in many parts of Tanga Region after MDA 8, in particular in the coastal areas. This calls for intensified control, which should include increased MDA treatment coverage, strengthening of bed net usage, and more male focus in LF health information dissemination. The low LF burdens observed in some inland districts suggest that MDA in these could be stepped down to provide more resources for upscale of control in the coastal areas. Monitoring should continue to guide the programme to ensure that the current major achievements will ultimately lead to successful LF elimination. [ABSTRACT FROM AUTHOR]

Background: Long-lasting insecticide treated blankets (LLIBs) may provide additional protection against malaria where use of long lasting insecticidal nets (LLIN) is low or impractical such as in disaster or emergency situations. Methods: Initial efficacy testing of a new candidate LLIB was carried out at LSHTM and KCMUCo, before and after washing, in cone and ball bioassays and arm-in-cage tests against pyrethroid susceptible Anopheles gambiae. A small scale field trial was conducted using veranda-trap experimental huts in northern Tanzania against wild An. arabiensis and Culex quinquefasciatus mosquitoes. Treatments included unwashed and 5 times washed permethrin treated LLIB and blankets hand-treated with permethrin (ITB), untreated blankets, and a holed unwashed Olyset net. Results: Cone test mortality was 75% for LLIB when unwashed, but decreased to 32% after 5 washes and <10% after 10 washes. In arm-in-cage tests protection against biting was 100% for LLIBs regardless of the number of washes while reduction in landings was 79% when unwashed, 75% after 5 washes, but declined to 41% after 10 and 33% after 20 washes. In ball bioassays using pyrethroid resistant An. arabiensis, mortality was low in all treatments (<35%) and there was no significant difference in mortality between Olyset net, LLIB or ITB (p > 0.05). Percentage mortality of An. arabiensis in huts with LLIB unwashed (26%) was not statistically different to Olyset net (31%, p = 0.5). The 5 times washed LLIB reduced blood-feeding by 49% which was equivalent to Olyset net (p > 0.086). There was no significant difference in percentage blood-feeding between LLIB and ITB unwashed or 5 times washed (p = 0.147 and p = 0.346 respectively). The 5 times washed LLIB reduced blood-feeding of Culex quinquefasciatus by 40%, although the Olyset provided the greatest protection with 85% inhibition. ELISA analysis of a sub-sample of blood fed mosquitoes showed that not all had fed on humans in the huts, therefore blood-feeding inhibition may have been underestimated. Conclusions: This trial demonstrated the potential of LLIBs to provide substantial personal protection even against pyrethroid resistant mosquitoes. LLIBs may prove particularly useful where LLINs are unsuitable or net usage is low. [ABSTRACT FROM AUTHOR]

Capacity building is considered a priority for health research institutions in developing countries to achieve the Millennium Development Goals by 2015. However, in many countries including Tanzania, much emphasis has been directed towards human resources for health with the total exclusion of human resources for health research. The objective of this study was to systematically investigate the capacity building process for the Tanzanian National Institute for Medical Research (NIMR) over a 30-year period and identify the challenges and opportunities in creating a critical mass of multi-disciplinary research scientists that is required for achieving the intended health benefits. A desk review of personnel database was conducted for information covering 1980-2009 on academic qualifications, training, research experience and research output. The current staff curriculum vitae (CV) were reviewed to gather information on researchers' employment record, training, training support, area of expertise and scientific output. Interviews were conducted with a cross section of researchers on capacity development aspects using a self-administered questionnaire. In-depth interviews were also conducted with the current and former NIMR Management to seek information on capacity development challenges. A review was also done on staff personal files, annual reports, strategic plans and other occasional documents. A total of 163 CV were assessed; of these, 76.7% (125) were for Research Scientists (RS), 20.9% (34) Laboratory Technologists (LT) and 2.4% (4) for System Analysts. The Institute had 13 research scientists upon its establishment. Since 1980, NIMR has recruited a total of 185 Research Scientists. By 2009, NIMR had a total scientific workforce of 170 staff (RS= 82.4%; LT= 17.6%). Of the 140 RSs, 37 (26.4%) were first degree; 77 (55.5%) second degree while 26 (18.6%) were PhD degree holders. Of the total of 78 researchers interviewed, 55 (70.5%) indicated to have accessed postgraduate training through their personal efforts and 23 through institutional arrangement. Sixty (77%) respondents were satisfied with their tenure at NIMR. Seventy (89%) indicated that they had not at any point considered leaving NIMR. Most (79%) research scientists were recruited while holding a first degree, a few (17%) with second degree while only one (0.7%) holding a PhD degree. NIMR has experienced a research scientist attrition rate of 17.5%. Staff retention factors included availability of training opportunities; passion for conducting research; and good career prospects. Despite having a training programme, the institute has never at any moment been able to hold its own training resources. Being a public research institution, NIMR receives its core funding from the government of the United Republic of Tanzania. The bulk of the funding appears to be spent on personnel emoluments that take up to 85% (mean= 66%) of the allocated budget. In conclusion, the current NIMR's research capacity building is dependent mainly on foreign funding and personal initiatives. There is an urgent need to increase local funding for capacity building and conduct of research. A programme should be put in place to ensure sustainability of the capacity building process. [ABSTRACT FROM AUTHOR]

Malaria transmission varies from one area to another and there are also local difference in time and space. The objective of the study was to determine the local variability of entomological parameters namely, mosquito abundance, human biting rate (HBR), sporozoite rate for Plasmodium falciparum and entomological inoculation rate (EIR). The study was carried out in Rufiji District south eastern Tanzania from October 2001 and September 2004. Adult mosquitoes were collected indoors by CDC light traps. PCR was employed to identify the species within the Anopheles gambiae complex. ELISA was used to determine the sporozoite rate. Over a three year sampling period a total of 64,875 female mosquitoes were caught using light-traps, and of these 28% were Anopheles gambiae complex, 25% An. funestus Giles, 1% An. pharoensis Theobald, 46% Culex species and the rest were Mansonia uniformis Theobald. Mosquito abundance and species composition varied seasonally, spatially and between years. Using PCR, three members of the Anopheles gambiae complex namely An. gambiae s.s. Giles (69%), An. arabiensis Paton (23%) and An. merus Dönitz (7%) were confirmed to occur in the study area. Plasmodium falciparum circumsporozoite antigen (CSA) rates were 3.5% for An. gambiae complex and 2.3% for An. funestus. The mean EIR ranged from 28-275 infective bites/person/year. Transmission indices varied over short distances, seasonally and between years. In conclusion, malaria transmission indices in the study area are one of the highest in Tanzania; and there is high variability of entomological parameters over a small geographical area. [ABSTRACT FROM AUTHOR]

An entomological survey to determine resting behaviour and species composition of malaria vectors was carried out in Uyui District in western Tanzania in May 2009. Mosquitoes were collected using indoor resting catch, window exit trap and outdoor "bed-net" techniques. They mosquitoes were identified using morphological key and polymerase chain reaction (PCR). A total of 672 Anopheles gambiae sensu lato were collected. Of these, 661 (98.4%) were collected outdoor whereas few (1.6%) were collected indoor. The exit trap catch: mechanical aspirator catch ratio was 1:1.75. The overall indoor resting density of An. gambiae s.l. as determined by mechanical aspirator and exit trap was 0.7 and 0.5 mosquitoes per room, respectively. The overall density of the host-seeking as determined by bed net trap outdoor was 44.1 mosquitoes per person. A sample of 44 specimens taken randomly from morphologically identified An.gambiae s.l. population was further analyzed to species level using PCR techniques. Of these 44 specimens 26 (59%) and 18 (41%) were Anopheles arabiensis and Anopheles gambiae sensu stricto respectively. This study contributes to the understanding of the distribution of malaria vectors with respect to species composition and their resting behaviour that could contribute to vector control operations in western Tanzania. A longitudinal study considering dry and wet seasons is recommended to provide more information on the seasonal distribution, abundance and biting behaviour of malaria vectors in the study area. [ABSTRACT FROM AUTHOR]

Abstract: In most countries of Sub-Saharan Africa the control of lymphatic filariasis (LF) is based on annual mass drug administration (MDA) with a combination of ivermectin and albendazole, in order to interrupt transmission. We monitored the effect of four repeated MDAs with this combination, as implemented by the Tanzanian National Lymphatic Filariasis Elimination Programme (NLFEP), on the circulating filarial antigen (CFA) status of young schoolchildren. A new batch of Standard 1 pupils from 10 rural primary schools in Tanga Municipality were examined for CFA each year in September/October (691–848 children per survey; mean age of 7.5–8.1 years), from immediately before the first MDA until eight months after the fourth MDA. The overall pre-MDA prevalence of CFA was 25.2%. Only minor and non-significant change in prevalence was seen after the first two MDAs. However, this was followed by substantial and statistically significant decreases in subsequent surveys, and eight months after the fourth MDA the prevalence was only 6.4%. Continuous entomological surveillance in a village accommodating one of the schools showed progressive decrease in transmission right from the first MDA. The usefulness of screening young schoolchildren for CFA as a tool for monitoring the impact of MDA on LF transmission is discussed. [Copyright &y& Elsevier]

A 1-year longitudinal study was conducted in Magugu in Babati district, northern Tanzania to determine malaria vector population structure and malaria transmission indices. Mosquitoes were sampled using the Centre for Disease Control (CDC) light traps. A total of 110,357 adult female mosquitoes were collected. Anopheles gambiae s.l. accounted 25% of the total female mosquito collected. Relatively fewer An. funestus were collected. Other mosquito species collected were An. pharoensis, An. coustani, An. maculipalpis, An. marshallii, Culex quinquefasciatus, Cx unnivittatus, Mansonia uniformis and Ma. africana. An analysis by Polymerase Chain Reaction revealed that An. arabiensis was the only member of the An. gambiae complex in the collected samples. The number of mosquito collected correlated with the increasing mean rainfall. Blood meal analysis showed a higher human enzymatic reaction among An. gambiae s.l. (63.5%) followed by An. funestus (42.9%). Bovine enzymatic reaction was higher among An. coustani (73.7%) followed by the An. pharoensis (66.7%). The Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Plasmodium falciparum circumsporozoites proteins in 10,000 female Anopheles mosquitoes. Only two An. arabiensis were found to be infected. The entomological inoculation rate (EIR) was estimated at 0.51 infectious bites per person per year. This EIR was considered to be relatively low, indicating that malaria transmission in this area is low. Variability in mosquito blood meal shows availability of variety of preferred blood meal choices and impact of other factors inhibiting mosquito--human host contact. The study has provided information considered useful in the mapping of the vector distribution and population structure in the country. Such information is considered to be among the essential tools for planning malaria control interventions. [ABSTRACT FROM AUTHOR]

Globally, tuberculosis-HIV co-infections are on the increase. In 2007, 15% (1.37 million) of the tuberculosis cases were HIV-positive tuberculosis (TB). This cross-sectional study was conducted in February 2009 to assess the effect of the level of CD4 lymphocyte counts on the development of smear positive pulmonary TB (PTB) among HIV patients before and after initiation of highly active antiretroviral therapy (HAART). A total of 155 HIV patients who were on HAART programme were enrolled and out of these 42 (27.1%) were smear positive PTB. Of the 42 PTB patients, 38 (90.5%) were also infected with HIV and were already at initiation of HAART. There was no association between the development of smear positive PTB and socio-demographic characteristics among HIV patients before and after HAART initiation (P>0.05). A larger proportion of HIV+PTB patients diagnosed before and after HAART initiation was found with CD4 lymphocyte count <200cells/µl. However, the difference was not statistically significant (P =0.092). Among HIV patients who were diagnosed to be smear positive PTB after HAART initiation, their CD4 lymphocyte counts at time of TB diagnosis was lower than their CD4 lymphocyte counts at time of HAART initiation. The four patients diagnosed with PTB after HAART initiation had mean CD4 lymphocyte counts at HAART initiation not statistically different from that at TB diagnosis (t=0.715, P=0.526). The median time period within which the diagnosis of smear positive PTB was made after HAART initiation was 22 weeks and the mean time was 66.75 weeks. These findings provide evidence that development of smear positive PTB after HAART initiation may occur at any level of CD4 lymphocyte count (P<0.05). This study was limited by the relatively small sample size, we therefore recommend more studies involving a larger sample size in order to estimate more accurately the effect of both level of CD4 lymphocyte count and HAART on the development of smear positive PTB among HIV patients on treatment. [ABSTRACT FROM AUTHOR]

Summary: 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. [Copyright &y& Elsevier]

The long-term effect of three different strategies for mass diethylcarbamazine (DEC) administration in bancroftian filariasis was assessed 10 years after start of treatment in three endemic communities in Tanzania. The strategies were the standard 12 day treatment (strategy I); a semi-annual single-dose treatment (strategy II); and a monthly low-dose treatment (strategy III). Treatment was given only during the first year. Following reductions immediately after treatment, overall community microfilaraemia levels were approaching pre-treatment levels in all three communities, 10 years later. In individuals who were microfilaria-positive and treated at baseline, the treatment had a long-term effect on microfilarial intensities, with geometric mean intensities being only 11%, 13% and 2% of pre-treatment levels 10 years later for strategies I, II and III, respectively. This suppressive effect was most pronounced for strategy III, which also cleared microfilaraemia and circulating filarial antigenaemia in a larger proportion of treated individuals than the other strategies. Most of the follow-up individuals who developed microfilaraemia between 2 and 10 years after start of treatment had also been microfilaraemic before treatment, suggesting that reappearance of microfilaraemia may be due to surviving female worms and/or that previously microfilaraemic individuals have a higher chance of reinfection than previously amicrofilaraemic individuals. [Copyright &y& Elsevier]

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 μg/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. [Copyright &y& Elsevier]