Co-endemicity of Plasmodium falciparum and Intestinal Helminths Infection in School Age Children in Rural Communities of Kwara State Nigeria

Background

Malaria and intestinal helminths co-infection are major public health problems particularly among school age children in Nigeria. However the magnitude and possible interactions of these infections remain poorly understood. This study determined the prevalence, impact and possible interaction of Plasmodium falciparum and intestinal helminths co-infection among school children in rural communities of Kwara State, Nigeria.

Methods

Blood, urine and stool samples were collected from 1017 primary school pupils of ages 4–15 years. Stool samples were processed using both Kato-Katz and formol-ether concentration techniques and microscopically examined for intestinal helminths infection. Urine samples were analyzed using sedimentation method for Schistosoma haematobium. Plasmodium falciparum was confirmed by microscopy using thick and thin blood films methods and packed cell volume (PCV) was determined using hematocrit reader. Univariate analysis and chi-square statistical tests were used to analyze the data.

Results

Overall, 61.2% of all school children had at least an infection of either P. falciparum, S. haematobium, or intestinal helminth. S. haematobium accounted for the largest proportion (44.4%) of a single infection followed by P. falciparum (20.6%). The prevalence of malaria and helminth co-infection in the study was 14.4%. Four species of intestinal helminths were recovered from the stool samples and these were hookworm (22.5%), Hymenolepis species (9.8%), Schistosoma mansoni (2.9%) and Enterobius vermicularis (0.6%). The mean densities of P. falciparum in children co-infected with S. haematobium and hookworm were higher compared to those infected with P. falciparum only though not statistically significant (p = 0.062). The age distribution of both S. haematobium (p = 0.049) and hookworm (p = 0.034) infected children were statistically significant with the older age group (10–15 years) recording the highest prevalence of 47.2% and 25% respectively. Children who were infected with S. haematobium (RR = 1.3) and hookworm (RR = 1.4) have equal chances of being infected with P. falciparum as children with no worm infection. On the other hand children infected with Hymenolepis spp. (p<0.0001) are more likely to be infected with P. falciparum than Hymenolepis spp. uninfected children (RR = 2.0)

Conclusions

These findings suggest that multiple parasitic infections are common in school age children in rural communities of Kwara State Nigeria. The Hymenolepis spp. induced increase susceptibility to P. falciparum could have important consequences on how concurrent infections affect the expression or pathogenesis of these infections.     

Combined Utilisation of Rapid Assessment Procedures for Loiasis (RAPLOA) and Onchocerciasis (REA) in Rain forest Villages of Cameroon

BACKGROUND: Individuals with high microfilarial loads of Loa loa are at increased risk of neurologic serious adverse (SAE) events following ivermectin treatment against onchocerciasis. RAPLOA (Rapid Assessment Procedure for loiasis), a newly developed rapid assessment procedure for loiasis that relates the prevalence of key clinical manifestation of loiasis (history of eye worm) to the level of endemicity of the infection (prevalence of high intensity), is a very useful tool to identify areas at potential risk of L. loa post ivermectin treatment encephalopathy. In a perspective of treatment decision making in areas of co-endemicity of loiasis/onchocerciasis, it would be advantageous (both in time and cost savings) for national onchocerciasis control programmes to use RAPLOA and the Rapid epidemiologic assessment for onchocerciasis (REA), in combination in given surveys. Since each of the two rapid assessment tools have their own specificities, the workability of combining the two methods needed to be tested. METHODS: We worked in 10 communities of a forest area presumed co-endemic for loiasis and onchocerciasis in the North-West Province of Cameroon where the mass-treatment with ivermectin had not been carried out. A four-step approach was used and comprised: (i) generating data on the prevalence and intensity of loiasis and onchocerciasis in an area where such information is scarce; (ii) testing the relationship between the L. loa microfilaraemia prevalence and the RAPLOA prevalence, (iii) testing the relationship between the O. volvulus microfiladermia prevalence and the REA prevalence, (iv) testing the workability of combining RAPLOA/REA by study teams in which a single individual can perform the interview for RAPLOA and the nodule palpation for REA. RESULTS: The microfilaraemia prevalence of loiasis in communities ranged from 3.6% to 14.3%. 6 (0.61%) individuals had L. loa microfilarial loads above 8000 mf/ml but none of them attained 30,000 mf/ml, the threshold value above which the risk of developing neurologic SAE after ivermectin treatment is very high. None of the communities surveyed had RAPLOA prevalence above 40%. All the communities had microfiladermia prevalence above 60%. The microfiladermia results could be confirmed by the rapid epidemiologic method (nodule palpation), with all the 10 communities having REA prevalence above 20%. For the first time, this study has demonstrated that the two rapid assessment procedures for loiasis and onchocerciasis can be carried out simultaneously by a survey team, in which a single individual can administer the questionnaire for RAPLOA and perform the nodule palpation for REA. CONCLUSION: This study has: (i) Revealed that the Momo valley of the North West province of Cameroon is hyperendemic for onchocerciasis, but is of lower level of endemicity for L. loa. (ii) Confirmed the previous relationships established between RAPLOA and the L. loa microfilaraemia prevalence in one hand and between the REA and the O. volvulus microfiladermia prevalence in another hand (iii) Shown that RAPLOA and REA could be used simultaneously for the evaluation of loiasis and onchocerciasis endemicity in areas targeted by the African Programme for onchocerciasis Control for community-directed treatment with ivermectin (CDTI).     

Exploring the Phylogenetic Structure of Ecological Communities: An Example for Rain Forest Trees

Because of the correlation expected between the phylogenetic relatedness of two taxa and their net ecological similarity, a measure of the overall phylogenetic relatedness of a community of interacting organisms can be used to investigate the contemporary ecological processes that structure community composition. I describe two indices that use the number of nodes that separate taxa on a phylogeny as a measure of their phylogenetic relatedness. As an example of the use of these indices in community analysis, I compared the mean observed net relatedness of trees (>/=10 cm diameter at breast height) in each of 28 plots (each 0.16 ha) in a Bornean rain forest with the net relatedness expected if species were drawn randomly from the species pool (of the 324 species in the 28 plots), using a supertree that I assembled from published sources. I found that the species in plots were more phylogenetically related than expected by chance, a result that was insensitive to various modifications to the basic methodology. I tentatively infer that variation in habitat among plots causes ecologically more similar species to co-occur within plots. Finally, I suggest a range of applications for phylogenetic relatedness measures in community analysis.     

Programmatic and Communication Issues in Relation to Serious Adverse Events Following Ivermectin Treatment in areas Co-endemic for Onchocerciasis and Loiasis

In areas co-endemic for loiasis and onchocerciasis, the classic Community-Directed Treatment using ivermectin (Mectizan(R)) must be adapted as additional program activities, better communication and tighter control of ivermectin stocks are required to minimize risk and manage serious adverse events following ivermectin treatment in patients co-infected with Loa loa. The importance of these serious adverse events on community participation in onchocerciasis control efforts has not been adequately studied. Program implementers do not as of yet fully understand the psychological impact of serious adverse events on communities and therefore have not designed communication strategies that adequately address the real concerns of community members. It is clear, however, that along with an effective case detection and management strategy, a reinforced communication strategy will be required to motivate at least 65% of the total population in onchocerciasis and loiasis co-endemic areas to participate in the treatment program and to take ivermectin over an extended period. This strategy must be based on research undertaken at the community level in order to address the concerns, fears and issues associated with adverse events due to ivermectin - to ensure that communities believe that the benefits of taking ivermectin outweigh the risks. In addition to an overall increase in the time required to sustain onchocerciasis control programs in co-endemic areas, each aspect of the reinforced program and communication strategy - rapid epidemiological assessments, materials development, training, advocacy, community sensitization and mobilization, case management and counselling, supervision, monitoring and evaluation will require additional resources and support from all stakeholders concerned.     

High Noon in the Rain Forest

Guido Boggiani. Fotograf. Fotografo. Fotografo. Photographer. Pavel Fric and Yvonna Fricova. eds. Nakladatelsvi Titanic, Praha, 1997. 82 photographs. 137 pp. Text and captions are in Czech, Italian, Spanish, Portuguese, and English.     

Clinical profile of parkinsonism and Parkinson's disease in Lagos, Southwestern Nigeria

Background  

Current data on the pattern of parkinsonism and Parkinson's disease in Nigerians are sparse.     

Exploring Consumer Perceptions and Economic Burden of Onchocerciasis on Households in Enugu State,South-East Nigeria

Introduction

Onchocerciasis or river blindness constitutes a major burden to households especially in resource-poor settings, causing a significant reduction in household productivity. There has been renewed interest from policy makers to reduce the burden of Neglected Tropical Diseases (NTDs) such as onchocerciasis on individuals and households. This paper provides new information on the patient’s perceptions of onchocerciasis and its economic burden on households in South-eastern Nigeria. The information will be useful to health providers and policy makers for evidence-informed resource allocation decisions.

Methods

Information was generated from a cross-sectional household survey conducted in Achi community, Oji River Local Government Area (LGA) of Enugu State, Southeast Nigeria. A pre-tested interviewer-administered questionnaire was used to collect data. A total of 747 households were visited randomly and data were collected using pre-tested interviewer administered questionnaire from 370 respondents. The respondents’ knowledge of the cause of symptoms of the disease, costs incurred for seeking treatment and productivity losses were elicited. Data were analyzed using tabulations and inferential statistics. A socio-economic status (SES) index was used to disaggregate some key variables by SES quintiles for equity analysis.

Results

Many people had more than one type of manifestation of onchocerciasis. However, more than half of the respondents (57%) had no knowledge of the cause of their symptoms. Male respondents had significantly more knowledge of the cause of symptoms than females (P = 0.04) but knowledge did not differ across SES (P = 0.82). The average monthly treatment cost per respondent was US$ 14.0. Drug cost (US$10) made up about 72% of total treatment cost. The per capita productivity loss among patients was US$16 and it was higher in the poorest (Q1) (US$20) and the third SES quintiles (Q3) (US$21). The average monthly productivity loss among caregivers was US$3.5.

Conclusion

Onchocerciasis still constitutes considerable economic burden on patients due to the high cost of treatment and productivity loss. Prioritizing domestic resource allocation for the treatment of onchocerciasis is important for significant and sustained reduction in the burden of the disease. In addition, focused health promotion interventions such as health education campaigns should be scaled up in onchocerciasis-endemic communities.     

Ants of Forest and Fallow Plots in Nigeria1

Pitfall traps were used to monitor the activity of ants in a forest floor and a one-year-old fallow plot in Ile-Ife, Nigeria, at monthly intervals between November 1980 and October 1981. Similar studies were carried out between October 1987 and June 1988. These studies also included manual collection of ants from the floor of the experimental plots Of all the 10 species of ants recorded, Pbeihk crassinoda was the most abundant in the forest and fallow plots both in 1980–81 and 1987–88. P. crassinoda accounted for 52 percent and 88 percent of the ant populations collected manually from the forest and fallow plots respectively between December 1987 and June 1988. This species was also significantly higher in the pitfall catches of the fallow than the forest plots. Pitfall traps were not effective in sampling the populations of the belligerent Dorylus nigricans. The data are consistent with the widely accepted notion that forested areas support less ants than unforested areas. Differences in physical habitat characteristics, food availability, nesting habits, predation and microenvironmental factors were considered responsible for the differences in activities and abundance of ants in the forest and fallow plots.     

Studies on epiphytic flora of a tropical rain forest in Southwestern Nigeria

A survey of epiphytes in Gambari Forest Reserve in Southwestern Nigeria was undertaken. A total of 26 epiphytes were recorded. These include five pteridophytes and 21 angiosperm species belonging to the following families; Acanthaceae, Araceae, Asteraceae, Commelinaceae, Moraceae, Orchidaceae, Palmae, Urticaceae Piperaceae, and Portulacaceae. The smooth-barked phorophytes had only one or two epiphytes on them because they are unable to accumulated dust, debris and moisture for germination and growth of the epiphytes. The palm trees with rough barks had points at which they can collect soil, nutrients and moisture for epiphytic growth, hence all the epiphytic species recorded on the site were present on palm trees. Presence of many of the epiphytes is thought to be due to the availability of propagules from reproducing adults in the surrounding vegetation. Also, epiphytes appear to have a dressing effect on the palm trees.     

Studies on epiphytic flora of a tropical rain forest in Southwestern Nigeria

Bark microflora of 12 rainforest trees were examined. Crustose, foliose, and fruticose forms of lichens were observed. Bacillus sp., Erwinia sp., Micrococcus sp., Proteus sp., and Pseudomonas sp. were the five genera of bacteria recorded while three genera of Cyanobacteria; Entophysalis, Gleocapsa and Stigonema were observed. In the algal division, three genera of Chlorophyta found are Chlorococcum, Pleurococcus and Physolinum. Only one diatom, Cocconeis sp. was present on just one tree. Most of the epiphytic microflora found are mainly terrestrial and their spores might have been deposited on the barks by air, or dust-currents. While moisture is regarded as the most critical factor in growth of bark microflora, other factors like texture of the bark, insolation and especially chemical characteristics of the barks may play a key role in occurrence and distribution of micro-organisms on them.     

游弋在热带雨林里的旗舰

展现在您眼前的神态各异的亚洲象,是热带雨林里的“旗舰种”。西双版纳拥有这样一个显赫的标志种．是大自然赐予的福分和财富。     

Forest Invasibility in Communities in Southeastern New York

While biological invasions have been the subject of considerable attention both historically and recently, the factors controlling the susceptibility of communities to plant invasions remain controversial. We surveyed 44 sites in southeastern New York State to examine the relationships between plant community characteristics, soil characteristics, and nonnative plant invasion. Soil nitrogen mineralization and nitrification rates were strongly related to the degree of site invasion (F= 30.2, P < 0.0001 and F= 11.8, P < 0.005, respectively), and leaf C : N ratios were negatively correlated with invasion (R ²= 0.22, P < 0.0001). More surprisingly, there was a strong positive relationship between soil calcium levels and the degree of site invasion (partial r= 0.70, P < 0.01), and there were also positive relationships between invasion and soil magnesium and phosphorus. We found, in addition, a positive factor-ceiling relationship between native species diversity and invasive species diversity. This positive relationship between native and invasive diversity contradicts earlier hypotheses concerning the relationships between species diversity and invasion, but supports some recent findings. Cluster analysis distinguished two broad forest community types at our sites: pine barrens and mixed hardwood communities. Invaders were significantly more abundant in mixed hardwood than in pine barrens communities (Mann–Whitney U = 682.5, P < 0.0001). Even when evaluating the mixed hardwood communities alone, invasion remained significantly positively correlated with soil fertility (calcium, magnesium, and net nitrogen mineralization rates). Soil texture and pH were not useful predictors of the degree to which forests were invaded. Nitrogen and calcium are critical components of plant development, and species better able to take advantage of increased nutrient availability may out-perform others at sites with higher nutrient levels. These results have implications for areas such as the eastern United States, where anthropogenic changes in the availability of nitrogen and calcium are affecting many plant communities.     

Seasonal Variation in Seed Dispersal by Tamarins Alters Seed Rain in a Secondary Rain Forest

Reduced dispersal of large seeds into degraded areas is one of the major factors limiting rain forest regeneration, as many seed dispersers capable of transporting large seeds avoid these sites with a limited forest cover. However, the small size of tamarins allows them to use small trees, and hence to disperse seeds into young secondary forests. Seasonal variations in diet and home range use might modify their contribution to forest regeneration through an impact on the seed rain. For a 2-yr period, we followed a mixed-species group of tamarins in Peru to determine how their role as seed dispersers in a 9-yr-old secondary-growth forest varied across seasons. These tamarins dispersed small to large seeds of 166 tree species, 63 of which were into a degraded area. Tamarins’ efficiency in dispersing seeds from primary to secondary forest varied across seasons. During the late wet season, high dietary diversity and long forays in secondary forest allowed them to disperse large seeds involved in later stages of regeneration. This occurred precisely when tamarins spent a more equal amount of time eating a high diversity of fruit species in primary forest and pioneer species in secondary forest. We hypothesized that well-balanced fruit availability induced the movement of seed dispersers between these 2 habitats. The noteworthy number of large-seeded plant species dispersed by such small primates suggests that tamarins play an important, but previously neglected, role in the regeneration and maintenance of forest structure.     

Richness and Abundance of Ichneumonidae in a Fragmented Tropical Rain Forest

Because of the magnitude of land use currently occurring in tropical regions, the local loss of animal species due to habitat fragmentation has been widely studied, particularly in the case of vertebrates. Many invertebrate groups and the ichneumonid wasps in particular, however, have been poorly studied in this context, despite the fact that they are one of the most species-rich groups and play an important role as regulators of other insect populations. Here, we recorded the taxonomic composition of ichneumonid parasitoids and assessed their species richness, abundance, similarity, and dominance in the Los Tuxtlas tropical rain forest, Mexico. We compared two forest types: a continuous forest (640 ha) and a forest fragment (19 ha). We sampled ichneumonids using four malaise traps in both forest types during the dry (September–October) and rainy (March–April) seasons. A total of 104 individuals of Ichneumonidae belonging to 11 subfamilies, 18 genera, and 42 species were collected in the continuous forest and 11 subfamilies, 15 genera, and 24 species were collected in the forest fragment. Species richness, abundance, and diversity of ichneumonids were greater in the continuous forest than in the forest fragment. We did not detect differences between seasons. Species rank/abundance curves showed that the ichneumonid community between the forest types was different. Species similarity between forest types was low. The most dominant species in continuous forest was Neotheronia sp., whereas in the forest fragment, it was Orthocentrus sp. Changes in the ichneumonid wasp community may compromise important tropical ecosystem processes.     

Status of Onchocerciasis Transmission after More Than a Decade of Mass Drug Administration for Onchocerciasis and Lymphatic Filariasis Elimination in Central Nigeria: Challenges in Coordinating the Stop MDA Decision

Background

This study was undertaken in five onchocerciasis/lymphatic filariasis (LF) co-endemic local government areas (LGAs) in Plateau and Nasarawa, Nigeria. Annual MDA with ivermectin had been given for 17 years, 8 of which were in combination with albendazole. In 2008, assessments indicated that LF transmission was interrupted, but that the MDA had to continue due to the uncertain status of onchocerciasis transmission. Accordingly, assessments to determine if ivermectin MDA for onchocerciasis could be stopped were conducted in 2009.

Methods

We evaluated nodule, microfilarial (mf) skin snip, and antibody (IgG4 response to OV16) prevalence in adults and children in six sentinel sites where baseline data from the 1990s were available. We applied the 2001 WHO criteria for elimination of onchocerciasis that defined transmission interruption as an infection rate of <0.1% in children (using both skin snip and OV16 antibody) and a rate of infective (L3) blackflies of <0.05%.

Results

Among adult residents in sentinel sites, mean mf prevalence decreased by 99.37% from the 1991–1993 baseline of 42.95% (64/149) to 0.27% (2/739) in 2009 (p<0.001). The OV16 seropositivity of 3.52% (26/739) among this same group was over ten times the mf rate. No mf or nodules were detected in 4,451 children in sentinel sites and ‘spot check’ villages, allowing the exclusion of 0.1% infection rate with 95% confidence. Seven OV16 seropositives were detected, yielding a seroprevalence of 0.16% (0.32% upper 95%CI). No infections were detected in PCR testing of 1,568 Simulium damnosum s.l. flies obtained from capture sites around the six sentinel sites.

Conclusion

Interruption of transmission of onchocerciasis in these five LGAs is highly likely, although the number of flies caught was insufficient to exclude 0.05% with 95% confidence (upper CI 0.23%). We suggest that ivermectin MDA could be stopped in these LGAs if similar results are seen in neighboring districts.     

Effects of Forest Fragmentation on Pteridophyte Diversity in a Tropical Rain Forest in Brazil

The impacts of forest fragmentation on the pteridophyte communities of the Una region of Bahia, Brazil, were investigated by comparing species richness and ensemble diversity among areas of large forest fragments (>900 ha), small forest fragments (<100 ha), and landscape matrix. We inventoried the pteridophytes below 1 m in height in interiors of small fragments, interiors of large fragments (control areas), edges of fragments, edges of continuous forest, capoeiras (initial stages of forest regeneration) and cabrucas (cocoa plantations). All ferns were collected following the plot method (plots of 120×10 m, each). Sampling units were established in the six main ecotypes of the Una region. These units were allocated within three sampling blocks of 5 per 5 km, which were chosen in order to include the largest forest patches that still remain. Results suggest that fragmentation has a negative impact on species richness at the matrix and the edges of forest remnants. A similar negative matrix end edge effect is reported for diversity of those sites measured by the α Log-series Index. However, small forest fragments have pteridophyte species richness and diversity rates similar to large ones so they should be considered of utmost importance to the conservation of forest-related species in the region.     

Effect of Bat Exclusion on Patterns of Seed Rain in Tropical Rain Forest in French Guiana

To assess the impact of bats on seed dispersal in a tropical mature forest (Nouragues, French Guiana), we conducted a bat exclusion experiment and tested the hypotheses that an artificial reduction in the abundance of bats would result in: (1) a decrease in seed species diversity, at the community level; and (2) an increase in seed limitation (a failure of seeds to reach all suitable sites for germination) at the species level. Seed rain was sampled in two contiguous forest plots for a total of 120 d, using 49 seed traps (1 m²) arranged in 7 × 7 grids and spaced at 5-m intervals. Using mist nets, bat activity was reduced in one forest plot for a total of 60 nights. Thirty-nine plant species, or species groups, likely to be consumed and dispersed by bats, were collected within a total sample of 50,063 seeds. The overall seed rain was dominated by epiphytic Araceae and Cyclanthaceae (83.3%) and tree species within the genera Cecropia and Ficus (16.0%). Seeds from bat-dispersed shrubs and treelets ( Piper , Solanum , and Vismia ) were relatively rare (0.7%). The bat exclusion resulted in a 30.5 percent reduction in seed species richness and increased seed limitation for most of the species sampled. Seed limitation was caused mainly by a reduced seed rain (seed source limitation) rather than a decrease in seed dispersal uniformity (seed dispersal limitation). Therefore, bat-dispersed plants with low seed production are likely to be particularly affected by a decline in bat abundance, as a result of anthropogenic change.