Reduction in the proportion of fevers associated with Plasmodium falciparum parasitaemia in Africa: a systematic review

BACKGROUND: Malaria is almost invariably ranked as the leading cause of morbidity and mortality in Africa. There is growing evidence of a decline in malaria transmission, morbidity and mortality over the last decades, especially so in East Africa. However, there is still doubt whether this decline is reflected in a reduction of the proportion of malaria among fevers. The objective of this systematic review was to estimate the change in the Proportion of Fevers associated with Plasmodium falciparum parasitaemia (PFPf) over the past 20 years in sub-Saharan Africa. METHODS: Search strategy. In December 2009, publications from the National Library of Medicine database were searched using the combination of 16 MeSH terms.Selection criteria. Inclusion criteria: studies 1) conducted in sub-Saharan Africa, 2) patients presenting with a syndrome of 'presumptive malaria', 3) numerators (number of parasitologically confirmed cases) and denominators (total number of presumptive malaria cases) available, 4) good quality microscopy.Data collection and analysis. The following variables were extracted: parasite presence/absence, total number of patients, age group, year, season, country and setting, clinical inclusion criteria. To assess the dynamic of PFPf over time, the median PFPf was compared between studies published in the years ≤2000 and > 2000. RESULTS: 39 studies conducted between 1986 and 2007 in 16 different African countries were included in the final analysis. When comparing data up to year 2000 (24 studies) with those afterwards (15 studies), there was a clear reduction in the median PFPf from 44% (IQR 31-58%; range 7-81%) to 22% (IQR 13-33%; range 2-77%). This dramatic decline is likely to reflect a true change since stratified analyses including explanatory variables were performed and median PFPfs were always lower after 2000 compared to before. CONCLUSIONS: There was a considerable reduction of the proportion of malaria among fevers over time in Africa. This decline provides evidence for the policy change from presumptive anti-malarial treatment of all children with fever to laboratory diagnosis and treatment upon result. This should insure appropriate care of non-malaria fevers and rationale use of anti-malarials

Evaluation and Validation of the Questionnaire Approach for the Diagnosis of Urinary Schistosomiasis amongst Nigerian School Pupils

Urinary schistosomiasis is endemic in some parts of Cross River State, in Nigeria. Due to the prohibitive cost of diagnosis and the focal nature of the disease, endemic areas cannot be easily delineated for control operations. In this study, we report the outcome of our assessment of the newly introduced questionnaire approach in the diagnosis of urinary schistosomiasis amongst 5,453 pupils and also validated its performance among a subset of 310 pupils in Biase Local Government Area. The questionnaire which enquired whether pupils had urinary schistosomiasis or blood in their urine in the preceding month, was administered by class teachers to the pupils. Urine samples collected for the validation of the questionnaire diagnosis was also examined using dipsticks (by teachers and the research team) and for the presence of ova of Schistosoma haematobium. There was a strong positive correlation between the pupil's knowledge of schistosomiasis as a disease and the reported presence of blood in urine (r=0.96) although the later was a better indicator of the disease. The questionnaire technique (blood in urine) gave a comparable sensitivity (85.8%), specificity (81.4%), positive and negative predictive values (96.6% and 47.9%) to the dipstick test with values of 93.6%, 88.4%, 98% and 69.1% respectively. Age had a statistically significant influence on the results of the different survey techniques (P 0.05). Teachers were able to detect haematuria with a high level of accuracy. We found this approach to be simple, cost-effect and reliable and have recommended its usage in other endemic settings with large land mass and dense populations like Nigeria. Key Words: Schistosomiasis, Diagnosis, Questionnaire, Cross River , Nigeria. Mary Slessor Journal of Medicine Vol.4(1) 2004: 63-7

Assessment of the Efficacy of Deltamethrin Impregnated Bed Nets for the Control of Malaria Infection in Ono Village, Akwa Ibom State Nigeria

The impact of deltamethrin treated bednets and walls were assessed on school children aged 12-18 years, in a community secondary school in Ono, Nigeria. Children with body weights of 45-60kg were given 2 tablets of fansidar to clear parasites in their system while those with body weights of 60kg and above were given 3 tablets each. The school children who tested negative for malaria after two weeks were enrolled for the study. These subjects were divided into four groups – control, users of ordinary bednets, deltamethrin-treated nets and, deltamethrin-treated nets and walls. Deltamethrin concentration of 20 ml per 5 liters of water was used for wall treatment while 25ml per 5 liters of water was used for nets. Packed cell volume (P.C.V.) was determined using microhaematocrit centrifuge method to access the level of anaemia with parasitaemia. Entomological surveillance was carried out on monthly bases in both the control and intervention dormitori9es. After eight months of close monitoring, the control group had a cumulative infection rate of 59% with mean haemoglobin percentage of 29.6±0.2 gm%; deltamethruin treated nets 25.0%, mean haemoglobin 34.6gm% and deltamethrin treated nets and walls act as a barrier to prevent human vector contact as well as killing the mosquito that come in contact with the nets and walls. Hence there is marked increase in the haemoglobin percentage and health of the subjects thus leading to improved performance in examination results. Children living in mosquito endemic areas should be encouraged to use pyrethroid treated mosquito nets since they have been proved to have no side effects and the chemicals are found to be biodegradable. Mary Slessor Journal of Medicine Vol.3(2) 2003: 57-6

Hydrological and rainfall patterns of Simuliumbreeding sites at Ugbem and Ukwepeyiere communities in Biase Local Government Area of Cross River State, Nigeria

No Abstract

Histochemical Characterization of Rain-Forest Strain of Onchocerca Volvulus Microfilariae Isolated in Akamkpa, Cross River State, Nigeria.

Abstract: The histochemical characterization of rain-forest strain of Onchocerca volvulus isolated in Akamkpa of Cross River State, Nigeria was studied. In a preliminary survey of 350 persons from eight villages, 75(21.4%) were found to be positive for the parasite. Males (23.6%) were more infected than the females but there was no statistically significant difference in the presence of infection by gender (p=0.506). Staining pattern of the parasite using Lead nitrate method for the demonstration of acid phosphatase activity revealed that of the six patterns, four corresponded to the enzyme types already described by some authors in West African rain-forest, and Sudan. One corresponded to the type found in Guinea savannas while the remaining did not correspond to any of the strains described elsewhere. The multiple enzyme staining patterns of Onchocerca volvulus microfilariae in the study area is indicative of polymorphic strain than that of West African strains. This variation in strain might contribute to the degree of pathogenicity and clinical manifestation of onchocerciasis in this endemic zone

Assessment of haematuria and proteinuria as diagnostic markers for monitoring treatment of urinary schistosomiasis with artesunate

Oral artesunate although originally manufactured for the treatment of malaria has recently been shown to be effective in the treatment of S. haematobium infection. The usage of the presence/absence of haematuria and proteinuria in monitoring the outcome of treatment of urinary schistosomiasis patients with artesunate was assessed in the present study. The mean ova count, haematuria and proteinuria of 87 infected subjects who were treated were significantly reduced from 55.5 ± 1.3 ova/10ml, 168.6 ± 1.23 eryl/&mu;gl and 458.6 ± 1.40 mg/dl to 1.8 ± 0 ova/10ml, 9.1 ± 0.4 eryl/&mu;gl and 65.4 ± 1.64mg/dl respectively (P < 0.05 in all cases). This effect was also demonstrated by gender. It is concluded that reagent strips (Haematuria and proteinuria) are reliable in monitoring the efficacy of artesunate. Keywords; urinary schistosomiasis, treatment, artesunate, diagnostic markers Mary Slessor Journal of Medicine Vol. 5(1), 2005: 1-

Efficacy of mass ivermictin administration for the control of onchocerciasis in Agbokim and Ajassor communities in Cross River State, Nigeria

No Abstract

Factors affecting the transmission of human onchocerciasis by Simulium damnosum s l. in a fringe savanna village in Cross River State, Nigeria

Factors affecting the transmission of human onchocerciasis by Simulium damnosum sensu lato were the focus of a study carried out in River Lewa, Etikpe, a fringe savanna village in Ikom LGA in Cross River State, Nigeria. The duration of the study was six months (August 1999 to January 2000). The thrust of the study was on ecological parameters that affected the transmission of this human scourge. Some entomological indices/parameters that are useful criteria in planning and evaluating the progress of onchocerciasis control programme were also considered. Trained flycatches working alternate hours (0700hr.-1800hr.) caught black flies used for the study. The black flies caught were either dissected fresh in the field to determine parity (physiological age) or processed in the laboratory to determine the infection/infective rates due to Onchocerca volvulus. Out of 844 black flies collected in the 30 days catching, 425 (50.4%) flies were parous. The monthly ecological parameters (that is, water pH and temperatures, dissolved oxygen, iron content, atmospheric temperatures, rainfall, relative humidity and conductivity) measured and recorded in the study area/site had no significant differences in their values (P>0.05). These observed parameters however, had fluctuations, changes and variations in values. The findings in this study, if corroborated with those of related studies based on parasitologic, ophthalmologic and socioeconomic monitoring will be useful for planning of effective treatments with ivermectin. Keywords: transmission, human onchocerciasis, savannah, Cross River State Mary Slessor Journal of Medicine Vol. 5(2) 2005: 59-6