An atlas of malaria in Africa

The Mapping Malaria Risk in Africa (MARA) project will use computerized geographic information systems (GIS) to create an atlas of malaria risk in Africa. This is the first time GIS will be used to predict such risk and the first attempt to map malaria risk on a continental scale. Many heterogenous data sets relevant to the transmission dynamics of the disease will be combined, including the manipulation of the climatic factors which affect vector distribution and malaria transmission into a new index of malaria risk, and its validation against actual data. Specifically, the MARA project will collate measures of malaria risk, mainly the parasite ratio and annual incidence, to obtain an index for Africa and to create a continental, spatial, and temporal database. Five planned regional centers will work with a coordinating center in Durban, South Africa. The effort recently received its first funding. Canada's International Development Research Center, the World Health Organization/TDR bednet task force, the Wellcome Trust, and the South African Medical Research Council are supporting the effort.     

Prevalence of unusual human rotavirus strains in Ghanaian children

Sixty-seven rotavirus-positive fecal samples, collected between January and April 1999, from children with diarrhea in the Upper East Region of Ghana were examined for rotavirus VP7 and VP4 types. Sufficient viral RNA could be obtained from 46 (68.7%) of the samples and all the isolates had short electrophoretic pattern and typed as subgroup I rotaviruses by subgroup ELISA. Three rotavirus strains with G8 specificity were identified for the first time in Ghana. G and P typing by PCR identified two distinct strains, P[6]G2 (50%) and P[6]G8 (4.3%). Eighty-two percent of the isolates (n = 38) were of the "putative" neonatal P[6] genotype. Two of these G8 isolates carried the VP4 P[6] genotype whereas the third could not be assigned a P type. Mixed infections of G1, G2, G3 and G8 were detected amongst the stool samples. The presence of these unusual strains, especially the high incidence of G2 rotavirus strains in Ghana, reinforces the need to put in place a surveillance system for the detection of new and exotic rotavirus strains, that will provide information on the spread of these strains in West Africa as well as useful data for the formulation of the next generation of rotavirus vaccines.     

HIV/AIDS selective infectivity–report of two peculiar cases

We report two peculiar cases that were observed in two communities of Anambra State, South East Nigeria. The first case was a woman of 44 with a history of blood transfusion from a donor of questionable HIV status. A pint of blood was transfused in a private Hospital on the 15 th January, 2000. She has had no form of antiviral therapy until 22nd April, 2008 when she came to the hospital for routine medical check up. Her HIV result came out confirmed positive while that of her husband came out negative. She has had active sexual life with her husband in the previous eight years as they have had some difficulties in getting their desired extra two children having earlier gotten a boy and a girl. The second case involves a family of six. A couple with four children of ages about 6 months, 2 years, 3 years and 5 years. The youngest, a female presented with fever and multiple lymphadenopathy. She tested HIV positive and so was her mother and her second sibling. But her father and two other siblings remained negative at post three and six months intervals from their very first test date with us. These reported cases appear to go contrary to earlier formed opinion on HIV transmission. We support the opinion on a naturally, occurring substance, APOBEC3G which possibly confers permanent immunity against the HIV virus. We recommend clinical trials of the characterized APOBEC3G as a vaccine for non HIV infected persons of all ages and to people living with as a therapeutic drug.     

Comparison of digital systems and conventional dental film for the detection of approximal enamel caries

Objectives

The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries.

Methods

160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman’s rank correlation coefficient.

Results

Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06).

Conclusions

The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements.     

Differential response of two cell lines sequentially irradiated with low X-ray doses

An experiment was designed to compare the effect of repeated low doses of X-rays in two different cell lines: one transformed, epithelial like and aneuploid Chinese hamster ovary K-1 (CHO-K1); the other originated from a human primary culture, fibroblast, diploid and non-transformed, MRC-5. CHO and MRC-5 cells were cultured for 14 or eight passages, respectively. Irradiation was performed once per passage when cells were in the quiescent state (90?–?95% in G1/G0). Cells were exposed to 10.0 mSv X-ray doses. Ionizing radiation did not induce apoptosis or necrosis in the exposed CHO cell population. Significant increases of low-level damaged cells (degrees 1 and 2) were found for the 14 cycles of radiation when compared with controls, except for the first irradiation cycle. No significant increases in the frequency of cells with severe damage were observed. The frequency of MRC-5 cells with low-level damage increased significantly when compared with controls for radiation cycles seven and eight. Significant increases of apoptosis, necrosis and severe damage were found only for the highest dose. Transformed and non-transformed cell types responded differently to direct and indirect damage using low-dose repeat exposures to ionizing radiation. Though more investigation is needed to understand the mechanisms of radiation effects in chronic low-dose-exposed cell populations, cellular type should be taken into account in the design of in vitro experiments for understanding low-dose-irradiation effects.     

LOCALIZED LEPROMATOUS LEPROSY AND ITS RESPONSE TO CHEMO-IMMUNOTHERAPY

Background. This is an unusual presentation of lepromatous leprosy (ll ) in a young boy, 12 years of age. The study forms part of a large scale immunotherapeutic trial with Mycobacterium w (M.w) antileprosy vaccine. The trial is being conducted in two major hospitals in New Delhi, India. Materials and Methods. This patient presented with three lesions: one on each forearm and the third on the left leg. He was classified initially as borderline tuberculoid leprosy. Slit-skin smears and histopathology from the lesions proved the diagnosis to be lepromatous leprosy with a bacterial index (bi ) 6+. The initial lepromin test was negative. The patient was treated with chemo-immunotherapy (standard multidrug therapy and immunotherapy with Mycobacterium w vaccine). Results. Investigations after 1 year (15 months) of multidrug therapy and three doses of vaccine, showed a remarkable fall in the bi from 6 to 0 in the lesions, a lepromin positivity of 5 mm, and a histological upgrading from lepromatous leprosy to borderline tuberculoid. Immunologic studies at 15 months revealed a good LTT response and high levels of cytokines, specifically IL-2 and IFN-γ. Conclusions. This report presents an LL patient with disease limited to a few sites. It stresses the importance of slit-smear and biopsy in all patients of leprosy, and it highlights the upgrading observed on administration of chemo-immunotherapy.     

Rotavirus diarrhea among children less than 5 years of age in urban Ghana

We collected clinical and morphologic data from children with diarrhea attending 3 diverse hospitals/clinics in Accra. Stool samples were tested for rotavirus and Cryptosporidium spp. In all, 58% of the children with diarrhea had rotavirus infections, 25% of which were of the G3 sero/genotype. The most common strains were G3P [6] (18.8%) and G2P [6] (12.5%). Cryptosporidium spp. infections were uncommon (3/143, 2.0%).