HIV infection drives IgM and IgG3 subclass bias in Plasmodium falciparum-specific and total immunoglobulin concentration in Western Kenya.

BACKGROUND: HIV infection is associated with more frequent and severe episodes of malaria and may be the result of altered malaria-specific B cell responses. However, it is poorly understood how HIV and the associated lymphopenia and immune activation affect malaria-specific antibody responses. METHODS: HIV infected and uninfected adults were recruited from Bondo subcounty hospital in Western Kenya at the time of HIV testing (antiretroviral and co-trimoxazole prophylaxis naïve). Total and Plasmodium falciparum apical membrane antigen-1 (AMA1) and glutamate rich protein-R0 (GLURP-R0) specific IgM, IgG and IgG subclass concentrations was measured in 129 and 52 of recruited HIV-infected and uninfected individuals, respectively. In addition, HIV-1 viral load (VL), CD4+ T cell count, and C-reactive protein (CRP) concentration was quantified in study participants. Antibody levels were compared based on HIV status and the associations of antibody concentration with HIV-1 VL, CD4+ count, and CRP levels was measured using Spearman correlation testing. RESULTS: Among study participants, concentrations of IgM, IgG1 and IgG3 antibodies to AMA1 and GLURP-R0 were higher in HIV infected individuals compared to uninfected individuals (all p < 0.001). The IgG3 to IgG1 ratio to both AMA1 and GLURP-R0 was also significantly higher in HIV-infected individuals (p = 0.02). In HIV-infected participants, HIV-1 VL and CRP were weakly correlated with AMA1 and GLURP-R0 specific IgM and IgG1 concentrations and total (not antigen specific) IgM, IgG, IgG1, and IgG3 concentrations (all p < 0.05), suggesting that these changes are related in part to viral load and inflammation. CONCLUSIONS: Overall, HIV infection leads to a total and malaria antigen-specific immunoglobulin production bias towards higher levels of IgM, IgG1, and IgG3, and HIV-1 viraemia and systemic inflammation are weakly correlated with these changes. Further assessments of antibody affinity and function and correlation with risk of clinical malaria, will help to better define the effects of HIV infection on clinical and biological immunity to malaria.

Provider knowledge of treatment policy and dosing regimen with artemether-lumefantrine and quinine in malaria-endemic areas of western Kenya.

BACKGROUND: Due to widespread anti-malarial drug resistance in many countries, Kenya included, artemisinin-based Combination Therapy (ACT) has been adopted as the most effective treatment option against malaria. Artemether-lumefantrine (AL) is the first-line ACT for treatment of uncomplicated malaria in Kenya, while quinine is preferred for complicated and severe malaria. Information on the providers' knowledge and practices prior to or during AL and quinine implementation is scanty. The current study evaluated providers' knowledge and practices of treatment policy and dosing regimens with AL and quinine in the public, private and not-for-profit drug outlets. METHODS: A cross-sectional survey using three-stage sampling of 288 (126 public, 96 private and 66 not-for-profits) providers in drug outlets was conducted in western Kenya in two Plasmodium falciparum-endemic regions with varying malarial risk. Information on provider in-service training, knowledge (qualification, treatment policy, dosing regimen, recently banned anti-malarials) and on practices (request for written prescription, prescription of AL, selling partial packs and advice given to patients after prescription), was collected. RESULTS: Only 15.6% of providers in private outlets had received any in-service training on AL use. All (100%) in public and majority (98.4%) in not-for-profit outlets mentioned AL as first line-treatment drug. Quinine was mentioned as second-line drug by 47.9% in private outlets. A total of 92.0% in public, 57.3% in private and 78.8% in not-for-profit outlets stated correct AL dose for adults. A total of 85.7% of providers in public, 30.2% in private and 41.0% in not-for-profit outlets were aware that SP recommendations changed from treatment for mild malaria to IPTp in high risk areas. In-service training influenced treatment regimen for uncomplicated malaria (P = 0.039 and P = 0.039) and severe malaria (P < 0.0001 and P = 0.002) in children and adults, respectively. Most (82.3%) of private outlets sell partial packs of AL while 72.4% do not request for written prescription for AL. In-service training influenced request for written prescription (P = 0.001), AL prescription (P < 0.0001) and selling of partial packs (P < 0.0001). CONCLUSION: Public-sector providers have higher knowledge on treatment policy and dosing regimen on recommended anti-malarials. Changes in treatment guidelines should be accompanied by subsequent implementation activities involving all sector players in unbiased strategies.

Prevalence and characterization of Escherichia coli O157:H7 isolates from meat and meat products sold in Amathole District, Eastern Cape Province of South Africa.

Meat and meat products have been implicated in outbreaks of Escherichia coli O157:H7 in most parts of the world. In the Amathole District Municipality of the Eastern Cape Province of South Africa, a large number of households consume meat and meat products daily, although the microbiological quality of these types of food is questionable. The present study investigated the prevalence of E. coli O157:H7 isolated from selected meat and meat products (45 samples each of biltong, cold meat, mincemeat, and polony) sold in this area. Strains of E. coli O157:H7 were isolated by enrichment culture and confirmed by polymerase chain reaction (PCR). Also investigated were the antibiogram profiles of the E. coli O157:H7 isolates. Five (2.8%) out of 180 meat and meat products examined were positive for E. coli O157:H7 that carried the fliC(H7), rfbE(O157), and eaeA genes. Two of the E. coli O157:H7 isolates were resistant against all the eight antibiotics tested. To prevent E. coli O157:H7 infections, meat and meat products such as biltong, cold meat, mincemeat and polony should be properly handled, and packed in sterile polyvinyl wrappers.