Extent Of Co-infection Research Articles

Interactions between seasonal temperature variation and temporal synchrony drive increased arbovirus co-infection incidence.

Though instances of arthropod-borne (arbo)virus co-infection have been documented clinically, the overall incidence of arbovirus co-infection and its drivers are not well understood. Now that dengue, Zika and chikungunya viruses are all in circulation across tropical and subtropical regions of the Americas, it is important to understand the environmental and biological conditions that make co-infections more likely to occur. To understand this, we developed a mathematical model of co-circulation of two arboviruses, with transmission parameters approximating dengue, Zika and/or chikungunya viruses, and co-infection possible in both humans and mosquitoes. We examined the influence of seasonal timing of arbovirus co-circulation on the extent of co-infection. By undertaking a sensitivity analysis of this model, we examined how biological factors interact with seasonality to determine arbovirus co-infection transmission and prevalence. We found that temporal synchrony of the co-infecting viruses and average temperature were the most influential drivers of co-infection incidence. Our model highlights the synergistic effect of co-transmission from mosquitoes, which leads to more than double the number of co-infections than would be expected in a scenario without co-transmission. Our results suggest that appreciable numbers of co-infections are unlikely to occur except in tropical climates when the viruses co-occur in time and space.

Field studies of the detection, persistence and spread of the Rispens CVI988 vaccine virus and the extent of co-infection with Marek's disease virus.

To use specific real-time qPCR to determine (1) the vaccination success of Rispens CVI988 vaccine in feathers and dust; (2) persistence of Rispens infection in vaccinated layer chickens; (3) extent of co-infection with wild-type Marek's disease virus (MDV) in vaccinated layers; and (4) presence of Rispens virus in unvaccinated broiler flocks. Feather, dust and serum samples were collected from birds aged 3 days to 91 weeks from three layer farms. qPCR was used to detect MDV and Rispens in DNA extracted from dust and feathers. Previously tested MDV-positive dust samples from 100 broiler flocks were tested for the presence of Rispens using qPCR, while serum samples were used to detect anti-MDV antibody using ELISA. Overall, 66% and 93% of feather and dust samples, respectively, from Rispens-vaccinated layers were Rispens-positive. Viral load in these samples varied between farms during early life, reaching readily detectable levels at 2-3 weeks of age. Vaccinated chickens maintained a high Rispens load in feathers and dust and high MDV antibody levels until 91 weeks of age. MDV infection was detected in 6.7% of feather samples from vaccinated chickens. Rispens virus was detected in 7% of samples from unvaccinated broiler flocks. Vaccine take can be measured effectively by Rispens-specific qPCR of feathers or dust from approximately 3 weeks post vaccination. Infection with Rispens is persistent, with lifelong shedding and serological response. The detectable infection rate of vaccinated chickens with MDV is low and there is preliminary evidence of escape of Rispens virus to unvaccinated flocks.

Effect of artemether-lumefantrine treatment of <i>falciparum</i> malaria on urogenital schistosomiasis in co-infected School Aged Children in North Central of Nigeria

The focus of the present study is to assess the effect of artemether-lumefantrine treatment of falciparum malaria on urogenital schistosomiasis in co-infected individuals. Urine samples were collected from 159 microscopically confirmed malaria patients and diagnosed for urogenital schistosomiasis before treatment. The schistosomiasis cure rate and egg reduction were determined in co-infected patients, who were treated with artemether-lumefantrine. Out of 103 malaria infected children, 56 were co-infected 54.4% (56/103) with schistosomiasis. All 56 co-infected patients were found urine-negative for Schistosoma haematobium eggs four weeks after treatment. The extent of co-infection was associated with age and sex level. Cure rate and egg reduction rate following the treatment of artemether-lumefantrine were 100% (p=0.0000). Artemetherlumefantrine was effective against S. haematobium in co-infected children. Further studies however, are needed for a better understanding of the efficacy of artemether lumefantrine against schistosome infection with ranges of intensity.Keywords: Urogenital haematobium, malaria, Cure rate, Egg reduction rate.

Plasmodium falciparum and Schistosoma mansoni coinfection and the side benefit of artemether-lumefantrine in malaria patients

The distribution of both malaria and schistosomiasis exhibits a large geographical overlap in tropical environments, particularly in sub-Saharan Africa. This part of the world currently harbours more than 85% of the estimated global burden of these diseases. Studies showed that artemisinin derivatives used for the treatment of malaria also have an antischistosomal effect. This study aimed to investigate the extent of malaria-schistosomiasis co-infection and the antischistosomal effect of artemether-lumefantrine when administered to treat falciparum malaria in Kemise, Northeast Ethiopia. Stool samples were collected from 152 microscopically confirmed malaria patients and diagnosed for schistosomiasis using the Kato-Katz technique before treatment. The schistosomiasis cure rate and egg reduction were determined in co-infected patients, who were treated with artemether-lumefantrine,. Twenty-eight out of 152 malaria patients were co-infected (18.4%, n = 152) with schistosomiasis. All 28 co-infected patients were found stool-negative for Schistosoma mansoni eggs four weeks after treatment. The extent of co-infection was associated with age, sex and educational level. Cure rate and egg reduction rate following the treatment of artemether-lumefantrine were 100%. The co-infection rate was associated with patient characteristics. Artemether-lumefantrine was effective against S. mansoni in co-infected patient. Multicenter and randomized trials, however, are needed for a better understanding of the efficacy of artemether-lumefantrine against schistosome infection with ranges of intensity.

Magnitude and Determinants of First-Time and Repeat Testing Among Individuals With Newly Diagnosed HIV Infection Between 2000 and 2001 in Alberta, Canada

The purpose of the study was to determine the magnitude and predictors of first-time and repeat testing for HIV infection among newly diagnosed cases in Alberta, Canada, and to determine the extent of co-infection with hepatitis C (HCV) and hepatitis B (HBV). Using the Provincial Laboratory for Public Health (PLPH) database, all newly diagnosed HIV cases in Alberta between 2000 and 2001 were identified and the testing history for HIV, HCV, and HBV among these cases since 1992 was reviewed. Significant differences in the characteristics of first-time and repeat testers were identified using the chi test, and where appropriate, the Fisher exact test. The independent variables examined included age, gender, risk factors, area and population of residence, testing agency, and co-infection with HCV and HBV. Logistical regression analyses were conducted to further explore independent factors associated with first-time vs. repeat testing for HIV infection. Of the 398 cases, 278 (69.8%) were newly diagnosed at their first test for HIV infection, 73.1% during 2000 and 67.3% during 2001 (P = 0.81). Among repeat testers, the mean number of previous negative tests was 3.4 (range = 2-11 tests). The median interval between the last negative and first positive test was 648 days (range = 53-2678 days). Repeat testers were 1.9 times more likely to be injecting drug users and 1.8 times more likely to reside in Northern Alberta. Among those with a laboratory test result in the PLPH database, 53.7% were positive for HCV, 47.7 and 64.5% of first-time and repeat testers, respectively; and 19.1% were positive for HBV, 22 and 13.6% of first-time and repeat testers, respectively. A high proportion of HIV cases newly diagnosed between 2000 and 2001 in Alberta had no previous testing history for HIV infection. Even among repeat testers, HIV testing was sought infrequently. There are significant regional differences within Alberta in the characteristics of the HIV epidemic and associated test-seeking behaviors. These data reinforce the need to make the most of each test-seeking event with proper counseling and other relevant support services. Given the high prevalence of co-infection with HCV, these results clearly support the need for testing and counseling strategies to take into account additional risks associated with HCV infections.