Contrary to previous reports, mosquitoes may not be able to transmit the hepatitis C virus (HCV), say researchers from two universities in Taiwan. They report their findings in the September 2001 issue of the Journal of Clinical Microbiology.
The researchers tested mosquitoes of the species Culex quinquefasciatus that had been fed HCV-infected blood, had been injected with HCV-infected blood, or had been captured at the home of an HCV-positive person. On day 1 all the experimentally infected mosquitoes and 11 percent of the captured mosquitoes tested positive for HCV, but after the first day the detection rate rapidly declined, suggesting that HCV does not replicate within mosquitoes.
"This evidence strongly weighs against mosquitoes being reservoirs of HCV," say the researchers.
(T.-T. Chang, T.-Y. Chang, C.-C. Chen, K.-C. Young, J.-N. Roan, Y.-C. Lee, P.-N. Cheng and, H.-L. Wu. 2001. Existence of hepatitis C virus in Culex quinquefasciatus after ingestion of infected blood: Experimental approach to evaluating transmission by mosquitoes. Journal of Clinical Microbiology, 39: 3353-3355.)
PATHOGENIC FUNGI PERSIST ON COMMON ITEMS IN HOSPITALS
Disease-causing fungi can survive for days and even weeks on common hospital fabrics and plastic items, supporting the need for appropriate disinfection and contact control precautions, say researchers from the University of Cincinnati College of Medicine in the September 2001 issue of the Journal of Clinical Microbiology.
The researchers investigated the ability of 11 different fungi to survive on a variety of items commonly found in hospitals including privacy curtains, towels, scrub suits, splash aprons and keyboard covers. While some fungi only survived a few days on the items, at least five of the species were still viable after 30 days.
"These survival results indicate the potential for various fabrics and plastics to serve as reservoirs or vectors for fungi," say the researchers. "In this age of increasing antifungal resistance, when treatments for patients are becoming more limited, appropriate disinfection of the environment and conscientious contact control procedures are essential for optimal control of infections in hospitals."
(A. Neely and M. Orloff. 2001. Survival of some medically important fungi on hospital fabrics and plastics. Journal of Clinical Microbiology, 39: 3360-3361.)
HEPATITIS C, HIV MAKE INTERESTING COMBINATION
HIV infection could play a role in making the hepatitis C virus a sexually transmissible disease. This is just one of the possible interactions that could be taking place between these two viruses suggest scientists at Johns Hopkins University in a guest commentary in the September 2001 issue of the journal Clinical and Diagnostic Laboratory Immunology.
The commentary is an overview of known research on the interaction between HIV and HCV in individuals who are infected with both viruses. It is estimated that as many as 1 in 4 HIV patients is co-infected with HCV.
One finding is that while HCV infection appears to have little effect on HIV progression and treatment, HIV infection does affect HCV. Co-infected individuals appear to have higher levels of HCV in their blood, progress to liver damage more quickly and require different treatment regimens than individuals infected with HCV alone.
On the issue of HCV as a sexually transmitted disease "coinfection with HIV appears to increase the rate of sexual transmission of HCV," say the authors. In one example, they cite a study in which 3 percent of female partners of co-infected men were HCV positive while there was no evidence of transmission in couples where the man was infected only with HCV.
"There are many interactions between HCV and HIV," say the authors. "It is important that research efforts be increased in order to better understand HIV-HCV coinfection and optimal means of treating the large number of coinfected persons."
(K. Nelson and D. Thomas. 2001. Reciprocal interaction of human immunodeficiency virus and hepatitis C virus infections. Clinical and Diagnostic Laboratory Immunology, 8: 867-870.)
Full text of the above articles can be access through the ASM homepage at: http://www.asmusa.org/pcsrc/tip.htm.