Deworming helminth co-infected individuals for delaying HIV disease progression.

Deworming helminth co-infected individuals for delaying HIV disease progression.

The HIV-1 pandemic has disproportionately affected individuals in resource-constrained settings where other infectious diseases, such as helminth infections, also are highly prevalent. There are biologically plausible reasons for possible effects of helminth infection in HIV-1-infected individuals, and findings from multiple studies suggest that helminth infection may adversely affect HIV-1 progression. Since initial publication of this review (Walson 2007), additional data from randomized controlled trials has become available. Walson and colleagues therefore sought to evaluate all currently available evidence to determine if treatment of helminth infection in HIV-1 co-infected individuals impacts HIV-1 progression. They set out to determine if treating helminth infection in individuals with HIV-1 can reduce the progression of HIV-1 as determined by changes in CD4 count, viral load, or clinical disease progression. In this 2008 update, the authors searched online for published and unpublished studies in The Cochrane Library, MEDLINE, EMBASE, CENTRAL, and AIDSEARCH. They also searched databases listing conference abstracts, scanned reference lists of articles, and contacted authors of included studies. The authors searched for randomized controlled trials and quasi- randomized controlled trials that compared HIV-1 progression as measured by changes in CD4 count, viral load, or clinical disease progression in HIV-1 infected individuals receiving anti-helminthic therapy. Data regarding changes in CD4 count, HIV-1 RNA levels, and/or clinical staging after treatment of helminth co-infection were extracted from identified studies. Of 7,019 abstracts identified (6,384 from original searches plus 635 from updated searches), 17 abstracts were identified as meeting criteria for potential inclusion (15 from previous review plus an additional two randomized controlled trials). After restricting inclusion to randomized controlled trials, a total of three studies were eligible for inclusion in this updated review. All three trials showed individual beneficial effects of helminth eradication on markers of HIV-1 disease progression (HIV-1 RNA and/or CD4 counts). When data from these trials were pooled, the analysis demonstrated significant benefit of deworming on both plasma HIV-1 RNA and CD4 counts. To date, three randomized controlled trials have evaluated the effects of deworming on markers of HIV-1 disease progression in helminth and HIV-1 co-infected individuals. All trials demonstrate benefit in attenuating or reducing plasma viral load and/or increasing CD4 counts. When taken together, there is evidence of benefit for deworming HIV-1 co-infected adults. Given that these studies evaluated different helminth species and different interventions, further trials are warranted to evaluate species-specific effects and to document long-term clinical outcomes following deworming.

Between one-third and one-half of the global population is infected with at least one species of helminth (worms), with most infections found in low- and middle-income countries. Three randomised, controlled trials have now shown the short-term benefit on markers of HIV disease progression (CD4 counts, viral load) of treating helminth infection. These short term trials evaluated different interventions and different helminth infections (schistosomiasis, soil-transmitted helminths, and lymphatic filariasis) so it is premature to recommend empiric anti-helminthic therapy or routine helminth screening of HIV-infected adults. What is needed now are larger trials with longer follow-up to determine whether there are significant meaningful differences in clinical progression. In the meantime, helminth infection should be treated when it is found.