Parasitic disease screening among HIV patients from endemic countries in a Toronto clinic

The cost-effectiveness of schistosomiasis screening and treatment among recently resettled refugees to Canada: an economic evaluation

BACKGROUND

Many refugees and asylum seekers from countries where schistosomiasis is endemic are infected with the Schistosoma parasite when they arrive in Canada. We assessed, from a systemic perspective, which of the following management strategies by health care providers is cost-effective: testing for schistosomiasis and treating if the individual is infected, treating presumptively or waiting for symptoms to emerge.

METHODS

We constructed a decision-tree model to examine the cost-effectiveness of 3 management strategies: watchful waiting, screening and treatment, and presumptive treatment. We obtained data for the model from the literature and other sources, to predict deaths and chronic complications caused by schistosomiasis, as well as costs and net monetary benefit.

RESULTS

Presumptive treatment was cost-saving if the prevalence of schistosomiasis in the target population was greater than 2.1%. In our baseline analysis, presumptive treatment was associated with an increase of 0.156 quality-adjusted life years and a cost saving of $405 per person, compared with watchful waiting. It was also more effective and less costly than screening and treatment.

INTERPRETATION

Among recently resettled refugees and asylum claimants in Canada, from countries where schistosomiasis is endemic, presumptive treatment was predicted to be less costly and more effective than watchful waiting or screening and treatment. Our results support a revision of the current Canadian recommendations.

Association of schistosomiasis and HIV infections: A systematic review and meta-analysis

Background:

Female genital schistosomiasis (FGS) affects up to 56 million women in sub-Saharan Africa and may increase risk of HIV infection.

Methods:

To assess the association of schistosomiasis with HIV infection, peer-reviewed literature published until 31 December 2018 was examined and a pooled estimate for the odds ratio was generated using Bayesian random effects models.

Results:

Of the 364 abstracts that were identified, 26 were included in the summary. Eight reported odds ratios of the association between schistosomiasis and HIV; one reported a transmission hazard ratio of 1.8 (95% CI, 1.2–2.6) among women and 1.4 (95% CI, 1.0–1.9) among men; 11 described the prevalence of schistosomiasis among HIV-positive people (range, 1.5–36.6%); and six reported the prevalence of HIV among people with schistosomiasis (range, 5.8–57.3%). Six studies were selected for quantitative analysis. The pooled estimate for the odds ratio of HIV among people with schistosomiasis was 2.3 (95% CI, 1.2–4.3).

Conclusions:

A significant association of schistosomiasis with HIV was found. However, a specific summary estimate for FGS could not be generated. A research agenda was provided to determine the effect of FGS on HIV infection. The WHO’s policy on mass drug administration for schistosomiasis may prevent HIV.

Should We Screen HIV-Positive Migrants for Strongyloidiasis?

BACKGROUND

Strongyloides stercoralis, a nematode endemic in all (sub)tropical regions, can cause life-threatening disease, especially in immunosuppressed patients. Many countries with high HIV-prevalence rates are also highly S. stercoralis endemic, and co-infection may occur.

METHODS

Retrospective study based on serological testing for S. stercoralis in all HIV-infected migrants followed at the Institute of Tropical Medicine, Antwerp, Belgium. If untested, serologic testing was performed on stored samples, dating from the first HIV viral load determination. The epidemiological, clinical and laboratory features of patients with and without strongyloidiasis were retrieved from the electronic medical files.

RESULTS

Of the 2846 HIV patients in active follow-up, 723 (25.4%) had a migration background. Thirty-six patients (5.1%) were diagnosed with Strongyloides co-infection, including 29 during their medical evaluation and seven retrospectively. Patients had a median age of 35.3 years (IQR 30.3-44.4), 28 patients (78%) originated from Sub-Saharan Africa and median time in Belgium was 3.5 years (IQR 0.8-5.7). Symptoms compatible with strongyloidiasis were present in 17 (47%) patients, of whom two were diagnosed retrospectively. Eosinophilia (eosinophil cell count > 450/µL) was observed in 19 (53%) participants. Median CD4 level was 386 /µL (IQR 299-518) at diagnosis of co-infection. Of note, 8 (22%) patients with strongyloidiasis had no reported symptoms nor eosinophilia. None of the patients developed hyperinfection syndrome. There were no differences in age, gender, geographic origin, clinical presentation, CD4 level or viral load between patients with and without strongyloidiasis. Only eosinophilia was strongly correlated with the presence of Strongyloides in multivariate analysis (OR 10.74 (95% CI 5.19-22.25), p < 0.001); the positive likelihood ratio (LR+) of eosinophilia for strongyloidiasis was 5.38 (95% CI 3.66-7.91).

CONCLUSION

Strongyloidiasis was diagnosed in 5.1% of HIV-infected migrants. Eosinophilia had good confirming power for the presence of the disease. However, a sizeable proportion (22%) of co-infected individuals were asymptomatic and had normal eosinophil count, supporting universal screening of all HIV-positive patients native to tropical countries.

Eosinophilia in patients infected with human immunodeficiency virus

Eosinophilia is not uncommonly encountered in patients infected with human immunodeficiency virus (HIV), particularly at initiation of care or among those with advanced disease. The clinical manifestation most commonly associated with eosinophilia in this patient population is skin rash. Management of these patients is challenging due to a paucity of data evaluating diagnostic testing and therapeutic strategies. Patients born in or with significant travel to parasite-endemic countries are more likely to have tissue-invasive helminthes, such as Strongyloides or Schistosoma. Patients without such risk factors are unlikely to have parasitic infections and frequently will have self-resolution of eosinophilia. When a detailed history, physical exam, and diagnostic work-up are unrevealing, we sometimes consider empirical therapy with ivermectin. Praziquantel may also be considered for those at risk for schistosomiasis.