Proliferative capacity and cytokine production by cells of HIV-infected and uninfected adults with different helminth infection phenotypes in South Africa

Demographic profile of HIV and helminth-coinfected adults in KwaZulu-Natal, South Africa

Background

Helminth and HIV infections are endemic among poor populations. Studies investigating the socio-demographic and economic risk factors associated with dual HIV and helminth coinfection are scarce.

Objectives

This study aimed to describe risk factors associated with HIV and helminth coinfections among peri-urban South African adults residing in poorly developed areas with high poverty levels, lack of sanitation and a clean water supply.

Method

Adult participants (n = 414) were recruited from clinics in the south of Durban, KwaZulu-Natal, South Africa. Participants' demographic, socio-economic, sanitation and household information, anthropometric measurements and HIV status were collected. Stool samples were donated for coproscopy to detect helminths using the Kato-Katz and Mini Parasep techniques. Blood was collected to confirm participants' HIV status and to determine Ascaris lumbricoides-specific immunoglobulin E (IgE) and immunoglobulin G4 (IgG4) levels to improve microscopy sensitivity.

Results

Overall coinfection was 15%, and single helminth and HIV prevalence were 33% and 52%, respectively. Ascaris lumbricoides was predominant (18%). Univariate analysis of variance (ANOVA) showed that coinfection was 11.9% and 19.8%, respectively, among the 18-34 years and 35-59 years age groups (p = 0.0006), 16.4% and 19.9%, respectively, for the no income and < R1000.00 groups (p = 0.0358) and 22.8% and 17.1%, respectively, for the pit or public toilets and toilets not connected to sewage groups (p = 0.0007).

Conclusion

Findings suggest that the dual infection with HIV and helminth infections among adults residing in under-resourced areas with poor sanitary conditions is frequent. Older age, poor toilet use and low income are associated with coinfection. More attention is required to break the cycle of coinfections and possible disease interactions.

Contribution

The study highlights the importance of determining and treating helminth infections among adult population during HIV and helminth coinfection and the influence of poor sanitation and socioeconomic status on disease transmission.

Concurrent allergy and helminthiasis in underprivileged urban South African adults previously residing in rural areas

This study investigated whether prior exposure to helminths (Ascaris IgE, Ascaris eggs and Trichuris eggs) either in childhood or in adulthood, and residence in rural and resource‐limited urban areas influence allergy outcomes (asthma, rhinitis, IgE atopy and food allergy) in a South African population. Participants historical and present allergies data were collected through questionnaires and clinical record files. Coproscopy and immunoassays (ImmunoCAP^TM Phadiatop, total IgE and allergen‐specific fx3 IgE immunoassays and Ascaris IgE radioallergosorbent [RAST] tests) were used for active helminthiasis and allergy screens respectively. Data were analysed using logistic regression analysis, and models were adjusted for age, gender and locality. High Ascaris IgE was significantly associated with asthma (adjusted odds ratio [aOR] = 2.20, p = .047), IgE atopy (aOR = 18.18, p < .0001) and food allergy (aOR = 14.47, p < .0001). Asthma was significantly less likely among participants with Ascaris eggs (aOR = 0.43, p = .048) and Trichuris eggs (aOR = 0.36, p = .024). The findings of co‐occurrent helminthiasis and allergic disorders in a population that has resided both in rural and peri‐urban informal settlements both oppose and agree with two main notions of the hygiene hypothesis that (i) individuals residing in rural settings with poor sanitation and geohelminth infection are less prone to allergy, and (ii) helminth infections protect against allergy respectively. Further research is warranted.

Immunological underpinnings of Ascaris infection, reinfection and co-infection and their associated co-morbidities

Human ascariasis is the most common and prevalent neglected tropical disease and is estimated that ~819 million people are infected around the globe, accounting for 0.861 million years of disability-adjusted life years in 2017. Even with the existence of highly effective drugs, the constant presence of infective parasite eggs in the environment contribute to a high reinfection rate after treatment. Due to its high prevalence and broad geographic distribution Ascaris infection is associated with a variety of co-morbidities and co-infections. Here, we provide data from both experimental models and humans studies that illustrate how complex is the interaction of Ascaris with the host immune system, especially, in the context of reinfections, co-infections and associated co-morbidities.

Tropical Parasitic Infections in Individuals Infected with HIV

PURPOSE OF REVIEW

Neglected tropical diseases share both geographic and socio-behavioral epidemiological risk factors with HIV infection. In this literature review, we describe interactions between parasitic diseases and HIV infection, with a focus on the impact of parasitic infections on HIV infection risk and disease progression, and the impact of HIV infection on clinical characteristics of tropical parasitic infections. We limit our review to tropical parasitic infections of the greatest public health burden, and exclude discussion of classic HIV-associated opportunistic infections that have been well reviewed elsewhere.

RECENT FINDINGS

Tropical parasitic infections, HIV-infection, and treatment with antiretroviral therapy alter host immunity, which can impact susceptibility, transmissibility, diagnosis, and severity of both HIV and parasitic infections. These relationships have a broad range of consequences, from putatively increasing susceptibility to HIV acquisition, as in the case of schistosomiasis, to decreasing risk of protozoal infections through pharmacokinetic interactions between antiretroviral therapy and antiparasitic agents, as in the case of malaria. However, despite this intimate interplay in pathophysiology and a broad overlap in epidemiology, there is a general paucity of data on the interactions between HIV and tropical parasitic infections, particularly in the era of widespread antiretroviral therapy availability.

SUMMARY

Additional data are needed to motivate clinical recommendations for detection and management of parasitic infections in HIV-infected individuals, and to consider the implications of and potential opportunity granted by HIV treatment programs on parasitic disease control.