Effect of Long-lasting Insecticide-treated Bednets and a Point-of-use Water Purification Device on HIV Disease Progression Among ART naïve Patients in Kenya

Introduction and Background:

Among the estimated 22.5 million HIV infected individuals in sub-Saharan Africa, malaria and diarrheal disease are important causes of morbidity and mortality[1]. Preventive care packages that protect against these co-infections may result in decreased HIV associated morbidity and may also delay HIV disease progression[2]. Long lasting insecticidal nets (LLIN) and water purification systems may be practical and effective interventions for reducing malaria and diarrheal disease incidence and delaying disease progression in HIV infected individuals.

The World Health Organization currently recommends TMP/SMX prophylaxis for immunocompromised HIV infected individuals[3]. TMP/SMX is active against a number of pathogens that cause morbidity and mortality amongst HIV infected individuals, including malaria and infectious causes of diarrhea[4]. Randomized clinical trials in HIV infected children and adults demonstrate marked survival benefits with use of TMP/SMX and cotrimoxazole prophylaxis is recommended for people with HIV in the Kenya Ministry of Health guidelines[5]. In addition, observational studies have suggested benefit on markers of HIV disease progression[5, 6].

HIV infected individuals are at increased risk for malaria infection[7]. LLIN have been associated with a 17% reduction in mortality and a 50% reduction in uncomplicated malaria in areas of stable malaria transmission in HIV-uninfected adults and are a cost-effective method of malaria prevention[8, 9]. In HIV infected individuals, TMP/SMX prophylaxis has been shown to decrease episodes of malaria from ~50/100 person-years (p-yrs) to 9 episodes/100 p-yrs[10]. LLIN may provide additive benefit when combined with TMP/SMX in HIV infected individuals. Amongst HIV infected individuals receiving HAART and TMP/SMX, the addition of LLIN resulted in a 42-60% reduction in the incidence of symptomatic malaria[10]. In HIV infected children receiving TMP/SMX, LLIN were associated with marked decreases in malarial parasitemia[11]. LLIN are simple to administer, requiring a single encounter for long term provision of the intervention, and, in contrast to TMP/SMX, do not pose risk to the individuals of drug toxicity or development of resistant microbial flora.

In addition to malaria, diarrheal disease remains a major cause of morbidity and mortality amongst HIV infected individuals in many parts of sub-Saharan Africa[12, 13]. Limited access to clean water for drinking and food preparation results in exposure to numerous bacterial, viral and parasitic agents of diarrheal disease. Prophylaxis with TMP/SMX has been shown to reduce diarrheal episodes in HIV infected adults from 204 to 148 per 100 person-years[6]. Among HIV-infected adults, the provision of purified drinking water resulted in a 25% reduction in the rate of diarrhea per person year. The addition of TMP-SMX in this cohort resulted in a 67% reduction in diarrheal episodes, suggesting an additive benefit of clean water and TMP/SMX in reducing diarrheal incidence among HIV infected individuals[14]. Similar to LLIN, water filtration devices provide benefit by preventing host ingestion of pathogens and are free of concerns regarding drug resistance or toxicity. Water filtration devices may require more intensive use/training/compliance than LLIN and compliance with daily use of these devices may reduce effectiveness.