Modulation of immune responses during HIV-malaria co-infection in pregnancy

Heterogeneity in the prevalence of subclinical malaria, other co-infections and anemia among pregnant women in rural areas of Myanmar: a community-based longitudinal study

BACKGROUND

Due to the low prevalence of clinically suspected malaria among pregnant women in Myanmar, little is known about its impact on mothers and newborns. Helminth and Human Immuno-deficiency Virus (HIV) co-infections cause anemia in pregnant women. This study assessed the prevalence of subclinical malaria and co-infections among pregnant women, and its association with adverse outcomes of pregnancy in the presence of infection.

METHODS

A prospective longitudinal study was conducted in 12 villages in two townships in Myanmar between 2013 to 2015. A total of 752 pregnant women, with a mean age of 27 years, were enrolled and followed up once a month until six weeks after childbirth. Prevalence ratio was calculated in the multivariable analysis.

RESULTS

The prevalence of subclinical malaria as measured by nested PCR was 5.7% for either P. falciparum or P. vivax, 2.7% prevalence of P. falciparum and 2.8% prevalence of P. vivax. Helminth infections were prevalent in 17% of women, and one woman with an HIV infection was found in our study. The burden of anemia was high, with an overall prevalence of 37% with or without helminth infection, 42% of the women were malaria positive and 43% had dual infections (both malaria and helminth). Only 11 abnormal pregnancy outcomes (7 stillbirths, 2 premature, 2 twins) were identified. Poisson regression showed that women in their first trimester had a 2.9 times higher rate of subclinical malaria compared to women in the third trimester (PR:2.9, 95%CI 1.19, 7.31, p = 0.019), women who were enrolled during the wet season were 2.5 times more likely to be malaria positive than the women enrolled in the dry season (PR: 2.5, 95%CI 1.27, 4.88, p = 0.008), and the malaria positivity rate decreased by 5% when increased in one year of woman's age (PR:0.95, 95%CI 0.91, 0.99, p = 0.02). In the multivariable regression, the age of respondents was the only significant factor associated with subclinical malaria in pregnancy.

CONCLUSIONS

A comprehensive approach of integrating interventions for malaria, anemia, and helminths should be delivered during antenatal care services for pregnant women in rural areas of Myanmar.

Malaria prevalence in HIV-positive children, pregnant women, and adults: a systematic review and meta-analysis

Background

Malaria in human immunodeficiency virus (HIV)-positive patients is an ever-increasing global burden for human health. The present meta-analysis summarizes published literature on the prevalence of malaria infection in HIV-positive children, pregnant women and adults.

Methods

This study followed the PRISMA guideline. The PubMed, Science Direct, Google Scholar, Scopus and Cochrane databases were searched for relevant entries published between 1 January 1983 and 1 March 2020. All peer-reviewed original papers evaluating the prevalence of malaria among HIV-positive patients were included. Incoherence and heterogeneity between studies were quantified by the I2 index and Cochran’s Q test. Publication and population biases were assessed with funnel plots, and Egger’s regression asymmetry test.

Results

A total of 106 studies were included in this systematic review. The average prevalence of malaria among HIV-positive children, HIV-positive pregnant women and HIV-positive adults was 39.4% (95% confidence interval [CI]: 26.6–52.9), 32.3% (95% CI = 26.3–38.6) and 27.3% (95% CI = 20.1–35.1), respectively. In adult patients with HIV, CD4+ (cluster of differentiation 4) < 200 cells/µl and age < 40 years were associated with a significant increase in the odds of malaria infection (odds ratio [OR] = 1.5, 95% CI = 1.2–1.7 and OR = 1.1, 95% CI = 1–1.3, respectively). Antiretroviral therapy (ART) and being male were associated with a significant decrease in the chance of malaria infection in HIV-positive adults (OR = 0.8, 95% CI = 0.7–0.9 and OR = 0.2, 95% CI = 0.2–0.3, respectively). In pregnant women with HIV, CD4+ count < 200 cells/µl was related to a higher risk for malaria infection (OR = 1.5, 95% CI = 1.1–1.9).

Conclusions

This systematic review demonstrates that malaria infection is concerningly common among HIV-positive children, pregnant women and adults. Among HIV-positive adults, ART medication and being male were associated with a substantial decrease in infection with malaria. For pregnant women, CD4+ count of < 200 cells/µl was a considerable risk factor for malaria infection.

Graphical Abstract

Should we care about Plasmodium vivax and HIV co-infection? A systematic review and a cases series from the Brazilian Amazon

BACKGROUND

Malaria and HIV are two important public health issues. However, evidence on HIV-Plasmodium vivax co-infection (HIV/PvCo) is scarce, with most of the available information related to Plasmodium falciparum on the African continent. It is unclear whether HIV can change the clinical course of vivax malaria and increase the risk of complications. In this study, a systematic review of HIV/PvCo studies was performed, and recent cases from the Brazilian Amazon were included.

METHODS

Medical records from a tertiary care centre in the Western Brazilian Amazon (2009-2018) were reviewed to identify HIV/PvCo hospitalized patients. Demographic, clinical and laboratory characteristics and outcomes are reported. Also, a systematic review of published studies on HIV/PvCo was conducted. Metadata, number of HIV/PvCo cases, demographic, clinical, and outcome data were extracted.

RESULTS

A total of 1,048 vivax malaria patients were hospitalized in the 10-year period; 21 (2.0%) were HIV/PvCo cases, of which 9 (42.9%) had AIDS-defining illnesses. This was the first malaria episode in 11 (52.4%) patients. Seven (33.3%) patients were unaware of their HIV status and were diagnosed on hospitalization. Severe malaria was diagnosed in 5 (23.8%) patients. One patient died. The systematic review search provided 17 articles (12 cross-sectional or longitudinal studies and 5 case report studies). A higher prevalence of studies involved cases in African and Asian countries (35.3 and 29.4%, respectively), and the prevalence of reported co-infections ranged from 0.1 to 60%.

CONCLUSION

Reports of HIV/PvCo are scarce in the literature, with only a few studies describing clinical and laboratory outcomes. Systematic screening for both co-infections is not routinely performed, and therefore the real prevalence of HIV/PvCo is unknown. This study showed a low prevalence of HIV/PvCo despite the high prevalence of malaria and HIV locally. Even though relatively small, this is the largest case series to describe HIV/PvCo.

Intermittent Preventive Treatment With Dihydroartemisinin-Piperaquine for the Prevention of Malaria Among HIV-Infected Pregnant Women

Background

Daily trimethoprim-sulfamethoxazole (TMP-SMX) and insecticide-treated nets remain the main interventions for prevention of malaria in human immunodeficiency virus (HIV)-infected pregnant women in Africa. However, antifolate and pyrethroid resistance threaten the effectiveness of these interventions, and new ones are needed.

Methods

We conducted a double-blinded, randomized, placebo-controlled trial comparing daily TMP-SMX plus monthly dihydroartemisinin-piperaquine (DP) to daily TMP-SMX alone in HIV-infected pregnant women in an area of Uganda where indoor residual spraying of insecticide had recently been implemented. Participants were enrolled between gestation weeks 12 and 28 and given an insecticide-treated net. The primary outcome was detection of active or past placental malarial infection by histopathologic analysis. Secondary outcomes included incidence of malaria, parasite prevalence, and adverse birth outcomes.

Result

All 200 women enrolled were followed through delivery, and the primary outcome was assessed in 194. There was no statistically significant difference in the risk of histopathologically detected placental malarial infection between the daily TMP-SMX plus DP arm and the daily TMP-SMX alone arm (6.1% vs. 3.1%; relative risk, 1.96; 95% confidence interval, .50-7.61; P = .50). Similarly, there were no differences in secondary outcomes.

Conclusions

Among HIV-infected pregnant women in the setting of indoor residual spraying of insecticide, adding monthly DP to daily TMP-SMX did not reduce the risk of placental or maternal malaria or improve birth outcomes.

Clinical Trials Registration

NCT02282293.

Impact of comorbidity on adverse drug reaction profile in a cohort of patients treated with Artemisinin combination therapies for uncomplicated malaria in Nigeria

Artemisinin‐based combination antimalarial therapy (ACTs), is still highly effective in uncomplicated falciparum malaria, however, there remain some concerns in relation to its safety and tolerability. Comorbid disease conditions may influence susceptibility to adverse drug reactions (ADRs) as the presence of multiple disease conditions may predisposes patients to ADRs due to the use of many medicines. There is therefore need to assess the impact of comorbidities on the ADR profile of malaria patients treated with ACTs. The study was carried out in health care facilities spread across Nigeria. From the database of over 10,000 patients recruited into an initial cohort, data for 1000 patients with comorbidities was extracted and matched with a control group of 1000 randomly selected patients with no comorbidity. There were 1105 adverse drug reactions in all, of which 66.2% were recorded in patients with comorbidity, and 34% are patients without comorbidity. The mean age of patients with comorbidities was 38.3 ± 17.5 years and 23.8 ± 17.2 for those without comorbidity. Out of the 979 patients with comorbidity, 36% were hypertensive, 2.2% hypertensive‐diabetes, 16.4% peptic ulcer disease, 10.4% HIV/AIDS, 4.4% diabetes and 4.3% were asthmatic. Patients with comorbidity were three times more likely to have adverse drug reaction than those without comorbidity (Odds ration = 2.96; 95% CI = 2.23–3.93). HIV/AIDS and osteoarthritis were significantly associated with development of adverse drug reactions. Probability was <0.0001. Age, weight, and height of patients were also found to be risk factor for development of adverse drug reactions.

The Effect of Malaria and HIV Co-Infection on Anemia: A Meta-Analysis

Malaria and human immunodeficiency virus (HIV) infections are globally important public health concerns. The objectives of this study were (i) to determine the prevalence of malaria and HIV co-infections in people living in endemic countries, and (ii) to assess the effect of co-infection on anemia.Studies were searched on electronic databases including PubMed, Embase, Medline, Google Scholar, and African Journals Online. Observational studies, assessing the prevalence of co-infection and reporting its association with anemia, were included. The methodological quality of included studies was assessed using a tool called the risk of bias assessment for non-randomized studies. Heterogeneity among studies was investigated with the I-square test. Pooled prevalence of the co-infection and its 95% confidence interval (CI) were estimated using the random-effect model, reflected on heterogeneity among studies. Summary odds ratio (OR), summary standardized mean difference (SMD), and their corresponding 95% CIs were estimated, as appropriate. Subgroup analysis and meta-regression were performed for robustness of results. Publication bias was assessed by visualization of a funnel plot.Twenty-three studies were included in the present study. Overall, the pooled prevalence of co-infection was 19% (95% CI: 15-23%, I: 98.1%), showing 26% (95% CI: 20-32%, I: 98.7%) in adults, 12% (95% CI: 7-17%, I: 95.0) in pregnant women, and 9% (95% CI: 6-11%, I: 68.6%) in children. Anemia was comparable between the monoinfected and co-infected adults (summary OR: 1.49, 95% CI: 0.93-2.37) and increased by 49% in co-infected pregnant women (summary OR: 1.49, 95% CI: 1.14-1.94). The mean hemoglobin concentration was significantly lower in the co-infected group than the monoinfected group (summary SMD: -0.47, 95% CI: -0.61 to -0.33). The results of meta-regression on the prevalence of co-infection using the publication year and total population as covariates showed the I value remained high implying a de facto random distribution of heterogeneity. An asymmetrical funnel plot indicated the presence of publication bias. Due to heterogeneity of the studies in this review, the results have to be interpreted with caution.The findings of this study suggest that the prevalence of malaria and HIV co-infection, particularly in pregnant women, requires special attention from healthcare personnel. Better understanding of the co-infection is crucial for designing treatment strategies. Future well-powered, prospective designs assessing the interaction between malaria and HIV are recommended.

HIV infection in pregnancy: maternal and perinatal outcomes in a tertiary care hospital in Calabar, Nigeria

BACKGROUND

Human immunodeficiency virus (HIV) infection is likely to have untoward effects on pregnancy and its outcome. This study assessed the impact of maternal HIV infection on pregnancy outcomes in a tertiary centre in Calabar, Nigeria.

METHODS

This retrospective study analysed delivery records of 258 HIV-positive and 257 HIV-negative women for pregnancy and delivery complications. Maternal and fetal outcomes of HIV-positive pregnancies were compared with those of HIV-negative controls.

RESULTS

Adverse pregnancy outcomes significantly associated with HIV status were: anaemia: 33 (8.1%) vs. 8 (3.1%) in controls; puerperal sepsis: 18 (7%) vs. 2 (0.8%); and low birth weight: 56 (21.7%) vs. 37 (14.4%). Caesarean delivery was higher among HIV-positive women than controls: 96 (37.2%) vs. 58 (22.6%). Preterm births were higher in those HIV cohorts who did not receive antiretroviral therapy (ART): 13 (16.9%) vs. 7 (3.9%).

CONCLUSION

HIV-positive status increased adverse birth outcome of pregnancy. ART appeared to reduce the risk of preterm births in HIV-positive cohorts.

Insights Into Circulating Cytokine Dynamics During Pregnancy in HIV-Infected Beninese Exposed to Plasmodium falciparum Malaria

We investigated the circulating plasma levels of Th1- (Interleukin-2 [IL-2], tumor necrosis factor-α [TNF-α], interferon-gamma [IFN-γ]) and Th2-type (IL-4, IL-5, IL-10) cytokines in human immunodeficiency virus (HIV)-infected pregnant women living in a malaria-endemic area. We analyzed samples from 200 pregnant women included in the prevention of pregnancy-associated malaria in HIV-infected women: cotrimoxazole prophylaxis versus mefloquine (PACOME) clinical trial who were followed until delivery. Cytokine concentrations were measured by flow cytometry-based multiplex bead array. Significantly elevated levels of IL-10 and lower levels of TNF-α were observed at delivery compared with inclusion (P = 0.005). At inclusion, the presence of circulating IFN-γ, a higher CD4(+) T cell count and having initiated intermittent preventive treatment of malaria with sulfadoxine pyrimethamine (SP-IPTp) were all associated with a lower likelihood of Plasmodium falciparum infection. At delivery, the inverse relationship between the presence of infection and circulating IFN-γ persisted, although there was a positive association between the likelihood of infection and the presence of circulating TNF-α. Initiation of antiretroviral therapy was associated with elevated IL-5 production. Consistent with our own and others' observations in HIV seronegative subjects, this study shows circulating IL-10 to be a marker of infection with P. falciparum during pregnancy even in HIV-infected women, although plasma IFN-γ may be a marker of anti-malarial protection in such women.

Interactions between malaria and human immunodeficiency virus anno 2014

Possible pathophysiological, clinical and epidemiological interactions between human immunodeficiency virus (HIV) and tropical pathogens, especially malaria parasites, constitute a concern in tropical areas. Two decades of research have shown that HIV-related immunosuppression is correlated with increased malaria infection, burden, and treatment failure, and with complicated malaria, irrespective of immune status. The recent role out of antiretroviral therapies and new antimalarials, such as artemisinin combination therapies, raise additional concerns regarding possible synergistic and antagonistic effects on efficacy and toxicity. Co-trimoxazole, which is used to prevent opportunistic infections, has been shown to have strong antimalarial prophylactic properties, despite its long-term use and increasing antifolate resistance. The administration of efavirenz, a non-nucleoside reverse transcriptase inhibitor, with amodiaquine–artesunate has been associated with increased toxicity. Recent in vivo observations have confirmed that protease inhibitors have strong antimalarial properties. Ritonavir-boosted lopinavir and artemether–lumefantrine have a synergistic effect in terms of improved malaria treatment outcomes, with no apparent increase in the risk of toxicity. Overall, for the prevention and treatment of malaria in HIV-infected populations, the current standard of care is similar to that in non-HIV-infected populations. The available data show that the wider use of insecticide-treated bed-nets, co-trimoxazole prophylaxis and antiretroviral therapy might substantially reduce the morbidity of malaria in HIV-infected patients. These observations show that those accessing care for HIV infection are now, paradoxically, well protected from malaria. These findings therefore highlight the need for confirmatory diagnosis of malaria in HIV-infected individuals receiving these interventions, and the provision of different artemisinin-based combination therapies to treat malaria only when the diagnosis is confirmed.

Lopinavir/ritonavir-based antiretroviral treatment (ART) versus efavirenz-based ART for the prevention of malaria among HIV-infected pregnant women

BACKGROUND

Human immunodeficiency virus (HIV)-infected pregnant women are at increased risk of malaria and its complications. In vitro and in vivo data suggest that the HIV protease inhibitors lopinavir/ritonavir may have potent antimalarial activity. We sought to evaluate whether lopinavir/ritonavir-based antiretroviral therapy (ART) reduced the risk of placental malaria.

METHODS

HIV-infected, ART-naive pregnant women were enrolled between gestational weeks 12 and 28 and randomly assigned to receive lopinavir/ritonavir-based or efavirenz-based ART. Women received daily trimethoprim-sulfamethoxazole prophylaxis and insecticide-treated bed nets at enrollment and were followed up to 1 year after delivery. The primary outcome was placental malaria, defined by the detection of malaria parasites, using microscopy or polymerase chain reaction (PCR) analysis of placental blood specimens. Secondary outcomes included placental malaria, defined by histopathologic results; adverse birth outcomes; incidence of malaria; and prevalence of asymptomatic parasitemia. Analyses were done using an intention-to-treat approach.

RESULTS

Of 389 subjects randomly assigned to a treatment group, 377 were followed through to delivery. There was no significant difference in the risk of placental malaria, as defined by thick smear or PCR findings, between the lopinavir/ritonavir-based and efavirenz-based ART arms (7.4% vs 9.8%; P = .45). Similarly, there were no differences in secondary outcomes between the 2 treatment arms.

CONCLUSIONS

Lopinavir/ritonavir-based ART did not reduce the risk of placental or maternal malaria or improve birth outcomes, compared with efavirenz-based ART.

CLINICAL TRIALS REGISTRATION

NCT00993031.

Analysis of a summary network of co-infection in humans reveals that parasites interact most via shared resources

Simultaneous infection by multiple parasite species (viruses, bacteria, helminths, protozoa or fungi) is commonplace. Most reports show co-infected humans to have worse health than those with single infections. However, we have little understanding of how co-infecting parasites interact within human hosts. We used data from over 300 published studies to construct a network that offers the first broad indications of how groups of co-infecting parasites tend to interact. The network had three levels comprising parasites, the resources they consume and the immune responses they elicit, connected by potential, observed and experimentally proved links. Pairs of parasite species had most potential to interact indirectly through shared resources, rather than through immune responses or other parasites. In addition, the network comprised 10 tightly knit groups, eight of which were associated with particular body parts, and seven of which were dominated by parasite-resource links. Reported co-infection in humans is therefore structured by physical location within the body, with bottom-up, resource-mediated processes most often influencing how, where and which co-infecting parasites interact. The many indirect interactions show how treating an infection could affect other infections in co-infected patients, but the compartmentalized structure of the network will limit how far these indirect effects are likely to spread.

Prevalence of malaria and anaemia among HIV infected pregnant women receiving co-trimoxazole prophylaxis in Tanzania: a cross sectional study in Kinondoni Municipality

Background

HIV-infected pregnant women are particularly more susceptible to the deleterious effects of malaria infection particularly anaemia. In order to prevent opportunistic infections and malaria, a policy of daily co-trimoxazole prophylaxis without the standard Suphadoxine-Pyrimethamine intermittent preventive treatment (SP-IPT) was introduced to all HIV infected pregnant women in the year 2011. However, there is limited information about the effectiveness of this policy.

Methods

This was a cross sectional study conducted among HIV-infected pregnant women receiving co-trimoxazole prophylaxis in eight public health facilities in Kinondoni Municipality from February to April 2013. Blood was tested for malaria infection and anaemia (haemoglobin <11 g/dl). Data were collected on the adherence to co-trimoxazole prophylaxis and other risk factors for malaria infection and anaemia. Pearson chi-square test, Fischer’s exact test and multivariate logistic regression were used in the statistical analysis.

Results

This study enrolled 420 HIV infected pregnant women. The prevalence of malaria infection was 4.5%, while that of anaemia was 54%. The proportion of subjects with poor adherence to co-trimoxazole was 50.5%. As compared to HIV infected pregnant women with good adherence to co-trimoxazole prophylaxis, the poor adherents were more likely to have a malaria infection (Adjusted Odds Ratio, AOR = 6.81, 95% CI = 1.35-34.43, P = 0.02) or anaemia (AOR = 1.75, 95% CI = 1.03-2.98, P = 0.039). Other risk factors associated with anaemia were advanced WHO clinical stages, current malaria infection and history of episodes of malaria illness during the index pregnancy.

Conclusion

The prevalence of malaria was low; however, a significant proportion of subjects had anaemia. Good adherence to co-trimoxazole prophylaxis was associated with reduction of both malaria infection and anaemia among HIV infected pregnant women.

Clinical burden and correlates of HIV and malaria co-infection, in northwest Nigeria

The clinical burden of malaria and HIV/AIDS in sub-Saharan Africa is well-described, but the dynamics of the interaction between the two diseases remain poorly understood. Using a cross-sectional study design, we assessed the prevalence and predictors of malaria infection among HIV-positive patients attending a referral center in urban Kano, northwest Nigeria. Structured questionnaires covering socio-demographic characteristics, HIV diagnosis and treatment, malaria preventive practices, clinical events and treatment were administered to HIV-infected adults (n=363). Information from questionnaires was supplemented with data from case notes. In the preceding year, nearly a third of respondents (32.2%; 95% CI=27.4-37.3) had at least one episode of fever, diagnosed as malaria on blood film examination. Half of all respondents (53.5%) admitted to using insecticide treated nets (ITN). One-third (35.8%) of participants were on malaria chemoprophylaxis at the time of the study. Female sex (adjusted Odds Ratio [aOR]=1.54, 95% confidence interval (CI): 1.32-2.73), immunosuppression (CD4+ cell count <350/μL vs. 600/μL, aOR=2.41, 95% CI 1.23-3.74) and non-use of ITN (aOR=1.97, 95% CI 1.17-2.85) predicted the occurrence of clinical malaria in patients. We report a high burden of malaria in HIV-infected patients attending a tertiary facility in urban Kano, Nigeria. Health communication, standardized protocols and ITN distribution should be integrated into comprehensive HIV programs in this setting.

Predictors of fetal anemia and cord blood malaria parasitemia among newborns of HIV-positive mothers

Background

Malaria and HIV infections during pregnancy can individually or jointly unleash or confound pregnancy outcomes. Two of the probable outcomes are fetal anemia and cord blood malaria parasitemia. We determined clinical and demographic factors associated with fetal anemia and cord blood malaria parasitemia in newborns of HIV-positive women from two districts in Ghana.

Results

We enrolled 1,154 antenatal attendees (443 HIV-positive and 711 HIV-negative) of which 66% were prospectively followed up at delivery. Maternal malaria parasitemia, and anemia rates among HIV+ participants at enrolment were 20.3% and 78.7% respectively, and 12.8% and 51.6% among HIV- participants. Multivariate linear and logistic regression models were used to study associations. Prevalence of fetal anemia (cord hemoglobin level < 12.5 g/dL) and cord parasitemia (presence of P. falciparum in cord blood at delivery) were 57.3% and 24.4% respectively. Factors found to be associated with fetal anemia were maternal malaria parasitemia and maternal anemia. Infant cord hemoglobin status at delivery was positively and significantly associated with maternal hemoglobin and gestational age whilst female gender of infant was negatively associated with cord hemoglobin status. Maternal malaria parasitemia status at recruitment and female gender of infant were positively associated with infant cord malaria parasitemia status.

Conclusions

Our data show that newborns of women infected with HIV and/or malaria are at increased risk of anemia and also cord blood malaria parasitemia. Prevention of malaria infection during pregnancy may reduce the incidence of both adverse perinatal outcomes.

Malaria and HIV co-infection and their effect on haemoglobin levels from three health-care institutions in Lagos, southwest Nigeria

BACKGROUND

Malaria and human immunodeficiency virus (HIV) are two major infections with enormous public health consequence. Together, they are endemic in many developing countries with anaemia being the most frequent haematological consequence of the infections.

OBJECTIVES

To determine the prevalence of malaria and HIV co-infection as well as anaemia among selected patients from three health-care institutions in Lagos, Nigeria.

METHODS

A cross-sectional study of 1080 patients was carried out to determine the prevalence of malaria and HIV co-infection as well as anaemia. Blood sera from each of the patients were screened for malaria parasites, HIV-1 and HIV-2 using Giemsa stain, Cambridge Biotech Recombigen HIV-1/HIV-2 rapid device, respectively while haemoglobin estimation was performed using cyanmethemoglobin method.

RESULTS

Our data showed that the total number of malaria infected patients were significantly higher in HIV sero-positive patients 47.7% (31/65) when compared with their HIV sero-negative counterparts 25.8% (262/1015) P = 0.047. The result also revealed that 25.8% (8/31) of the patients co-infected with malaria and HIV had anaemia as compared to 11.1% (29/262) infected with malaria alone. Multivariable logistic regression analysis showed that patients with dual infection of malaria and HIV were twice likely to be anaemic than those infected with malaria alone [adjusted OR 2.4, 95% CI, 1.3 to 2.7, P = 0.014].

CONCLUSIONS

Our data indicated a higher prevalence of malaria in HIV infected patients and also revealed that patients co-infected with malaria and HIV were more likely to be anaemic.

Effect of malaria on HIV/AIDS transmission and progression

Malaria and HIV are among the two most important global health problems of developing countries. They cause more than 4 million deaths a year. These two infections interact bidirectionally and synergistically with each other. HIV infection increases the risk of an increase in the severity of malaria infection and burdens of malaria, which in turn facilitates the rate of malaria transmission. Malaria infection is also associated with strong CD4+ cell activation and up-regulation of proinflammatory cytokines and it provides an ideal microenvironment for the spread of the virus among the CD4+ cells and for rapid HIV-1 replication. Additionally, malaria increases blood viral burden by different mechanisms. Therefore, high concentrations of HIV-1 RNA in the blood are predictive of disease progression, and correlate with the risk of blood-borne, vertical, and sexual transmission of the virus. Therefore, this article aims to review information about HIV malaria interactions, the effect of malaria on HIV transmission and progression and the implications related to prevention and treatment of coinfection.

Malaria and helminthic co-infection among HIV-positive pregnant women: prevalence and effects of antiretroviral therapy

The impact of malaria on anemia and the interplay with helminths underline the importance of addressing the interactions between HIV/AIDS, malaria and intestinal helminth infections in pregnancy. The aim of this study was to determine the prevalence of malaria-helminth dual infections among HIV positive pregnant mothers after 12 months of ART. A cross sectional study was conducted on intestinal helminths and malaria dual infections among HIV-positive pregnant women attending antenatal health centers in Rwanda. Stool and malaria blood slide examinations were performed on 328 women residing in rural (n=166) and peri-urban locations (n=162). BMI, CD4 cell count, hemoglobin levels, type of ART and viral load of participants were assessed. Within the study group, 38% of individuals harbored helminths, 21% had malaria and 10% were infected with both. The most prevalent helminth species were Ascaris lumbricoides (20.7%), followed by Trichuris trichiura (9.2%), and Ancylostoma duodenale and Necator americanus (1.2%). Helminth infections were characterized by low hemoglobin and CD4 counts. Subjects treated with a d4T, 3TC, NVP regimen had a reduced risk of T. trichiura infection (OR, 0.27; 95% CIs, 0.10-0.76; p<0.05) and malaria-helminth dual infection (OR, 0.29; 95% CI, 0.11-0.75; p<0.05) compared to those receiving AZT, 3TC, NVP. This study shows a high prevalence of malaria and helminth infection among HIV-positive pregnant women in Rwanda. The differential effect of ARTs on the risk of helminth infection is of interest and should be examined prospectively in larger patient groups.

Humoral immune responses to Plasmodium falciparum among HIV-1-infected Kenyan adults

INTRODUCTION

Humoral immune responses play a pivotal role in naturally acquired immunity to malaria. Understanding which humoral responses are impaired among individuals at higher risk for malaria may improve our understanding of malaria immune control and contribute to vaccine development.

METHODS

We compared humoral responses with 483 Plasmodium falciparum antigens between adults in, Kisumu (high, year-long malaria transmission leading to partial immunity), and adults in Kisii (low, seasonal malaria transmission). Then within each site, we compared malaria-specific humoral responses between those at higher risk for malaria (CD4(+) ≤500) and those at lower risk for malaria (CD4(+) >500). A protein microarray chip containing 483 P. falciparum antigens and 71 HIV antigens was used. Benjamini-Hochberg adjustments were made to control for multiple comparisons.

RESULTS

Fifty-seven antigens including CSP, MSP1, LSA1 and AMA1 were identified as significantly more reactive in Kisumu than in Kisii. Ten of these antigens had been identified as protective in an earlier study. CD4(+) T-cell count did not significantly impact humoral responses.

CONCLUSION

Protein microarrays are a useful method to screen multiple humoral responses simultaneously. This study provides useful clues for potential vaccine candidates. Modest decreases in CD4 counts may not significantly impact malaria-specific humoral immunity.

HIV and malaria interactions: where do we stand?

Reversing the spread of HIV infection and the incidence of malaria constitute two of the Millenium Development Goals. However, despite recent achievements, both diseases still entail global heath problems. Furthermore, their overlapping geographical distribution raises concerns and challenges for potential immunological, clinical and therapeutic interactions. It has been reported that HIV infection increases malaria susceptibility and reduces the efficacy of antimalarial drugs. On the other hand, the effect of malaria on HIV-infected individuals has also been explored, with the parasitic infection increasing the risk of HIV disease progression and mother-to-child transmission of HIV. The spread of malaria and parasite resistance to antimalarials could also be accelerated by HIV-associated immunosuppresion. Current knowledge of the epidemiological, clinical, immunological and therapeutic interactions of the two diseases is reviewed in this article. We focus on the latest available data, pointing out key future research areas and challenges of the field.

Consequences of HIV infection on malaria and therapeutic implications: a systematic review

Despite recent changes in the epidemiology of HIV infection and malaria and major improvements in their control, these diseases remain two of the most important infectious diseases and global health priorities. As they have overlapping distribution in tropical areas, particularly sub-Saharan Africa, any of their clinical, diagnostic, and therapeutic interactions might have important effects on patient care and public health policy. The biological basis of these interactions is well established. HIV infection induces cellular depletion and early abnormalities of CD4+ T cells, decreases CD8+ T-cell counts and function (cellular immunity), causes deterioration of specific antigen responses (humoral immunity), and leads to alteration of innate immunity through impairment of cytolytic activity and cytokine production by natural killer cells. Therefore, HIV infection affects the immune response to malaria, particularly premunition in adolescents and adults, and pregnancy-specific immunity, leading to different patterns of disease in HIV-infected patients compared with HIV-uninfected patients. In this systematic review, we collate data on the effects of HIV on malaria and discuss their therapeutic consequences. HIV infection is associated with increased prevalence and severity of clinical malaria and impaired response to antimalarial treatment, depending on age, immunodepression, and previous immunity to malaria. HIV also affects pregnancy-specific immunity to malaria and response to intermittent preventive treatment. Co-trimoxazole (trimethoprim-sulfamethoxazole) prophylaxis and antiretroviral treatment reduce occurrence of clinical malaria; however, these therapies interact with antimalarial drugs, and new therapeutic guidelines are needed for concomitant use.

Fetal immune activation to malaria antigens enhances susceptibility to in vitro HIV infection in cord blood mononuclear cells

Mother-to-child-transmission (MTCT) of human immunodeficiency virus (HIV) remains a significant cause of new HIV infections in many countries. To examine whether fetal immune activation as a consequence of prenatal exposure to parasitic antigens increases the risk of MTCT, cord blood mononuclear cells (CBMCs) from Kenyan and North American newborns were examined for relative susceptibility to HIV infection in vitro. Kenyan CBMCs were 3-fold more likely to be infected with HIV than were North American CBMCs (P=.03). Kenyan CBMCs with recall responses to malaria antigens demonstrated enhanced susceptibility to HIV when compared with Kenyan CBMCs lacking recall responses to malaria (P=.03). CD4(+) T cells from malaria-sensitized newborns expressed higher levels of CD25 and human leukocyte antigen DR ex vivo, which is consistent with increased immune activation. CD4(+) T cells were the primary reservoir of infection at day 4 after virus exposure. Thus, prenatal exposure and in utero priming to malaria may increase the risk of MTCT.

Micronutrients and HIV infection

The immune system requires several essential micronutrients to maintain an effective immune response. HIV infection destroys the immune system and promotes nutritional deficiencies, which further impair immunity. This article reviews the role of several micronutrients (vitamins A, C, E and D, the B vitamins, and minerals, selenium, iron and zinc) that are relevant for maintaining immune function. In addition, the deficiencies of these micronutrients have been associated with faster progression of HIV-1 disease. This review examines the evidence from observational studies of an association between micronutrient status and HIV disease, as well as the effectiveness of micronutrient supplementation on HIV-disease progression, pregnancy outcomes and nutritional status, among others, utilizing randomized clinical trials. Each micronutrient is introduced with a summary of its functions in human physiology, followed by the presentation of studies conducted in HIV-infected patients in relation to this specific micronutrient. Overall findings and recommendations are then summarized.

Infections in Pregnancy

Despite advances in peripartum care, maternal morbidity and mortality associated with infections in pregnancy are increasing even in developed countries. Recently published data from the Center for Disease Control's Pregnancy Mortality Surveillance System indicates that although maternal mortality from hemorrhage, embolism, and anesthesia has declined in the United States, the proportion of maternal deaths due to infections has increased. During 1991–7 infection accounted for 13.2% of pregnancy-related deaths overall and 36.3% of abortion-related deaths. The greatest infection risk is found in blacks, older women, women without prenatal care, and women with multiple pregnancy. In the United States pregnancy rates are stable or increasing in these groups. Infection is also a major cause of morbidity and mortality for the fetus and newborn. Many perinatal infections are associated with intra-uterine growth retardation and low birthweight, or cause fetal and neonatal brain injury. Infections, particularly bacterial vaginosis and chorioamnionitis, can result in preterm delivery of live-born infants (delivery before 37 weeks gestation), or stillbirth. A multitude of immunologic, endocrinologic, metabolic, physiologic, and anatomic changes influence the likelihood and course of many infections during pregnancy. Some of these changes are intrinsic, and occur in all normal pregnancies, while others occur to varying degrees in normal and abnormal pregnancies.

Placental malaria among HIV-infected and uninfected women receiving anti-folates in a high transmission area of Uganda

Background

HIV infection increases the risk of placental malaria, which is associated with poor maternal and infant outcomes. Recommendations in Uganda are for HIV-infected pregnant women to receive daily trimethoprim-sulphamethoxazole (TS) and HIV-uninfected women to receive intermittent sulphadoxine-pyrimethamine (SP). TS decreases the risk of malaria in HIV-infected adults and children but has not been evaluated among pregnant women.

Methods

This was a cross sectional study comparing the prevalence of placental malaria between HIV-infected women prescribed TS and HIV-uninfected women prescribed intermittent preventive therapy with sulphadoxine-pyrimethamine (IPT-SP) in a high malaria transmission area in Uganda. Placental blood was evaluated for malaria using smear and PCR.

Results

Placentas were obtained from 150 HIV-infected women on TS and 336 HIV-uninfected women on IPT-SP. The proportion of HIV-infected and HIV-uninfected women with placental malaria was 19% vs. 26% for those positive by PCR and 6% vs. 9% for those positive by smear, respectively. Among all infants, smear+ placental malaria was most predictive of low birth weight (LBW). Primigravidae were at higher risk than multigravidae of having placental malaria among HIV-uninfected, but not HIV-infected, women. Adjusting for gravidity, age, and season at the time of delivery, HIV-infected women on TS were not at increased risk for placental malaria compared to HIV-uninfected women on IPT-SP, regardless of the definition used.

Conclusion

Prevalence of placental malaria was similar in HIV-infected women on TS and HIV-uninfected women on IPT-SP. Nonetheless, while nearly all of the women in this study were prescribed anti-folates, the overall risk of placental malaria and LBW was unacceptably high. The population attributable risk of placental malaria on LBW was substantial, suggesting that future interventions that further diminish the risk of placental malaria may have a considerable impact on the burden of LBW in this population.

Relationship between human immunodeficiency virus type 1 coinfection, anemia, and levels and function of antibodies to variant surface antigens in pregnancy-associated malaria

Human immunodeficiency virus type 1 (HIV-1) coinfection decreases antibodies to variant surface antigens implicated in pregnancy-associated malaria (VSA-PAM) caused by Plasmodium falciparum. The effect of HIV-1 on antibody functions that may protect mothers from pregnancy-associated malaria is unknown. Sera from multigravid pregnant women with malaria and HIV-1 coinfection (n=58) or malaria alone (n=29) and from HIV-1-infected (n=102) or -uninfected (n=54) multigravidae without malaria were analyzed for anti-VSA-PAM antibodies by flow cytometry, the ability to inhibit adhesion to chondroitin sulfate A, or to opsonize CS2-infected erythrocytes for phagocytosis by THP-1 cells. In women with malaria, anti-VSA-PAM levels correlated better with opsonic activity (r=0.60) than with adhesion-blocking activity (r=0.33). In univariate analysis, HIV-1 coinfection was associated with lower opsonic activity but not adhesion-blocking activity or anti-VSA-PAM levels. Malaria-infected women with anemia (hemoglobin levels of <11.0 g/dl) had lower opsonic activity than nonanemic women (P=0.007) independent of HIV-1 status. By multivariate analysis, in malaria-infected women, anemia (but not HIV status) was associated with opsonic activity. In women without malaria, opsonic activity was not associated with either anemia or HIV-1 status. In multigravid pregnant women with malaria, impaired serum opsonic activity may contribute to anemia and possibly to the decreased immunity to pregnancy-associated malaria associated with HIV-1.

New approaches to pathogenesis of malaria in pregnancy

Malaria infection during pregnancy is associated with poor maternal and foetal outcomes including low birth weight. In malaria-endemic areas, low birth weight is primarily a consequence of foetal growth restriction. Little is known on the pathogenesis of foetal growth restriction and our understanding of the relationship between epidemiological observations and the pathogenesis or consequences of disease is incomplete. In this review, we describe these gaps in our knowledge and also try to identify goals for future research into malaria in pregnancy. Foetal growth restriction results from a complex four-dimensional interaction between the foetus, the mother and the malaria parasite over gestation, and research into its pathogenesis may be advanced by combining longitudinal studies with techniques and approaches new to the field of malaria in pregnancy. Such approaches would greatly increase our knowledge on the pathogenesis of this disease and may provide new avenues for intervention strategies.

Malaria in pregnancy: pathogenesis and immunity

Understanding of the biological basis for susceptibility to malaria in pregnancy was recently advanced by the discovery that erythrocytes infected with Plasmodium falciparum accumulate in the placenta through adhesion to molecules such as chondroitin sulphate A. Antibody recognition of placental infected erythrocytes is dependent on sex and gravidity, and could protect from malaria complications. Moreover, a conserved parasite gene-var2csa-has been associated with placental malaria, suggesting that its product might be an appropriate vaccine candidate. By contrast, our understanding of placental immunopathology and how this contributes to anaemia and low birthweight remains restricted, although inflammatory cytokines produced by T cells, macrophages, and other cells are clearly important. Studies that unravel the role of host response to malaria in pathology and protection in the placenta, and that dissect the relation between timing of infection and outcome, could allow improved targeting of preventive treatments and development of a vaccine for use in pregnant women.

Co-infection of malaria with HIV: an immunological perspective

Human immunodeficiency virus (HIV) and Plasmodium parasites are pathogens that induce significant perturbation and activation of the immune system. Due to their geographical overlap, there have been concerns that co-infection with the two pathogens may be a factor in the modification of their development, and in the severity and rate of disease progression that they induce. In this article, we have reviewed some of the studies that have addressed this topic and we have tried to provide immunological mechanisms to explain these potential interactions.

Tumour necrosis factor-alpha stimulates HIV-1 replication in single-cycle infection of human term placental villi fragments in a time, viral dose and envelope dependent manner

Background

The placenta plays an important role in the control of in utero HIV-1 mother-to-child transmission (MTCT). Proinflammatory cytokines in the placental environment are particularly implicated in this control. We thus investigated the effect of TNF-α on HIV-1 expression in human placental tissues in vitro.

Results

Human placental chorionic villi fragments were infected with varying doses of luciferase reporter HIV-1 pseudotypes with the R5, X4-Env or the vesicular stomatitis virus protein G (VSV-G). Histocultures were then performed in the presence or absence of recombinant human TNF-α. Luciferase activity was measured at different time points in cell lysates or on whole fragments using ex vivo imaging systems.

A significant increase in viral expression was detected in placental fragments infected with 0.2 ng of p24 antigen/fragment (P = 0.002) of VSV-G pseudotyped HIV-1 in the presence of TNF-α seen after 120 hours of culture. A time independent significant increase of viral expression by TNF-α was observed with higher doses of VSV-G pseudotyped HIV-1. When placental fragments were infected with R5-Env pseudotyped HIV-1, a low level of HIV expression at 168 hours of culture was detected for 3 of the 5 placentas tested, with no statistically significant enhancement by TNF-α. Infection with X4-Env pseudotyped HIV-1 did not lead to any detectable luciferase activity at any time point in the absence or in the presence of TNF-α.

Conclusion

TNF-α in the placental environment increases HIV-1 expression and could facilitate MTCT of HIV-1, particularly in an inflammatory context.

Increased severe anemia in HIV-1-exposed and HIV-1-positive infants and children during acute malaria

OBJECTIVE

Since the primary hematological complication in both pediatric HIV-1 and malaria is anemia, co-infection with these pathogens may promote life-threatening severe malarial anemia (SMA). The primary objective of the study was to determine if HIV-1 exposure [HIV-1(exp)] and/or HIV-1 infection [HIV-1(+)] increased the prevalence of SMA in children with acute malaria.

DESIGN

The effect of HIV-1 exposure and HIV-1 infection on the prevalence of SMA (hemoglobin < 6.0 g/dl), parasitemia (parasites/microl), and high-density parasitemia (HDP, >or= 10 000 parasites/mul) was investigated in children <or= 2 years of age presenting at hospital with acute Plasmodium falciparum malaria in a rural holoendemic malaria transmission area of western Kenya.

METHODS

Upon enrollment, a complete hematological and clinical evaluation was performed on all children. Malaria parasitemia was determined and children with acute P. falciparum malaria were evaluated for HIV-1 exposure and infection by two rapid serological antibody tests and HIV-1 DNA PCR, respectively.

RESULTS

Relative to HIV-1(-) group (n = 194), the HIV-1(exp) (n = 100) and HIV-1(+) (n = 23) groups had lower hemoglobin concentrations (P < 0.001 and P < 0.001, respectively), while parasitemia and HDP were equivalent between the three groups. Multivariate analyses demonstrated that the risk of SMA was elevated in HIV-1(exp) children (odds ratio, 2.17; 95% confidence interval, 1.25-3.78; P < 0.01) and HIV-1(+) children (odds ratio, 8.71; 95% confidence interval, 3.37-22.51; P < 0.0001). The multivariate model further revealed that HIV-1 exposure or infection were not significantly associated with HDP.

CONCLUSIONS

Results presented here demonstrate that both HIV-1 exposure and HIV-1 infection are associated with increased prevalence of SMA during acute P. falciparum infection, independent of parasite density.