# Presentation: 656659

## Interaction of HIV and Malaria

**Malaria Branch**
**Division of Parasitic Diseases**
**National Center for Infectious Diseases**

**Notes:**
Today I will be providing you with an overview of CDC’s global tuberculosis control activities with an emphasis on the rationale behind our efforts, the principles that guide these efforts, specific examples of the work we do in this arena, and future steps we will be taking to continue our efforts.

## Malaria and HIV disease in sub Saharan Africa	

- Malaria and HIV are leading causes of morbidity and mortality, particularly in sub Saharan Africa
- Both diseases are highly endemic and have a wide geographic overlap
- A small effect of malaria on HIV or vice-versa could have substantial population-level implications

- HIV

- Malaria

**Notes:**
-Malaria and HIV are leading causes of morbidity and mortality in sub Saharan Africa
-Both diseases are highly endemic and have a wide geographic overlap, 
- Therefore, small effect of malaria on HIV could have substantial population-level implications

STATS ON HIV AND MALARIA IN AFRICA? 300 million cases worldwide, 90% in ssA; 5000 reported

## Malaria and HIV disease in sub Saharan Africa	

- Background on malaria
- What we do and don’t know:
-  Malaria <-> HIV interaction
-  Science & program

**Notes:**
-Malaria and HIV are leading causes of morbidity and mortality in sub Saharan Africa
-Both diseases are highly endemic and have a wide geographic overlap, 
- Therefore, small effect of malaria on HIV could have substantial population-level implications

STATS ON HIV AND MALARIA IN AFRICA? 300 million cases worldwide, 90% in ssA; 5000 reported

## Scope of the Malaria Problem:	

- Malaria is the most common life-threatening infection
- 1 million deaths/yr
- 300-500 million infections/yr
- ~90% of these deaths occur in sub-Saharan Africa
- most victims are children <5 yrs
- Pregnant women are also especially vulnerable.

## MALARIA 101 

- Human Malaria is caused by one of 4 protozoan parasites:

*Plasmodium falciparum*
*Plasmodium vivax*
*Plasmodium ovale*
*Plasmodium malariae*

- Malaria is transmitted through the bite of an infected
- female *Anopheles *mosquito

## Malaria Life Cycle

- Liver stage

## MALARIA 101 – clinical syndromes

- Non-severe
- Acute Febrile
- disease

- Cerebral
- Malaria

- Death

## Effective Malaria Interventions Include:

- Providing prompt access to curative treatment
- Preventing and controlling malaria during pregnancy
- Promoting the use of insecticide-treated mosquito nets
- 	shown to reduce _all-cause_ child mortality by 20%-25%

## Malaria Interventions  - Costs

- Insecticide-treated mosquito nets:   $2.50 -- 5.00
- Malaria treatment:
- CQ, SP, AQ, Lap-Dap:                 $0.10 – 0.50
- Artemisinin-combinations:            $2.00 or more
- Intermittent Preventive Tx in preg:   $0.35

## HIV and Malaria Interaction

**HIV and Malaria Interaction**

## Early studies – mid/late 1980s

- HIV transmission modes: mosquitoes?
- Does HIV make malaria worse?
- Does malaria make HIV worse?
- Malaria is not an “opportunistic infection”
- Curious because CD4-dependant immune response is thought to be important for malaria
- Malarial anemia    blood transfusion    HIV infection

- No

- “probably No”

## Recognition of the effect of HIV on malaria in pregnant women

- Malawi study (1987-1991):
- During pregnancy, malaria was more common and of higher density in HIV(+) vs. HIV(-) women
- These findings were repeated in other studies and countries -Malawi (2 sites), Kenya (3), Rwanda (1)

##  Placental parasitemia by HIV status and pregnancy number, Kenya

**Parasite density/mm****3**

**% parasitemic**

**HIV (+)**

**HIV (-)**

- 231

- 159

- 197

- 772

- 402

- 479

**Total n = 2263**

**Summary RR = 1.63 (1.41-1.89), p<0.001**

## Current knowledgeMalaria and HIV interactions 

- Does HIV make malaria worse?
- Does malaria make HIV worse?
- Anemia and Blood safety
- Pregnant women and their fetus/newborn
- Non-pregnant adults
- Children
- Program overlap

## Anemia and Blood Safety

- Not much new to report
- Remains a serious problem
- Despite available technology, universal blood screening is not yet achieved, especially in some high HIV prevalence settings
- Important unmet needs include:
-  anemia prevention
-  clarity on best criteria to limit transfusions except when truly needed
-  universal and quality-controlled HIV testing

## Pregnant women and their fetus/newborn

- HIV _does_ make malaria in pregnancy worse
- More and higher density malaria, more illness, more anemia, more low birth weight
- Malaria _may_ make HIV worse
- Higher HIV viral load
- ? impact on Mother-to-Child Transmission (MTCT)

## HIV-associated Risk of Placental and Peripheral Parasitemia in Pregnant Women

**1.27**

**1.70**

**2.39**

**1.60**

**1.58**

**0**

**1**

**2**

**3**

**Placental parasitemia**
**(4 studies)**

**Primigravidae**
**389 HIV+; 1589 HIV-**

**Secundigravidae**
**241 HIV+; 774 HIV-**

**Multigravidae**
**382 HIV+; 1606 HIV-**

**     ****Total**
**982 HIV+; 4049 HIV-**

**Peripheral parasitemia**
**(7 studies)**
**2336 HIV+; 8667 HIV-**

**Relative risk (95% CI)**

*****

**Notes:**
Since the initial study by Steketee & colleagues, many other studies in several countries have confirmed the finding that HIV+ women are at increased risk of malaria parasitemia
I have summarized most of them in this slide, which represents the relative risk for peripheral malaria parasitemia reported in these studies
This shows a consistent increased risk ranging between 1.2 and 2. The summary estimate is in the order of 1.5-fold increased risk for peripheral parasitemia and a 1.75-fold increased risk for placental malaria.
- This slide, by the way, represents the increased risk in all gravidae, irrespective of the number of previous pregnancies a women might have had.

## Hemoglobin Level by HIV Status Malaria and Gravidity Kisumu, Kenya, 1996 –1999 (N= 4,608)

- van Eijk et al, AJTMH, 2001

**Notes:**
- This slides compares haemoglobin levels in the 3rd trimester in 4608 women, 25% of women were HIV[+]
You can see that HIV affects mean hemoglobin in all gravidae groups, with the mean hemoglobin being approximately 0.6 g/dL lower than uninfected women without malaria.
In contrast, malaria is only a significant risk factor in G1+2, but Hb levels are similar in multigravid women with and without malaria (first and third group)
Please also note that, the effects of malaria and HIV were independent; there was no statistical interaction. 
As you can see, the effect of Malaria and HIV were additive in G1+G2

## HIV and Malaria: Associated Reductions in Mean Birth Weight (grams) Kisumu, Kenya, 1996-99 (N=2,466)

|  | 
Primi-gravidae | 
Multi-gravidae |
| --- | --- | --- |
| HIV alone |   44 (-32-112) | 138 (78-199) |
| Malaria alone | 145 (82-209)* |    8 (-71-88) |
| Dual infection |   206 (115-298)* | 161 (63-259) |
| 
*In Primigravidae, both malaria (RR 2.24, p=0.003) and dual infection (3.45, p<0.001) associated with significant increased relative risk of LBW (< 2,500 grams) compared with uninfected women |  |  |

- Ayisi et al, AIDS, 2003

**Notes:**
Similar effects were seen on birth weight. 
This is from recently published work by Dr Ayisi et al, in AIDS. 
Here he showed the reduction in mean birth weight relative to uninfected women;i.e. HIV[-] women without evidence of malaria. Malaria in this slide represents peripheral or placental malaria at the time of delivery.
A significant effect of HIV on birth weight was seen in the multigravidae. Although the effect was not statistically significant in primi-gravidae on mean birth weight, there was a borderline increased risk of LBW in HIV infected primi-gravidae compared with uninfected primi-gravidae. Malaria alone affected birth weights in primi gravidae only.
Of note is that co-infected women had greater reductions in birth weight than women with HIV or malaria infections alone.
Thus, both HIV and malaria influence birth weight; HIV is the predominant factor in multi’s and malaria is the predominant factor in primi’s. 
There is no interaction in the statistical sense, thus the effects of malaria and HIV appear independent, with no evidence that HIV modifies the effect of malaria on birth weight in primi’s. 
It appears, however, that the effects is additive.

## Effect of HIV on Malaria illness in pregnancy Kisumu, Kenya, 1996-1999

| N=2539 | Prevalence |  | RR (95% CI) |
| --- | --- | --- | --- |
| HIV (24.9%) | HIV+ | HIV- |  |
| Clinical malaria | 9.4% | 3.1% | 3.01 (2.36-3.85) |
| Hospitalization
 (all causes) | 4.3% | 2.7% | 1.59 (1.16-2.20) |

- van van Eijk et al, AIDS, 2003

**Notes:**
-This slide shows that, in addition to having more malaria parasitemia, HIV+ women also had 3 times the increased risk of slide confirmed clinical malaria
- They were also more likely to be hospitalized, although the diagnosis of malaria at admission was equally likely for HIV[+] and HIV[-] women. 

## Does HIV make Malaria worse?Pregnant women, fetus, and newborn

- In western Kenya, where HIV prevalence in pregnant women exceeds 25%
- HIV accounts for one-quarter of all malaria infections in pregnancy
- HIV contributes to anemia, low birth weight, and poor infant survival (in both HIV+ and HIV- infants)
- Nearly one-half of all malarious sub-Saharan African countries have HIV seroprevalence in pregnant women in excess of 10%

## Pregnant women and their fetus/newborn

- HIV _does_ make malaria in pregnancy worse
- More and higher density malaria, more illness, more anemia, more low birth weight
- Malaria _may_ make HIV worse
- Higher HIV viral load
- ? impact on Mother-to-Child Transmission (MTCT)

## Malaria’s impact on HIV Replication 

- Malaria antigens induce HIV-1 replication in-vitro                      (Xiao et al, JID, 1998)
- HIV transgenic mouse model --  Murine malaria triggered increased P24 antigen production                (Freitag, JID 2001)

**Notes:**
Malaria antigens are able to increases HIV-1 replication in-vitro
Additionally in an HIV transgenic mouse model, murine malaria triggered an increase in  P24 antigen production, with antigen-presenting cells appearing to be the principal source of virus 
And there is some evidence from the studies by Hoffman and Pisell that this also the case in vivo. 
In their studies from Malawi, non-pregnant adults with symptomatic malaria had a 7-fold higher HIV viral load than malaria un-infected controls
And, importantly, the viral load decreased after successful malaria treatment. 
Further studies on these patients indicated that the origin of the increased HIV replication appeared to be CD14 macrophages – implications of this may be that these relatively long-lived cells could have a relatively sustained effect on viral propagation and dissemination to other cells 

## Malaria and HIV viral load in pregnancy

- _Dar es Salaam, Tanzania_ (Kapiga et al, JAIDS, 2002):                      Peripheral viral load >2-fold higher in parasitemic pregnant women
- _Kisumu, Kenya_ (Ayisi, in press)                                                                            Peripheral viral load 1.4-fold higher in parasitemic women (p=0.096); ↑ viral load with ↑ parasite density
- _Blantyre, Malawi_ (Victor Mwapasa, 10th CROI, Boston, 2003)                     Placental viral load 2.4-fold higher in HIV+ women with placental malaria than in those without malaria
- _Mangochi, Malawi_  (Tkachuk et al. JID 2001)                                           Significant 3-fold higher CCR5 mRNA expression in placentas of malaria-infected women

**Notes:**
Since these studies, there have been several studies conducted to date that have assessed the relationship between viral load and malaria in pregnancy; one of which is published. 
The 1st study by Kapiga and colleagues indeed showed that peripheral viral loads in Tanzanian pregnant women with peripheral malaria were considerably higher than HIV[+] women without malaria. 
Of note most of the women in that study had asymptomatic malaria infections, unlike in the Hoffman study in non-pregnant adults from Malawi
More recently, Victor Mwanesa presented data from Malawi at the 10th conference on retroviruses and opportunistic infections in Boston last Feb, where they assessed both peripheral and placental viral loads
Their findings suggest that placental malaria results in elevation of the placental viral load

## Malaria contribution to HIV-MTCT?

- _Malawian pregnant women_ (Bloland, AJTMH 1995)
- Malaria and HIV co-infection
-  Infants born to dually infected mothers had increased post-neonatal mortality, beyond independent risk associated with exposure to either maternal HIV or placental malaria
-  Increased viral load or altered placental architecture        increased MTCT?

- *MTCT = Mother-to-child transmission

**Notes:**
This raises the question whether this also occurs, and to what extend, in pregnant women in whom malaria is predominantly asymptomatic and tends to sequester in one organ. 
Maternal HIV-1 viral load is the single most important risk factor for HIV MTCT and a 10-fold increase in VL has been associate with, approximately, a 2.5-fold increase in MTCT. 
Thus, this is an important question, in SSA, where few women are on anti-retroviral treatment. 
If malaria were to increases HIV MTCT by increasing the HIV-1 viral load than prevention of malaria with antimalarial drugs or ITNs may reduce this risk.
Of further note is that in the large cohort study from the early 1990s, Bloland and Steketee from Malawi reported an increased risk of post-neonatal mortality in infants born to co-infected mothers, beyond the independent risk associated with either exposure to either maternal HIV or placental malaria 
Although the HIV status in the infant was not determined, the authors hypothesized that PM either stimulates HIV viral replication or disturbs the placental architecture, thereby facilitating transfer of HIV-infected cells or free virus 

## Malaria contribution to HIV-MTCT?

| Bloland et al. |  | >> Infant mortality |
| --- | --- | --- |
| Verhoeff et al. |  | << Infant mortality |
| St Louis et al. |  | No association |
| Brahmbhatt et al. |  | RR 2.9 (1.1 -7.5) |
| Inion et al. |  | RR 0.6 (0.2-1.7) |
| Mwapasa et al. |  | RR 1.2 (0.7-2.3) |
| Ayisi et al. |  | RR 0.4 (0.3-0.7) |

## Placental Malaria & HIV-MTCT Kisumu, Kenya, 1996-1999Ayisi et al, in press EID

- 512 mother-infant pairs with known perinatal HIV transmission status
- 128 women (25%) had placental malaria
- 102 infants (20%) acquired HIV perinatally by 4 months (HIV DNA PCRs).

- Ayisi, in press

**Notes:**
What about the effect of malaria on MTCT of HIV?
In this same study in Kisumu, Kenya, a total of 512 enrolled mother infant pairs with known perinatal HIV transmission status were analyzed
25% had placental malaria
And 102 infants, or 20%, acquired HIV perinatally, defined as positive HIV DNA PCRs at or before the age of 4 months.

Don’t say but informational 
[Infants were considered to have acquired HIV perinatally if they had a first positive HIV PCR at or before 4 months of age and:]
Died, and had or more 2 consecutive positive HIV PCR tests, or
Were lost to follow-up, and at that time had 3 or more positive HIV PCR tests, or
Remained alive with continued and consistent PCR positive results
Infants were considered negative for perinatally acquired HIV if:
3 PCR tests were performed, all tests were negative, and  1 of these tests were at or after 4 months of age

Because infants had to be at least 4 months old to be classified as uninfected, those who died or were lost to follow-up before 4 months of age were excluded from the analysis.  Infants who acquired HIV at or after 5 months of age were considered to have acquired HIV postnatally, and were included in the analysis as non-transmitters from the perinatal perspective.  Infants on whom we had insufficient PCR data to determine their status were classified as indeterminate and were excluded from this analysis. 

## Perinatal HIV Transmission by Placental Malaria Density Kisumu, Kenya 1996-

- Ayisi et al, in press

**Notes:**
The results were CONTRARY to the investigators expectation:
Women with placental malaria had lower perinatal HIV transmission than women without placental malaria.
To further examine the effect of placental malaria on perinatal HIV transmission, placental malaria density was grouped into 3 categories, as shown on this slide – none, low, and high (POINT)
Perinatal HIV transmission rates were significantly lower among women with low density placental malaria infection compared to women with no placental malaria.  
Among women with placental malaria, perinatal HIV transmission rates were 2 fold greater among those with high density placental malaria
However, the perinatal HIV transmission rates among women with high density placental malaria did not differ significantly from rates among women with no placental malaria
This relationship held true in multivariate Poisson regression models, adjusted for maternal HIV viral load, and other co-variates such as episiotomy or perineal tear, birth weight, gravidity, and CD4 counts. 

## Potential Immunologic Basis: Effect of Malaria on MTCT

**Placental malaria**

**Low density**

**High density**

**Th1 response**

**HIV replication**

**MTCT**

**LIF**

**MIP-1-beta**

**Block cellular entry HIV**

**TNF-alpha**

**HIV replication**

**MTCT**

- MIP-1-beta = Macrophage Inflammatory Protein-beta; LIF = Leukemia Inhibitory Factor

**Notes:**
This diagram gives more details on a hypothesis of some of the complex interactions that may be occurring at the placental level
Recent immunologic studies conducted in a sub-set of women in the Kisumu study showed that MIB1b (macrophage inflammatory Protein-beta) and RANTES, chemokines known to block the entry of HIV-1 virus (co-receptor CCR5), were significantly elevated in the intervillous blood plasma of women with PM, irrespective of their HIV status
, a chemokine known to block the entry of HIV-1 virus (receptor CCR5), was significantly elevated in the intervillous blood plasma of women with PM, irrespective of their HIV status
One hypothesis may be that in low density parasitemia this increase in chemokine production occurs, which limits MTCT
Malaria infection also induces a Th1/Th2 disequilibrium favoring the Th1 proinflammmatory response– which may limit HIV replication
Additionally, Leukemia Inhibitory Factor (LIF) is upregulated in placental malaria & is known to inhibit HIV replication

On the other hand, high density infections may be a marker for decreased immunocompetence – which may alter the balance of pro-inflammatory cytokine production
For example, Moore & colleagues have shown that TNF-alpha production was enhanced from intravillous blood mononuclear cells from HIV+ women with placental malaria compared to those HIV+ women without placental malaria
And Stevenson has shown that TNF levels are elevated in placental malaria 
TNF increases HIV replication and thus incerase MTCT

## Conclusions: Malaria & HIV during pregnancy

- Some _clear_ interactions
- Preventing/managing placental malaria and HIV would reduce maternal anemia and low birth weight
- Some _unclear_ interactions that require characterization
- Will clearing placental malaria affect MTCT ?

**Notes:**
So in summary of the biological interaction between malaria and HIV during pregnancy:
The studies show some clear, but also and some unclear interactions
The effect of malaria on HIV in particular required further studies to find out why some women with PM may have an increased risk of passing the HIV virus on to their children, whereas in others PM may be protective. 
A better characterization of local cytokine and chemokine mediated immune responses in the placenta and its relationship with peri-natal transmission of HIV, while taking HIV disease progression into account, is warranted.
There is little doubt though that HIV increases the risk of malaria in pregnant women, placing women with dual infections at much higher risks of maternal anemia and delivering a LBW infant. 
Prevention of placental malaria would reduce some of these adverse consequences, but the available evidence with regard to the relationship between placental malaria and MTCT of HIV is controversial, and it is therefore difficult to predict the potential impact of antimalarial interventions on perinatal HIV transmission.

## Non-pregnant adults

- HIV with immune compromise (CD4 depletion) _does_ make malaria in adults worse
- More malaria, higher density parasitemia, more illness, more severe disease
- Reduced efficacy of antimalarial therapy?
- Malaria _may_ make HIV worse
- Higher HIV viral load
- Impact on clinical illness?; survival?; transmission?

## Non-pregnant adults

- HIV with immune compromise (CD4 depletion) _does_ make malaria in adults worse
- More malaria, higher density parasitemia, more illness, more severe disease
- Reduced efficacy of antimalarial therapy?
- Malaria _may_ make HIV worse
- Higher HIV viral load
- Impact on clinical illness?; survival?; transmission?

## Impact of HIV on malaria in non-pregnant adults

- Advanced HIV immunosuppression is associated with higher density parasitemia and more clinical illness in adults
- French et al, AIDS 2001; Whitworth et al. Lancet 2000; Francesconi et al, AIDS 2001.
- Advanced HIV immunosuppression is also associated with poorer response to malaria treatment
- Shah S et al, personal communication 2004

## Non-pregnant adults

- HIV with immune compromise (CD4 depletion) _does_ make malaria in adults worse
- More malaria, higher density parasitemia, more illness, more severe disease
- Reduced efficacy of antimalarial therapy?
- Malaria _may_ make HIV worse
- Higher HIV viral load
- Impact on clinical illness?; survival?; transmission?

## Malaria contributes to increased HIV Viral Load

- Several intercurrent infections have been shown to increase HIV replication *in vivo:*
*Mycobacterium tuberculosis*
*Mycobacterium avium* complex
*Pneumocystis carini*
*Herpes simplex*
- STIs?

## Studies of the effect of malaria on HIV RNA levels

- Malawian adults with acute malaria
-  7-fold increase in HIV-1 viral load
-  Reversible with treatment (in some patients)
-  Induction of HIV-1 replication in CD14 macrophages    Hoffman, 1999; Pisell, 2002
- Follow-up study in Malawian adults
-     Kublin et al, 2003 Am Soc Trop Med Hyg Mtg

## Clinical & public health significance

- Individual
- Brief increase in viral load due to malaria _may_ worsen clinical prognosis
- Population
- Higher viral load associated with higher infectivity
- Probability of HIV transmission _may_ be elevated around a malaria episode, especially during the lag time post-malaria before RNA levels return to baseline

## Infants and Children

- Difficult to study
- Low incidence/prevalence of HIV in this group
- Already highly susceptible to malaria and HIV-associated immune deficiency may not make this susceptibility much worse
- Dual Malaria and HIV is associated with poor outcome
- Anemia
- Survival?

## Malaria in HIV+ infants Kisumu, Kenya, June 1996-April 2000

- HIV+ infants _were not at risk_ of
- more malaria parasitemia
- higher parasite density
- However, if parasitemic, _were at risk_ to:
- be febrile
- have severe anemia
- have splenomegaly
- be admitted to the hospital

**Source: van Eijk et al, unpublished**

## Hemoglobin in infants by HIV status and malaria Kisumu, Kenya, June 1996-April 2000

**Source: van Eijk et al, AJTMH, 2002**

**Notes:**
The shape of the mean hemoglobin curve in the first year of life includes a lack of nadir at age 2 month(normally seen in healthy children), hemoglobin levels decrease up to 8 to 10 months, with little variation thereafter.
1. HIV infection of the infant is a consistent risk factor for infant anemia (Attributable fraction anemia 17%), thus 17% of the anemia could be attributed to HIV alone.
2. As expected, (concurrent) malaria was a risk factor for anemia also in early infancy when most children are protected.
3. HIV Pos were particularly vulnerable to the adverse effect of malaria associated anemia 

## Post-neonatal Infant mortalityby maternal HIV-status and placental malariaKisumu, Kenya, June 1996-July 2001, N=866

- A: No infection (N=96)

- B: placental malaria only
-      (N=117)

- D: HIV only (N=494)

- C: Dual infection (N=159)

**A**

**B**

**C**

**D**

**Source: van Eijk et al, unpublished**

- A vs C or D: *P*<0.01
- A vs B: *P*=0.06

## Malaria and HIV biologic interactions– summary 2004

- HIV-associated immunosuppression _contributes_ to more and worse malaria and it’s consequences in adults, pregnant women, and children.
- Malaria _contributes_ to stimulus of HIV replication and _possibly(?)_ to its consequences: disease progression, transmission in adults, and MTCT.
- Co-infection with Malaria and HIV in pregnant women _contributes_ to anemia, low birth weight,and their risk for poor infant survival.
- Malarial anemia in children too frequently requires blood transfusion and may still lead to HIV transmission

## Malaria & HIV program overlap

**Population overlaps**
- Anemic children; pregnant women; adults with CD4
**Intervention overlaps**
- Diagnostics
- Treatments: complexity and costs of Tx, resistance
- Protease inhibitors block endothelial CD36 binding of malaria-infected red blood cells
- OI prophylaxis with co-trimoxazole (an antimalarial)
- HIV-infected persons need malaria prevention
**Site of activity overlaps**
- GFATM and Country Coordinating Mechanisms
- Antenatal clinics; under-5 clinics; communities, VCT sites? ARV delivery systems

## Malaria & HIV program overlap

**Recommendations for coordinated program action**
- Jointly strengthen health service delivery:
-  Laboratories
- Antenatal and delivery care
- ITNs & IPT for malaria; VCT & MTCT prevention
- Child care – anemia prevention
**Specific Interventions**
- ITN distribution with ARV delivery
- Use highly efficacious antimalarials in HIV+ persons with malaria infection
- HIV+ persons on cotrimoxazole for OI prophylaxis who get malaria should receive highly effective antimalarials