February 19, 2011

Malaria: A pregnant woman’s worst enemy


The craving for children is a basic instinct. Unfortunately, attempts to fulfill this desire often ends in disaster as several women lose their lives in the process. It is no longer news that within the African region, Nigeria has the highest maternal and infant mortality rates.

Maternal mortality is estimated at 800 per 100,000 live births with wide regional disparities. A woman in Nigeria is subjected to a life time risk of dying from pregnancy related complications to the ratio of 1 in 8 compared to 1in 10,000 in developed countries.
One of the major factors fueling maternal death in Nigeria is Malaria in Pregnancy (MiP). Data shows that  11 per cent of maternal death is attributable to malaria.

To buttress the worrisome malaria picture, many researchers have reported high prevalence rates of malaria in pregnancy ranging from 19.7 per cent to 72.0 percent and it is the leading cause of morbidity in pregnant women.

Experts note that malaria in pregnancy (MiP) is an obstetric, social and medical problem requiring multidisciplinary and multidimensional solution.

Despite the clear evidence that many pregnant women could be saved from complications of malaria through the use of insecticide-treated nets (ITNs) and intermittent preventive treatment (IPT), many still die.

Concerned health watchers have raised concern, warning that if the situation is not remedied speedily, the targets to reduce the incidence of malaria in pregnancy will not be met and the complications caused by this old ailment will continue to wreak havoc on our women and their unborn babies.

Statistics show that an estimated 30 million women per year become pregnant. These women are at risk of Plasmodium falciparum, the most deadly  form of malaria, which medical experts have implicated as the major cause of serious illness for pregnant women. Studies have shown that Plasmodium Falciparum infection cause as many as 10,000 maternal deaths each year, contributes to approximately 2 to 5 per cent of maternal anemia, 8 – 14 per cent of low birth weight infants and 3 – 8 per cent of all infant deaths.

More pathetic is that most times, the victims do not present any symptoms or feel ill.  Clinical records show that the malaria parasites attack the placenta even at low infection rates and this invasion of the placenta leads to ill health for the mother and may cause abortion of the foetus as well as premature labour.

Malaria in pregnancy reduces a woman’s immunity to malaria, making her more susceptible to malaria infection and increasing the risk of illness, severe anaemia and death. For the unborn child, maternal malaria increases the risk of spontaneous abortion, stillbirth, premature delivery and low birth weight.

Tackling malaria in pregnancy contributes to three of the Millennium Development Goals, namely goals 4 (reduce child mortality), 5 (improve maternal health) and 6 (combat HIV/AIDS, malaria and other diseases). In addition, the Roll Back Malaria initiative set itself the target of ensuring that 100 per cent of pregnant women receive IPT and 80 per cent of all people in affected areas use ITNs to keep mosquitoes at bay.

To further buttress that malaria is really an enemy, Finally, African leaders gathered in Abuja, in 2000, pledged to take steps to provide 60 per cent of pregnant women in malaria-endemic areas like Nigeria with effective intervention measures.

In a study conducted by Mr. Chimere O. Agomo and colleagues at the Nigerian Institute of Medical Research (NIMR) on “Prevalence of Malaria in Pregnant Women in Lagos, south-west Nigeria” it was reported that the prevalence rates in pregnancy vary considerably.

The report also states that malaria control still remains a serious challenge in Africa where 45 countries, including Nigeria, are endemic for malaria, and about 588 million people are at risk.

According to Agomo and colleagues, the principal impact of malaria infection is due to the presence of parasites in the placenta causing maternal anemia (potentially responsible for maternal death when severe) and low birth weight (LBW)

However, a recent World Malaria Report, which indicated that Nigeria accounts for a quarter of all malaria cases in the 45 malaria-endemic countries in Africa, clearly shows  the challenge of malaria in Nigeria.  Thus, pregnant women, who are known to be one of the groups at high risk of the effects of malaria infection, need special protective measures to ensure their survival and improve birth outcomes.

To tackle the challenges of prevention and treatment of malaria in pregnancy, the World Health Organisation has recommended that pregnant women use ITNs and IPTs to lower their risk of developing malaria.

Overview of Malaria in Pregnancy

It is estimated that 10,000 women and 200,000 infants die as a result of malaria infection during pregnancy; severe maternal anemia, prematurity, and low birth weight contribute to more than half of these deaths.

Causes and types
Human malaria is primarily caused by four species of Plasmodia: P. falciparum, P. vivax, P. ovale, and P. malariae. Most infections are due to either P. falciparum or P. vivax, but mixed infections with more than one malarial species also occur. The majority of malaria-related deaths are due to P. falciparum.

The continued public health burden of malaria is due to a combination of factors, including:  Increasing resistance of malarial parasites to chemotherapy

* Increasing resistance of the Anopheles mosquito vector to insecticides
* Ecologic and climatic changes

Plasmodium falciparum and Plasmodium vivax are the most common. Plasmodium falciparum is the most deadly.

Malaria is transmitted exclusively through the bite of Anopheles mosquito. The intensity of transmission depends on factors related to the parasite, the vector, the human host, and the environment.

Malaria is an acute febrile illness. Symptoms appear seven days or more (usually 10–15 days) after the infective mosquito bite. The first symptoms are fever, headache, chills and vomiting – may be mild and difficult to recognise as malaria. If not treated within 24 hours, P. falciparum malaria can progress to severe illness often leading to death.

Who is at risk?
* Young children in stable transmission areas who have not yet developed protective immunity against the most severe forms of the disease.
* Non-immune pregnant women are at risk
* Semi-immune pregnant women in areas of high transmission.

* Semi-immune HIV-infected pregnant women in stable transmission areas are at increased risk of malaria during all pregnancies.
* People with HIV&AIDS are at increased risk of malaria disease when infected.

Diagnosis and treatment
Early diagnosis and treatment of malaria reduces disease and prevents deaths.

The best available treatment, particularly for P. falciparum malaria, is artemisinin-based combination therapy (ACT). The WHO recommends that malaria be confirmed by parasite-based diagnosis before giving treatment. Treatment solely on the basis of symptoms should only be considered when a parasitological diagnosis is not possible.

Vector control is the primary public health intervention for reducing malaria transmission at the community level. It is the only intervention that can reduce malaria transmission from very high levels to close to zero.

Two forms of vector control are effective in a wide range of circumstances. These are
* insecticide-treated mosquito nets (ITNs):

* indoor spraying with residual insecticides: Indoor residual spraying (IRS) with insecticides is the most powerful way to rapidly reduce malaria transmission. Drugs can also be used to prevent malaria.

The WHO three- pronged approach to the prevention and management of malaria during pregnancy is:
Sleeping under Insecticide-treated nets (ITNs): This  remains an important strategy for protecting pregnant women and their newborns from malaria-carrying mosquitoes. In addition, in areas of high and moderate transmission of Plasmodium falciparum malaria (the most prevalent type of malaria in Africa), intermittent treatment with an antimalarial drug is a cost-effective means of preventing malaria in pregnancy. The current recommendation is to give at least two doses of a safe and effective antimalarial (currently, sulphadoxine-pyrimethamine) to all pregnant women living in these areas.

In areas of low or unstable malaria transmission, pregnant women have low immunity to malaria and a two- to threefold higher risk of severe malarial illness than non-pregnant women. In these areas, use of ITNs and prompt case management of pregnant women with fever and malarial illness are the main strategies for malaria prevention and treatment.

Delivering malaria interventions through antenatal care: Intermittent preventive treatment – to pregnant women should be part of the routine antenatal care, using and strengthening the existing antenatal care infrastructure. This strategy is now an integral part of WHO’s “Making Pregnancy Safer” initiative.