CHAPTER ONE

GENERAL INTRODUCTION

USAGE OF INSECTICIDE TREATED BED NETS AND IT EFFECTS ON MALARIA PREVALENCE IN PREGNANT WOMEN IN THE TIKO HEALTH DISTRICT

1.1 BACKGROUND OF THE STUDY  

An estimated 125 million pregnancies are exposed to malaria each year (Dellicour  et al.,2007). Pregnant women are more susceptible to malaria compared with non-pregnant women placing both mother and fetus at risk of the adverse consequences (Desai  et al.,2007).

In areas of low transmission, women acquire limited antimalarial immunity and are susceptible to symptomatic and sometimes severe malaria, and fetal and maternal death (Nosten et al., 2004). In areas of stable malaria transmission, such as in most of sub-Saharan Africa, infection with Plasmodium falciparum in pregnancy is frequently classified as ‘asymptomatic’ (afebrile) and therefore remain undetected (Chen I et al., 2016).

If left untreated these infections cause maternal anaemia (Guvatt  et al.,2001)  A major cause of preventable low birth weight (LBW) (Guvatt et al., 2004), a significant risk factor for neonatal and infant death (Guvatt et al., 2001). The prevalence of malaria in pregnancy is highest in first time pregnancies and in women aged 15–19 years and decreases with each subsequent pregnancy (Desai et al.,2007).

Malaria is also much more prevalent in HIV-infected women regardless of the number of previous pregnancies (Tel Kuile et al.,2004).

Current malaria control strategies involve early diagnoses and treatment of infected individuals and the reduction of human-mosquito contact rates through vector control efforts (Mushinzimana et al., 2006). Malaria-related mortality, morbidity and economic loss could, therefore, be averted if the available effective preventive and treatment interventions are made universally accessible to those in need (Breman et al., 2007).

Nevertheless, inadequate access to information, healthcare and antimalarial resources result in the inability to properly implement malaria interventions (Welch et al., 2012). Furthermore, disparities in access between rural and urban locations exist (Welch K et al., 2012), with rural areas found to have less access to malaria control interventions (Kazembe L et al., 2007).

The World Health Organization (WHO) recommends universal coverage with long lasting insecticide-treated nets (LLINs) for the prevention of malaria in pregnancy (Tel Kuile et al.,2004) and, in malaria-endemic areas in Africa, intermittent preventive treatment in pregnancy (IPTp) with at least three doses of sulphadoxine-pyrimethamine (SP) beginning in the second trimester (WHO  2004).

Insecticide Treated Nets (ITNs) have been shown to reduce morbidity and mortality, but coverage and proper utilization continue to be moderate in many parts of sub-Saharan Africa. The gains made through a nationwide free distribution were explored as well as the effect on malaria prevalence in semi-urban and rural communities in southwestern Cameroon.

A cross-sectional survey was conducted between August and December 2013. Information on net possession, status and use were collected using a structured questionnaire while malaria parasitaemia was determined on Giemsa-stained blood smears.

Insecticide-treated nets (ITNs) and indoor residual spraying (IRS) have both been demonstrated to reduce malaria (Mabaso et al., 2004) and, to date, are the mainstay for controlling malaria vectors and associated malaria transmission (Plues  et al., 2010).

Nevertheless, long-lasting insecticide-treated bed nets (LLINs)/ITNs are the major and most promising components of the selective vector control strategies (WHO,UNICEF 2005) . In fact, a massive scale-up in malaria control programmes between 2008 and 2010 resulted in the provision of ITNs to protect more than 578 million people at risk and the concomitant reduction in mortality from 985,000 in 2000 to 781,000 in 2009 (WHO 2010).

Therefore, the government of Cameroon embarked on a scaling-up of ITN coverage in 2011, in line with the Roll Back Malaria (RBM) recommendation of universal coverage (Kilian et al., 2010).

However, bed nets as a tool for malaria control can present challenges, such as coverage, proper use and replacement of old and torn nets (Rehman et al., 2011). Recent data (Cameroon DHS-MICS 2011) suggest that net possession and use remain low in Cameroon, with only 36% ITN ownership and 21% of children below 5 years reportedly sleeping under an ITN.

The coverage and proper utilization of this malaria preventive measure in the country may be limited by the lack of sustainable distribution and issues related to replacement of nets, seasonality of malaria, and poor knowledge of the community about the link between mosquitoes and malaria (Biadgilign et al., 2012).

The possible shift in local malaria epidemiology also necessitates the evaluation of their proper use and effectiveness in ensuring their long-term benefit (Deribew et al.,2010). In Addition, establishing determinants of infection and evaluating the effectiveness of vector control interventions can identify possible ways to improve malaria control (West  et al.,2012).

The World Health Organization (WHO 2011), therefore, recommends periodic surveys to assess whether populations at risk receive sufficient LLINs/ITNs and that these are properly used.

Nevertheless, assessments on possession and utilization of the LLINs in Cameroon have been limited (Tchinda et al., 2012) and have not been done in the study area since the last free distribution from district health offices to the community.

While challenges to increasing ITN ownership may diminish as a result of the expansion of large-scale distribution efforts, ITN impact on transmission will be minimized if they are not properly and consistently used, especially among populations vulnerable to increased malaria morbidity and mortality, such as children and pregnant women (Keating et al., 2012). In addition, the considerable disparity has been observed between ITN possession and usage (Macintyre et al., 2006).

1.2 PROBLEM STATEMENT

Insecticide-treated nets are a widely used tool that has been proven to be effective in the prevention and control of malaria in malaria-endemic countries thereby reducing disease morbidity and mortality.Since 2000, Cameroon has benefited from the support of various international partners to implement malaria control interventions (Plan Strategique Nationale de Lutte Contre le Paludisme, 2011-2015).

Over 20 million LLINs have so far been freely distributed to the population through several campaigns (Minsante,2018), Despite these efforts made by to scale up ITNs distribution, coverage and usage remain low(Njumkeng et al.,2019,Cho Frederick et al., 2018).

Furthermore, pregnant women being more vulnerable to malaria due to their weak immune system during pregnancy in order to accommodate the growing fetus. It is necessary to carry out research to evaluate the prevalence of malaria among pregnant women using ITNs in other to inform decision making and to better coordinate control intervention strategies towards this endemic area.

1.3 RESEARCH QUESTIONS

1. What is the prevalence of malaria among pregnant women in the Tiko health district?
2. How many of these pregnant women own and use ITNs?

iii. Is there any relationship between ITNs usage and malaria prevalence among pregnant women?

1.4 GENERAL OBJECTIVE

   To determine the usage of ITNs and their effects on malaria prevalence in pregnant women in the Tiko health district.

1.5 SPECIFIC OBJECTIVES

1. To determine the prevalence of malaria among pregnant women in the Tiko health district.
2. To determine how many of these pregnant women own and use ITNs

iii. To determine the relationship between ITNs usage and malaria prevalence among pregnant women in the Tiko health district.