IPTp Policy in Zanzibar toward Pre-Elimination of Malaria:

Results from a Study of Placental Parasitemia

Mwinyi Issa Msellem1; Marya Plotkin2; Khadija Said1; Natalie Hendler2; Asma Ramadhan Khamis2, Elaine Roman3, Raz Stevenson4 Chonge Kitojo5, Julie Gutman5, Peter McElroy5

1Zanzibar National Malaria Control Programme, Zanzibar Ministry of Health2Jhpiego Tanzania3Jhpiego Baltimore4United States Agency for International Development5Centers for Disease Control and Prevention and President’s Malaria Initiative

Background

• Due to scale-up of malaria prevention and treatment by the Zanzibar Malaria Control Programme (ZMCP) of the Ministry of Health (MOH), Zanzibar is in the pre-elimination phase of malaria control.

• P. falciparum prevalence in the general population is currently less than 0.5% [1], and the diagnostic positivity rate among febrile patients was 1.2% in 2011. [2]

• Control of malaria in pregnancy (MIP) follows the three-pronged approach recommended by the World Health Organization:• Intermittent preventive treatment for pregnant

women (IPTp) with sulfadoxine-pyrimethamine (SP) distributed through antenatal care (ANC) services

• Long-lasting insecticide-treated nets• Case management of MIP

• IPTp-SP was implemented in 2004 when malaria prevalence exceeded 20%.

• Coverage among pregnant women remains low. In their last pregnancy:• 69% women reported taking any SP• 43% women reported taking 2+ doses of SP [3]

• The MOH of Zanzibar is reconsidering provision of IPTp through ANC services in light of very low malaria prevalence.

• ZMCP has introduced screening for malaria in ANC services:• In 2011 and 2012, 0.2% of ANC clients tested

positive for malaria using mRDT (19,724 malaria tests were performed in 2011 and 27,186 performed in 2012). [4]

The Placental Parasitemia Study

A prospective observational study was conducted in selected health facilities in Zanzibar with the objective of measuring placental parasitemia rates among pregnant women who did not receive IPTp.

•Policy question: • Is IPTp useful at current level of transmission in

preventing maternal and neonatal morbidity?

The rainy season is March–May, and peak malaria transmission is May–June

Methods

• Convenience sample of pregnant women enrolled at six hospitals in Zanzibar on day of delivery.

• September 2011–April 2012.• Client card checked for documentation of provision of IPTp

(eligible = no doses of SP, resident of Zanzibar).• Informed consent obtained from eligible clients.• Sample taken from maternal side of placenta by labor ward

midwives.• Dried blood spots (DBS) on filter paper were prepared from

placental blood specimens. • DBS were analyzed via polymerase chain reaction

indicating active Plasmodium infection (all species).

Results

• 1,423 deliveries were enrolled from Pemba (52%) and Unguja (48%), representing 6% of the total deliveries at the six facilities.

• Average age of women was 26.9 years.• 376 (32%) were primigravidae.

• 9 of 1,349 (0.8%, 95% confidence interval 0.2–3.3%) placental specimens were PCR positive.

• Only P. falciparum was detected.

Table 1. Facilities and Annual Delivery Volume

Island Facility Annual Deliveries (2011) Number of Samples

Analyzed

Unguja Mnazi Mmoja Hospital 10,338 380

Mwembeladu Hospital 5,665 208

Kivunge Health Centre 1,420 67

Pemba Chake Chake Hospital 2,838 415

Wete Hospital 1,607 184

Micheweni Health Centre 645 90

Total 1,349

Case

Number

Health Facility of

Delivery

Month of Delivery Village of

Residence

Parity Birth Weight

(kg)

1 Micheweni Sep 2011 Shumba Viamboni 1 2.5

2 Micheweni Apr 2012 Mjini Wingwi 1 2.5

3 Micheweni Apr 2012 Mjini Wingwi 3 1.8 (macerated

stillbirth)

4 Mwembeladu Sep 2011 Kama 4 2.6

5 Mwembeladu Oct 2011 Bumbwini 6 3.6

6 Mwembeladu Oct 2011 Mbuzini 2 3.1

7 Mwembeladu Oct 2011 Magogoni 3 2.8

8 Kivunge Oct 2011 Unknown 1 3.5

9 Mnazi Mmoja Nov 2011 Kilimahewa 5 4.2

Table 2. Positive Cases in the Placental Parasitemia Study

The majority of the samples were collected in the first five months of the study (August–December 2011). A shipment of SP received in November 2011 increased availability of SP in the islands, and a dramatic drop in eligible clients was seen by January 2012.

Figure 1. Timing of Sample Collection for the Parasitemia Study

• Six (66%) of the nine placental infections were from Unguja deliveries.

• Eight placental infections were accompanied by a normal birth weight delivery (≥ 2500 g).

• Placental infections were not more common during the seasonal transmission increases of 2011–2012.

Conclusions • Malaria infection among pregnant women who

have not had IPTp is extraordinarily low (0.8%).• Given the low prevalence of placental malaria

infection among women who had not had IPTp, in combination with the overall low prevalence of malaria on the islands, a policy shift away from IPTp is not an unreasonable option, if it is done with expanded surveillance of MIP and strengthening of detection and case management of women with MIP.

• Enhance surveillance of MIP through expansion of the existing surveillance system, MEEDS, to capture symptomatic pregnant women diagnosed at ANC and ensure that pregnancy status is recorded for women diagnosed at the outpatient department.

• Strengthen case management of MIP and ensure continued high ownership and use of insecticide-treated nets, particularly among women of reproductive age.

• Conduct an internal review of costs and findings from surveillance to inform on whether the cost of screening every pregnant woman in antenatal care is justified.

Recommendations

References

1. Bhattarai A, Ali AS, Kachur SP, et al. 2007. Impact of artemisinin-based combination therapy and insecticide-treated nets on malaria burden in Zanzibar. PloS Med 4(11): e309.

2. Zanzibar Malaria Control Programme. 2011. Zanzibar Malaria Epidemic Early Detection System Biannual Report, Mid-Year 2011; Vol. 3(1).

3. Tanzania HIV/AIDS and Malaria Indicator Survey (THMIS) 2011–12.

4. Zanzibar Malaria Control Programme. 2012. Unpublished National surveillance data.