Tropical Health Matters

The recent fatal crash of Dana Air in Lagos, Nigeria claimed the life of a renown parasitologist and educator, Professor C.O. Onwuliri, most recently the Vice Chancellor of the Federal University of Technology Owerri. In his remembrance we are sharing the abstracts of two recent malaria publications of which he was a co-author. His various publications also focus on onchocerciasis, lymphatic filariasis and other parasitic diseases.

Perceptions on the use of insecticide treated nets in parts of the Imo River Basin, Nigeria: implications for preventing malaria in pregnancy. Chukwuocha UM, Dozie IN, Onwuliri CO, Ukaga CN, Nwoke BE, Nwankwo BO, Nwoke EA, Nwaokoro JC, Nwoga KS, Udujih OG, Iwuala CC, Ohaji ET, Morakinyo OM, Adindu BC. Afr J Reprod Health. 2010; 14(1): 117-28.

ABSTRACT: This study aimed at assessing perceptions on use of ITNs in parts of the Imo River Basin, Nigeria and its implications in preventing malaria in pregnancy. Data was collected using focus group discussions, key informant interviews and structured questionnaires. Results showed high awareness on the benefits of ITNs. Factors affecting use of ITNs included its high cost, perceptions of chemicals used to treat them as having dangerous effects on pregnancy, low utilization of antenatal care, husband’s lack of interest in malaria prevention and perceptions  that adolescent girls are at low risk of getting malaria. The implications of these findings include demystifying the negative perceptions on the chemicals used for net treatment and subsidizing the cost of ITNs to increase access. These findings provide important lessons for malaria programmes that aim at increasing  access to ITNs by pregnant women in developing countries.

Malaria infection in HIV/AIDS patients and its correlation with packed cell volume (PCV). Goselle ON, Onwuliri CO, Onwuliri VA. J Vector Borne Dis. 2009; 46(3): 205-11.

OBJECTIVES: The study was designed: (i) to determine the prevalence of malaria parasites; (ii) to determine the relationship between parasitaemia and age/sex; (iii) to correlate the PCV levels with parasitaemia; and (iv) to determine the influence of protection against natural transmission on the prevalence of malaria.

METHODS: Participants were recruited at the Plateau State Human Virology Research Laboratory (PLASVIREC), Robert Gallo House at the Plateau State Specialist Hospital, Jos and grouped into: (i) Malaria and HIV co-infection group (n = 64);  and (ii) HIV infected group without concurrent malaria infection (n = 136). Standard laboratory procedures were used for the HIV and Plasmodium parasites screening, malaria parasite density, and packed cell volume.

RESULTS: The results showed a significant difference (p >0.05) among the sexes and age groups. About 64 (32%) of the individuals had Plasmodium infection (30% Plasmodium falciparum, 0.5% P. malariae, and 1.5% mixed infections of P. falciparum and P. malariae). Malaria parasites were more common among the rural dwellers and in the age group of 21-30 yr. Regression analysis showed a negative  association of malaria parasitaemia and PCV among the malaria-HIV positive and malaria-HIV negative (r2 = 0.529; p < 0.001). CONCLUSION: In the present study, PCV might be of useful indicator and if not monitored could lead to AIDS establishment especially where  high malaria parasitaemia is noted. The findings further suggest that the defined stage of HIV infection in the study, malaria coinfection may moderate the impact  of HIV infection on PCV.

The push toward universal coverage of long lasting insecticide-treated bed nets (ITNs/LLINs) does not negate the fact that pregnant women are still a more vulnerable group that needs protection from anemia and death themselves and miscarriage, low birth weight and greater infant and child mortality for their offspring. So far the data on net coverage for pregnant women is not encouraging. Nets are extremely important because they are the one safe malaria control intervention that women can use right from the start of pregnancy.

Recent Demographic and Health and Malaria Indicator Surveys (DHS and MIS) show a common problem.  The graph here shows general access to LLINs is low (orange bars) in many countries relative to the Roll Back Malaria target of 80% coverage by 2010. What is of equal concern is that even when households possess nets, pregnant women do not always use them (blue bars).  Rwanda with its strong national network of community health workers is the exception. What is discouraging women?

The Liberia MIS asks why people do not own nets, and since these surveys prioritize interviewing women of reproductive age, we may assume that these reasons express the views of women.  A few do not perceive mosquitoes to be a problem (especially in the dry season), some simply do not like to sleep under nets while others complain of the cost.  The latter is curious because nets are primarily provided for free these days.

Clearly we need more information on the dynamics of net use at the household level.  Field visits after a universal coverage campaign in Akwa Ibom State discovered that women themselves see alternative uses of for nets.  One picture shows LLINs covering vegetable gardens that are tended by women in this community. Maybe they believe the nets will keep insects off their vegetables, although the sun will soon render the insecticide ineffective.

Another picture shows that a woman has protected the wares in her small kiosk buy covering it with a LLIN. Customers can still see the wares but insects can’t nibble at the food items on sale (nor children easily pilfer some).

Both of these examples highlight the economic roles of women in the community. Are women making net decisions on their perceptions of what is in their best economic interest? In most communities in Nigeria, income from a woman is crucial to the welfare of her child.

The issue of nets for pregnant women will be one of the issues discussed during the upcoming summit, Malaria in Pregnancy: a Solvable Problem—Bringing the Maternal Health and Malaria Communities Together, a meeting in Istanbul, Turkey, June 26-28, 2012, organized by the Maternal Health Task Force at Harvard School of Public Health.  We will be covering the deliberations as they unfold.

Kelly M. Searle, ScM and her advisor at the Johns Hopkins Bloomberg School of Public Health, William J. Moss, MD MPH share the findings from her masters thesis: “Evaluation of Reactive Case Finding to Target Focal Malaria Transmission in Two Different Settings in Macha, Zambia.” They offer ideas on how we can move toward the challenging target of malaria elimination…

With malaria elimination in the minds of many, new methods of identifying and treating asymptomatic parasite carriers are being investigated. The current study evaluated reactive case detection as a malaria transmission intervention. Reactive case detection is the result of a malaria case being identified in a clinic by passive case detection, testing and treating that individual and their household contacts, and surrounding neighbors.

Survey sample data from different areas of Macha, Zambia in 2007 and 2008 were used to determine proportions of malaria infected individuals caught passively and reactively. Simulations were done to extrapolate this data to non-sampled households. Radii surrounding identified positive households (index households) were examined to determine the proportion of positive households in each radius.

In the 2007 transmission setting, screening 500 meters surrounding index households would have identified 89% of all households with an RDT positive resident and 90% of all RDT positive individuals. Screening 1 kilometer surrounding index households would have identified 95% of all households with an RDT positive resident and 94% of all RDT positive individuals (Figure 1). In the 2008 transmission setting, screening 500-meters surrounding index households would have identified 77% of all households with an RDT positive resident and 76% of all RDT positive individuals. Screening 1 kilometer surrounding index households would have identified 89% of all households with an RDT positive resident and 89% of all RDT positive individuals (Figure 2).

Reactive case detection has the potential to be an effective malaria intervention for populations of both moderate transmission settings and transmission settings transitioning (or that have recently transitioned) from moderate to low. With reactive case detection, a large proportion of malaria-infected individuals are accounted for using screening radius of 500 meters. A greater proportion of total households would have to be screened in the lower transmission setting, likely due to the overall lower numbers of cases existing. For reactive case finding to be most effective, it should be targeted at malaria foci and hotspots where transmission is greater than the overall area.