U.S. Investments to Battle Malaria Show Results

Progress against Malaria is one area where U.S. investments in global health have made an great impact. Just five years ago, it was estimated that malaria killed nearly one million children annually in sub-Saharan Africa. The economic cost to the continent was estimated to be nearly $30 billion each year in lost productivity.

“Today, the U.S. along with its partners have helped cut malaria cases in half in more than 40 countries and reduced childhood malarial deaths by 200,000, and even seen a reduction in all-cause child mortality in seven initial Presidential Malaria Initiative countries,” said USAID Administrator Raj Shah. He added, “I find that statistic astounding.”

The President’s Malaria Initiative, which is led by the U.S. Agency for International Development and implemented jointly with the Centers for Disease Control and Prevention, has led the fight against this preventable and curable disease which is currently the leading cause of death among children in Africa.

“Today, we have a lot to celebrate, because the rates of death resulting from malaria infection are decreasing,” said Rear Admiral Tim Ziemer, the U.S. Global Malaria Coordinator. “However, we need to be sobered by the job ahead of us.”

That’s because despite lower infection and death rates, and despite the fact that the disease is both preventable and treatable, it is estimated that a child in Africa still dies every 45 seconds from malaria.

The President’s Malaria Initiative, now a central part of the Global Health Initiative, was introduced in 2005 to concentrate on fighting the disease.  Its goal is to reduce malaria-related deaths by 50 percent in 15 focus countries by the year 2016.

[“We] believe we can push the Initiative’s success even further,” said USAID Administrator Raj Shah.  “Over the next five years, . . . .we can save an additional 500,000 lives a year, most of them young children.”

To do so, the U.S will work with partners to train health care workers to quickly identify whether a fever is caused by malaria; develop more effective insecticides that kill the mosquitoes without harming people; and we must find cheaper, more efficient ways to produce artemisinin.

“Finally,” said Dr. Shah, “we need to seek the ultimate answer to malaria: a cheap, effective vaccine. Through the Malaria Vaccine Initiative, USAID will support the development and testing of promising candidates.”

Source: VOA News

Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Malaria

Partial mosquito-proofing of houses with screens and ceilings has the potential to reduce indoor densities of malaria mosquitoes. We wish to measure whether it will also reduce indoor densities of vectors of neglected tropical diseases.

Methodology: The main house entry points preferred by anopheline and culicine vectors were determined through controlled experiments using specially designed experimental huts and village houses in Lupiro village, southern Tanzania. The benefit of screening different entry points (eaves, windows and doors) using PVC-coated fibre glass netting material in terms of reduced indoor densities of mosquitoes was evaluated compared to the control.

Findings: 23,027 mosquitoes were caught with CDC light traps; 77.9% (17,929) were Anopheles gambiae sensu lato, of which 66.2% were An. arabiensis and 33.8% An. gambiae sensu stricto. The remainder comprised 0.2% (50) An. funestus, 10.2% (2359) Culex spp. and 11.6% (2664) Mansonia spp. Screening eaves reduced densities of Anopheles gambiae s. l. (Relative ratio (RR) = 0.91; 95% CI = 0.84, 0.98; P = 0.01); Mansonia africana (RR = 0.43; 95% CI = 0.26, 0.76; P<0.001) and Mansonia uniformis (RR = 0.37; 95% CI = 0.25, 0.56; P<0.001) but not Culex quinquefasciatus, Cx. univittatus or Cx. theileri. Numbers of these species were reduced by screening windows and doors but this was not significant.

Significance: This study confirms that across Africa, screening eaves protects households against important mosquito vectors of filariasis, Rift Valley Fever and O’Nyong nyong as well as malaria. While full house screening is required to exclude Culex species mosquitoes, screening of eaves alone or fitting ceilings has considerable potential for integrated control of other vectors of filariasis, arbovirus and malaria.

Author Summary: Mosquito vectors that transmit filariasis and several arboviruses such as Rift Valley Fever, Chikungunya and O’Nyong nyong as well as malaria co-occur across tropical Africa. These diseases are co-endemic in most rural African countries where they are transmitted by the same mosquito vectors. The only control measure currently in widespread use is mass drug administration for filariasis. In this study, we used controlled experiments to evaluate the benefit of screening the main mosquito entry points into houses, namely, eaves, windows and doors.

This study aims to illustrate the potential of screening specific house openings with the intention of preventing endophagic mosquitoes from entering houses and thus reducing contact between humans and vectors of neglected tropical diseases. This study confirms that while full house screening is effective for reducing indoor densities of Culex spp. mosquitoes, screening of eaves alone has a great potential for integrated control of neglected tropical diseases and malaria.

Citation: Ogoma SB, Lweitoijera DW, Ngonyani H, Furer B, Russell TL, et al. (2010) Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Endophagic Filariasis, Arbovirus and Malaria Vectors. PLoS Negl Trop Dis 4(8): e773. doi:10.1371/journal.pntd.0000773

Editor: Neal D. E. Alexander, London School of Hygiene and Tropical Medicine, United Kingdom

Funding: SBO was supported by a scholarship kindly provided by Valent Bioscience Corporation. This study was also supported by the Centers for Disease Control and Prevention and the United States Agency for International Development through the U.S. President’s Malaria Initiative (Award Number 621-A-00-08-0007-00), the Addessium Foundation (Reenwijk, The Netherlands) and a Research Career Development Fellowship (076806) provided to GFK by the Wellcome Trust. The funders of this study had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Copyright: © 2010 Ogoma et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

More information: Full text: Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Endophagic Filariasis, Arbovirus and Malaria Vectors (PDF)