Complex Interactions between Soil-Transmitted Helminths and Malaria in Pregnant Women on the Thai-Burmese Border

Abstract

BackgroundDeworming is recommended by the WHO in girls and pregnant and lactating women to reduce anaemia in areas where hookworm and anaemia are common. There is conflicting evidence on the harm and the benefits of intestinal geohelminth infections on the incidence and severity of malaria, and consequently on the risks and benefits of deworming in malaria affected populations. We examined the association between geohelminths and malaria in pregnancy on the Thai-Burmese border.MethodologyRoutine antenatal care (ANC) included active detection of malaria (weekly blood smear) and anaemia (second weekly haematocrit) and systematic reporting of birth outcomes. In 1996 stool samples were collected in cross sectional surveys from women attending the ANCs. This was repeated in 2007 when malaria incidence had reduced considerably. The relationship between geohelminth infection and the progress and outcome of pregnancy was assessed.Principal FindingsStool sample examination (339 in 1996, 490 in 2007) detected a high prevalence of geohelminths 70% (578/829), including hookworm (42.8% (355)), A. lumbricoides (34.4% (285)) and T.trichuria (31.4% (250)) alone or in combination. A lower proportion of women (829) had mild (21.8% (181)) or severe (0.2% (2)) anaemia, or malaria 22.4% (186) (P.vivax monoinfection 53.3% (101/186)). A. lumbricoides infection was associated with a significantly decreased risk of malaria (any species) (AOR: 0.43, 95% CI: 0.23–0.84) and P.vivax malaria (AOR: 0.29, 95% CI: 0.11–0.79) whereas hookworm infection was associated with an increased risk of malaria (any species) (AOR: 1.66, 95% CI: 1.06–2.60) and anaemia (AOR: 2.41, 95% CI: 1.18–4.93). Hookworm was also associated with low birth weight (AOR: 1.81, 95% CI: 1.02–3.23).Conclusion/Significance A. lumbricoides and hookworm appear to have contrary associations with malaria in pregnancy.

Coinfection with Plasmodium falciparum and Schistosoma haematobium: Additional Evidence of the Protective Effect of Schistosomiasis on Malaria in Senegalese Children

“…[4][5][6]17 In this study, we focused on the interaction between schistosomiasis and malaria infection. Several biological studies have shown a synergistic effect of coinfection, 16,[18][19][20][21] whereas other studies suggested an acceleration or regulation toward protective profile of the acquired immunity against malaria in children coinfected with malaria and schistosomiasis 9,22 and another study did not find an association. 23 A study on children conducted in Mali in 2002-2003 presented both epidemiological and biological approaches and concluded on a protective effect of infection with urinary schistosomiasis on malaria.…”

Prevalence of Anemia and Its Risk Factors Among Lactating Mothers in Myanmar

“…Although we did not collect data on parasite infection, we can infer that drinking unboiled water, especially from a spring or river, easily caused parasite infections, which led to intestinal bleeding and anemia. 25,26 Boel and others 27 reported that the prevalence of helminth infection in Karen and Burmese pregnant women on the Thai-Burmese border was as high as 70%.…”

Prevalence of Anemia and Its Risk Factors Among Children 6–36 Months Old in Burma

“…According to the recent report, the prevalence of helminths infection was as high as 70% in Burmese pregnant women on the Thailand/Burma border. 23 Drinking unboiled water is related to parasitic infection. 20 In the investigation, another limitation is that we used only a brief food frequency to estimate the status of food intake; as a result, the status of micronutrient intake or total caloric intake of the subjects was not accessed.…”