During 2003–2007, a promising 43% reduction in infant and 48% reduction in child mortality were recorded in the KEMRI/CDC HDSS, which were coincident with scale-up of proven child survival interventions and modest improvement in SES. Unfortunately, a marked increase in mortality rates occurred in 2008.
The decrease in under-five malaria/anemia-specific mortality mirrors a decrease in community malaria and anemia prevalence, and in this area of high ITN use, coincides with the change in 2004 of first-line malaria treatment from sulfadoxine-pyrimethamine, an antimalarial drug that was failing as a treatment because of increased drug resistance, to amodiaquine, a more effective drug, and finally in 2006, to AL, a highly effective, rapidly acting drug. During August 2006–September 2007, when AL was reliably available in health facilities, triannual mortality rates were notably less compared with rates for the same periods in prior and subsequent years.
The steady decrease in pneumonia-specific mortality occurred concurrent with the change to a more effective first-line treatment for pneumonia,18
improved care-seeking, improved vaccination coverage,5
and a decrease in malaria, which may contribute to pneumonia incidence.19
Diarrhea-specific mortality decreased considerably during 2004–2005, coincident with hygiene and in-home water treatment promotion, and increased use of oral rehydration salts.5
Meningitis-specific mortality decreased as Haemophilus influenzae
b vaccination coverage increased.
Increased PMCT should have resulted in reductions in under-five mortality. However, verbal autopsy data showed no substantial sustained reductions in under-five HIV-specific mortality during 2003–2008, and a possible increase during 2007–2008. This finding could be attributed to a lack of specificity for verbal autopsy pediatric HIV diagnosis.20
However, if PMCT is not resulting in measurable reductions in under-five mortality, this finding is critical information that might indicate that perinatal antiretroviral therapy was not readily accessible or used in this area, where 80% of births occur at home,21
or that perinatal antiretroviral therapy might not be sufficient in an area where breast-feeding is nearly universal and mixed feeding practices are common.22
The increase in malnutrition deaths in the context of improving SES may be an indication of continued perinatal HIV transmission with nutritional decline or wasting among HIV infected children. Likewise, the increase in stillbirths and premature births that contributed to the rise in neonatal deaths could be a result of perinatal HIV infection. An alternative explanation might be increased malaria infections during pregnancy. It cannot be overlooked that increased use of routine antiretroviral therapy by mothers might have contributed to overall reductions in child mortality independent of PMCT. Both HIV-infected and HIV-uninfected children born to HIV-infected mothers with lower viral loads are less likely to die, perhaps because of greater functionality of mothers who are not sick.23
The increase in under-five mortality in 2008 is a robust finding; it was observed in community-based HDSS data, among inpatients at Siaya District Hospital, and in all rounds of 2008. Notably, there were no major changes in the methods of HDSS during 2007–2008, and increased mortality was not global; minimal increases in mortality among older children and adults were observed during this period.
Although increases were measured in most major causes of childhood mortality in 2008, a major contributor to increased under-five mortality was an increase in malaria-specific mortality. This occurred in the context of widespread antimalarial drug stock-outs at health facilities during a time when malaria infection and illness were increasing. The first stock-outs of children's dosages of AL were documented in October 2006, although adult AL was available. Stock-outs of both adult and pediatric dosages of AL began in September 2007 and became more frequent in 2008, when AL was unavailable for seven months of the year, including three months during peak malaria transmission season. Simultaneous stock-outs of pediatric and adult dosages precluded the common practice of dividing adult AL packets into appropriate child dosages.
During times of AL stock-out, antimalarial treatment options were limited, and children may have remained untreated or inadequately treated. Drawing from the standard health facility formulary, the health worker had the option of providing quinine, which is bitter and can be difficult to administer for the full seven-day treatment regimen, sulfadoxine-pyrimethamine, which is well tolerated and easily administered, but has poor treatment efficacy in Kenya because of high levels of resistance,24
or a prescription, which may not be filled as prescribed in this rural setting with few licensed pharmacies, and an impoverished population. Thus, the increase in malaria-specific mortality may have been caused by lack of access to any effective antimalarial drug during times of AL stock-out.
Community data showed decreasing malaria prevalence among children < 5 years of age until 2008 and anemia until 2007. The parasitemia data contrast with inpatient data from SDH and Lwak Mission Hospital that showed malaria admissions increased beginning in late 2007. The lag between increased parasitemia prevalence in health facilities and the community may indicate wide-spread antimalarial drug stock-outs resulted in inadequate treatment of malaria-infected children, who progressed to severe disease and hospitalization before the increase in community parasitemia. Notably, AL stock-outs were not particular to Nyanza Province, being documented nationwide in 2008.25,26
The increase in malaria prevalence and mortality occurred despite high ITN use, a worrisome finding that indicates that ITNs alone are not sufficient to prevent increases in malaria.
The increase in mortality in 2008 was not restricted to malaria, but occurred in other common causes of childhood mortality, including pneumonia, diarrhea, malnutrition, and infection with HIV. Studies from other parts of Africa have shown a decrease in all-cause and non-malaria-specific causes of mortality in parallel with a decrease in malaria mortality.27,28
To our knowledge, the simultaneous increase in pneumonia, diarrhea, and malnutrition mortality with increased malaria mortality has not been reported. It is possible that the increase in these other non–malaria-specific causes of mortality reflect a widespread change in vulnerability or access to health care of the population. Increasing malnutrition likely contributed to deaths from these common causes of childhood death. It might also be the case that these synchronous temporal changes in the cause of death in children was related to the impact that malaria has on children's nutritional and immune status, which puts them at greater risk for death from other infectious diseases.29
Alternatively, it might also be related to the non-specificity of verbal autopsy for the cause of death in children, particularly in malarious areas where it has been shown that malaria and pneumonia can be difficult to distinguish.30,31
Malnutrition can contribute to mortality directly or indirectly, increasing the risk of death from common childhood illnesses. Community-based malnutrition deaths in the HDSS first increased in 2005 during a time when mortality from other causes was decreasing. In-patient deaths increased in 2007 and 2008, in parallel with the other mortality increases described above.
Although the first increases in under-five mortality were measured during the last four months of 2007, some increase in child mortality observed in 2008 may be attributable to civil unrest associated with post-election violence that began December 29, 2007. The HDSS experienced a sudden population growth as internally displaced persons (IDPs) returned to their ancestral areas. The IDP status did not result in increased childhood mortality; IDPs living in the HDSS had lower under-five mortality rates than resident children.32
Moreover, IDP childhood deaths did not contribute to HDSS population-based estimates of mortality until after April 27, 2008, the earliest IDPs would become HDSS residents. However the consequences of post-election violence, including limited access to health care and essential drugs during the first 3–4 months of 2008, and an increased strain on already limited household resources, might have contributed to increased under-five deaths, particularly HIV-related and malnutrition-related deaths. Notably, increases in under-five mortality began before post-election violence, increased mortality rates continued well after disruptions in services normalized, and almost half the IDPs left the study area by July 2008,32
indicating that although post-election violence likely contributed to the observed increase in under-five mortality, it cannot explain it fully.
The analysis had limitations. As mentioned, verbal autopsy is an inexact method for determining causes of mortality, and can particularly confuse malaria and pneumonia in malarious areas.30,31
However, in resource-poor settings, where most deaths occur outside medical institutions, it is a useful tool for following mortality trends. Coding of the cause of death was conducted by the same clinical officers over time, providing longitudinal internal validity. HIV-specific mortality was affected by modifications in coding made in accordance with WHO recommendations, and implemented in the HDSS in 2006.7,33
Data on AL stock-outs in Siaya were not available and were assumed to be similar to Asembo. However, differences in consumption might have resulted in different stock-out dates. Factors that may have contributed to increased mortality are speculative, and cannot be proved as causal.
In conclusion, promising gains in child survival occurred in western Kenya over a five-year period during a time when the Kenyan Ministry of Health adopted numerous child-survival public health policies. Unfortunately, a setback occurred in 2008 in the context of good policy and established child survival programs. To sustain reductions in child mortality, good policy is not enough; reliable supply and access to effective essential drugs are critical. Anticipation of and concrete action plans to address potential disruptions in services are needed. The establishment of reliable mechanisms to ensure the availability of effective essential drugs, such as antimalarial drugs and antiretroviral drugs, and full scale-up of PMCT and pediatric anti-retroviral therapy could put this area of Kenya back on track to reaching the Fourth Millennium Development Goal.